| 摘要: |
| 通过理论分析和计算机仿真研究了LDPC码在非相干BFSK系统中的性能。首先证明单
输入双输出的非相干BFSK系统满足信道对称条件，然后分别利用离散密度进化（DDE）和高
斯近似（GA）算法给出了LDPC码的性能下界，后者与前者相比性能非常接近而且计算量要小
很多。通过仿真得到几种常用LDPC码的性能并与译码门限以及香农极限进行了比较，在相同
码长条件下，度参数为(3,6)的码字具有最优的性能，并且其译码门限距离香农极限只有
约0.67 dB。 |
| 关键词: LDPC码 非相干检测 BFSK 对称条件 离散密度进化 |
| DOI： |
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| 基金项目: |
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| Performance Analysis of LDPC Code in Non coherent BFSK Systems |
| DAI Jing-ke,GUO Dao-xing,ZHANG Bang-ning,CHEN Xue-bing |
| (Institute of Communications Engineering, PLA University of Science & Techno
logy,Nanjing 210007,China;Unit 61068 of PLA,Chang′an 710100,China) |
| Abstract: |
| The performance of low density parity check(LDPC) code in non-coherent
binary frequency shift keying (BFSK) system is investigated by theoretical anal
ysis and computer simulation. It is shown that the symmetry conditions are fulfi
lled in the system with one input and two outputs, and then the lower bound of L
DPC code is given by discrete density evolution(DDE) and Gaussian approximation
(GA), respectively. The performances of the two algorithms are very close to ea
ch other, though the later costs much less computation. The performances of
certain LDPC codes in common use are obtained by simulations, which are also com
pared with the decoding threshold and Shannon limit. As long as the code lengths
are equal to each other, the (3,6) code has the best performance, and the deco
ding threshold is approximate 0.67 dB within the Shannon limit. |
| Key words: low density parity check (LDPC) code non-coherent detection binary frequency s
hift keying (BFSK) symmetry conditions discrete density evolution |
