WO2011091642A1

WO2011091642A1 - Method and base station for detecting ranging signals

Info

Publication number: WO2011091642A1
Application number: PCT/CN2010/074261
Authority: WO
Inventors: 曾璐; 张玉杰
Original assignee: 中兴通讯股份有限公司
Priority date: 2010-02-01
Filing date: 2010-06-22
Publication date: 2011-08-04
Also published as: CN102142909B; CN102142909A

Abstract

A method for detecting ranging signals is disclosed. The method comprises: a base station receives signals from a mobile station, and according to the received signals, the time domain correlation value and carrier-to-noise ratio of each antenna of the base station are determined; the carrier-to-noise ratio of each antenna is normalized for getting corresponding weight coefficient of each antenna; and according to the weight coefficients and time domain correlation values of all the antennas, the power parameter of the base station is determined, and the power parameter is compared with the predetermined power threshold; if the power parameter is greater than or equal to the predetermined power threshold, it can be sure that a ranging signal is comprised in the received signals. The present invention also provides a base station. The present invention can decrease the effects on ranging detection caused by channel fade and noise interference, promote data utilization efficiency and anti-noise ability, and reduce misdetection probability, thus enhancing the system performance and the detection performance.

Description

Method for detecting ranging signal and base station

The present invention relates to the field of communications, and in particular, to a method and a base station for detecting a ranging signal.

Background technique

Orthogonal Frequency Division Multiplexing (OFDM) technology is a multi-carrier digital modulation technology and a frequency reuse technology. The main idea of OFDM technology is to divide the channel into orthogonal sub-channels, convert the high-speed data signals into parallel low-speed sub-data streams, and modulate them for transmission on each sub-channel. Compared with other modulation technologies and multiplexing technologies, OFDM technology has been widely used in broadcast audio and video fields and military and civil communication systems because of its efficient spectrum utilization efficiency and good multipath immunity. The 802.16 series and 802.11 series standards using OFDM technology as the main physical layer technology have been widely used. In the OFDMA system specified by the IEEE 802.16 protocol, uplink synchronization between a mobile station and a base station is performed by a ranging signal (Ranging signal). Its main function is to obtain the target parameters such as Time Offset Estimation and Frequency Offset Estimation of the mobile station relative to the base station by detecting the Ranging signal transmitted by the mobile station, and then base station and then request the mobile station according to these parameters. Adjust its transmit signal to achieve uplink synchronization. That is, the Ranging signal has the function of timing synchronization and carrier synchronization. In addition, the function of the Ranging signal also includes issuing a bandwidth request and a handover request. At present, Ranging detection is mainly performed with power as a threshold.

Summary of the invention

At present, Ranging detection is mainly performed with power as a threshold. When data on a single antenna is used for Ranging detection only with power as a threshold, it is susceptible to channel fading and interference, and the data on multiple antennas is used as a threshold for Ranging detection. When the detection process only uses the power of each antenna signal as a reference, the Ranging detection cannot provide an effective gain for the system. That is to say, if the Ranging detection only uses power as a threshold, regardless of the signal-to-noise ratio of the signal, it is easy to cause false detection. It can be seen that in the prior art, for the problem that the Ranging detection only uses power as a threshold to cause false detection, an effective solution has not been proposed yet. The present invention proposes a method for detecting a ranging signal, which can detect a Ranging in a more reasonable manner and reduce the probability of false detection. The present invention also proposes a base station capable of detecting Ranging in a more reasonable manner, and reducing the probability of false detection, in view of the problem that the Ranging detection only uses power as a threshold to cause false detection. The technical solution of the present invention is implemented as follows: A method for detecting a ranging signal, comprising: receiving, by a base station, a signal from a mobile station, determining, according to the received signal, a time domain correlation value of each antenna of the base station and each Carrier-to-noise ratio of each antenna; normalizing the carrier-to-noise ratio of each antenna to obtain a weighting coefficient corresponding to each antenna; and determining power parameters of the base station according to weighting coefficients and time domain correlation values of all antennas, And comparing the power parameter with a preset power threshold, where the power parameter is greater than or equal to the preset power threshold, determining that the received signal includes a ranging signal. The step of determining a carrier-to-noise ratio of each antenna of the base station includes: determining, for each antenna of the base station, a carrier-to-noise ratio of the antenna according to a useful power and a useless power of a signal received by the antenna. Determining a time domain correlation value of each antenna of the base station includes: for each antenna of the base station, extracting a carrier sequence including a ranging signal in a signal received by the antenna; and extracting the extracted The carrier sequence is separately associated with multiple local code sequences of the base station Calculating, and performing inverse Fourier transform on the result of the correlation operation, determining a local code sequence corresponding to the carrier sequence and a time domain correlation value of the signal received by the antenna; wherein the determined time domain correlation The value includes the time domain correlation peak of the antenna. A carrier sequence of a ranging signal included in a signal received by the antenna is represented by the following formula

