Optimal power allocation for transmitter selection in MISO Rayleigh fading channels

In this paper we derive optimal power allocation (PA) in space and time that minimizes BER for transmitter selection in multi-input-single-output (MISO) Rayliegh fading channels assuming perfect channel state information (CSI) is available at receiver and transmitter. This power allocation scheme achieves exponential diversity order with a single RF front end and requires feedback of the best channel only. The presented scheme results in 7.5 dB gain over optimal single-input-single-output (SISO) power allocation scheme for 4-QAM modulation at SER of 10^-4.