Patent ID: 7400572

Claim:
A multipoint-to-point, orthogonal frequency division multiplexed (OFDM) communication system comprising: a host unit; a plurality of remote units that access the host unit using an orthogonal frequency division multiple access scheme wherein adjacent carriers transmitted from the plurality of remote units overlap spectrally in an OFDM waveform; wherein each of the remote units modulates upstream information into an OFDM signal modulated using a Fourier transform; wherein the host unit receives upstream OFDM signals from a plurality of the remote units, wherein portions of the upstream OFDM signals arrive at the host unit at the same time; wherein a first remote unit transmits a first upstream signal to the host unit on a first orthogonal tone; and wherein the first remote unit retransmits the first upstream signal to the host unit in the event a collision occurs on the first orthogonal tone.