Recursive LMMSE-based Equalization in Wireless Mobile Coded OFDM

Orthogonal frequency division multiplexing (OFDM) system suffers extra performance degradation in fast fading channels due to intercarrier interference (ICI). Combining frequency domain equalization and bit-interleaved coded modulation (BICM), the iterative receiver is able to harvest both temporal and frequency diversity. Using the fact that ICI energy is clustered in adjacent subcarriers, frequency domain equalization is made localized. A computational efficient recursive q-tap SIC-LMMSE equalizer is derived. Comparing to conventional method which requires matrix inversion using O(32 ldr q²K²), where K is number of subcarriers, the proposed recursive equalizer only uses O(20 ldr qK²) but without sacrificing performance.