Constrained Maximum-Sinr Equalization With Channel Estimation Capabilities for Nbi-Corrupted OFDM Systems

Constrained optimization techniques, based on the maximum signal-to-noise-plus-interference (SINR) criterion,, are considered for joint equalization and narrowband interference (NBI) suppression in orthogonal frequency-division multiplexing (OFDM) systems. Specifically, we show that a recently proposed linear receiver (D. Darsena et al., 2005), which mitigates, in the minimum mean-output-energy sense, the NBI contribution at the receiver output, can be regarded as the solution of a constrained maximum-SINR optimization criterion and, moreover, admits an interesting three-stage decomposition. This decomposition improves the receiver robustness against errors in the estimated statistics of the received data and, most important, allows one to greatly simplify the channel estimation problem. Computer simulations are earned out to illustrate the performance improvements achievable by adopting the constrained maximum-SINR equalizer, in comparison with its unconstrained counterpart