該文分析了空時分組碼-正交頻分復用(STBC-OFDM)系統中，空載波對基于離散傅里葉變換(DFT)信道估計的性能影響，推導得出空載波影響下信道估計均方誤差及誤碼率的解析式，并提出一種新的信道估計方法，通過時域乘以干擾因子矩陣的逆消除空載波引起的混疊，提高信道估計精度。仿真結果與理論結果相符，且表明改進的信道估計算法有效消除均方誤差地板現象，提高系統性能。
關鍵詞：正交頻分復用；信道估計；空時分組碼；空載波

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