||LDPC code used by the advanced communication standard of the next generation is an error control code. Its error correction ability may approach the Shannon’s theoretical value. With the MP algorithm, it can decode received samples in high speed from transmitter. However, the MP method is suboptimum and optimum solution is not guaranteed. In this thesis, a hybrid decoding method is formed by combing the MP and the A* methods. We first make comparison between the MP and A* method and then show their combined performance. From the results, the coding gain of A* model is higher than that of MP model. The decoding complexity increases exponentially with the codeword length for A* method, but the MP method assumes linear increase.|
Using the hybrid structure, its coding gain is the same as that of A* method. Moreover, decoding complexity is slightly greater than that of MP one. For codeword length 96 bits and coding rate 1/2 and BER = 10E-5, the hybrid structure outperforms 1.4 dB coding gain than the MP method. This improvement only required 1% received sequences to be sent to A* decoding block. Our newly designed hybrid structure can solve both of the high coding gain and low decoding complexity while it has the ability to yield the optimum solution.
|| C. E. Shannon, “A Mathematical Theory of Communication,” Bell Syst. Tech. J., pp. 379-423(Part 1); pp. 623-56(Part 2), July 1948.|
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