Where, for the original signal sent by the mobile station, N is the number of total frequency points, r. The time offset relative to the mobile station when the antenna receives the signal, m is the time offset required to search. Use the following formula to perform correlation operations and get the result of the correlation operation. M:

= §Q3⁄4 exp(-2^ {T ₀ -m)/N) where is the local code of the base station, the original signal sent by the mobile station, N is the number of total frequency points, τ. The time offset relative to the mobile station when the antenna receives the signal is the time offset that needs to be searched. Before the step of determining the carrier-to-noise ratio of the antenna, the method further includes: determining the useful power by using the following formula

P _l = E _Carrier E^ _arrier , where E _Carrier = _max = ∑ _{Jk = 0 k} Y _k , Lc _k = Y _k , ηι = τ ₀ . Before the step of determining the carrier-to-noise ratio of the antenna, the method further comprises: determining, by using Y _k = f _k exp ( j2nkz ₀ 1 N); calculating the interference/noise signal 4 of the antenna as:

I _k =Y _k -Y _k ^ _V {j2nk N) . Before the step of determining the carrier-to-noise ratio of the antenna, the method further comprises: determining the useless power Ρ ₂ by using the following formula:

P = (y ^N I ) (y ^N I Preferably, the weighting coefficient corresponding to each antenna is determined according to the following formula ^: = C/N / C/NR, where C/N is the carrier noise of the ith antenna Ratio, CINRi two P _2i , is the useful power of the ith antenna, Ρ _2ζ · is the unwanted power of the ith antenna. Preferably, the step of determining a power parameter of the base station includes: for each antenna, multiplying a weighting coefficient of the antenna by a time domain correlation peak corresponding to the antenna to obtain a first multiplication result of the antenna, and The first multiplication result of all the antennas of the base station is added to obtain a power peak of the base station as the power parameter; and the step of comparing the power parameter with a preset power threshold comprises: setting a power peak of the base station Comparing with the power peak threshold in the preset power threshold; determining that the received signal includes a ranging signal includes: when the power peak is greater than or equal to the preset power peak threshold, It is determined that the received signal includes a ranging signal.

Preferably, the step of determining a power parameter of the base station includes: for each antenna, multiplying a weighting coefficient of the antenna by a time domain correlation value corresponding to the antenna to obtain a second multiplication result of the antenna, and The second multiplication result of all the antennas of the base station is added, and the power average of the base station is obtained as the power parameter. The step of comparing the power parameter with a preset power threshold includes: performing work of the base station

Determining that the received signal includes a ranging signal comprises: determining that the received signal includes a ranging signal if the power average is greater than or equal to the preset power mean threshold.

Preferably, the step of determining a power parameter of the base station includes: for each antenna, multiplying a weighting coefficient of the antenna by a time domain correlation peak corresponding to the antenna to obtain a first multiplication result of the antenna, and Adding a first multiplication result of all antennas of the base station to obtain a power peak of the base station, and multiplying a weighting coefficient of the antenna by a time domain correlation value corresponding to the antenna to obtain a second multiplication result of the antenna Adding a second multiplication result of all the antennas of the base station to obtain a power average of the base station, and a power peak of the base station and a power average of the base station are used as the power parameter; The step of comparing the preset power thresholds includes: comparing a power peak of the base station with a power peak threshold of the preset power threshold, and comparing the base station

Determining that the received signal includes a ranging signal includes: the power peak is greater than Or equal to the preset power peak threshold, and if the power average is greater than or equal to the preset power average threshold, it is determined that the received signal includes a ranging signal. The step of extracting the carrier sequence including the ranging signal in the signal received by the antenna comprises: performing Fourier transform on the signal received by the antenna, and extracting a carrier sequence including the ranging signal at a specific carrier position.

