US20080233907A1

US20080233907A1 - Method And System For Determining Channel Spacing And Configuring An FM Transmitter

Info

Publication number: US20080233907A1
Application number: US11/846,989
Authority: US
Inventors: Brima Babatunde Ibrahim; Scott Bibaud; Siukai Mak; John Walley; Bojko Marholev
Original assignee: Broadcom Corp
Current assignee: Avago Technologies International Sales Pte Ltd
Priority date: 2007-03-19
Filing date: 2007-08-29
Publication date: 2008-09-25
Also published as: US7925220B2; US7983617B2; US8467745B2; US20080233911A1; US20120021706A1; US20080233883A1; US20080232446A1; US20080232448A1; US20080233869A1; US20080231375A1; US20080232447A1; US20080233954A1; US20100279633A1; US8391810B2; US20110171916A1; US20080233900A1; US20080233881A1; US7974590B2; US20080233890A1; US20080233882A1

Abstract

In a wireless communication system which may include a mobile device having an integrated FM radio transmitter and a FM radio receiver, a geographic location of the mobile device may be determined. A FM channel map may be determined based on the location and the FM radio transmitter may be configured for transmitting FM signals based on the FM channel map, which may include a list of ranked FM channels. The geographic location may be acquired from received RDS or RBDS signals, received GPS signals, other received wireless signals, and/or from user data. Channel spacing, channel offset and/or frequency band may be determined for the FM channel map. A frequency for transmitting FM signals via the FM radio transmitter may be selected based on the determined FM channel map. The FM radio receiver may also be configured for receiving FM signals based on the determined FM channel map.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS/INCORPORATION BY REFERENCE

This application makes reference to and claims priority to U.S. Provisional Application Ser. No. 60/895,665 (Attorney Docket No. 18371US01), filed on Mar. 19, 2007, entitled “METHOD AND SYSTEM FOR A SINGLE CHIP INTEGRATED BLUETOOTH AND FM TRANSCEIVER AND BASEBAND PROCESSOR,” which is incorporated herein by reference in its entirety.
This application also makes reference to:
U.S. patent application Ser. No. 11/755,395 filed on May 30, 2007;
U.S. patent application Ser. No. 11/832,844 filed on Aug. 2, 2007;
Each of the above stated applications is hereby incorporated herein by reference in its entirety.

FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

[Not Applicable]

MICROFICHE/COPYRIGHT REFERENCE

[Not Applicable]

FIELD OF THE INVENTION

Certain embodiments of the invention relate to FM communication. More specifically, certain embodiments of the invention relate to a method and system for determining channel spacing and configuring an FM transmitter.

BACKGROUND OF THE INVENTION

With the popularity of portable electronic devices and wireless devices that support audio applications, there is a growing need to provide a simple and complete solution for audio communications applications. For example, some users may utilize Bluetooth-enabled devices, such as headphones and/or speakers, to allow them to communicate audio data with their wireless handset while freeing to perform other activities. Other users may have portable electronic devices that may enable them to play stored audio content and/or receive audio content via broadcast communication, for example.
Some wireless devices may have the capability to handle a plurality of protocols and may require separate processing hardware and/or separate processing software. Moreover, coordinating the reception and/or transmission of data to and/or from these mobile wireless devices may require significant processing overhead that may impose certain operation restrictions and/or design challenges. In addition, radio communication standards for a variety of radio technologies may not have taken into consideration methods for communication between multiple technology devices.
Furthermore, handling a plurality of protocols may result in significant increases in power consumption. Power being a precious commodity in most wireless mobile devices requires careful design and efficient processes in order to minimize battery usage. Additional overhead such as sophisticated power monitoring and power management techniques are required in order to maximize battery life.
Further limitations and disadvantages of conventional and traditional approaches will become apparent to one of skill in the art, through comparison of such systems with some aspects of the present invention as set forth in the remainder of the present application with reference to the drawings.

BRIEF SUMMARY OF THE INVENTION

A system and/or method for determining channel spacing and configuring an FM transmitter, substantially as shown in and/or described in connection with at least one of the figures, as set forth more completely in the claims.
Various advantages, aspects and novel features of the present invention, as well as details of an illustrated embodiment thereof, will be more fully understood from the following description and drawings.

BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS

FIG. 1A is a block diagram of an exemplary FM receiver that communicates with handheld devices that utilize a single chip with FM radios and one or more integrated radios such as Bluetooth, GPS, WLAN, WWAN or a wire line connection, in accordance with an embodiment of the invention.

FIG. 1B is a block diagram of an exemplary single chip with multiple integrated radios that supports radio data processing, in accordance with an embodiment of the invention.

FIG. 2 is a block diagram of an exemplary single chip that supports FM operations and one or more of a plurality of optional integrated transceivers. For example, in addition to FM, the chip may support Bluetooth, GPS, WLAN, WWAN or other transceivers, in accordance with an embodiment of the invention.

FIG. 3 is a block diagram of an exemplary FM core with FM transmitter and PTU for processing RDS and digital audio data, in accordance with an embodiment of the invention.

FIG. 4A is a flow chart for an exemplary algorithm that enables determining channel spacing offsets when RDS/RBDS data and user input are not available, in accordance with an embodiment of the invention.

FIG. 4B is a block diagram of a plurality of exemplary radio devices that enable frequency modulation (FM) transmission and reception, in accordance with an embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

