An Analytical Multimodulus Algorithm for Blind Demodulation in a Time-Varying MIMO Channel Context

Steredenn Daumont,Daniel Le Guennec

doi:10.1155/2010/307927

Abstract

This paper addresses the issue of blind multiple-input multiple-output (MIMO) demodulation of communication signals, with time-varying channels and in an interception context. A new adaptive-blind source separation algorithm, which is based on the implementation of the Multimodulus cost function by analytical methods, is proposed. First a batch processing analysis is performed; then an adaptive implementation of the (Analytical Multi-Modulus Algorithm) AMMA and its simplified version named (Analytical Simplified Constant Modulus Algorithm) ASCMA is detailed. These algorithms, named adaptive-AMMA and adaptive-ASCMA, respectively, are compared with the adaptive (Analytical Constant Modulus Algorithm) ACMA and the MMA (Multi-Modulus Algorithm). The adaptive-AMMA and adaptive-ASCMA achieve a lower residual intersymbol interference and bit error rate than those of the adaptive-ACMA and MMA.

Highlights

The context of this study is the Multiple-Input MultipleOutput (MIMO) interception, and blind demodulation in reception
This paper addresses the issue of blind multiple-input multiple-output (MIMO) demodulation of communication signals, with time-varying channels and in an interception context
The MM and the Simplified Constant Modulus (SCM) cost functions associated with analytical methods have never been tried so far

Summary

Introduction

The context of this study is the Multiple-Input MultipleOutput (MIMO) interception, and blind demodulation in reception. The algorithms in [1,2,3,4,5,6] use the stochastic gradient to minimize these cost functions, so they are slow to converge and with time-varying environments they are less accurate Analytical Constant Modulus Algorithm (ACMA) [7,8,9,10], which converges quickly, should be used with time-varying channels Another particularity of the BSS algorithms is their ability to restore, in the output, the sources with a certain permutation and a certain rotation or phase. International Journal of Digital Multimedia Broadcasting (BER), than those obtained with the adaptive-ACMA and the MMA Both proposed methods perform a source separation and a carrier phase recovery, unlike the adaptiveACMA.

System Model

The AMMA: A BSS Analytical Method so as to Minimize the MM Cost Function

Cost Function

Simulation Results

Conclusion