Performance of equalizers employing a re-training RLS algorithm for digital mobile radio communications

Abstract

To improve the transmission performance of high bit-rate digital mobile radio communications in frequency-selective fading environments, a retraining recursive least squares (RT-RLS) algorithm for a decision feedback equalizer (DFE) is proposed. Performance evaluation experiments were carried out with a real-time experimental system that includes a DFE implemented by a single-chip digital signal processor (DSP). Experiments were performed by transmitting 250 kbit/s quadrature phase shift keying (QPSK) at a maximum Doppler frequency up to 160 Hz. The experiment assumes a two-wave model, in which waves have the same power and fluctuate independently with Rayleigh distribution. A bit error ratio (BER) performance below 10/sup -2/ was realized.<>