Certain aspects of the invention may be found in a method and system for determining channel spacing and configuring an FM transmitter. In a wireless communication system which may include a mobile device having an integrated FM radio transmitter and FM radio receiver, a geographic location of the mobile device may be determined. A FM channel map may be determined based on the location and the FM radio transmitter may be configured for transmitting FM signals based on the FM channel map, which may include a list of ranked FM channels. The geographic location may be acquired from received RDS or RBDS signals, received GPS signals, other received wireless signals, and/or from user data. Channel spacing, channel offset and/or frequency band may be determined for the FM channel map. A frequency for transmitting FM signals via the FM radio transmitter may be selected based on the determined FM channel map. The FM radio receiver may also be configured for receiving FM signals based on the determined FM channel map.
The FM radio transmitter and/or FM radio receiver may be configured via an in-band FM signal and/or via an out-of-band signal based on the determined FM channel map. The out-of-band signal may comprise one or more of a Bluetooth signal, a WLAN signal, a ZigBee signal, and a wireless signal. A signal may be generated to indicate a channel being used by the FM radio transmitter based on the configuration. The generated signal may comprise a visual signal and/or an audio signal for example, text-to-speech translation and/or one or more audible tones.
FIG. 1A is a block diagram of an exemplary FM receiver that communicates with handheld devices that utilize a single chip with FM radios and one or more integrated radios such as Bluetooth, GPS, WLAN, WWAN or a wire line connection, in accordance with an embodiment of the invention. Referring to FIG. 1A, there is shown an FM receiver 110, a cellular phone 104 a, a smart phone 104 b, a computer 104 c, and an exemplary FM device equipped with one or more integrated transceivers 104 d. In this regard, the FM receiver 110 may comprise and/or may be communicatively coupled to a listening device 108. A device equipped with the FM and one or more integrated transceivers, such as the single chip 106, may be able to broadcast its respective signal to a “deadband” of an FM receiver for use by the associated audio system. For example, a cellphone or a smart phone, such as the cellular phone 104 a and the smart phone 104 b, may transmit a telephone call for listening over the audio system of an automobile, via usage of a deadband area of the car's FM stereo system. One advantage may be the universal ability to use this feature with all automobiles equipped simply with an FM radio with few, if any, other external FM transmission devices or connections being required.
In another example, a computer, such as the computer 104 c, may comprise an MP3 player or another digital music format player and may broadcast a signal to the deadband of an FM receiver in a home stereo system. The music on the computer may then be listened to on a standard FM receiver with few, if any, other external FM transmission devices or connections. While a cellular phone, a smart phone, and computing devices have been shown, a single chip that combines a Bluetooth and FM transceiver and/or receiver may be utilized in a plurality of other devices and/or systems that receive and use an FM signal.
FIG. 1B is a block diagram of an exemplary single chip with multiple integrated radios that supports radio data processing, in accordance with an embodiment of the invention. Referring to FIG. 1B, there is shown a single chip 130 that may comprise a radio portion 132 and a processing portion 134. The radio portion 132 may comprise a plurality of integrated radios. For example, the radio portion 132 may comprise an FM receive and transmit (Rx/Tx) radio 140 c that supports FM communications and a plurality of optional integrated radios. For example, a cellular radio 140 a that supports cellular communications, a Bluetooth radio 140 b that supports Bluetooth communications, a global positioning system (GPS) 140 d that supports GPS communications, and/or a wireless local area network (WLAN) 140 e that supports communications based on one or more of the IEEE 802.11 standards.
The processing portion 134 may comprise at least one processor 136, a memory 138, and a peripheral transport unit (PTU) 140. The processor 136 may comprise suitable logic, circuitry, and/or code that enable processing of data received from the radio portion 132. In this regard, each of the integrated radios may communicate with the processing portion 134. In some instances, the integrated radios may communicate with the processing portion 134 via a common bus, for example. The memory 138 may comprise suitable logic, circuitry, and/or code that enable storage of data that may be utilized by the processor 136. In this regard, the memory 138 may store at least a portion of the data received by at least one of the integrated radios in the radio portion 132. Moreover, the memory 138 may store at least a portion of the data that may be transmitted by at least one of the integrated radios in the radio portion 132. The PTU 140 may comprise suitable logic, circuitry, and/or code that may enable interfacing data in the single chip 130 with other devices that may be communicatively coupled to the single chip 130. In this regard, the PTU 140 may support analog and/or digital interfaces.
FIG. 2 is a block diagram of an exemplary single chip that supports FM operations and one or more of a plurality of optional integrated transceivers. For example, in addition to FM, the chip may support Bluetooth, GPS, WLAN, WWAN or other transceivers, in accordance with an embodiment of the invention. Referring to FIG. 2, there is shown the single chip 200 that may comprise a processor system 202, a peripheral transport unit (PTU) 204, one or more optional transceiver cores 205 and 206, a frequency modulation (FM) core 208 with the FM transmitter 226 and the FM receiver 224 integrated into the FM core 208, and a common bus 201.
In this regard, the FM core 208 may support FM reception and/or transmission of FM data. The FM transmitter 226 may utilize signals based on the reference signal generated by the LO 227. The FM core 208 may enable transmission of data received via the PTU 204 and/or a Bluetooth core 206, for example.
The processor system 202 may comprise a central processing unit (CPU) 210, a memory 212, a direct memory access (DMA) controller 214, a power management unit (PMU) 216, and an audio processing unit (APU) 218. The APU 218 may comprise a sub-band coding (SBC) codec 220. At least a portion of the components of the processor system 202 may be communicatively coupled via the common bus 201.
The CPU 210 may comprise suitable logic, circuitry, and/or code that may enable control and/or management operations in the single chip 200. In this regard, the CPU 210 may communicate control and/or management operations to the optional transceiver cores 205 and 206, the FM core 208, and/or the PTU 204 via a set of register locations specified in a memory map. Moreover, the CPU 210 may be utilized to process data received by the single chip 200 and/or to process data to be transmitted by the single chip 200. The CPU 210 may enable processing of data received via the optional transceiver cores 205 and 206, via the FM core 208, and/or via the PTU 204. For example, the CPU 210 may enable processing of A2DP data and may then transfer the processed A2DP data to other components of the single chip 200 via the common bus 201. In this regard, the CPU may utilize the SBC codec 220 in the APU 218 to encode and/or decode A2DP data, for example. The CPU 210 may enable processing of data to be transmitted via the FM core 208, one or more of the optional transceiver cores 205 and 206 and/or via the PTU 204. The CPU 210 may be, for example, an ARM processor or another embedded processor core that may be utilized in the implementation of system-on-chip (SOC) architectures.
The CPU 210 may time multiplex FM data processing operations and data processing operations from another integrated transceiver such as Bluetooth for example. In this regard, the CPU 210 may perform each operation by utilizing a native clock, that is, Bluetooth data processing based on a Bluetooth clock and FM data processing based on an FM clock. The Bluetooth clock and the FM clock may be distinct and may not interact. The CPU 210 may gate the FM clock and the Bluetooth clock and may select the appropriate clock in accordance with the time multiplexing scheduling or arrangement. When he CPU 210 switches between Bluetooth operations and FM operations, at least certain states associated with the Bluetooth operations or with the FM operations may be retained until the CPU 210 switches back.
For example, in the case where the Bluetooth function is not active and is not expected to be active for some time, the CPU 210 may run on a clock derived from the FM core 208. This may eliminate the need to bring in a separate high-speed clock when one is already available in the FM core 208. In the case where the Bluetooth core 206 may be active, for example when the Bluetooth is in a power-saving mode that requires it to be active periodically, the processor may chose to use a clock derived separately from the FM core 208. The clock may be derived directly from a crystal or oscillator input to the Bluetooth core 206, or from a phase locked loop (PLL) in the Bluetooth core 206. While this clocking scheme may provide certain flexibility in the processing operations performed by the CPU 210 in the single chip 200, other clocking schemes may also be implemented.
The CPU 210 may also enable configuration of data routes to and/or from the FM core 208. For example, the CPU 210 may configure the FM core 208 so that data may be routed via an I²S interface or a PCM interface in the PTU 204 to the analog ports communicatively coupled to the PTU 204.
The CPU 210 may enable tuning, such as flexible tuning, and/or searching operations in Bluetooth for example, and/or FM communication by controlling at least a portion of the Bluetooth core 206 and/or the FM core 208. For example, the CPU 210 may generate at least one signal that tunes the FM core 208 to a certain frequency to determine whether there is a station at that frequency. When a station is found, the CPU 210 may configure a path for the audio signal to be processed in the single chip 200. When a station is not found, the CPU 210 may generate at least one additional signal that tunes the FM core 208 to a different frequency to determine whether a station may be found at the new frequency.
