Design And Performance Analysis Of Mimo Channels In Cellular Networks

MIMO (Multiple Input-Multiple Output) the tool to multiple antennas between the Rx and Tx to increase the performance of the Cellular networks especially the communication link. This thesis gives an overview of basic requirements to a complete cellular network.First, some basic cellular networks communications theory is given. The transmission from the base station to a mobile is typically referred as downstream, forward-link or downlink. The corresponding terms for transmission from a mobile to the base station are upstream, reverse link and uplink. An introduction to the communication concept between the transmitting part and the receiving part is also developed where elements for a better and communication system are discussed. Second chapter, the main radio propagation phenomena are discussed, namely path loss, and shadowing and different types of small-scale fading. An overview of the main parameters for channel characterization is also given.And an introduction to the topic of MIMO communications is given, including a classification of MIMO systems and the signals models used throughout this work. The channel capacity in case of multiple antennas at the receiver and/or transmitter is given. Followed by different approaches in modeling MIMO channels. At the end of this chapter some algorithms applied in MIMO systems are overviewed. Information theory gives an expression for channel capacity that is an important metric for channel characterization. The expression for channel capacities depending on the number of antennas at the receiver and transmitter side is given.Application of MIMO brings some of challenges to the design of the whole system, like the available limited bandwidth and a hostile environment (fading and multipath)In the fourth chapter, a designed MIMO wireless communication; will deliver either maximal diversity to enhance transmission reliability or to increase maximal multiplexing gain to support high data rate. Therefore the channel capacity and the spectral efficiency of MIMO system are usually much higher than that of SISO system. This is achieved by using multiple antennas at both transmitter and receiver. Multiple modulated signals are simultaneously transmitted and received using RF front-ends. The multi-branch MIMO transceiver is a simple case of MIMO transceiver architecture, which can improve the power and diversity gain.The purpose of this paper is a MIMO design and performance analysis with multiple radio frequency (RF) front-ends. It uses multiple parallel RF front-ends, and the number of RF front-ends is equal to the number of antennas. At the receiver the baseband processing unit denotes N received baseband paths to recover the signal and also to obtain the diversity gain.RF front-end architecture in multiple antennas design, usually leads to a higher complexity and the hardware costs in the RF section. Furthermore, increasing the number of antennas causes growth in RF circuit mismatches and coupling. These issues limit the application of a high number of antennas at the transceiver. To overcome this,adopting a single RF front-end in a MIMO system reduces the complexity and cost of an RF section and also enables a compact design with lower power consumption.Finally, the designed MIMO performance is analyzed through SU and MU respectively to a fixed PHY mode.Evaluation of channel aware schedulers with fixed PHY mode, the downlink of the AP scenario is used.As The distortion effects from the HW will add the degradation effects to the overall link performance. Thus, undergood channel conditions the HW distortion willultimately determine the maximum performance ofthe link in some cases.