Low-complexity iterative receiver design for mobile OFDM systems

Iterative receivers with minimum mean square error turbo equalization are computationally involved, as they require some form of matrix inversion. In this article, we propose a low complexity iterative receiver that implements successive interference cancelation-based MAP decoding (SIC-MAP) in doubly dispersive channels for orthogonal frequency division multiplexing systems. SIC-MAP leverages the soft feedback symbol estimates to remove the intercarrier interference from the received data. Numerical simulation results show that the proposed scheme achieves BER performance comparable to that of the equalization schemes proposed in Schniter et al. and Fang et al. but with significant computational savings. A low-complexity least squares-based iterative channel estimation scheme using soft feedback information is also proposed. This scheme is especially suitable when the number of significant channel taps is higher than the number of pilots, a phenomenon that is encountered by receivers in Single Frequency Networks (for example, DVB deployments in Europe).