Space-Time Semi-Blind Equalizer for Dispersive QAM MIMO System Based on Modified Newton Method

作者：Li, Jin; Feng, Da-Zheng^*; Zheng, Wei Xing

来源：IEEE Transactions on Wireless Communications, 2014, 13(6): 3244-3256.

DOI：10.1109/TWC.2014.041714.121735

• Space-time semi-blind equalizer
• modified Newton method
• constant modulus algorithm
• multimodulus algorithm
• soft decision-directed scheme

This paper proposes a space-time semi-blind equalizer (ST-SBE) for dispersive multiple-input multiple-output (MIMO) communication systems that employ high throughput quadrature amplitude modulation (QAM) signals. A novel cost CF) that integrates multimodulus algorithm (MMA) with soft decision-directed (SDD) scheme is established to efficiently obtain the weight vector associated with the ST-SBE. In the ST-SBE, a very short training sequence is used to provide a rough initial least squares estimate of the weight vector. An efficient modified Newton method (MNM) for minimizing the established cost function is proposed to fast search the optimal weight vector. Very interestingly, we prove that the proposed MNM has the same quadratic order of convergence as Newton methods. In addition, the proposed MNM has much lower computational complexity than Newton methods. Simulation results are provided to demonstrate that the ST-SBE has better performances than the gradient-Newton (GN)-based concurrent constant modulus algorithm (CMA) with SDD scheme (GN-CMA+SDD).

• 出版日期2014-6
• 单位西安电子科技大学