Patent ID: RE42236

Claim:
A system comprising: a host unit; a plurality of remote units using a multiple access scheme to communicate at the same time with the host unit on adjecent spectrally overlapping carriers of an orthogonal frequency division multiplexing (OFDM) waveform; wherein the host unit sends an adjustment signal to at least one remote unit instructing the at least one remote unit to adjust the timing of transmissions from the at least one remote unit to improve orthogonality of OFDM transmissions received at the host unit, wherein the host unit sends an adjustment signal to at least one remote unit instructing the at least one remote unit to adjust the frequency of transmissions from the remote unit to improve orthogonality of OFDM transmissions received at the host unit, wherein the host unit allocates a first orthogonal tone to at least one remote unit to carry payload data during a first time interval, and wherein the host unit allocates the first orthogonal tone to carry control data during a second time interval.