Two novel symbol estimation approaches for wireless systems with ISI and CCI

Abstract

Li (see IEEE Transactions on Communications, 1999) has proved that for a multiple receiver system with both co-channel interference (CCI) and intersymbol interference (ISI), CCI suppression and equalization can be treated separately when an optimum spatial-temporal filter is used. Our emphasis here is equalization for wireless system with both CCI and ISI. Two novel equalization approaches, the linear equalizer with joint decisions and the MLSE with noise-domain truncation are proposed. The linear equalizer with joint decisions exploits the noise correlation at the output of the linear equalizer to reduce the probability of symbol decision errors. The noise-domain truncation MLSE has the same complexity as an MLSE with channel truncation, but it has better performance. Computer simulations demonstrate that the two novel equalization approaches can improve the SNR by 1-2 dB.