Searching algorithms may enable the FM core 208 to scan up or down in frequency from a presently tuned channel and stop on the next channel with received signal strength indicator (RSSI) above a threshold. The search algorithm may be able to distinguish image channels. The choice of the IF frequency during search is such that an image channel may have a nominal frequency error of 50 kHz, which may be used to distinguish the image channel from the “on” channel. The search algorithm may also be able to determine if a high side or a low side injection provides better receive performance, thereby allowing for a signal quality metric to be developed for this purpose. One possibility to be investigated is monitoring the high frequency RSSI relative to the total RSSI. The IF may be chosen so that with the timing accuracy that a receiver may be enabled to provide, the image channels may comprise a frequency error that is sufficiently large to differentiate the image channels from the on channel.
The CPU 210 may enable a host controller interface (HCI) in Bluetooth. In this regard, the HCI provides a command interface to the baseband controller and link manager, and access to hardware status and control registers. The HCI may provide a method of accessing the Bluetooth baseband capabilities that may be supported by the CPU 210.
The memory 212 may comprise suitable logic, circuitry, and/or code that may enable data storage. In this regard, the memory 212 may be utilized to store data that may be utilized by the processor system 202 to control and/or manage the operations of the single chip 200. The memory 212 may also be utilized to store data received by the single chip 200 via the PTU 204 and/or via the FM core 208. Similarly, the memory 212 may be utilized to store data to be transmitted by the single chip 200 via the PTU 204 and/or via the FM core 208. The DMA controller 214 may comprise suitable logic, circuitry, and/or code that may enable transfer of data directly to and from the memory 212 via the common bus 201 without involving the operations of the CPU 210.
The PTU 204 may comprise suitable logic, circuitry, and/or code that may enable communication to and from the single chip 200 via a plurality of communication interfaces. In some instances, the PTU 204 may be implemented outside the single chip 200, for example. The PTU 204 may support analog and/or digital communication with at least one port. Digital audio data may be transferred by a digital interface, for example, inter-IC-sound (I²S), inter-integrated circuit (I²C), pulse code modulation (PCM), universal serial bus (USB), secure digital input/output (SDIO) and/or universal asynchronous receiver transmitter (UART). For example, the PTU 204 may support at least one USB interface that may be utilized for Bluetooth data communication, at least one SDIO interface that may also be utilized for Bluetooth data communication, at least one UART interface that may also be utilized for Bluetooth data communication, and at least one inter-integrated circuit (I²C) bus interface that may be utilized for FM control and/or FM and RDS/RBDS data communication. The PTU 204 may also support at least one PCM interface that may be utilized for Bluetooth data communication and/or FM data communication, for example.
The PTU 204 may also support at least one inter-IC sound (I²S) interface, for example. The I²S interface may be utilized to send high fidelity FM digital signals to the CPU 210 for processing, for example. In this regard, the I²S interface in the PTU 204 may receive data from the FM core 208 via a bus 203, for example. Moreover, the I²S interface may be utilized to transfer high fidelity audio in Bluetooth. For example, in the A2DP specification there is support for wideband speech that utilizes 16 kHz of audio. In this regard, the I²S interface may be utilized for Bluetooth high fidelity data communication and/or FM high fidelity data communication. The I²S interface may be a bidirectional interface and may be utilized to support bidirectional communication between the PTU 204 and the FM core 208 via the bus 203. The I²S interface may be utilized to send and receive FM data from external devices such as coder/decoders (CODECs) and/or other devices that may further process the I²S data for transmission, such as local transmission to speakers and/or headsets and/or remote transmission over a cellular network, for example.
The transceiver core 206 may for example be a Bluetooth core and may comprise suitable logic, circuitry, and/or code that may enable reception and/or transmission of Bluetooth data. The Bluetooth core 206 may comprise a Bluetooth transceiver 229 that may perform reception and/or transmission of Bluetooth data. In this regard, the Bluetooth core 206 may support amplification, filtering, modulation, and/or demodulation operations, for example. The Bluetooth core 206 may enable data to be transferred from and/or to the processor system 202, the PTU 204, and/or the FM core 208 via the common bus 201, for example.
The FM core 208 may comprise suitable logic, circuitry, and/or code that may enable reception and/or transmission of FM data. The FM core 208 may comprise an FM receiver 222, an FM transmitter 226 and a local oscillator (LO) 227. The LO 227 may be utilized to generate a reference signal that may be utilized by the FM core 208 for performing analog and/or digital operations. The FM receiver 222 may handle demodulation, amplification and/or filtering operations, for example. The FM transmitter 226 may handle modulation, amplification and/or filtering operations. Moreover, the FM receiver 222 may receive FM audio data and demodulate the audio data in a digital domain. The demodulated digital audio data may be converted to analog via the D/A converter 224 and analog audio may be output from the chip to a listening device. Also, analog audio may be input from an external device to the FM transmitter 226. The FM transmitter 226 may comprise an analog to digital converter (A/D) 228 that may be utilized to convert analog audio information to a digital signal for modulation in the digital domain prior to FM transmission. The FM core 208 may enable data to be transferred to and/or from the processor system 202, the PTU 204, and/or one or more optional radio cores 206 via the common bus 201 and/or the bus 203, for example.
The FM core 208 may enable radio transmission and/or reception at various frequencies, such as, 400 MHz, 900 MHz, 2.4 GHz and/or 5.8 GHz, for example. The FM core 208 may also support operations at the standard FM band comprising a range of about 76 MHz to 108 MHz, for example.
The FM core 208 may also enable reception of RDS data and/or RBDS data for in-vehicle radio receivers. In this regard, the FM core 208 may enable filtering, amplification, and/or demodulation of the received RDS/RBDS data. The RDS/RBDS data may comprise, for example, information for retuning to a new channel such as a channel spacing offsets and a list of alternate channels available for transmission. The RDS/RBDS may comprise a traffic message channel (TMC) that provides traffic information that may be communicated and/or displayed to an in-vehicle user.
Digital circuitry within the FM core 208 may be operated based on a clock signal generated by dividing down a signal generated by the LO 227. The LO 227 may be programmable in accordance with the various channels that may be received by the FM core 208 and the divide ratio may be varied in order to maintain the digital clock signal close to a nominal value.
The RDS/RBDS data may be buffered in the memory 212 in the processor system 202. The RDS/RBDS data may be transferred from the memory 212 via the I²C interface when the CPU 210 is in a sleep or stand-by mode. For example, the FM core 208 may post RDS data into a buffer in the memory 212 until a certain level is reached and an interrupt is generated to wake up the CPU 210 to process the RDS/RBDS data. When the CPU 210 is not in a sleep mode, the RDS data may be transferred to the memory 212 via the common bus 201, for example.
Moreover, the RDS/RBDS data received via the FM core 208 may be transferred to any of the ports communicatively coupled to the PTU 204 via the HCI scheme supported by the single chip 200, for example. The RDS/RBDS data may also be transferred to the transceiver cores 205 and 206 for communication to Bluetooth-enabled devices, for example.
In one exemplary embodiment of the invention, the single chip 200 may receive Bluetooth data, such as A2DP, SCO, eSCO, and/or MP3, for example, the Bluetooth core 206 may transfer the received data to the processor system 202 via the common bus 201. At the processor system 202, the SBC codec 220 may decode the Bluetooth data and may transfer the decoded data to the FM core 208 via the common bus 201. The FM core 208 may transfer the data to the FM transmitter 226 for communication to an FM receiver in another device.
In another exemplary embodiment of the invention, the single chip 200 may operate in a plurality of modes. For example, the single chip 200 may operate in one of an FM-only mode, a Bluetooth-only mode, and an FM-Bluetooth mode. For the FM-only mode, the single chip 200 may operate with a lower power active state than in the Bluetooth-only mode or the FM-Bluetooth mode because FM operation in certain devices may have a limited source of power. In this regard, during the FM-only mode, at least a portion of the operation of the Bluetooth core 206 may be disabled to reduce the amount of power used by the single chip 200. Moreover, at least a portion of the processor system 202, such as the CPU 210, for example, may operate based on a divided down clock from a phase locked-loop (PLL) in the FM core 208. In this regard, the PLL in the FM core 208 may utilize the LO 227, for example.
Moreover, because the code necessary to perform certain FM operations, such as tuning and/or searching, for example, may only require the execution of a few instructions in between time intervals of, for example, 10 ms, the CPU 210 may be placed on a stand-by or sleep mode to reduce power consumption until the next set of instructions is to be executed. In this regard, each set of instructions in the FM operations code may be referred to as a fragment or atomic sequence. The fragments may be selected or partitioned in a very structured manner to optimize the power consumption of the single chip 200 during FM-only mode operation. In some instances, fragmentation may also be implemented in the FM-Bluetooth mode to enable the CPU 210 to provide more processing power to Bluetooth operations when the FM core 208 is carrying out tuning and/or searching operations, for example.
