Frequency-Domain Oversampling Based Receivers for Orthogonal Frequency Division Multiplexing: Linear MMSE and Nonlinear VBLAST Algorithms

We propose to use frequency-domain oversampling (FDO) to efficiently exploit diversity inherent in a multipath channel. Both linear minimum mean square error (LMMSE) and nonlinear Vertical-Bell Laboratories-Layered-Space-Time (VBLAST) receivers are considered. Numerical results show that compared with conventional counterparts without FDO, the proposed receivers yield significantly better uncoded as well as coded symbol error rate (SER) performance. In addition, we find through simulations that an minnimum FDO exists, which is determined by the number of subcarriers and the number of multipath components.