An OFDM receiver with smoothed FFT-window and RLS-MLSE for fast multipath fading environments with large delay spread

This paper proposes a new OFDM receiver for fast varying multipath fading environments with large delay spread. The delay difference that is greater than the GI of the OFDM signal results in inter-symbol interference (ISI) and inter-channel interference (ICI). The new OFDM receiver consists of equalizers for both ISI and ICI, and an accurate channel impulse response estimator. In addition, it introduces the smoothed FFT-window in order to reduce ICI. The channel impulse responses are estimated by RLS-MLSE which is a novel joint processing parameter estimation and signal detection. Computer simulations in the IEEE 802.11a format show that the proposed OFDM receiver is very effective in ISI and ICI fading environments.