High efficiently joint LDPC coded recursive MSK modulation
Jianhua Lü · Journal of Tsinghua University(Science and Technology) · 2010
The differential encoding of the recursive minimum shift keying(MSK) induces correlations between the adjacent modulated symbols which affect the design of joint low-density parity-check(LDPC) coded recursive MSK modulation systems.A factor graph-based method was developed to design the optimal joint LDPC coded MSK modulation by increasing the length of the combined shortest loops in the encoding part of the MSK and the LDPC code.Simulations show that the method gives efficiently joint LDPC coded recursive MSK modulation that is 1.3 dB better than simple concatenation for LDPC code(2560,1024) at a bit error rate(BER) of 10-5 in an additive white Gaussian noise(AWGN) channel.