Performance study of Kalman adaptive equalizer for high speed data transmission over the HF channel

摘要

BER performance of the Kalman recursive least squares adaptive equalizer at 2400-b/s data rate for DPSK (differential phase-shift keyed) modulation is obtained for various HF channel conditions using Monte Carlo simulation. A channel-tracking scheme of 63 bits of training for each 363 bits is used. The choice of the weighting constant w which determines the algorithm memory length is found to have a significant effect on equalizer performance. The optimum value of w is found to be around 0.95 for the channel tracking scheme used. The adaptive equalizer used with fixed training scheme is found to perform well for fading rates up to 0.5 Hz and for differential Doppler shift values under 0.5 Hz. Equalizer performance degrades with more rapidly changing channel conditions.