Patent ID: 7535822

Claim:
A remote communication device, the device comprising: at least one symbol mapper for mapping symbols using quadrature amplitude modulation (QAM) symbol mapping and phase-shift keying (PSK) symbol mapping; a Fast Fourier Transform (FFT) engine that receives a frame of parallel data based on symbol data generated by the symbol mapper, the Fast Fourier Transform (FFT) engine generating a frame of time domain in-phase and quadrature phase data from the symbol data generated by the symbol mapper; at least one converter generating an analog signal based on the stream of time domain in-phase and quadrature phase data; a radio frequency transmitter for transmitting a radio frequency signal based on the analog signal; and a processor, wherein the symbol mapper is responsive to the processor; the symbol mapper mapping a first ranging pattern to at least one symbol based on a PSK constellation; the processor estimating whether the first ranging pattern was transmitted without collision and causing the at least one symbol mapper to map a second ranging pattern based on a PSK constellation, when the processor estimates that a collusion has occurred; the processor providing a second ranging pattern to the at least one symbol mapper, after a delay determined by a backoff timer; the processor adjusting a transmission delay based on synchronization information received on a downstream communication link in response to one of the first ranging pattern and the second ranging pattern.