A Semi-Blind Adaptive GSM Beamformer Using Re-Encoded Data

Abstract

An adaptive beamforming algorithm for the Global System for Mobile communications (GSM) is presented where the weights are updated using re-encoded data and a semi-blind technique. The receiver consists of several stages operating on the synchronization channel (SCH) in an iterative manner to improve the reliability of the cochannel signal decisions. An extension of the constant modulus algorithm (CMA) with a least-squares (LS) formulation is used to implement the semi-blind technique. Iterative semi-blind processing is introduced to further refine the beamformer weights. The performance of the enhanced GSM receiver is evaluated using real and simulated data.