Frequency domain pre-equalization with transmit diversity for MISO broadband wireless communications

In this paper, we introduce a frequency domain pre-equalization scheme with multiple transmit antennas to combat intersymbol interference (ISI) and fading in the downlink of broadband wireless communicadons. MIMO processing in the frequency domain is performed at the base station so that the mobile station can have a simplified receiver. The optimal transmit frequency domain coefficient matrix is derived by minimizing the mean square errors (MUSE). Moreover, we derive an expression for the signal to interference-plus-noise ratio (SINR) and error probability based on the Gaussian approximation of the interference term. Improved performance is demonstrated by analysis and simulation results. In particular, it is shown that this pre-equalization scheme can equalize the channel and attain multipath or frequency diversity. Therefore, our proposed scheme can obtain transmit antenna diversity as well as frequency diversity.