The Precoding Technology For Multi-User MIMO Spatial Modulation

Multiple-input multiple-output (MIMO) technology for its high multiplexing gain and diversity gain other advantages,has been a research focus of wireless communications and signal processing.MIMO pre-coding technique can reduce the complexity of the receiver of the detector, reduce the error rate and improve the system capacity. Therefore,the transmission signal preprocessing, this processing is the mainstream in the MIMO system. Spatial modulation is a novel multi-antenna transmission technique proposed in recent years, has been widely used in single-user MIMO system, for reducing the complexity of the detection to eliminate inter-symbol interference. In fact, multi-user MIMO systems is the future direction of the mainstream communication technologies. Research shows that the multi-user MIMO transmitter spatial modulation system appropriate pretreatment avoid multi-user MIMO channel interference caused by the internal (ICI), to eliminate the interference between users and improve system performance. Thesis transmitter preprocessing and power allocation for multi-user MIMO spatial modulation systems studied, the specific contents are as follows:(1):The paper describes the pre-coding MIMO technique, the analysis of a single user MIMO and multi-user MIMO precoding more typical model and pre-coding method, comprising zero-forcing precoding, the MMSE precoder, SVD precoding and block diagonalization precoding, and analyzes their advantages and disadvantages.(2):The transmitter precoding MIMO spatial modulation applied to multi-user systems. Applied first precoder block diagonalization completely eliminate interference between users, into a plurality of multi-user MIMO parallel single-user MIMO channel secondly, each separate single multi-user MIMO system is spatially modulated received by the receiving antenna serial number and the traditional phase modulation amplitude while carrying signals effectively avoid interference between the antenna and the receiver end to reduce the detection complexity. In multiuser MIMO spatial modulation pretreatment system, using a gradient descent solution each user power allocation factor calculated by the theoretical value of the power factor of the allocation and distribution of the power factor of the system in case of power distribution is not under the comparing the bit error rate under the circumstances boundary. Concluded after power distribution system, the error rate was significantly lower boundary.