Closed loop transmit diversity and power control with single bit feedback

A simple scheme is proposed to implement both closed loop power control (CLPC) and closed loop transmit diversity (CLTD) with only single bit feedback. This is realized by carefully defining the meaning of the feedback command bit and an algorithm which control both the transmit power and the phase of transmit antennas. The simulation results show that the proposed scheme can save the transmit power considerably in Ricean channel or correlated Rayleigh channel compared to its open loop alternative space time block coding (STBC)/CLPC scheme with the same amount of feedback. In addition, the proposed scheme does not require secondary pilot as STBC/CLPC scheme does.