Study On The Hybrid Precoding Scheme In Millimeter-wave System With Multiple Users

High spectrum performance and larger bandwidth at millimeter-wave(mmWave)frequencies can support the gigabit-per-second data rates required for wireless networks of the next decade.Multiple-input multiple-output(MIMO)with a wide number of antennas is usually used to allow beamforming and compensate for the high propagation loss in the mm Wave bands.As a consequence,a combination of a significant number of antennas that could be referred to as massive MIMO technology with mm Wave frequencies is thought to be one option for significantly raising the data rate for forthcoming wireless communication networks.The potential advantages of large antenna array technologies are focus on the assumption that the number of radio-frequency(RF)chains is equal to the number of antennas in the traditional wireless communication network known as a fully digital network.However,as more antennas are deployed,implementing a large number of RF chains can be challenging as it results in excessively high material costs,complexity,and power consumption.Conventional precoding techniques then become prohibitively expensive for massive MIMO systems whereas analog beamforming can only process a single data signal at a time.Therefore,a hybrid analog/digital precoding architecture in which a small number of radio frequency chains are connected to a large number of antennas via a network of phase shifters has recently been introduced as the cost-effective solution to benefit from the gains of massive MIMO.However,in this new architecture,the reduction in hardware costs comes at the expense of reduced degrees of precoding freedom,thereby deteriorating the network's spectral efficiency.The overall objective of this thesis is to investigate the design and analysis of low complexity yet efficient hybrid precoding scheme in mm Wave systems.Currently,two main architectures called fully-connected and partially-connected structures are adopted in the literature for hybrid precoding design.Considering that each structure has its functional advantage,this work focuses on the fully-connected structure and proposes a hybrid precoders design scheme for the downlink multi-user mmWave system,to enhance the system total sum-rate with low computational complexity.Simulation results showing the spectral efficacy of the proposed solution are discussed and compared with various precoding techniques.I first started writing this thesis with an introduction that provides the research goals and objectives and gives an overview of the thesis.After that,the background knowledge needed to understand the technical concepts discussed in this thesis and a brief literature review has been given.I continue with the description of the system model used for creating the simulation environment,problem formulation,and analyze some existing solutions.Then,I introduce the derivation of the technique proposed and explain its steps.Through MATLAB simulation numerical results are obtained,discuss,and compare with existing techniques.The present thesis ends by providing the conclusion and possible future works on this research.