Research On SINR-based Wireless Network Link Scheduling Problem

As a typical wireless multi-hop communication network,Wireless Sensor Networks(WSN)has become one of the hottest topics in the mobile technology field and wireless communication technology field all over the world.In WSN,thousands of sensor nodes are randomly deployed in their designated areas and connected in a self-organizing manner to jointly serve users.WSN has the typical advantages of easy deployment,low cost,and strong self-healing capabilities.It has been massively invested in all aspects of human life such as smart homes,smart cities,monitoring tsunami volcanic eruptions,and deploying rescue resources.However,since the communication links use the transmission medium in common,when multiple links in the network simultaneously transmit with the overlapping frequency bands of the electromagnetic spectrum,the sender of one link may seriously interfere with the reception of signals arriving at other links.Therefore,it is of great significance for the design of high energy efficiency algorithm to choose an interference model that is close to the real network environment.Compared with other interference models,the physical interference(Signal to Interference plus Noise Ratio,SINR)model is the interference model that is closest to the real network scenario.It can better describe the cumulative interference between concurrent transmission links.As one of the key supporting technologies of WSN,link scheduling technology aims to schedule the communication links in the network reasonably and efficiently.This is for improving the overall performance of the network,especially for the strict and high quality of service(QoS)application of constraints is of vital importance.Link scheduling problems in wireless networks can generally be divided into two sub-categories,the Maximum Link Scheduling(MLS)problem and the Shortest Link Scheduling(SLS)problem.This paper studies the MLS problem and the SLS problem based on SINR model.It mainly includes the following two parts:For the MLS problem,this paper proposes an O(1)-approximation algorithm based on the SINR model.It aims to find the subset of the maximum number of links that can simultaneously transmit without interference.First,according to the specific network environment,the appropriate SINR bidirectional transmission model is set.Secondly,combined with the consistent power allocation method,it can be judged whether the communication link can be added to the feasible set according to the Relative Interference(RI),and the constraints of the Safe Distance(SD).The communication links that can meet the RI and SD constraints simultaneously are added to the feasible set,in order to maximize the number of communication links for without interference transmission.Simulation results show that compared with existing related algorithms,the network capacity of the proposed algorithm is increased by about 25% to 35%.For the SLS problem,an approximation algorithm based on SINR and regular hexagonal partitioning is proposed.Its purpose is to schedule the whole communication links in the network with the shortest time.First,the network model and the SINR interference model are established.Then,the entire planar area is divided into hexagonal cells with the equal side lengths.Finally,combined with an algorithm with the Successive Interference Cancellation(SIC)mechanism,the links that meet the conditions are selected into the feasible set iteratively,for decoding concurrently transmitted signals in the same time slot.Finally,the correctness and effectiveness of the algorithm were proved through rigorous theoretical analysis.