| With the progress of the high-technology industry and the national economy,the number of vehicles and the amount of data generated by vehicles has exploded.Connecting the vehicle nodes that have communication requirements to the original communication system will lead to a series of problems,such as the significant rise in transmission conflict rate,the continuous increase of channel access delay time,the sharply heighten of the competition intensity between vehicles’ channel access,the shortage of communication spectrum resources,etc.By introducing the device-to-device(D2D)communication technology into vehicle-to-vehicle(V2V)communication,adjacent vehicle users(VUE)can communicate with each other and transmit data directly,thereby reducing the service load of the base station and alleviating the problem of resource shortage.However,the VUE communication based on the D2 D underlay mode will inevitably cause additional interference to both VUE and CUE.The higher resource reuse rate of the same CUE,the severer the interference aroused.We need to formulate an effective resource allocation strategy to guarantee the communication quality of CUE and V2 V links.This paper focuses on the high-density vehicular communication environment where spectrum resources are scarce and studies the resource allocation problem of improving the number of V2 V communication links that meet the requirements of communication reliability and delay time while ensuring the reliability of CUE communication.The specific work content includes the following two aspects:(1)Proposed a serial resource allocation strategy based on D2 D technology in a high-density vehicle environment.First,we model a single base station communication scenario with high-density traffic flow,establish the communication model and the resource allocation optimization model.Then we transform and simplify the NP-difficult resource allocation problem by using series theorem and mathematical derivation.The interference intensity is managed by controlling the transmission power of VUE and CUE.And a serial resource allocation algorithm is proposed.Simulation results indicate that under the premise of ensuring the reliability of CUE communications,this solution maximizes the number of V2 V links that fulfill the requirements of high reliability and low delay.(2)Improve the serial resource allocation strategy by exploring graph theory and auction theory.We use the clustering algorithm to ameliorate the shortcomings of the constant CUE transmission power in the serial resource allocation strategy,which also simplifies the M-N(M ? N)resource allocation problem to the M-M resource allocation problem,and proposes a parallel resource allocation algorithm combined with KM algorithm firstly.Secondly,based on the auction theory,we establish the resource allocation model as an auction model and model the power limitation as the auction revenue.Therefore,we improve the spectrum resource wasting problem of the parallel resource allocation strategy and propose the resource allocation auction algorithm.Finally,the simulation experiment results show the effectiveness of the two improved schemes.Compared with the serial resource allocation algorithm,it can further improve the overall resource utilization rate of the system by 17.9% and 21.7% respectively. |
