Systems and methods for an orthogonal frequency division multiplexing multipoint-to-point communications system are provided. In one embodiment, a method comprises establishing communication between a first remote unit of a plurality of remote units and a host unit, the plurality of remote units communicatively...http://www.google.es/patents/US7623440?utm_source=gb-gplus-sharePatente US7623440 - Method and system for adaptive modulation