A base station, comprising: a receiving module, configured to: receive a signal from a mobile station, determine a time domain correlation value of each antenna of the base station, and a carrier-to-noise ratio of each antenna according to the received signal; , the setting is: normalizing the carrier-to-noise ratio of each antenna to obtain a weighting coefficient corresponding to each antenna; and determining a module, configured to: determine the weighting coefficient and the time domain correlation value according to all antennas a power parameter of the base station, and comparing the power parameter with a preset power threshold, where the power parameter is greater than or equal to the preset power threshold, determining that the received signal includes a ranging signal. The determining module is configured to determine a power parameter of the base station according to the following manner: for each antenna, multiplying a weighting coefficient of the antenna by a time domain correlation peak corresponding to the antenna to obtain a first multiplication result of the antenna Adding a first multiplication result of all antennas of the base station to obtain a power peak of the base station as the power parameter; and/or, for each antenna, matching a weighting coefficient of the antenna to the antenna Multiplying the time-domain correlation values to obtain a second multiplication result of the antenna, and adding a second multiplication result of all the antennas of the base station to obtain a power average of the base station, as the power parameter; The determining module is configured to compare the power parameter with a preset power threshold as follows: comparing a power peak of the base station with a power peak threshold of the preset power threshold; The determining module is configured to determine, in the manner that the received signal includes a ranging signal: if the power peak is greater than or equal to the preset power peak threshold, and/or at the power average When the preset power average threshold is greater than or equal to, the received signal is determined to include a ranging signal.

With the above technical solution of the present invention, the power of the received signal of the base station is determined by performing a weighting operation on the signal of the antenna by the carrier-to-noise ratio of each antenna, and the Ranging signal is detected by using the power, thereby reducing channel fading and noise interference. The impact of Ranging detection improves data utilization and noise immunity, reduces the probability of false detections, and improves system performance and detection performance.