FIG. 3 is a block diagram of an exemplary FM core with FM transmitter and PTU for processing RDS and digital audio data, in accordance with an embodiment of the invention. Referring to FIG. 3, there is shown a portion of a single chip 200 from FIG. 2, comprising an FM core 208, a memory 212, a CPU 210, a common bus 201. Also shown are portions of a PTU which may comprise an interface multiplexer 310, a universal peripheral interface (UPI) 304, a bus master interface 302, a digital audio interface controller 306, an I² S interface block 308, and an I² C interface block 312.
The FM core 208 may comprise an FM/MPX demodulator and decoder 317, an FM/MPX modulator and encoder 317 a, rate adaptors 314 and 314 a, a buffer 316, an RDS/RBDS demodulator and decoder 318, a RDS/RBDS modulator and encoder 318 a, and a control registers block 322. Narrowly spaced hashed arrows as illustrated by the flow arrow 332 show the flow of digital audio data. Broadly spaced hashed arrows as illustrated by the flow arrow 334 show the flow of RDS/RBDS data. Clear or blank arrows, as illustrated by the dual flow arrow 336, show the flow of control data.
The FM/MPX demodulator and decoder 317 may comprise suitable logic, circuitry, and/or code that may enable processing of FM and/or FM MPX stereo audio, for example. The FM/MPX demodulator and decoder 317 may demodulate and/or decode audio signals that may be transferred to the rate adaptor 314. The FM/MPX demodulator and decoder 317 may demodulate and/or decode signals that may be transferred to the RDS/RBDS demodulator and decoder 318.
The FM/MPX encoder 317 a may comprise suitable logic, circuitry, and/or code that may enable processing of FM and/or FM MPX stereo audio, for example. The FM/MPX encoder 317 a may encode audio signals that may be transferred from the rate adaptor 314 a. The FM/MPX encoder 317 a may encode signals that may be transferred to the RDS/RBDS modulator and encoder 318 a.
The rate adaptors 314 and 314 a may comprise suitable logic, circuitry, and/or code that may enable controlling the rate of the FM data received from the FM/MPX demodulator and decoder 317. The rate adaptors 314 and 314 a may adapt the output sampling rate of the audio paths to the sampling clock of the host device or the rate of a remote device when a digital audio interface is used to transport the FM data. An initial rough estimate of the adaptation fractional change may be made and the estimate may then be refined by monitoring the ratio of reading and writing rates and/or by monitoring the level of the audio samples in the output buffer. The rate may be adjusted in a feedback manner such that the level of the output buffer is maintained. The rate adaptors 314 and 314 a may receive a strobe or pull signal from the digital audio interface controller 306, for example. Audio FM data from the rate adaptors 314 and 314 a may be transferred to the buffer 316. The U.S. application Ser. No. 11/176,417 filed on Jul. 7, 2005, discloses a method and system comprising a rate adaptor, and is hereby incorporated herein by reference in its entirety.
The buffer 316 may comprise suitable logic, circuitry, and/or code that may enable storage of digital audio data. The buffer 316 may receive a strobe or pull signal from the digital audio interface controller 306, for example. The buffer 316 may transfer digital audio data to the digital audio interface controller 306.
The RDS/RBDS demodulator and decoder 318 may comprise suitable logic, circuitry, and/or code that may enable processing of RDS/RBDS data from the FM/MPX demodulator and decoder 317. The RDS/RBDS demodulator and decoder 318 may provide further demodulation and/or decoding to data received from the FM/MPX demodulator and decoder 317. The output of the RDS/RBDS demodulator, and decoder 318 may be transferred to the interface multiplexer 310.
The RDS/RBDS modulator and encoder 318 a may comprise suitable logic, circuitry, and/or code that may enable processing of RDS/RBDS data from the FM/MPX modulator and encoder 317 a. The RDS/RBDS modulator and encoder 318 a may provide further modulation and/or encoding to data received from the FM/MPX modulator and encoder 317. The output of the RDS/RBDS modulator and encoder 318 may be transferred to the interface multiplexer 310.
The control registers block 322 may comprise suitable logic, circuitry, and/or code that may enable the storage of register information that may be utilized to control and/or configure the operation of at least portions of the FM core 208.
In operation, the FM core 208 may enable radio transmission and/or reception at various frequencies, such as, 400 MHz, 900 MHz, 2.4 GHz and/or 5.8 GHz, for example. The FM core 208 may also support operations at the standard FM band comprising a range of about 76 MHz to 108 MHz, for example. The FM core 208 may also enable reception of RDS data and/or RBDS data for in-vehicle radio receivers. In this regard, the FM core 208 may enable filtering, amplification, and/or demodulation of the received RDS/RBDS data. The RDS/RBDS data may comprise, for example, a traffic message channel (TMC) that provides traffic information that may be communicated and/or displayed to an in-vehicle user.
The memory 212 may comprise suitable logic, circuitry, and/or code that may enable data storage. In this regard, the memory 212 may be utilized to store data that may be utilized by the CPU 210 to control and/or manage the operations of the single chip 200. The memory 212 may also be utilized to store data received by the single chip 200 via the FM core 208. Similarly, the memory 212 may be utilized to store data to be transmitted by the single chip 200 via the FM core 208.
The CPU 210 may comprise suitable logic, circuitry, and/or code that may enable control and/or management operations in the single chip 200. In this regard, the CPU 210 may communicate control and/or management operations to the FM core 208 via a set of register locations specified in a memory map. Moreover, the CPU 210 may be utilized to process data received by the single chip 200 and/or to process data to be transmitted by the single chip 200. The CPU 210 may enable processing of data received the FM core 208. For example, the CPU 210 may enable processing of A2DP data and may then transfer the processed A2DP data to other components of the single chip 200 via the common bus 201. In this regard, the CPU may utilize the SBC codec 220 in the APU 218 to encode and/or decode A2DP data, for example. The CPU 210 may enable processing of data to be transmitted via the FM core 208. The CPU 210 may be, for example, an ARM processor or another embedded processor core that may be utilized in the implementation of system-on-chip (SOC) architectures.
The CPU 210 may also enable configuration of data routes to and/or from the FM core 208. For example, the CPU 210 may configure the FM core 208 so that data may be routed via an I²S interface or a PCM interface.
The CPU 210 may enable tuning, such as flexible tuning, and/or searching operations in FM communication by controlling at least a portion of the FM core 208. For example, the CPU 210 may generate at least one signal that tunes the FM core 208 to a certain frequency to determine whether there is a station at that frequency. When a station is not found, and interference is below a specified threshold, the CPU 210 may configure a path for the audio signal to be transmitted in the single chip 200. When a station is found with RSSI above a specified threshold, the CPU 210 may generate at least one additional signal that tunes the FM core 208 to a different frequency to determine whether a channel may be clear for transmission at the new frequency. The CPU 210 may create a list of available channels for FM transmission and rank the list according to lowest receive signal strength indicator (RSSI) and other factors for improved channel searching times.
The bus master interface 302 may comprise suitable logic, circuitry, and/or code that may enable communication of control data, digital audio data, and/or RDS/RBDS data between the portions of the PTU 204 shown in FIG. 2 and the common bus 201. The bus master interface 302 may transfer digital audio data and/or RDS/RBDS data to the common bus 201. The RDS/RBDS data may be transferred to the memory 212, for example. In some instances, the RDS/RBDS data may be transferred to the memory 212 when the CPU 210 is in a stand-by or sleep mode. The bus master interface 302 may push RDS/RBDS data into a buffer in the memory 212 or may pull RDS/RBDS data from a buffer in the memory 212, for example. The digital audio data may be transferred to the CPU 210 for processing, for example. The CPU 210 may generate and/or receive control data that may be communicated with the PTU 204 and/or the FM core 208 via the common bus 201.
The UPI 304 may comprise suitable logic, circuitry, and/or code that may enable the transfer of RDS/RBDS data to the bus master interface 302 from the interface multiplexer 310. The UPI 304 may also enable the communication of control data between the bus master interface 302 and the interface multiplexer 310.
The digital audio interface controller 306 may comprise suitable logic, circuitry, and/or code that may enable the transfer of digital audio data to the bus master interface 302 and/or the I² S interface block 308. The I²S interface 308 may comprise suitable logic, circuitry, and/or code that may enable transfer of the digital audio data to at least one device communicatively coupled to the single chip. The I²S interface 308 may communicate control data with the bus master interface 302.
The I²C interface 308 may comprise suitable logic, circuitry, and/or code that may enable transfer of the RDS/RBDS data to at least one device communicatively coupled to the single chip. The I²C interface 308 may also communicate control data between external devices to the single chip and the interface multiplexer 310. In this regard, the interface multiplexer 310 may communicate control data between the I²C interface 308, the UPI 304, and/or the control registers block 322 in the FM core 208.
The interface multiplexer 310 may comprise suitable logic, circuitry, and/or code that may enable the transfer of RDS/RBDS data to the UPI 304 and/or the I² C interface block 312. In this regard, the UPI 304 may generate a signal that indicates to the interface multiplexer 310 the interface to select.
