Nonlinear signalling with unevenly distributed phase states

A class of signals called nonlinear uneven signals is constructed by extending regular nonlinear signals and employing unevenly distributed phase states. Nonlinear uneven signals are constructed with CPFSK, CPM and PSK signals at two different numbers of states N=4 and N=8. Numerical results indicate that nonlinear uneven signals can achieve distances significantly higher than those of regular nonlinear signals. Numerical results also indicate that, besides a higher minimum distance, many of the nonlinear uneven signals that are discussed here occupy a narrower bandwidth than regular nonlinear signals