Patent ID: 7391712

Claim:
A method for an orthogonal frequency division multiplexing (OFDM) multipoint-to-point communications system, the method comprising: establishing communication between a plurality of remote units and a host unit, the plurality of remote units communicatively coupled to the host unit in a multipoint-to-point configuration; transmitting a plurality of tones from the plurality of remote units, such that tones from more than one remote unit are simultaneously received at the host unit, the plurality of tones modulated with upstream information using orthogonal frequency division multiplexing; adjusting a characteristic of at least one tone of the plurality of tones at at least one remote unit, in response to adjustment commands from the host unit, such that the orthogonality of the simultaneously received tones is improved as received at the host unit, wherein adjusting the characteristic comprises adjusting a carrier frequency and a phase; and dynamically switching modulation from at least a first tone of the plurality of tones to a second tone within the OFDM system based at least in part on a channel quality history of the second tone.