The Research of MSK Maximum Likelihood Noncoherent Detection Algorithm

In this paper, we study a lowcomplexity receiving model with good performance based on maximum likelihood noncoherent detection (MLNCD) for Minimum Shift Key (MSK) signal. In the receiving model, middle symbol can be detected by using observed sequence constituted of few symbols. Besides, decision expressions are proposed based on MLNCD model and simplified expressions of MSK demodulation soft information are derived based on MLNCD algorithm, which reduce implement complexity. Furthermore, bit error rate (BER) performance of uncoded MSK system and coded MSK system using MLNCD algorithm are analyzed by simulation. Results show that the BER performance of MLNCD algorithm is much better than that of conventional MSK noncoherent demodulation algorithm, and close to MSK coherent demodulation algorithm performance. In addition, the simplification of soft information causes nearly no loss to system performance.