| With the rapid increase of network data traffic and the diversification of users’multimedia service requirements,it’s significant for wireless communication system to provide high-quality communication services with limited time-frequency resources.Multimedia Broadcast/Multicast Services(MBMS)through which data on time-frequency resources is transmitted to all users in the transmission area has important application value in communication scenarios which require high system resource utilization.3GPP defined the requirements for the 5G terrestrial broadcast transmission system in Release 16.In terms of system transmission quality,broadcast service should support reliable delivery in the scenario of large geographical area and high-speed mobile user reception.In terms of service transmission mode,the system should support concurrent delivery of unicast,multicast and broadcast services and dynamic resource scheduling among multi-services.However,the current MBMS transmission system with fixed physical layer numerology and fixed service transmission mode cannot meet the requirements 3 GPP proposed,which results in a waste of spectrum resources.Meanwhile,the transmission models and resource allocation strategies of broadcast,multicast and unicast are different.Therefore,designing a new multi-service transmission system has significant application value considering above research background.This article focuses on the multi-service cooperative transmission technology,and mainly studies the following:Firstly,aiming at 3GPP’s demands for 5G broadcast service transmission system and combining different service transmission modes of broadcast,multicast and unicast,this thesis proposes a multi-service transmission scheme based on heterogeneous network deployment.Through cooperative transmission of High Power High Towers(HPUTs)and Cellular Base Stations(CBSs),as well as scheduling of bandwidthparts,the service requirements of transmitting broadcast service in the scenario of large geographical area and user high-speed reception,delivering broadcast,multicast and unicast to users concurrently and resource scheduling among multi-services are realized.Meanwhile,this thesis designs a logical architecture of the multi-service transmission system based on heterogeneous network,which verifies the feasibility of protocol architecture.Simulation analysis shows that t multi-service transmission scheme proposed has great performance gain of broadcast transmission in the scenario of ISD=100km large geographical area and mobile reception with terminal speed up to 250km/h.Secondly,considering the transmission characteristics of HPHT and CBS in heterogeneous network and the diverse transmission modes of broadcast,multicast and unicast,this thesis designs resource allocation schemes for HPHT and CBS transmission scenarios respectively under the multi-service transmission system based on heterogeneous network deployment.The optimization objective of the HPHT transmission scenario is to maximize the minimum broadcast service receiving rate of served users.This article proposes a resource allocation algorithm based on dynamic bandwidth,genetic algorithm and lagrange multiplier to solve the HPHT scenario resource allocation problem.The optimization objective of the CBS transmission scenario is to maximize unicast sum rate under the constraint of ensuring broadcast transmission threshold rate and multicast transmission threshold rate in the cooperative transmission area.This article proposes a step-by-step multi-service resource allocation algorithm to solve the CBS scenario resource allocation problem,in which the resource allocation problems of broadcast,multicast and unicast are solved respectively.Simulation results show that the resource allocation scheme can achieve the optimization objectives of HPHT scenario and CBS scenario effectively. |
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