Simplified noncoherent MAP decoding algorithm based on SCCC structure

Differential encoding used in conjunction with sequence decoding is a primary method to implement high performance noncoherent demodulation. Though noncoherent decoding based on serially concatenated convolutional codes (SCCC) with differential encoding is almost similar to coherent demodulation in performance, its high decoding complexity makes its engineering application difficult. To solve this problem, two simplified noncoherent MAP decoding algorithms based on SCCC structure are proposed by using an approximate formula of zero-order Bessel function in this paper. Theoretical analysis and simulation results show that the proposed algorithms can largely reduce the decoding computational complexity and have good performance.