Low-complexity calculating scheme of feedback information for receiver in EBSTBC

Extended balanced space-time block coding (EBSTBC) is able to achieve large coding gain and guarantee full diversity for any number of transmit antennas. However, the calculation of feedback information at the receiver employs exhaustive searching scheme which is at a high complexity. In this work, a low-complexity calculating scheme of feedback information is proposed for the receiver in EBSTBC systems. The scheme firstly choose the coding matrix according to the channel state information (CSI), and the value of extension parameters for achieving maximum coding gain are decided, then the two parts of the information are sent to the transmitter as the feedback information. Theoretical analysis and simulation results show that the calculating complexity of feedback information is greatly decreased, and almost the same reliability performance is achieved as the former scheme.