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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 ,该算法在未来宽带OFDM系统中具有应用潜力
In order to improve the channel estimation accuracy of orthogonal frequency division multiplexing (OFDM) system, a channel estimation algorithm based on Walsh transform and low density parity check (LDPC) code is proposed. The algorithm uses the frequency domain correlation of the channel transfer function to reduce the channel estimation variance of the OFDM system by Walsh transform and transform domain filtering. At the same time, utilizing the powerful error correction capability of the L DPC code improves the overall performance of the system, Under the standard organization channel model, the bit-to-bit SNR threshold has been reduced by nearly 2 days. The results show that this algorithm has potential application in the future broadband OFDM system