The Performance Of Uplink MIMO Relaying System Over Rician Fading Channel

As various handheld devices such as smartphones and tablets are widely applied,it poses a huge challenge to the existing 4G(fourth-generation)mobile communication systems and technologies.The new generation of mobile communication technology 5G(fifth-generation)can not only support massive mobile terminals at the same time,but also ensure communication quality while multi-user communication.Two advantages make MIMO systems widely used in 5G mobile communications.On the one hand,when the number of MIMO system antennas is large enough,multiple signals can be transmitted simultaneously on the same spectrum resource,while improving the frequency band utilization rate and increasing the capacity of the communication system.On the other hand,massive MIMO can support a large number of mobile devices while increasing the system capacity.The MIMO relay technology combines the advantages of MIMO and relay technology,which not only meets the needs of 5G mobile communication,but also can expand the coverage of communication and improve the service quality of mobile communication.Therefore,in this paper,the uplink performance of a two-hop MIMO relay system will be studied.Based on the existing literature,this paper has made the following three contributions:(1)Based on the two-hop high-resolution ADCs(analog-to-digital converters)MIMO relay system,a closed-form expression for the uplink realization rate under the Rician channel is proposed.In view of the current research status of MIMO relay systems mostly under single hop Rayleigh fading channels,in the second chapter of this paper,the uplink of two-hop high-resolution ADCs quantized MIMO relay system is studied.In order to make the system model closer to the actual application scenario of 5G similar to the Internet of Things,the second chapter of this article uses a Rician channel with a LOS(light of sight)path.Under the perfect CSI(channel state information),the closed-form expression of the uplink rate of the MIMO relay system with two-hop high-resolution ADCs under the Rican fading channel is deduced by processing the transmission signal and combining the higher-order statistical information of the Rican channel.The limit analysis is performed on the Rician factor to further derive a closed-form expression for the rate in the other three scenarios.(2)Based on the two-hop low-resolution ADCs MIMO relay system,a closed-form expression is proposed for the two-hop low-resolution ADCs MIMO relay uplink rate under the Rician channel.In order to improve the anti-interference performance of the MIMO relay system,there are a large number of antennas at the relay.If the receiving antenna uses high-resolution ADCs,the energy consumption of ADCs increases exponentially with the number of quantized bits,so that highresolution ADCs will bring energy burden.For the high energy consumption problem of using highresolution ADCs in Chapter 2,in Chapter 3 of this paper,the uplink model of MIMO relay system with two-hop low-resolution ADCs under the Rican channel is proposed.In the perfect channel state,the high-order statistics of the Rican channel yield a closed expression of the two-hop low-resolution ADCs MIMO relay system over the Rican channel.Simulation results show that low-precision ADCs increase energy efficiency and reduce energy consumption during signal transmission,at the expense of limited energy loss.(3)In the fourth chapter of this paper,the uplink performance of two-hop high-resolution and low-resolution ADCs MIMO relay system under the Rican channel is analyzed.As the number of relay antennas and the Rician factor tend to be positive infinity,the asymptotic expression is analyzed.The generalized scaling analysis is performed on the transmission power of the user and the relay,and the uplink power scaling laws of the two-hop high-resolution and low-resolution ADCs quantized MIMO relay system under the Rician channel are obtained.