Synchronization techniques and guard-band-configuration scheme for single-antenna vector-OFDM systems

Vector orthogonal frequency division multiplexing (OFDM) was proposed for single-antenna systems as a generalization of OFDM. It converts an intersymbol interference (ISI) channel into multiple "ISI-free" vector channels while involving channel matrices instead of channel coefficients in one-tap equalization. Over multipath fading channels, it benefits from signal-space diversity. This paper addresses practical issues such as guard-band configuration, timing estimation, and carrier- and sampling-frequency synchronization for vector OFDM. An equivalent structure derived for vector OFDM manifests the relation between vector OFDM and conventional OFDM so that the solutions to guard-band configuration as well as carrier- and sampling-frequency synchronization for conventional OFDM can be modified to fit into the vector-OFDM framework. It is also shown by analysis that the pre-fast Fourier transform (FFT) algorithms for timing estimation and carrier-frequency synchronization in the conventional OFDM framework can be extended straightforwardly to vector OFDM with comparable performance. Simulation results of uncoded systems are given to show the effectiveness of the proposed synchronization techniques.