A new optimal transmit and receive diversity scheme

The effects of fading in mobile radio channels can be mitigated with the use of space (or antenna) diversity. One diversity scheme which is applicable to any number of transmit and receive antennas is maximum ratio transmission (MRT). In this paper, it is shown that a certain constraint on the MRT receiver combining weights results in performance degradation. A new transmit and receive diversity scheme, MRTC, is proposed which maximizes the output signal-to-noise ratio (SNR). The MRTC scheme optimizes the transmit and receive weights. It is found that MRTC can offer significant gains over MRT. Another slightly sub-optimal but simpler-to-implement diversity scheme, IMRT, is also proposed. The IMRT scheme uses the same transmit weights as MRT; however, in contrast to MRT, it uses optimal MRC-based receive weights.