Patent ID: 9571326
Date: 2017-02-14
CPC Classifications: H04L

Claim:
1. In a communication system including a data transmitter coupled through a signal channel to a data receiver, a method for transferring data through the signal channel comprising the steps of: encoding the data to produce a first baseband modulating signal I(t) and a second baseband modulating signal Q(t) whose amplitudes together represent a time series of complex symbols (I, Q) each selected from a two-dimensional (2-D) constellation of symbols distributed on the phase plane about the origin such that at least one of the baseband modulating signals has a substantially non-zero mean amplitude; multiplying the first baseband modulating signal I(t) by a first baseband symbol clock signal to produce a first modulation product signal and multiplying the second baseband modulating signal Q(t) by a second baseband symbol clock signal to produce a second modulation product signal, where the phases of the first and second baseband symbol clock signals are generally fixed in quadrature; summing the first and second modulation product signals to produce a transmitter output signal; coupling the transmitter output signal through the signal channel to the data receiver; and demodulating the first and second modulation product signals at the data receiver to recover the series of complex symbols (I, Q).