Performance Of MIMO-60GHz System And Research On Antenna Selection Algorithm

With the development of multimedia technology, the transmission rates ofwireless communication cannot meet the desire of people, so the market demandstimulates the research of broadband wireless communication.60GHz wirelesscommunication technology can supply data rates as much as multi-Gigabits per second,good security, high safety, so the research of60GHz wireless communication systemwill be a focus in the future. In a multipath fading environment, the MIMO technologycan realize high speed transmission, and improve the transmission quality, so it hasbecome a research hot spot in the field of wireless communications.60GHz signals have very high frequency and highly directional. In the process ofcommunication, the obstacles can have a very strong absorption function of60GHzsignals, and the scattering effect of60GHz signals is very weak, so the use of MIMOtechnology for60GHz wireless communication system, can inhibit the large pathlossand serious multipath fading, which can improve the performance of60GHz wirelesscommunication system.So this thesis mainly studies that the MIMO technology is introduced in a60GHzwireless communication system to build MIMO-60GHz wireless communicationsystem, and on this basis, the capacity and bit error rate of MIMO-60GHz wirelesscommunication system are studied respectively under independent channels andcorrelated channels.The main work in the thesis is as follows:1. The capacity and bit error rate of MIMO-60GHz wireless communication systemare studied under independent channels. The capacity of MIMO-60GHz wirelesscommunication system is investigated for two power allocation schemes, equal andwater-filling; the bit error rate of MIMO-60GHz wireless communication system isstudied for orthogonal space-time code, which is represented by the Alamouti code.2. It is known that scattering is a limiting factor in independent channels. In many practical situations, for60GHz and above, multipath is attenuated by high reflectionlosses and thus cannot always provide a rich scattering environment. This non-richscattering environment results in a relatively high spatial correlation which is known toreduce the potential performance improvements with SM.The60GHz channels are notindependent of each other, but correlated. This motivates the study of a correlatedMIMO-60GHz system in indoor environments. So we build the correlated channelmodel of MIMO-60GHz wireless communication system. The effect of the antennaspacing, angular spread and the mean angle of arrival (AOA) on the capacity and biterror rate of MIMO-60GHz wireless communication system is mainly studied.3. In order to improve the performance of MIMO-60GHz wireless communicationsystem under correlated channels, different antenna selection algorithms are studied,and on this basis, a fast antenna selection algorithm based onDoolittle-QR-decomposition is proposed. The corresponding simulation is carried out.Based on the performance of MIMO-60GHz wireless communication systemunder independent channels and correlated channels，two conclusions are derived asfollows:1. The antenna spacing, angular spread and the mean angle of arrival (AOA) has aneffect on the capacity and bit error rate of MIMO-60GHz wireless communicationsystem. In order to improve the performance of MIMO-60GHz wirelesscommunication system, it is important to design appropriate multiple antenna structure.The antenna spacing, angular spread and the mean angle of arrival (AOA) present deepeffects on the design of multiple antenna structure.2. To maximize the capacity of MIMO-60GHz wireless communication system, a fastantenna selection algorithm based on Doolittle-QR-decomposition is proposed.Compared to the optimal antenna selection algorithm, the incremental antennaselection algorithm, and random antenna selection algorithm, the effect of the fastantenna selection algorithm based on Doolittle-QR-decomposition on the capacity ofMIMO-60GHz wireless communication system is investigated. By MATLABsimulation, the experimental results show that: compared with the random antenna selection algorithm, the antenna selection algorithm based onDoolittle-QR-decomposition can achieve better performance; the capacity gap betweenthe optimal antenna selection algorithm and the antenna selection algorithm based onDoolittle-QR-decomposition is not great. The antenna selection algorithm based onDoolittle-QR-decomposition not only can keep a very good diversity effect, but alsocan reduce the complexity of the system coding. The antenna selection algorithm basedon Doolittle-QR-decomposition is suitable for60GHz channels in indoorenvironments.This thesis mainly studies that the MIMO technology is introduced in a60GHzwireless communication system to build MIMO-60GHz wireless communicationsystem, and on this basis, build the correlated channel model. The study on thecapacity and bit error rate of MIMO-60GHz wireless communication system underindependent channels and correlated channels can provide theoretical support for thedevelopment of MIMO-60GHz wireless communication system, and guidance for thedesign of related products,which is significant to promote applications of60GHzwireless communication technology.