Low Complexity Hybrid Beamforming For 28GHz Multi-receivers Mimo System

The demands of higher data rates is rapidly increasing due to the revolutionary explode in the social media world and the user's enormous need for the high speed wireless communication,the current wireless services has been saturated almost all the spectrum below 6GHz so the millimeter wave(mm-wave)frequency band can be a brilliant solution for the for the next generation of wireless communication and beyond.The essential target of choosing the 28 GHz frequency band is wide unused bandwidth and the scattered nature of the channel.In the higher frequencies wireless communication environment such as mm-wave the antenna arrays become a significant ingredient.Therefor the normal application for the antenna arrays is the simultaneous transmission for the multiple receivers.But the major problem in mm-wave systems is the hardware constraints which makes the implementation of the multi receiver MIMO beamforming techniques at the classic lower frequency bands difficult.In order to improve the links budget in the 28 GHz frequency band,we developed a dual phase Low-complexity hybrid analog-digital beamforming for the downlink multi-receiver 28 GHz systems,while we presume an analog only combining at the receivers' side.In this thesis the hybrid beamforming included analog and digital combined processing which is inspired by the combined signal hardware and full radio frequency power consumption.The proposed algorithm designs the transmitter hybrid beamformer and the receiver's analog combiners with feedback overhead and by a small training.The performance analysis of the proposed algorithm has been taken for two cases,in the single path channels and with multi path channels with large number of transmitter and receivers antennas and with two types of uniform arrays uniform linear array(ULA)and uniform rectangular array(URA).Both the beamforming vectors the analog and the digital has been chosen from quantized coodbooks,so the rate loss characterization due to joint quantization and the visions are given among the performance of the hybrid beamforming compared with analog only beamforming and all digital(block diagonalization algorithm)beamforming.The performance Analysis and the simulation results demonstrates that the proposed model offers a higher sum rates against the analog only beamforming and almost achieves the same approach of the block diagonalization all digital system by relatively small codebooks.