1 is a flowchart of a method for detecting a ranging signal according to an embodiment of the present invention; FIG. 2 is a schematic diagram of a principle of Ranging multi-antenna combining according to an embodiment of the present invention; FIG. 3 is a ranging according to an embodiment of the present invention. FIG. 4 is a schematic diagram of an algorithm for Ranging multi-antenna combining based on MRC according to an embodiment of the present invention; FIG. 5 is a correlation operation between available codeword sequences and frequency domain data traversal according to an embodiment of the present invention; Schematic diagram of the principle; FIG. 6 is a structural connection diagram of a base station according to an embodiment of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION The present invention provides a Ranging detection method for multi-antenna combining, which is based on a maximum output signal-to-noise ratio (SNR) based on the principle of Maximal Ratio Combining (MRC). The combination of carrier-to-noise ratios is achieved to reduce the impact of channel fading and noise interference on Ranging detection and improve system performance. MRC is a relatively simple and effective multi-antenna combining technique, which can automatically adjust the weighting coefficients of each antenna data according to the instantaneous signal-to-noise ratio/carrier-to-noise ratio conditions of each antenna to track the characteristics of environmental changes, so that the antenna data can be fully utilized. , The signal is processed without interruption. In addition, the MRC algorithm has the characteristics of simple implementation and stable performance, and can adapt to the needs of Ranging detection of OFDM system, and can effectively improve system gain. 1 is a flow chart of steps of a method for detecting a ranging signal according to an embodiment of the present invention. In the present invention, the principle of performing Ranging detection by multiple antennas is to perform weighted combining on data on different antennas according to the signal quality of the received signal, as shown in FIG. The method includes the following steps: Step S101: The base station receives a signal from the mobile station, and determines a carrier-to-noise ratio of each antenna of the base station according to the received signal. Step S102: normalize the carrier-to-noise ratio of each antenna. Obtaining a weighting coefficient corresponding to each antenna; Step S103, determining a power parameter of the base station according to the weighting coefficient and the time domain correlation value of all the antennas, and comparing the power parameter with a preset power threshold, where the power parameter is greater than or equal to the preset power In the case of a threshold, it is determined that the received signal contains a ranging signal. In order to better illustrate the present invention, the following description will be made by taking a base station including two antennas (antenna 1 and antenna 2) as an example. Those skilled in the art will appreciate that the present invention is equally achievable for a base station including other numbers of antennas. The schematic diagram of the Ranging multi-antenna combining shown in FIG. 2 is described. In the specific implementation process, both the antenna 1 and the antenna 2 receive the OFDM signal transmitted by the mobile station, and the OFDM signal received by the antenna 1 is used for various reasons. The original OFDM signal transmitted by the mobile station may be biased by 1 when the OFDM signal received by the antenna 2 and the original OFDM signal transmitted by the mobile station may be biased by 2. For each antenna on the base station, the following processing is performed. Antenna 1 is taken as an example: First, antenna 1 performs Fast Fourier Transform (FFT) on the received OFDM signal, and extracts a carrier sequence including a Ranging signal at a specific carrier position according to the protocol IEEE802.16; The base station generates a local code. Specifically, according to the IEEE 802.16 protocol and the base station side codeword search range, the base station generates all local pseudo random code sequences that may be used by the mobile station, and each pseudo random code sequence includes 144 1 Or a pseudo-random code of -1, and then antenna 1 separates the extracted carrier sequence containing the Ranging signal into a plurality of local code sequences generated by the base station Correlation calculation, the correlation calculation result obtained, and the correlation calculation sequence is mapped Returning to the corresponding carrier position; then, the antenna 1 performs the inverse inverse Fourier Transform (IFFT) on the correlation operation result, and calculates the peak power and the interference noise power of the antenna 1, and according to the peak power And the interference noise power, calculate the carrier-to-noise ratio of the antenna 1. Similarly, according to the above manner, the carrier-to-noise ratio of the antenna 2 can also be calculated. The carrier-to-noise ratio of the antenna 1 and the carrier-to-noise ratio of the antenna 2 are normalized, and the weighting coefficients of the signals on the antenna 1 and the antenna 2 are respectively obtained, and the weighting coefficients of the antenna 1 and the time domain correlation peak corresponding to the antenna 1 are phased. After multiplying, the multiplication result 1 of the antenna 1 is obtained, and the weighting coefficient of the antenna 2 is multiplied by the time domain correlation peak corresponding to the antenna 2 to obtain the multiplication result 2 of the antenna 1, and the multiplication result 1 and the multiplication result 2 are added. Obtaining a power peak of the base station, comparing the power peak with a power peak threshold in the preset power threshold, and determining, when the power peak is greater than or equal to a preset power peak threshold, determining that the received signal is included Ranging signal; and/or, multiplying the sum of all correlation values (including time domain correlation peaks) corresponding to antenna 1 and the weighting coefficient of antenna 1 to obtain multiplication result 3 of antenna 1, and correlating all correlations of antenna 2 The sum of the values (including the time domain correlation peaks) is multiplied by the weighting coefficient of the antenna 2 to obtain the multiplication result 4 of the antenna 2, and the multiplication result 3 and the multiplication result 4 are added to obtain the power average of the base station, and the power is obtained. Mean and preset Mean rate threshold is compared, in the case of power mean value is greater than or equal to a preset threshold power mean value, the determination signal contained in the received ranging signal. Generally, an uplink receiving system (for example, a base station) generally includes a plurality of antennas. For a mobile station attempting to access a base station, multiple antennas of the base station may receive Ranging signals transmitted by the mobile station, and these signals are different. The transmission path has different power and signal-to-noise ratio/carrier-to-noise ratio. If the data received on antenna 1 is small but the signal-to-noise ratio is high, the data received on antenna 2 is large but the signal-to-noise ratio is low. When combining, the data of the two antennas are weighted by different weights, so that the data received on the antenna 1 accounts for a large proportion in the combined data, and the output data has the highest signal-to-noise ratio, thereby improving the Ranging detection capability. . The key of the MRC-based Ranging antenna merging algorithm is to obtain the carrier-to-noise ratio of the received data on each antenna at a certain moment, and the signal is weighted and combined by this value. The Ranging multi-antenna merging algorithm in the OFDM system is described below with reference to FIG. 3 and FIG. 4. FIG. 3 is a detailed processing flowchart of the method for detecting the ranging signal according to the embodiment of the present invention. As shown in FIG. 3, the following steps are included: S301. The mobile station attempts to access the base station, and sends a Ranging Code to the base station on the corresponding subcarrier, and each antenna on the base station receives the OFDM signal from the mobile station, and each antenna receives the antenna. The resulting OFDM signal (which is a time domain signal) is transformed into the frequency domain by a Fast Fourier Transform (FFT). Among them, the first antenna received ⁷ due to transmission delay. The time domain signal sent by the mobile station at the moment is:

γ(τ ₀ -ηι) = Η(τ ₀ )χ(τ ₀ ) + η(τ ₀ ) ( 1 ) where r. The time offset relative to the mobile station when the first antenna receives the signal, m is the time offset required to search. Then, (.-m) is transformed into the frequency domain by FFT, then the frequency domain form of the received data (signal) on the A subcarriers (ie, the Ranging carrier sequence), and the Ranging signal related carrier A can be extracted according to the protocol 802.16. , P ..., Ρ _κ .

Wherein, the frequency domain form of the signal received by the first antenna is the original signal sent by the mobile station, and N is the number of total frequency points. Step S302, the base station generates all available local pseudo-random code sequences: PW 'PN _T , each sequence contains f code words: and each sequence is composed of _ 1 or 1, each local pseudo-random sequence The correlation operation is performed separately with the Ranging carrier sequence, and the result M of the correlation operation is:

M = ∑ C _k Y _k exp(-2^ {T ₀ -m)/N) (3) If the data of the Ranging carrier is not zero-padded, the correlation result can be transformed into: M = _j C _k Y _k exp( -2^- jkr ₀ 1 N) exp {injkmlN) (4) In step S302, mainly a Correlation Process is performed, and FIG. 5 is a correlation of available codeword sequences with frequency domain data traversal according to an embodiment of the present invention. The schematic diagram of the operation, specifically, the Ranging frequency domain data obtained is correlated with each local pseudo random code sequence; the traversal process is because the pseudo random code sequence sent by the mobile station is randomly selected in a set of available sequences The base station side does not know which pseudo-random code sequence the mobile station specifically transmits. Therefore, it is necessary to correlate all possible pseudo-random code sequences with the received data. According to the nature of the pseudo-random code sequence, only when the bits are consistent, the correlation The accumulated result will show a peak, and the correlation will be based on the carrier. The mapping relationship maps the data back to the corresponding carrier location. Step S303, the form of the correlation result obtained by the above formula (4) is consistent with the form obtained by the inverse fast Fourier transform (IFFT) transform, and the multiplication is performed by the IFFT operation on the formula (4). The cumulative result, where the formula after performing the IFFT transformation is:

The nature of the pseudo-random code, when the code word sequence of G W _f = i, and time offset = τ. When M appears, the maximum value is recorded as the carrier signal E _Carrier :

(6)

Step S304, passing the time offset τ. To restore the original signal i = e _X p( '2^./N;> from the mobile station, then for the first antenna, the size of the interference/noise signal 4 introduced by time offset and noise is:

Step S305, obtaining the useful power of the carrier signal on the first antenna according to formula (6), carrier p = π π ^Η

Carrier ― Carrier Carrier

According to formula (7), the interference/noise power of the fourth antenna is obtained as:

P 2=P Interference + p Noise =

Where ^^«^/^^ is the interference power and ^Vtee is the noise power.

Then, according to the useful power of the carrier signal on the first antenna and the interference/noise power p ₂ , the carrier-to-noise ratio of the antenna is determined as:

CINR _F ― P _CARRIER ^ ^Interference + ^Noise ) (10) Step S306, normalizing the carrier-to-noise ratio on each antenna to obtain a weighting coefficient of each antenna, where the first antenna The weighting factor is:

Where C/NR is the sum of the weighting coefficients of all antennas in the base station. Step S307, multiplying the time domain power of each antenna by the weighting coefficient accumulation of the antenna as the result of the antenna combining, wherein the output result P of the antenna combining is:

