An adaptive hybrid MIMO scheme

Hybrid MIMO scheme applies some of the transmit antennas with pure diversity schemes (e.g. STBC) while others with pure spatial multiplexing schemes (e.g. VBLAST), in order to achieve the diversity gain and multiplexing gain at the same time. However, the spatial multiplexing schemes without diversity gain are susceptible to the fading effect. In this paper, we propose an adaptive hybrid MIMO scheme that the perfect STBC is adopted to transmit together with the Alamouti STBC. Since the perfect STBC obtains the full diversity gain and full rate, it can increase the reliability without loss of efficiency. Meanwhile, according to the feedback from the receiver, this scheme adaptively adjusts the allocation of transmit antennas. According to the simulation, this hybrid scheme can improve the system performance significantly.