Interference canceling equalizer (ICE) for mobile radio communications

This paper proposes an adaptive interference canceling equalizer (ICE) that not only equalizes intersymbol interference (ISI), but also cancels co-channel interference (CCI) in the received signal in Rayleigh fading environments. ICE employs a novel detection scheme, the recursive least squares maximum likelihood sequence estimation (RLS-MLSE), which simultaneously estimates time varying channel parameters. Diversity reception is used to enhance the signal detection performance of ICE. A computer simulation of 40 kb/s QPSK mobile radio transmission demonstrates the possibility of system capacity improvement by ICE. Simulations of ICE with diversity are carried out under the conditions of a two-path Rayleigh frequency selective fading channel with 50 /spl mu/sec delay, 40 Hz maximum Doppler frequency, and 15 dB average E/sub b//N/sub 0/. ICE for single CCI cancellation attains an average BER of 10/sup -2/ under a carrier-to-interference ratio (CIR) of -14 dB. ICE with two independent CCI signals attains less than 1.5/spl times/10/sup -2/ average BER for average CIR/spl ges/-10 dB.<>