一种新的混合信道盲均衡算法
doi: 10.3724/SP.J.1146.2008.00742
A Novel Hybrid Blind Channel Equalization Algorithm
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摘要: 为同时提高盲均衡的稳态MSE性能和收敛速度，该文提出了一种混合信道盲均衡算法。该算法采用判决反馈均衡器结构，在判决可靠时采用DD-LMS(Directed Decision-Least Mean Square)误差项进行迭代，而判决不可靠时采用改进恒模算法(Modified Constant Modulus Algorithm，MCMA)误差项进行迭代，同时判决可靠区间根据直接判决误差进行自适应迭代。该文采用经过数字无线信道的64QAM信号进行了信道均衡仿真。仿真结果表明，相比MCMA算法，该文提出的混合盲均衡算法有效地提高了收敛速度，并具有良好的稳态MSE性能，在误比特率为10-6时，能提高SNR约2dB。Abstract: To improve MSE performance in steady-state and convergence rate of blind equalization, a hybrid blind channel equalization algorithm is proposed in this paper. With decision feedback equalizer, the proposed algorithm applies the error item of DD-LMS (Directed Decision-Least Mean Square) for adaptation when decision is reliable, and error item of MCMA (Modified Constant Modulus Algorithm) is applied when decision is unreliable. And the reliable interval of decision is adapted according to the errors of directed-decisions. The proposed algorithm has been simulated with 64QAM signals through severe digital wireless channel, simulation results show that the proposed algorithm has faster convergence rate and better MSE performance in stead-state than MCMA, and brings 2dB advantage when BER is 10-6.
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