The I²C interface 312 may comprise suitable logic, circuitry, and/or code that may enable transfer of the RDS/RBDS data to at least one device communicatively coupled to the single chip. The I²C interface 312 may also communicate control data between external devices to the single chip and the interface multiplexer 310. In this regard, the interface multiplexer 310 may communicate control data between the I²C interface 312, the UPI 304, and/or the control registers block 322 in the FM core 208.
FIG. 4A is a flow chart for an exemplary algorithm that enables determining channel spacing offsets when RDS/RBDS data and user input are not available, in accordance with an embodiment of the invention. Information regarding found channels which may comprise channel frequencies, offsets between frequencies, received signal strength indicator (RSSI) and/or carrier error for example, may be determined and recorded in a database, in accordance with an embodiment of the invention. The database may be utilized during channel scanning or search operations to improve the scan or search time.
Referring to FIG. 4A, there is shown the flow diagram. After start 468, in step 470, scanning may begin at the low end of the band, a current channel or at a programmed start point. In step 470, RSSI and carrier error may be recorded for a first channel found. In step 474, in instances where the RSSI may be above a specified threshold and carrier error may be below a specified threshold, the exemplary steps may proceed to step 476. In step 476, tuning to this channel may occur. Additionally, in step 476, channel information may be recorded and it may be noted whether the least significant byte (LSB) is odd or even. In step 478, if the band edge has been reached, the exemplary steps may proceed to proceed to step 480. In step 480, the list of channels in the database may be reviewed. In step 482, if the number of odd channels and the number of even channels recorded are close, for example if one is within a multiple of twenty, of the other, the exemplary steps may proceed to step 484. In step 484, a frequency offset between channels of, for example, 100 kHz may be determined. The exemplary steps may proceed to end step 486.
In step 474, if the RSSI recorded in step 472 was below a specified threshold, and/or the carrier error recorded was above a specified threshold, the exemplary steps may proceed to step 488. In step 488, if the edge of the scanning band has not been reached, proceed to step 490. In step 490, the frequency may be increased until the next step is reached. Tuning to a channel may occur and the exemplary steps may proceed to step 472. In step 488, if the edge of the scanning band has been reached, the exemplary steps may proceed to step 480 as indicated by marker A.
In step 482, if the number of odd channels and the number of even channels are not close, the exemplary steps may proceed to step 492. In step 492, if the number of odd channels is much greater than the number of even channels, for example, if the number of odd channels is at least twenty times greater then number of even channels, the exemplary steps may proceed to step 494. In step 494, it may be determined that the FM channels may have, for example, a 200 kHz spacing between channel frequencies and use odd numbered frequencies. For example in one location, channels may occur at 99.1 MHz, 99.3 MHz, 99.5 MHz, etc.). The exemplary steps may proceed to 486.
In step 492, if the number of even channels is much greater than the number of odd channels, for example, if the number of even channels is at least twenty times greater then number of odd channels, proceed to step 494. In step 494, it may be determined that the FM channels may have, for example, a 200 kHz spacing between channel frequencies and use even numbered frequencies. For example in one location, channels may occur at 99.2 MHz, 99.4 MHz, 99.6 MHz, etc.). The exemplary steps may proceed to 486.
For future scans, if a FM channel frequency offset or frequency spacing between channels has been determined prior to scan operations, the scan algorithm may use a known frequency offset to jump between FM channel frequencies. If no channels are found when reaching a scanning band edge in a scan that presumed one type of offset, a second scan through the scanning spectrum may utilize an alternate frequency offset before stopping.
FIG. 4B is a block diagram of a plurality of exemplary radio devices that enable frequency modulation (FM) transmission and reception, in accordance with an embodiment of the invention. Referring to FIG. 4B, there is shown an FM receiver device 410 comprising a speaker 412, a processor 414, a visual display 416, a user input interface 418, a memory 420, an FM radio receiver 422 and an optional alternate technology transmitter and receiver 424. The device 430 may comprise a speaker 432, a processor 434, an FM radio transmitter and FM radio receiver 436, an optional alternate technology transmitter and receiver 438, a display 440, a user input interface 442, a memory 444 and an optional global positioning system (GPS) receiver 446.
The FM receiver device 410 may comprise suitable logic, circuitry and/or code to receive signals within the FM frequency band and may for example be a car radio, home stereo system or computer system. The FM receiver device 410 may demodulate and decode audio signals as well as Radio Data System (RDS) and/or Radio Broadcast Data System (RBDS) signals. In this regard the FM receiver device may store RDS data as well as FM channel candidate information for quicker scanning of available FM channels. The FM receiver device 410 may process RDS/RBDS signals and tune to an FM channel based on RDS/RBDS information channel selection algorithms. The FM receiver device 410 may be capable of receiving manual input from a user such as channel selection. It may also display information for the user with regard to channel selection and RDS/RBDS data.
The speaker or listening device 412 may be suitable for converting electrical output from the receiver device to appropriate audio acoustical waves for a listener. The speaker may also output text to speech (TTS) information for the listener. For example, TTS may enable alerting a user to conditions that require input from the user such as selecting a channel and/or configuration modifications. The speaker or listening device may be communicatively coupled with the processor 414.
The processor 414 may comprise suitable logic, circuitry and/or code that may enable management of scanning, detecting and tuning operations based on a plurality of inputs comprising user input, RDS/RBDS or GPS data such as location information, RSSI levels, carrier error, programmed algorithms and a candidate channel database received from the transceiver device 430. The processor 414 may create a list of available channels for FM reception and rank the list according to lowest receive signal strength indicator (RSSI) and other factors for improved channel searching times. The processor 414 may also be enabled to process audio data. The processor 414 may be communicatively coupled with the FM radio receiver 422, the memory 420, the display 416 and the speaker or listening device 412.
The display 416 may comprise suitable logic, circuitry and/or code to display visual information for the user. The receiver device 410 may display operational conditions of the device, selected FM channel information and RDS/RBDS information. The visual display may be utilized to inform a user when input may be needed such as selecting an FM channel or making a configuration modification. The display 416 may be communicatively coupled with the processor 414 and the memory 420.
The user input interface 418 may comprise a suitable interface for manual input of information that may be utilized by the receiver device 410 to make channel selections or input configuration parameters. The user input may comprise a voice recognition system where input may be spoken by a user and converted to digital information for use as parameters in receiver device 410 operations.
The memory 420 may comprise suitable logic, circuitry and/or code to store and retrieve information that supports scanning, detecting and tuning operations within the receiver device 410. The memory 420 may store: user input, RDS/RBDS or GPS data such as location information, RSSI levels, carrier error, programmed algorithms and a channel database received from the transceiver device 430. The memory 420 may store information that maps FM channels and locally regulated operating constraints, to geographic or market areas in a plurality of continents around the world. The memory 420 may store audio data as well.
The FM radio receiver 422 may comprise suitable logic, circuitry and/or code to demodulate and decode FM signals comprising at least audio and RDS/RBDS information. The FM radio receiver 422 may be coupled with one or more antennas and may receive transmissions from the transceiver device 430, make measurements of the FM spectrum, for example RSSI levels and carrier error, which may be utilized for scanning, detecting and tuning operations and, receive. The FM radio receiver 422 may comprise filters and amplifiers that are designed to adapt to RF signals conditioned and transmitted from the transceiver device 430 according to local regulations regarding pre-emphasis time constants and transmit (TX) power levels. The FM radio receiver 422 may be communicatively coupled with the processor 414, the memory 420, and an FM antenna 426. If the receiver device 410 comprises an alternate technology transmitter and receiver 424, for example a Bluetooth or wireless local area network (WLAN) receiver, the FM radio receiver 422 and alternate technology transmitter and receiver 424 may each have their own antenna or may share a wide band or dual band antenna. In this regard, the FM radio receiver 422 and the alternate band transmitter and/or receiver signals may be decoupled in a diplexer and/or duplexer between the receivers and shared antenna 426. Additional optional alternate technology transceivers may share antennas in a similar manner.
The alternate technology transmitter and receiver 424 may be optional and may facilitate operations regarding one or more embodiments of the invention. The alternate technology transmitter and receiver 424 may comprise one or more of a plurality of radio technologies which may be for example, Bluetooth, WLAN, WWAN, RFID, infrared or a wire-line connection. The receiver portion of the alternate technology transmitter and receiver 424 may receive information from the transmitter portion of the alternate technology transmitter and receiver 438 on transceiver device 430 with regard to location, configuration or FM channel selection operations. In this regard, a new FM channel for re-tuning may be transmitted or a candidate channel database comprising one or more channels and information regarding channel selection and/or configuration.
