A Joint Coded Modulation Scheme and Its Iterative Receiving for Deep-Space Communications

Space exploration missions have become increasingly complicated and various, and the current deep-space communication schemes can´t meet the demand of high-speed and real-time multimedia correspondence. Therefore, the design of a fast and efficient transmission scheme is one of the important ways to solve the conflict. With organic combination of LDPC codes, continuous phase modulation (CPM) and turbo iterative detection, a scheme of joint coded modulation based on turbo principle is presented. In this paper, the model of LDPC-CPM system is established firstly, then realization scheme of CPM is proposed, and the effect of main parameters on the performance of the system is studied finally, which can provide the reference basis for practical application. The research results show that the proposed scheme can not only improve power efficiency and BER performance in the background of extremely low SNR effectively, but also give consideration to validity of information transmission and improve the band efficiency, and partly solve the problem of failing to give attention to both high-speed transmission and reliable transmission. Meanwhile, the receiver whose implementation is achievable can reach a good compromise between performance and complexity.