Development of pilot symbols contamination mitigation techniques in massive MIMO/mmwave systems

Abstract

Millimiter waves and Massive MIMO are considered an enabling keys for future 5G cellular systems. Our work is subjected towards the two problems in such systems, that are Interference signal and pilot contamination (PC). We propose to incorporate oblique projection (OP) with conventional ZF beamforming in the downlink of a massive MIMO communication system. Resulting beamformer uses OP spaces to separate the received signal into two subspaces: the one pertaining to the desired user signal and the other to interference signals, thus achieving a high degree of interference suppression. For the PC problem, we propose a scheme based on beamspace unitary ESPRIT (BU-ESPRIT) algorithm for the parameter channel estimation to combat the PC in massive MIMO system, and the incorporation of AST in mmwave massive MIMO system to cancel out the interfering signals