In addition, information regarding location, configuration and/or FM channel selection operations may be transmitted from the transmitter portion of the alternate technology transmitter and receiver 424 on the receiver device 410 to the receiver portion of the alternate technology transmitter and receiver 438 on transceiver device 430. The alternate technology transmitter and receiver 424 may be communicatively coupled with the processor 414, the memory 420 and an antenna. The alternate technology transmitter and receiver 424 may utilize a simplex or duplex antenna. The alternate technology transmitter and receiver 424 and the FM radio receiver 422 may each have their own antenna or may share a wide band or dual band antenna. In this regard, the FM radio receiver 422 signals and the alternate band transmitter and/or receiver signals may be decoupled in a diplexer and/or duplexer between the receivers and shared antenna 426. Additional optional alternate technology transmitters and receivers may share antennas in a similar manner.
The FM transceiver device 430 may comprise suitable logic, circuitry and/or code to receive and transmit signals within the FM frequency band and may for example be a handheld or portable device. For example the FM transceiver device 430 may be an MP3 player or another content rendering device, a laptop or a wireless phone. The FM transceiver device 430 may handle modulation/demodulation and code/decode operations for audio signals as well as Radio Data System (RDS) and/or Radio Broadcast Data System (RBDS) signals. In this regard the FM transceiver device 430 may store RDS data as well as FM channel candidate information for quicker scanning of available FM channels.
The FM transceiver device 430 may process RDS/RBDS signals and tune to an FM channel based on RDS/RBDS information channel selection algorithms. The FM transceiver device 430 may be capable of receiving manual input from a user such as channel selection. It may also display information for the user with regard to channel selection, RDS/RBDS data, and/or transmitter configuration information. In addition information regarding channel selection for retuning operations may be communicated from the FM transceiver device 430 to the FM receiver device 410 in a plurality of ways.
The speaker or listening device 432 may be suitable for converting electrical output from the receiver device to appropriate audio acoustical waves for a listener. The speaker may also output text to speech (TTS) information for the listener. For example, TTS may enable alerting a user to conditions that require input from the user such as selecting a channel or transmitter configuration modifications. The speaker or listening device may be communicatively coupled with the processor 434.
The processor 434 may comprise suitable logic, circuitry and/or code that may enable management of scanning, detecting and tuning operations based on a plurality of inputs comprising user input, RDS/RBDS or GPS data such as location information, RSSI levels, carrier error, programmed algorithms and a candidate channel database stored in memory 444. The processor 444 may create a list of available channels for FM transmission and rank the list according to, for example, lowest receive signal strength indicator (RSSI) and other factors for improved channel searching times. Other ranking criteria may be utilized. The processor 434 may process audio data as well. The processor 434 may be communicatively coupled with the FM radio transmitter and FM radio receiver 436, the memory 444, the display 449 and the speaker or listening device 432.
The display 440 may comprise suitable logic, circuitry and/or code to display visual information for the user. The transceiver device 430 may display operational conditions of the device, selected FM channel information and RDS/RBDS information. The visual display may be utilized to inform a user when input may be needed such as selecting an FM channel or making a configuration modification. The display 440 may be communicatively coupled with the processor 434 and the memory 444.
The User input interface 442 may comprise a suitable interface for manual input of information that may be utilized by the transceiver device 430 to make channel selections or input configuration parameters. The user input may comprise a voice recognition system wherein input may be spoken by a user and converted to digital information for use as parameters in transceiver device 430 operations.
The memory 444 may comprise suitable logic, circuitry and/or code to store and retrieve information that supports scanning, detecting and turning operations within the transceiver device 430. The memory 444 may store: user input, RDS/RBDS or GPS data such as location information, RSSI levels, carrier error, programmed algorithms and a candidate channel database. The memory 444 may store information that maps FM channels and locally regulated transmitter configuration parameters such as filter time constants and transmit power level constraints, to geographic or market areas in a plurality of continents around the world. The memory 444 may store audio data as well.
The FM radio transmitter and FM radio receiver 436 may comprise suitable logic, circuitry and/or code to modulate/demodulate and code/decode FM signals comprising at least audio and RDS/RBDS information. The FM radio transmitter and FM radio receiver 436 may be coupled with one or more antennas for transmission to the receiver device 410 and, to make measurements of the FM spectrum, for example RSSI levels and carrier error, which may be utilized for scanning, detecting and tuning operations. The FM radio transmitter and FM radio receiver 436 may be utilized for transmitting and receiving a plurality of other signals. The FM radio receiver 422 may comprise filters and amplifiers that may be configured to condition RF signals according to local regulations which may for example comprise pre-emphasis time constants and transmit (TX) power levels.
The FM radio transmitter and FM radio receiver 436 may be communicatively coupled with the processor 434, the memory 444, and one or more FM antennas 448. If the transceiver device 430 comprises an optional alternate technology transmitter and receiver 438, for example a Bluetooth or wireless local area network (WLAN) transmitter receiver, the FM transmitter receiver and alternate technology transmitter receiver may each have their own antennas which may be duplex or simplex, or, they may share wide band or dual band antennas. In this regard, the FM radio transmitter and FM radio receiver 436 input and the alternate technology transmitter and receiver 438 input may be coupled in a diplexer between the FM radio transmitter and FM radio receivers 436 and, the alternate technology transmitter and receiver 438, and the shared the antenna 448. Additional optional alternate technology transmitter receivers may share antennas in a similar manner.
The alternate technology transmitter receiver 448 may be optional and may facilitate operations regarding one or more embodiments of the invention. The alternate technology may comprise one or more of a plurality of radio technologies which may be for example, Bluetooth, WLAN, WWAN, RFID, infrared or simply a wire-line connection. The alternate technology transmitter and receiver 448 may transmit information to the alternate technology transmitter and receiver 424 on receiver device 410 with regard to location, configuration and/or channel selection operations. In this regard, a new FM channel for re-tuning may be transmitted or a database comprising one or more channels and information regarding channel selection may be transmitted to the alternate technology transmitter and receiver 424.
In addition, alternate technology receiver 448 on FM receiver device 430 may receive information from the transmitter portion of the alternate technology transmitter and receiver 424 on FM receiver device 410 regarding location, configuration and/or channel selection operations. The alternate technology transmitter and receiver 438 may be communicatively coupled with the processor 434, the memory 444 and an antenna 448. The alternate technology transmitter and receiver 438 and the FM radio transmitter and FM radio receiver 436 may each have their own antennas which may be duplex or simplex, and/or, they may share wide band or dual band antennas. In this regard, the FM radio transmitter and FM radio receiver 436 signals and the alternate technology transmitter and receiver 438 signals may be decoupled in a diplexer between the FM radio transmitter and FM radio receiver 436, and the alternate technology transmitter and receiver 438, and shared the antenna 448. Any additional optional alternate technology transmitters and receivers may share antennas in a similar manner.
In operation, the transceiver device 430 in FIG. 4B may be for example, a handheld device such as an MP3 player or another digital music format player, equipped with an FM radio. The receiver device 410 may be an FM radio, for example a car radio or home stereo system. The transceiver device 430 may transmit an audio signal via an FM channel to the receiver device 410 and the receiver device may demodulate the FM signal and amplify the acoustical audio output over a speaker or listening device 412.
A channel suitable for transmission from the FM transceiver device 430 to the FM receiver device 410 may be chosen based on a plurality of criteria and in a plurality of ways. For example, channels within a local FM frequency band may be scanned and measured for received signal strength (RSSI) and carrier frequency error. A list of channels which are candidates for FM transmission may be compiled and utilized in future scans or channel searches to improve the scan or search time by one or both of the FM devices. A channel selected for transmission may be auto-determined by one or both of the FM devices or, a user may assist in the selection of a channel by providing input via a user interface on one or both of the devices.
In this regard, a scan function within the FM transceiver 430 and/or the FM receiver 410, may increment a local oscillator in specified frequency steps. Step size may vary depending frequency offsets between FM channels. Frequency offsets are determined by government regulations for a country or location of FM operations. Different countries specify different offsets between FM channels. Offsets could be for example, 50 kHz, 100 kHz or 200 kHz. When the frequency offset and best size scan step are known prior to scanning operations, the time duration for scanning, detecting and selecting FM channels may be improved.
