Linear Time Encoding of Low-Density Parity -Check Codes and Its Performance in Weak Atmospheric Turbulent Channels

摘要：

A major drawback of Low-Density Parity -Check (LDPC) Codes is their apparently high encoding complexity and consequent encoding delay. A linear time encoding method proposed by Richardson and Urbanke can effectively reduce the encoding complexity to only linear encoding complexity. In this paper, LDPC codes based on the linear time encoding method is adopted for improving the bit-error rate (BER) performance of an ON-OFF keying (OOK) modulated optical signal through a weak atmosphere turbulence channel. The optical atmosphere channel is modeled as a stationary ergodic channel with lognormal intensity fading. We simulate and analyze the BER performance of the channel using the linear time encoding method. Simulation results show that the presented encoding method can be greatly reduce the BER. Moreover, as the code length increases or code rate decreases, the coding gain of LDPC codes over the uncoded system becomes large. Therefore, the presented encoding method with both large code length and low code rate obtain high encode gain for the optical atmosphere turbulence channel.

关键词： linear time encoding low-density parity-check codes atmospheric turbulence lognormal channel

作者: Jiajie Chen Xiaofeng Li Yanhui Liu

作者单位: School of Physical Electronics University of Electronic Science and Technology of China Chengdu, Chi School of Electronic Engineering University of Electronic Science and Technology of China Chengdu, C

会议类型: 国际会议

会议名称: 第三届IEEE无线通讯、网络技术暨移动计算国际会议

会议地点: 上海

会议语种:英文

在线出版日期: 2007-09-21（万方平台首次上网日期，不代表论文的发表时间）