On Performance of Vector OFDM with Zero-Forcing Receiver

Vector OFDM (Orthogonal Frequency Division Multiplexing) for single transmit antenna systems is a general transmission scheme, where OFDM and SC-FDE (Single-Carrier Frequency Domain Equalization) can be treated as two special/ extreme cases. Due to its flexibility, it has drawn more and more attention recently. So far, all the studies about Vector OFDM assume the ML (Maximum Likelihood) receiver. In this paper, we investigate the performance of Vector OFDM with the ZF (Zero-Forcing) receiver. We firstly show that for the ZF receiver, all the transmitted symbols have equal performance. This is different from the Vector OFDM with ML receiver, where different VBs may have different coding gain, and thus may have different performances. We then analyze the diversity order for Vector OFDM with ZF receiver, and show that the diversity order equals 1 and the performance is the same as the conventional OFDM at high SNR.