In addition, the FM transceiver device 430 may determine configuration parameters for FM transmissions based on government regulations for the country or location of operation. For example, specified maximum transmit power and pre-emphasis time constants for transmit filters may vary by country or location.
The memory 444 within FM transceiver device 430 and/or the memory 420 within receiver device 410 may comprise one or more databases that map for example, FM channels, frequency offsets and configuration parameters to geographic location. Such mappings may assist in improving time for channel scanning and transmitter configuration.
The FM transceiver device 430 may auto-determine its location or may be assisted by input from a user in order to identify channel spacing and to configure components for transmission according to local government regulations. Location information, channel spacing and/or configuration parameters may be input during setup of the transceiver device 430 and stored for future use.
In one embodiment of the invention, the FM transceiver device 430 may prompt a user for input of geographic location or configuration parameters via visual display 440 for example or via audible communication utilizing text to speech (TTS) technology and the listening device 432. In this regard, the user may input their location or configuration parameters by keying in text or by indicating with voice via the user input interface 442.
In another embodiment of the invention, the FM transceiver device 430 may determine its location via Radio Data System (RDS) or Radio Broadcast Data System (RBDS) information received from an FM host system in the country of operation. In this regard, the FM transceiver device 430 may detect an active channel and demodulate and decode the RDS/RBDS signal. The RDS/RBDS information may provide a country code and/or location code that may be utilized to search for channel offsets and configuration parameters within the database of memory 444. In another embodiment of the invention, the FM transceiver device 430 may comprise a global positioning system (GPS) receiver that may enable the device to determine its location from received GPS data.
If RDS/RBDS and user input information is not available and the location of operation is unknown, the FM transceiver device 430 may auto-determine the frequency offset between FM channels by scanning frequency spectrum and, based upon channels found, determine optimum parameters to use for future or remaining scan activities as illustrated in the flow chart of FIG. 4A. A database may be populated comprising found FM channel information in order to improve future scanning and detecting times.
Once the frequency spacing between FM channels is known, an FM channel with low interference may be selected for FM transmissions to the receiver device 410. The FM transceiver device 430 may jump by known frequency offsets to FM channels and measure RSSI and carrier error on the channels. The FM transceiver device 430 may select a channel on a plurality of criteria. For example, it may select a channel with the lowest RSSI. In another embodiment of the invention, the FM transceiver device may select a channel with an RSSI below a specified threshold and a history of the longest duration of an RSSI below a specified threshold.
Once a channel is selected by the FM transceiver device 430, it may be communicated in a plurality of ways to the FM receiver 410. In one embodiment of the invention, a user may intervene to set a channel on the FM receiver 410. For example, once the FM transceiver device 430 has selected an FM channel for transmission, the selected channel may be displayed on the display 440 or indicated in an audible alert to the user utilizing text to speech via the speaker or listening device 432. The user may then set the selected channel on the FM receiver 410 utilizing a keying input or voice instruction via the user input interface 418. In another embodiment of the invention, the selected channel number may be communicated to the FM receiver via an FM channel, a sideband or via an alternate technology frequency band such as Bluetooth or WLAN for example or WLAN. In this regard, the FM receiver 410 may display the selected channel on the display 416 or indicate the selected channel in an audible alert to the user utilizing text to speech via the speaker or listening device 412. The user may then set the selected channel on the FM receiver 410 utilizing a keying input or voice instruction via the user input interface 418.
In another embodiment of the invention, the re-tuning process may take place autonomously, without user intervention. For example, the FM transceiver device 430 and the FM receiver device 410 may both go into a scanning mode and update and rank their channel candidate lists which may be very similar to each other due to their close proximity within a radio frequency (RF) environment. In this regard the scanning mode may be initiated by user input or initiated dynamically for example, via RDS/RBDS transmission on the FM channel to the FM receiver device 410. In addition, information may be sent to the FM receiver device 410 on a sideband or on an alternate technology frequency band for example, Bluetooth, WLAN, WWAN and/or on a wire-line. Moreover, the FM receiver device 410 may provide information to the FM transceiver device 430, regarding location, configuration preferences or FM channels via the alternate technology transmitter and receiver 424 and alternate technology transmitter and receiver 438.
In an exemplary embodiment of the invention, the FM transceiver device 430 may update its channel candidate list and transmit it to the FM receiver device 410 via RDS/RBDS, a side band or via another frequency band such as Bluetooth, WLAN, WWAN or a wire-line. Once both FM devices comprise the same or similar ranked channel candidate lists, the FM transceiver device 430 may select a channel from its channel candidate list and begin to transmit an FM signal on it. The FM receiver device 410 may search for the strongest signal on its list and re-tune to the new channel
In an embodiment of the invention, the FM radio transmitter and FM radio receiver in block 430 disclosed in FIG. 4B may be an integrated circuit in an end user portable or mobile communication device that enables determining of geographic location and FM channel map and configuring the FM transmitter based on the channel map. The channel map may comprise a list of ranked FM channels. The FM receiver may acquire geographic location from a plurality of sources comprising radio data system (RDS) or Radio Broadcast Data System (RBDS) signals, Global Position System (GPS) data via an integrated GPS receiver on the mobile device, from wireless or wire-line network data via an integrated receiver on the mobile device and/or from user data. The FM radio transmitter and FM radio receiver in block 430, may determine channel spacing, channel offset and/or frequency band for the FM channel map. A frequency for transmitting FM signals may be selected based on the FM channel map. In addition, the FM radio receiver and/or FM radio transmitter may be configured based on information from an in-band FM signal or an out-of-band signal and the FM channel map. The out-of-band signal may comprise one or more of a Bluetooth signal, a WLAN signal, a ZigBee signal and a wireless signal. An audio or visual signal may be generated that indicates a channel being used by the FM radio transmitter. The audio signal may text to speech translation and/or one or more audible tones.
Certain embodiments of the invention may comprise a machine-readable storage having stored thereon, a computer program having at least one code section for determining channel spacing and configuring an FM transmitter, the at least one code section being executable by a machine for causing the machine to perform one or more of the steps described herein.
Accordingly, aspects of the invention may be realized in hardware, software, firmware or a combination thereof. The invention may be realized in a centralized fashion in at least one computer system or in a distributed fashion where different elements are spread across several interconnected computer systems. Any kind of computer system or other apparatus adapted for carrying out the methods described herein is suited. A typical combination of hardware, software and firmware may be a general-purpose computer system with a computer program that, when being loaded and executed, controls the computer system such that it carries out the methods described herein.
One embodiment of the present invention may be implemented as a board level product, as a single chip, application specific integrated circuit (ASIC), or with varying levels integrated on a single chip with other portions of the system as separate components. The degree of integration of the system will primarily be determined by speed and cost considerations. Because of the sophisticated nature of modern processors, it is possible to utilize a commercially available processor, which may be implemented external to an ASIC implementation of the present system. Alternatively, if the processor is available as an ASIC core or logic block, then the commercially available processor may be implemented as part of an ASIC device with various functions implemented as firmware.
The present invention may also be embedded in a computer program product, which comprises all the features enabling the implementation of the methods described herein, and which when loaded in a computer system is able to carry out these methods. Computer program in the present context may mean, for example, any expression, in any language, code or notation, of a set of instructions intended to cause a system having an information processing capability to perform a particular function either directly or after either or both of the following: a) conversion to another language, code or notation; b) reproduction in a different material form. However, other meanings of computer program within the understanding of those skilled in the art are also contemplated by the present invention.
While the invention has been described with reference to certain embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the scope of the present invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the present invention without departing from its scope. Therefore, it is intended that the present invention not be limited to the particular embodiments disclosed, but that the present invention will include all embodiments falling within the scope of the appended claims.

