Nonstationary multiple-antenna interference cancellation for unsychronized OFDM systems with distributed training

Adaptive interference cancellation is addressed in an orthogonal fre- quency division multiplexing (OFDM) system with a frame contain- ing a number of temporally distributed pilot symbols, e.g., as in the IEEE 802.16-2004 standard. A nonstationary symbol-by-symbol switching technique based on banks of training-based and semi-blind estimators is analyzed by means of comparison with the nonasymptotic maximum-likelihood benchmark especially developed for assessment of the proposed nonstationary interference cancellation algorithm.