Research On Decoding Algorithms For Block Coded Modulation

Shannon information theory gave a quantitative description of the effectiveness and reliability in communication systems. In wireless mobile communication system, under the premise of effectiveness, how to solve the problem of higher errors rate and lower reliability which is caused by burst errors brought from fading, interference and noise is a hot issue in recently research. This paper combines the encoding with modulation method to increase the reliability of communication system.Block coded modulation is one of main methods of coded modulation. In BCM system, choosing set partitioning and decoding method directly impact the performance of this system. This paper structures the BCM codes using different component codes under different set partitioning. On the basis of theoretical analysis of Viterbi decoding, MSD and PDL, we stimulate the block coded modulation system and get comparison results of different decoding performances and complexities. Upon this research, a new decoding decision method for PDL is proved under BP, and this method can increase the performance of system.In addition, Appling the structured BCM codes to the concatenated coded modulation system, stimulation result show that this system achieves higher spectrum efficiency and greater coding gain. Besides, analyzing the problem of unequal error protection in this system, this paper uses high order modulation 16-QAM, new set partitioning and modified PDL, gets some coding gain without reduce spectrum efficiency.