Comparison of two reduced complexity maximum-likelihood sequence detectors for continuous phase modulation scheme

Continuous phase modulation (CPM) consists of a large family of signals that are especially suitable for wireless communication. CPM signals are optimally demodulated applying maximum-likelihood sequence detection (MLSD). However, since MLSD is too complex, great effort has been devoted to reduce the complexity with minimal loss on the performance. A reduced complexity receiver has recently been proposed for this purpose. We compare this new receiver with a previous reduced complexity receiver with respect to the reduction in complexity and, at the same time, the degradation from the optimum performance. We demonstrate that the new receiver achieves better performance at the same complexity.