Where P = [ , Ρ _Ί , ... is the result of the antenna combination; = [^, p _n , ... is the time domain power of each antenna. Step S308, calculating the average power and the search peak power respectively compared with the power average threshold and the power peak threshold. If a threshold is met or both thresholds are met, the Ranging code is considered to be detected. Specifically, the following three methods may be used to determine Whether the Ranging signal is detected: Mode 1: For each antenna, the weighting coefficient of the antenna is multiplied by the time i or the correlation peak corresponding to the antenna to obtain the first multiplication result of the antenna, and the antenna of the base station is A multiplication result is added to obtain a power peak of the base station as a power parameter, and then comparing a power peak of the base station with a power peak threshold in a preset power threshold, where the power peak is greater than or equal to a preset power peak threshold. In the case, it is determined that the received signal contains a ranging signal. Manner 2: For each antenna, multiplying the weighting coefficient of the antenna by the time i or correlation value corresponding to the antenna to obtain a second multiplication result of the antenna, and adding the second multiplication result of all antennas of the base station Obtaining a power average of the base station as a power parameter, and then comparing the power average of the base station with a preset power average threshold in the preset power threshold, and determining that the power is greater than or equal to the preset power average threshold. The signal contains a ranging signal. Manner 3: For each antenna, multiplying the weighting coefficient of the antenna by the time i or the correlation peak corresponding to the antenna to obtain a first multiplication result of the antenna, and adding the first multiplication result of all antennas of the base station Obtaining a power peak of the base station as a power parameter, and then comparing a power peak of the base station with a power peak threshold of the preset power threshold, and determining the received when the power peak is greater than or equal to a preset power peak threshold The signal includes a ranging signal; at the same time, for each antenna, the weighting coefficient of the antenna is multiplied by a time domain correlation value corresponding to the antenna to obtain a second multiplication result of the antenna, and the second antenna of all the antennas of the base station is obtained. The multiplication results are added to obtain the power average of the base station, and the limits are compared. When the power average is greater than or equal to the preset power average threshold, it is determined that the received signal includes the ranging signal. Mode 3: for each antenna, multiplying the weighting coefficient of the antenna by a time domain correlation peak corresponding to the antenna to obtain a first multiplication result of the antenna, and multiplying the first multiplication result of all antennas of the base station Adding, obtaining a power peak of the base station, and multiplying a weighting coefficient of the antenna by a time domain correlation value corresponding to the antenna to obtain a second multiplication result of the antenna, and Adding a power multiplication result of the base station, a power peak value of the base station and a power average value of the base station as the power parameter; and a power peak of the base station and the preset power threshold Comparing the power peak thresholds, and comparing the power average of the base station with a preset power average threshold in the preset power threshold; wherein the power peak is greater than or equal to the preset power peak threshold, and In a case that the power mean is greater than or equal to the preset power mean threshold, it is determined that the received signal includes a ranging signal. In the above steps S301 to S306, each antenna calculates a weighting coefficient of the antenna data according to the received signal, and steps S307 to S308 multiply each antenna data by a weighting coefficient and accumulate, respectively, by using a power peak threshold and/or a power average threshold. Ranging detection. By means of the above technical solution of the present invention, the influence of channel fading and noise interference on Ranging detection is reduced by combining multi-antenna data based on the maximum output signal-to-noise ratio/carrier-to-noise ratio, thereby improving data utilization and anti-noise. The ability to reduce the probability of false detections, thereby improving system performance and detection performance. FIG. 6 is a structural diagram of a base station according to an embodiment of the present invention. As shown in FIG. 6, the base station includes: a receiving module 61 configured to: receive a signal from a mobile station, and determine each antenna of the base station according to the received signal. The processing module 62 is configured to: normalize the carrier-to-noise ratio of each antenna to obtain a weighting coefficient corresponding to each antenna; and determine a module 63, which is set to: The coefficient and the time domain correlation value determine the power parameter of the base station, and compare the power parameter with the preset power threshold. When the power parameter is greater than or equal to the preset power threshold, it is determined that the received signal includes the ranging signal. The invention combines antennas for Ranging detection, and improves data utilization and resistance without increasing detection complexity compared with prior art single antenna detection or multi-antenna decision detection. The ability of noise reduces the probability of false detection. Moreover, the invention realizes real-time tracking of the signal-to-noise ratio on each antenna, and continuously detects the Ranging signal with high sensitivity, thereby improving the stability and gain of the system. FIG. 6 is a system corresponding to the previous method. The working process and working principle of the system have been described in detail in the method part, and details are not described herein again, and the description of the corresponding parts in the method may be referred to.

