Side Lobe Canceller Structure-Based Spatial Interference Cancellation and performance enhancement of the MIMO wireless systems

In some telecommunication systems, the signals received or sent by different antennas are combined with each other in a way that has the most benefit in a specific spatial direction. The signal sent or received by all antennas is the same and differs only in amplitude and phase. On the other hand, in some array systems, the transmitted signal is different from different antennas. Similarly, the receiver has a separate processor for each antenna. In MIMO systems where the transmitted signals from various antennas are different and each antenna has a separate receiver in reception, the physical distance between the different antennas must be greater than a certain value so that the paths of each antenna to the destination are independent. In this paper, considering this distance in practical systems, a number of auxiliary antennas are placed between the main antennas of the MIMO system. The main antenna together with its adjacent auxiliary antennas forms antenna assemblies. The function of auxiliary antennas is to eliminate co-channel interference by performing appropriate irradiation.  In this paper, the considered model is a channel with a feed rail that has a full order. For this channel model, different radiators such as MVDR, LCMV, GSC, ZF and maxSNR were investigated. And two different modes were considered for the transmitter. One of them is when the desired transmitter has one antenna and the other is when the desired transmitter has two antennas and uses Alamouti coding. In addition, both the state that the receiver is aware of the interference channel and the state that is not aware were examined. For each of these radiators, the output signal of the radiator was presented in order to decode the Alamouti coding. In addition, the LCMV radiator was examined under different conditions. In all these cases, the effect of the presence or absence of auxiliary antennas in eliminating all-channel interference was investigated. The simulations performed show the superiority of the performance of the methods proposed in this paper in the face of inter-channel interference

Keywords:

MIMO system , Alamouti coding , Interference cancellation , Side Lobe Canceller , Normalized LCMV method