Performance of CPM using a discriminator based data detector

Abstract

It is demonstrated that the error rate performance of continuous phase modulation (CPM), when detected using a limiter discriminator followed by a 2-bit integrate-and-dump filter (IDF), is far superior to the performance obtained using a discriminator followed by a 1-bit IDF. The performance obtained at a modulation index h=1/2 is quite comparable to that of the 2-bit differentially coherent detector. A parameterized performance study shows that drastic improvements are achievable by properly selecting the modulation index and simultaneously optimizing the receive filter bandwidth. The investigation also shows that the error performance is sensitive to the type of IF filter response, i.e., the Butterworth response yields superior performance in comparison to the Gaussian filter response.<>