One of ordinary skill in the art will appreciate that all or a portion of the steps above may be accomplished by a program to instruct the associated hardware, such as a read-only memory, a magnetic disk, or an optical disk. Alternatively, all or part of the steps of the above embodiments may also be implemented using one or more integrated circuits. Correspondingly, each module/unit in the above embodiment may be implemented in the form of hardware or in the form of a software function module. The invention is not limited to any specific form of combination of hardware and software.

The above is only the preferred embodiment of the present invention, and is not intended to limit the present invention. Any modifications, equivalents, improvements, etc., which are included in the spirit and scope of the present invention, should be included in the present invention. Within the scope of protection.

INDUSTRIAL APPLICABILITY With the above technical solution of the present invention, the power of the received signal of the base station is determined by performing a weighting operation on the signal of the antenna by the carrier-to-noise ratio of each antenna, and the Ranging signal is detected by the power, thereby reducing channel fading and The influence of noise interference on Ranging detection improves the data utilization and anti-noise ability, reduces the probability of false detection, and improves system performance and detection performance.

Claims

Claim

A method for detecting a ranging signal, comprising: receiving, by a base station, a signal from a mobile station, determining, according to the received signal, a time domain correlation value of each antenna of the base station and a carrier-to-noise ratio of each antenna; The carrier-to-noise ratio of each antenna is normalized to obtain a weighting coefficient corresponding to each antenna; and the power parameters of the base station are determined according to weighting coefficients and time domain correlation values of all antennas, and the power parameters are And setting a power threshold for comparing, if the power parameter is greater than or equal to the preset power threshold, determining that the received signal includes a ranging signal.

2. The method according to claim 1, wherein the determining a carrier-to-noise ratio of each antenna of the base station comprises: for each antenna of the base station, according to a useful power of a signal received by the antenna Unwanted power, determining the carrier-to-noise ratio of the antenna.

3. The method according to claim 2, wherein determining the time domain correlation value of each antenna of the base station comprises: extracting, for each antenna of the base station, a signal included in the antenna received a carrier sequence from the signal; and correlating the extracted carrier sequence with a plurality of local code sequences of the base station, and performing inverse Fourier transform on the result of the correlation operation to determine the carrier sequence Corresponding local code sequence and a time domain correlation value of the signal received by the antenna; wherein the determined time domain correlation value comprises a time domain correlation peak of the antenna.

4. The method according to claim 3, wherein the carrier sequence of the ranging signal contained in the signal received by the antenna is represented by the following formula: f _k = Y _k exp (^k (T ₀ - m ) / N) Where, for the original signal sent by the mobile station, N is the number of total frequency points, r. For the time offset of the antenna when receiving the signal, TM is the time offset that needs to be searched.

5. The method according to claim 3, wherein the correlation operation is performed by using the following formula, and the result of the correlation operation is obtained.

^M =∑ C _k Y _k exp(- 2;r ( ₀ -m

Wherein, the local code of the base station is the original signal sent by the mobile station, and N is the number of total frequency points, τ. The time offset relative to the mobile station when the antenna receives the signal is the time offset that needs to be searched.

6. The method according to claim 5, wherein before the step of determining a carrier-to-noise ratio of the antenna, the method further comprises: determining a useful power by using the following formula: = ^E Carrier ^E Carrier, where ^E Carrier = ^max = Σ^ ₌₀ ^C k ^Y k, SC _k =Y _k , = 7. .

7. The method according to claim 4, wherein before the step of determining a carrier-to-noise ratio of the antenna, the method further comprises: determining, Y _k =Y _k exp ( j2 ki ₀ 1 N); The interference/noise signal 4 of the antenna is: I _k = Y _{k -} Y _k ^ _V {j2nkT N).

