Research On Novel Indoor Heterogeneous Communication Systems

As people’s requirements for indoor communication quality and coverag e increase,more and more indoor communication methods emerged as the times require,such as visible light communication and power line communication.Both visible light communication and power line communication u se the existing infrastructure for data transmission,which has the advantages of easy implementation,low cost,high security,and free spectrum.However,the single mode communication system such as visible light communication and power line communication has the problem of high propagation loss and narrow coverage.Aiming at this problem,this thesis studies the two different types of heterogeneous networks,based on reconfigurable intelligent surfaces-assisted mixed dual-hop visible light/radio frequency communication system and mixed dual-hop power line/radio frequency communication system.The two links of the two heterogeneous schemes work in differen t frequency ranges,which can avoid interference between each system,and expand the propagation distance to a certain extent.The main research contents of this thesis are as bellows:(1)A reconfigurable intelligent surface-assisted mixed dual-hop visible light communication/radio frequency system in indoor scenarios is proposed,in which the first link of the system is the visible light communication link,and the reconfigurable intelligent surface is used to assist the radio frequency link.More specifically,the photoelectric detector on the relay first converts the optical signal into an electrical signal,and then forwards the electromagnetic signal to the reconfigurable intelligent surface using the decode-and-forward or amplify-and-forward relay protocol.Subsequently,the reconfigurable intelligent surface changes the electromagnetic response and direction of the incident wave,and builds a virtual line-of-sight link between the relay and the destination.So that the destination and the signal end can be connected,and the coverage of the communication system is expanded.Moreover,the quality of the received signal at the receiving end is enhanced by increasing the number of reflective surfaces on the reconfigurable intelligent surface.Based on the above system,we derive the closed expressions of the outage probability under different relay protocols and the exact expression of the average bit error rate under decode-and-forward relay protocol.In order to draw more meaningful conclusions,we also provide the asymptotic analysis of outage probability.The simulation results verify the above analysis results.(2)A mixed dual-hop power line communication/radio frequency communication system is studied.In this thesis,the power line link and radio frequency link of the system are connected through decode-and-forward or amplify-and-forward relay.It is assumed that the power line channel is affected by additive background noise and Poisson–Gaussian impulsive noise,accompanied by log-normal fading,and the radio frequency link is assumed to be the generalized Rician fading.Based on this model,accurate expressions for the diversity order,outage probability,average bit error rate,and the average channel capacity are derived.Furthermore,the outage probability and average bit error rate are analyzed asymptotically as well as the upper bound expression for the average channel capacity is given.Finally,numerical results are provided to analyze the influence of system parameters such as impulse noise and generalized Rician factor on the overall performance.