MMSE Equalization for Serially Concatenated CPM over ISI Channels

It is well known that continuous phase modulation (CPM) serially concatenated with convolutional codes facilitates powerful error correction. CPM also has the advantage of being bandwidth efficient and compatible with non-linear amplifiers. The downfall of CPM systems is their poor performance over ISI channels. We propose a simple receiver consisting of a linear filter used to cancel ISI and improve the statistics for the iterative receiver that follows. We present results for the receiver based on three well known ISI channels and show that the performance is comparable to that of serially concatenated CPM (SCCPM) on an AWGN channel with no ISI.