基于伪随机后缀的OFDM信道估计方法

OFDM channel estimation based on pseudo random postfix

提出了一种基于伪随机后缀的正交频分复用(Orthogonal frequency division multiplexing,OFDM)系统模型,并针对其在缓变信道下的信道估计需求,提出了一种基于一阶统计的信道估计方法和利用广义循环矩阵对角化性质的均衡方法。在高斯白噪声(Additivewhite-Gaussian-noise,AWGN)信道、频率选择性衰落信道和多普勒信道下,对误码率性能进行了仿真分析。仿真结果表明:该方法适合缓变信道,其误码率性能优于传统插入导频的循环前缀(Cyclic prefix,CP)-OFDM;但对于多普勒信道其性能会变差。

A new model of orthogonal Frequency Division Multiplexing （OFDM） system based on pseudo-random-postfix was proposed. In view of the requirements of channel estimation under slow time-varying channel, a channel estimation method based on first-order statistics and a low-complexity equalization using the property of circular matrix diagonalization were proposed. The performance of Bit-Error-Rate （BER） was simulated and analyzed under the Additive-White-Gaussian-Noise （AWGN） channel, frequency selective fading channel and Doppler channel. The simulation results show that the proposed method can be applied to the slowly time-varying channels, such as the slow- moving case, and can achieve better BER performance than the traditional Cyclic Prefix （CP）-OFDM. However, the performance may get worse for the Doppler scenarios.