Claims

1. A method for wireless communication, the method comprising:

in a mobile device comprising an integrated FM radio transmitter and FM radio receiver:

determining a geographic location of said mobile device;

determining a FM channel map based on said determined location of said mobile device; and

configuring said FM radio transmitter for transmitting FM signals based on said determined FM channel map.

2. The method according to claim 1, comprising acquiring said geographic location from RDS or RBDS signals received by said radio receiver.

3. The method according to claim 1, comprising acquiring said geographic location from GPS data received via a GPS receiver located said mobile device.

4. The method according to claim 1, comprising acquiring said geographic location from wireless data received from a wireless network via a wireless receiver integrated within said mobile device.

5. The method according to claim 1, comprising acquiring said geographic location from user data received by said mobile device.

6. The method according to claim 1, comprising determining channel spacing, channel offset and/or frequency band for said determined FM channel map.

7. The method according to claim 1, comprising selecting a frequency for transmitting FM signals via said FM radio transmitter based on said determined FM channel map.

8. The method according to claim 1, comprising configuring said FM radio receiver for receiving FM signals based on said determined FM channel map.

9. The method according to claim 1, comprising configuring one or both of said FM radio transmitter and FM radio receiver via an in-band FM signal based on said determined FM channel map.

10. The method according to claim 1, comprising configuring one or both of said FM radio transmitter and FM radio receiver via an out-of-band signal based on said determined FM channel map

11. The method according to claim 10, wherein said out-of-band signal comprises one or more of a Bluetooth signal, a WLAN signal, a ZigBee signal, and a wireless signal.

12. The method according to claim 1, wherein said determined FM channel map comprises a list of ranked FM channels.

13. The method according to claim 1, comprising generating a signal that indicates a channel being used by said FM radio transmitter based on said configuration.

14. The method according to claim 13, wherein said generated signal comprises one or more of an audio signal, and/or a visual signal.

15. The method according to claim 14, wherein said audio signal comprises text-to-speech translation and/or one or more audible tones.

16. A system for wireless communication, the system comprising:

a mobile device comprising at least one processor, and an integrated FM radio transmitter and FM radio receiver, wherein:

said at least one processor enables determination of a geographic location of said mobile device;

said at least one processor enables determination of a FM channel map based on said determined location of said mobile device; and

said at least one processor enables configuration of said FM radio transmitter for transmitting FM signals based on said determined FM channel map.

17. The system according to claim 16, wherein said at least one processor enables acquisition of said geographic location from RDS or RBDS signals received by said radio receiver.

18. The system according to claim 16, wherein said at least one processor enables acquisition of said geographic location from GPS data received via a GPS receiver located said mobile device.

19. The system according to claim 16, wherein said at least one processor enables acquisition of said geographic location from wireless data received from a wireless network via a wireless receiver integrated within said mobile device.

20. The system according to claim 16, wherein said at least one processor enables acquisition of said geographic location from user data received by said mobile device.

21. The system according to claim 16, wherein said at least one processor enables determination of channel spacing, channel offset and/or frequency band for said determined FM channel map.

22. The system according to claim 16, wherein said at least one processor enables selection of a frequency for transmitting FM signals via said FM radio transmitter based on said determined FM channel map.

23. The system according to claim 16, wherein said at least one processor enables configuration of said FM radio receiver for receiving FM signals based on said determined FM channel map.

24. The system according to claim 16, wherein said at least one processor enables configuration of one or both of said FM radio transmitter and FM radio receiver via an in-band FM signal based on said determined FM channel map.

25. The system according to claim 16, wherein said at least one processor enables configuration of one or both of said FM radio transmitter and FM radio receiver via an out-of-band signal based on said determined FM channel map

26. The system according to claim 25, wherein said out-of-band signal comprises one or more of a Bluetooth signal, a WLAN signal, a ZigBee signal, and a wireless signal.

27. The system according to claim 16, wherein said determined FM channel map comprises a list of ranked FM channels.

28. The system according to claim 16, wherein said at least one processor enables generation of a signal that indicates a channel being used by said FM radio transmitter based on said configuration.

29. The system according to claim 28, wherein said generated signal comprises one or more of an audio signal, and/or a visual signal.

30. The system according to claim 29, wherein said audio signal comprises text-to-speech translation and/or one or more audible tones.