Adaptive equalization techniques for multipath fading and co-channel interference

The performance of an adaptive fractionally spaced decision feedback equalizer (DFE) in the presence of cyclostationary cochannel interference (CCI) for a frequency-selective quasistatic channel environment is investigated. Simulation and calculation results show that the mean squared error (MSE) convergence for a DFE adapted directly with either the least mean square (LMS) or recursive least squares (RLS) algorithm is prohibitively slow or relatively rapid, respectively. Simulation results also indicate that the performance of an alternative adaptive approach with a computed DFE is limited by its CCI auto-correlation estimation, which requires an unrealistically accurate channel impulse response (CIR) estimate. The preferred approach is to employ an RLS DFE which does not require explicit CIR or CCI autocorrelation estimation.