空载波对STBC-OFDM系统信道估计性能的影响分析与改进

该文分析了空时分组码-正交频分复用(STBC-OFDM)系统中，空载波对基于离散傅里叶变换(DFT)信道估计的性能影响，推导得出空载波影响下信道估计均方误差及误码率的解析式，并提出一种新的信道估计方法，通过时域乘以干扰因子矩阵的逆消除空载波引起的混叠，提高信道估计精度。仿真结果与理论结果相符，且表明改进的信道估计算法有效消除均方误差地板现象，提高系统性能。
关键词：正交频分复用；信道估计；空时分组码；空载波

Abstract: Performance of Discrete Fourier Transform (DFT) based channel estimation for Space Time Block Code-Orthogonal Frequency Division Multiplexing (STBC-OFDM) systems with virtual subcarriers is analyzed.The concise expressions for Mean Squared Error (MSE) and corresponding Bit Error Rate (BER) with the effect of virtual subcarriers are provided. Besides, a new channel estimation method based on zero-forcing is presented to eliminate aliasing distortion caused by virtual subcarriers. Simulation results demonstrate the accuracy of the analysis and the efficiency of new method.Key words: Orthogonal Frequency Division Multiplexing (OFDM); Channel estimation; Space Time Block Code (STBC); Virtual subcarriers