The Performance And DSP Implementation Of Serially Concatenated Continuous Phase Modulation

Recently, serially concatenated CPM (SCCPM) systems with high spectral efficiency, power efficiency and some turbo-like coding performance draw more attention. Since CPM can be decomposed into a continuous-phase encoder(CPE) and a memory-less modulator(MM),and the CPE is equivalent to a convolutional encoder, there is no need of inner code in SCCPM which has the similar structure compared with serially concatenated convolutional codes. SCCPM with iterative decoding based on soft-input soft-output (SISO) shows a large interleaving gain. It is robust under highly dynamic and fading environment, which is suitable to frequency hopping system and military'ad hoc'networks.In this thesis Serially Concatenated Continuous Phase Modulation (SCCPM) and its performance are mainly studied, as well as the algorithms of iterative decoding and the implementation of this system with digital signal processor (DSP). First of all, based on the principle of the CPM signal, a decomposition approach to CPM is developed, and then we present the system model of SCCPM and obtain its performance through computer simulation; secondly, through analysis to the stopping algorithm of dynamic iterative decoding, a new stopping algorithm based on average extrinsic information exchange is proposed, simulation result shows that the combination of average extrinsic information exchange and stopping algorithm of dynamic iterative decoding can improve the BER performance as well as reduce iterative decoding time. Finally we primarily explore the application of SCCPM, and implement it in DSP simulation environment.