A Modified T/2 Fractionally Spaced Coordinate Transformation Blind Equalization Algorithm

作     者：Yecai GUO Xueqing ZHAO Zhenxin LIU Min GAO 

作者机构：不详 

出 版 物：《International Journal of Communications, Network and System Sciences》 (通讯、网络与系统学国际期刊（英文）)

年 卷 期：2010年第3卷第2期

页      面：183-189页

学科分类：0810[工学-信息与通信工程] 08[工学] 081001[工学-通信与信息系统] 

主　　题：Blind Equalization Underwater Acoustic Channel Coordinate-Transformation Fractionally Spaced Equalizer 

摘      要：When T/2 Fractionally Spaced blind Equalization Algorithm based Constant Modulus Algorithm (T/2-FSE- CMA) is employed for equalizing higher order Quadrature Amplitude Modulation signals (QAM), it has disadvantages of low convergence speed and large Mean Square Error (MSE). For overcoming these disadvantages, a Modified T/2 Fractionally Spaced blind Equalization algorithm based on Coordinate Transformation and CMA (T/2-FSE-MCTCMA) was proposed by analyzing the character of 16QAM signal constellations. In the proposed algorithm, real and imaginary parts of input signal of T/2 fractionally spaced blind equalizer are equalized, respectively, and output signals of equalizer are transformed to the same unit circle by coordinate transformation method, a new error function is defined after making coordinate transformation and used to adjust weight vector of T/2 fractionally spaced blind equalizer. The proposed algorithm can overcome large misjudgments of T/2 fractionally spaced blind equalization algorithm for equalizing multi-modulus higher order QAM. Simulation results with underwater acoustic channel models demonstrate that the proposed T/2-FSE-MCTCMA algorithm outperforms T/2 Fractionally Spaced blind Equalization algorithm bas-ed on Coordinate Transformation and CMA (T/2-FSE-CTCMA) and the T/2-FSE-CMA in convergence rate and MSE.