A simple and robust modulation classification method via counting

Automatic modulation classification (or recognition) is an intrinsically interesting problem with a variety of regulatory and military applications. We developed a method which is simple, fast, efficient and robust. The feature being used is the counts of signals falling into different parts of the signal plane. Compared with the likelihood method and the high order correlation method, it is much easier to be implemented, and the execution is much faster. When the channel model is correct, our method is efficient, in the sense that it will achieve the "optimal" classification rate. When unknown contamination is present, our method can automatically overcome it to certain degree. At SNRs of 10 and 15 dB, examples of classifying two modulation types-QAM4 and PSK6-are given. Simulations demonstrate its ability to deal with unknown noise.