Patent ID: 8638655
Filing Date: 2014-01-28
Classification: G06F,H03M,H04B,H04H,H04J,H04K,H04L,H04M,H04N,H04W,Y02D

Abstract:
1. A remote unit using frequency guard bands in a multipoint-to-point communication system in which orthogonal frequency division multiplexed carriers are used for carrying upstream and downstream communications, and in which more than one remote unit, after receiving allocations of orthogonal frequency division multiplexed carriers for upstream communications, may transmit upstream communications that are received at a host at the same time, the remote unit comprising: a radio frequency receiver communicatively coupled with the host unit, the radio frequency receiver receiving downstream communications carried on orthogonal carriers; a radio frequency transmitter communicatively coupled with the host unit in a multipoint-to-point configuration, the radio frequency transmitter configured to transmit upstream payload communications using orthogonal carriers allocated by the host; the radio frequency transmitter including at least one converter that generates an analog signal based on a stream of time domain in-phase and quadrature phase data, wherein the radio frequency transmitter transmits the analog signal using orthogonal carriers; a multi-carrier modulator coupled to the radio frequency transmitter and configured to modulate upstream payload data onto orthogonal carriers; wherein the multi-carrier modulator is synchronized with the host unit such that when orthogonal carriers from the remote unit are received at the host at the same time as orthogonal carriers from at least one other remote unit, the orthogonal carriers from the remotes are substantially orthogonal to each other when received at the host unit; wherein the multi-carrier modulator further includes: wherein the remote transmits a non-payload signal separated from payload bearing carriers of another remote unit by a frequency guard band.