摘要
针对低压电力线信道噪声强、衰减大的问题,基于OFDM技术的电力线通信系统采用时域扩充结构,提高导频数据的可靠性.确定了在OFDM时域扩充结构中应用LMMSE准则时最大多径时延的最优取值.在此基础上提出一种更适合时域扩充系统的信道估计优化算法,通过利用OFDM符号内所有导频参与信道估计从而在低信噪比条件下获得更低的误码率.仿真结果表明提出的改进算法与传统LMMSE算法相比具有更好的信道估计性能,在信噪比低于0dB时改进算法的性能优势更加明显.
To suppress the noise and attenuation of power line communications （PLC）, OFDM PLC systems use time-domain spread structure which can improve the reliability of pilot and data. This paper Confirms the best value of maximum multipath delay in LMMSE algorithm for time-domain spread structure. An improved channel estimation algorithm utilizing pilots in channel estimation as much as possible is proposed, which performs better than LMMSE algorithm through. Simulation results indicate that the bit error rate （BER） of the proposed algorithm is lower than that of the conventional LMMSE algorithm, especially when signal-to-noise ratio （SNR） is under 0dB.
出处
《微电子学与计算机》
CSCD
北大核心
2012年第10期89-93,共5页
Microelectronics & Computer
基金
国家科技重大专项项目(2009ZX01034)
国家高技术研究发展计划项目(2008AA010704)
