Closed-loop STBC for two transmit antenna MIMO systems with 1-bit feedback

Abstract

The closed-loop multiple-input multiple-output (C-MIMO) systems with feedback channel significantly improve performance of systems. There are many recent researches proposed space time block codes (STBCs) for closed-loop MIMO systems which have number of transmit antennas greater 2. However, to the best of our knowledge, the STBC for closed-loop MIMO systems with 2 transmit antennas is not available. In this paper, we present a STBC rate of one for C-MIMO systems with two transmit antennas. By rotating constellation and coordinate interleaving symbols in codeword, the proposed code also achieves full diversity and linear decoding complexity as Alamouti code. In addition, the proposed code with 1-bit feedback achieves a significant improvement in performance and outperforms open-loop Alamouti code.