A reduced-state soft decision feedback Viterbi equaliser for mobile radio communications

Abstract

The paper presents a new reduced-state soft decision feedback Viterbi equalizer (RSSDFVE) with a channel estimator and predictor. A multi-ray Rayleigh fading channel model with a Doppler frequency shift is used in the simulation. For fast convergence, a channel estimator with fast start-up is proposed. The channel estimator obtains the sampled channel impulse response (CIR) from the training sequence and updates the RSSDFVE during the bursts in order to track the changes of the channel. According to the simulation results, the proposed RSSDFVE gives much better performance than the DFE for severe Rayleigh multipath fading channels with much less implementation complexity than MLSE. The fast start-up (FS) channel estimator gives a faster convergence than a Kalman channel estimator and can achieve the same performance as the Kalman estimator with a shorter training sequence. >