Multi-user OFDM employing parallel interference cancellation assisted decision-directed channel estimation

Multiple reception antenna assisted space division multiple access (SDMA) techniques designed for wireless orthogonal frequency division multiplexing (OFDM) systems have drawn wide interest. These techniques facilitate the implementation of effective multi-user detection algorithms at the receiver. A prerequisite of their operation is the availability of an estimate of the channels´ frequency domain transfer functions. This contribution analyses a recursive decision-directed channel estimator (DDCE). Our simulation results demonstrate that this channel transfer function estimator is capable of outperforming state-of-the-art transversal filter based DDCEs in terms of the mean-square estimation error in scenarios, where the product of the number of transmit antennas and the number of CIR taps to be estimated per transmit antenna approaches the number of subcarriers hosted by an OFDM symbol.