LDPC码的一种高效加权比特翻转译码算法

摘要

针对低密度奇偶校验(LDPC)码中加权比特翻转(WBF)译码算法在迭代过程中绝大多数情况都是进行单比特翻转,导致译码效率低并且可能会发生比特翻转"死循环"的现象,提出一种更为高效的加权比特翻转(EWBF)算法.该算法对翻转阈值进行了改进,使得每次迭代能够翻转多个比特,提高译码效率,并且能够避免译码过程出现的翻转"死循环"现象.仿真结果表明,所提译码算法与WBF算法、改进的WBF(MWBF)算法和IMWBF(Improved MWBF)算法相比,平均迭代次数分别降低51.6%~56.2%、49.6%~54.2%和48.1%~51.3%;而在译码性能方面,算法性能接近甚至优于IMWBF算法,当最大迭代次数设定为30次时,相比于IMWBF算法,在误码率为10-4时可获得0.92 dB的增益.%The weighted bit flipping ( WBF ) decoding algorithm of low density parity-check ( LDPC ) codes produces the single-bit flipping phenomenon during the iteration in most cases,which can result in the low decoding efficiency and may give rise to the "endless loop" of the bit flipping. For this phenome-non, a more efficient WBF( EWBF) algorithm is proposed. The proposed EWBF algorithm has improved the flipping threshold so as to flip the multiple-bit in each iteration and improve the decoding efficiency while avoiding the"endless loop" phenomenon during the decoding. Simulation results show that the aver-age decoding iteration number of the proposed decoding algorithm, compared with the WBF algorithm, the modified WBF(MWBF) algorithm and the Improved MWBF(IMWBF) algorithm, can be reduced 51. 6%~56. 2%, 49. 6% ~54. 2% and 48. 1% ~51. 3%. In terms of the decoding performance, the proposed algorithm's performance is close to or even better than the IMWBF algorithm's. When the maximum itera-tion number is set to 30 times, the net coding gain of the improved scheme is 0. 92 dB better than that of IMWBF algorithms at the bit error rate( BER) of 10-4 .