结合Walsh变换与LDPC码的OFDM信道估计算法

Channel estimation algorithm in OFDM systems combined with the Walsh transform and LDPC codes

为了提高正交频分复用 (OFDM)系统的信道估计精度 ,提出了一种结合 Walsh变换和低密度奇偶校验 (L D-PC)码的信道估计算法。该算法利用信道传输函数的频域相关性 ,通过 Walsh变换和变换域滤波降低了 OFDM系统的信道估计方差 ,同时利用 L DPC码强大的纠错能力提高了系统的整体性能 ,使系统在欧洲电信标准组织信道模型下每比特信噪比门限降低了近 2 d B。结果表明 。

An algorithm was developed for orthogonal frequency division multiplexing (OFDM) to improve channel estimation accuracy. The algorithm uses low-density parity check (LDPC) codes combined with the Walsh transform and filtering in the transform domain with correlations of the channel transfer function in the frequency domain. Simulations with the European Telecommunication Standard Institute (ETSI) channel model show that the system performance is significantly improved, with a 2-dB improvement in the signal-to-noise ratio threshold due to the powerful error-correction capability of the LDPC codes. The result shows that the proposed algorithm has potential in future wide-band OFDM systems.