A concatenated coded modulation scheme and its iterative receiving for deep space communications

Due to the long propagation distance between spacecraft and Earth station the high power efficiency is more important for deep space communication than others communication systems. One novel coded modulation scheme based on AR4JA code and FQPSK (Feher´s QPSK) is proposed out in this paper, which can alleviate the challenge of huge loss in space communications. The novel approach utilizes the property that AR4JA code enables communication at very low signal noise rate and constant envelope property of FQPSK to overcome the nonlinear impact of high power amplifier. At receiver, large gain can be attained by iterative demodulation and decoding. The paper presents the system model of coded modulation and proposes out iterative receive algorithm. Finally, the bit error rate performance of new scheme is confirmed by computer simulation.