Optimum Structure for the Combination of Tx Diversity and Beamforming

This paper derives an optimal combination of the transmit diversity and beamforming for wireless communication systems. It is known that the requirements of transmit diversity and beamforming are absolutely opposite, such as antenna distance. Therefore, the tradeoff between the transmit diversity and beamforming is necessary. The optimum configuration of multiple antennas for getting the maximum performance is derived under the condition that the total number of antennas is fixed and the total power of transmitter is fixed. Using it, we can easily combine the transmit diversity (Tx diversity) and beamforming for any multiple antenna systems with the optimal group-divided method.