8. The method according to claim 7, wherein before the step of determining a carrier-to-noise ratio of the antenna, the method further comprises: determining the useless power P ₂ by using the following formula:

The method according to any one of claims 2 to 8, wherein the weighting coefficient W _t corresponding to each antenna is determined according to the following formula

= CINR, I∑ CINR, where CINI^ is the carrier-to-noise ratio of the ith antenna, C/NR,. = PIP _2i , which is the useful power of the ith antenna, Ρ _2ζ · is the unwanted power of the ith antenna .

The method according to any one of claims 1 to 8, wherein: Determining the power parameter of the base station includes: for each antenna, multiplying a weighting coefficient of the antenna by a time domain correlation peak corresponding to the antenna to obtain a first multiplication result of the antenna, and obtaining the base station Adding a first multiplication result of the antenna to obtain a power peak of the base station as the power parameter;

The step of comparing the power parameter with a preset power threshold includes: comparing a power peak of the base station with a power peak threshold of the preset power threshold; determining that the received signal includes a ranging signal The step of determining includes: in the case that the power peak is greater than or equal to the preset power peak threshold, determining that the received signal includes a ranging signal.

The method according to any one of claims 1 to 8, wherein: determining the power parameter of the base station comprises: for each antenna, a weighting coefficient of the antenna and a time domain correlation value corresponding to the antenna Multiplying to obtain a second multiplication result of the antenna, and adding a second multiplication result of all antennas of the base station to obtain a power average of the base station, as the power parameter;

The step of comparing the power parameter with a preset power threshold includes: performing work of the base station

The method according to any one of claims 1 to 8, wherein: determining the power parameter of the base station comprises: for each antenna, a weighted coefficient of the antenna and a time domain correlation peak corresponding to the antenna Multiplying to obtain a first multiplication result of the antenna, and adding a first multiplication result of all antennas of the base station to obtain a power peak of the base station, and a weighting coefficient of the antenna corresponding to the antenna Multiplying the time domain correlation values to obtain a second multiplication result of the antenna, and adding a second multiplication result of all antennas of the base station to obtain a power average of the base station, a power peak of the base station, and the The power average of the base station is used as the power parameter; The step of comparing the power parameter with a preset power threshold includes: comparing a power peak of the base station with a power peak threshold of the preset power threshold, and comparing the base station

Determining that the received signal includes a ranging signal includes: the power peak is greater than or equal to the preset power peak threshold, and wherein the power average is greater than or equal to the preset power average threshold Next, it is determined that the received signal includes a ranging signal.

The method according to any one of claims 3 to 8, wherein extracting a carrier sequence including a ranging signal in a signal received by the antenna comprises: performing a Fourier transform on a signal received by the antenna And extracting a carrier sequence containing the ranging signal at a specific carrier position.

A base station, comprising: a receiving module, configured to: receive a signal from a mobile station, determine a time domain correlation value of each antenna of the base station, and a carrier-to-noise ratio of each antenna according to the received signal; a processing module, configured to: normalize a carrier-to-noise ratio of each antenna to obtain a weighting coefficient corresponding to each antenna; and a determining module, configured to: determine according to weighting coefficients and time domain correlation values of all antennas a power parameter of the base station, and comparing the power parameter with a preset power threshold, where the power parameter is greater than or equal to the preset power threshold, determining that the received signal includes a ranging signal .

15. The base station according to claim 14, wherein: the determining module is configured to determine a power parameter of the base station as follows: for each antenna, a weighting coefficient of the antenna is associated with a time domain corresponding to the antenna Multiplying a peak to obtain a first multiplication result of the antenna, and adding a first multiplication result of all antennas of the base station to obtain a power peak of the base station as the power parameter; and/or, for each Antennas, multiplying a weighting coefficient of the antenna by a time domain correlation value corresponding to the antenna to obtain a second multiplication result of the antenna, and adding a second multiplication result of all antennas of the base station to obtain the The average power of the base station, as described a power parameter; the determining module is configured to compare the power parameter with a preset power threshold by: comparing a power peak of the base station with a power peak threshold of the preset power threshold Comparing; the determining module is configured to determine that the received signal includes a ranging signal in a manner that: when the power peak is greater than or equal to the preset power peak threshold, and/or When the power mean is greater than or equal to the preset power mean threshold, it is determined that the received signal includes a ranging signal.