Research On Topology Control Technology For Directional Antenna Enabled Wireless Ad Hoc Networks

With the characteristics of mobility,needless for fixed infrastructure,and strong networking flexibility,the wireless ad hoc network is widely used in military and disaster area emergency areas.Its topology control has a direct impact on the performance of the network.Furthermore,the use of narrow beam directional antennas can improve the performance of the network.In a wireless ad hoc network using narrow beam directional antennas,if nodes want to communicate with each other,they must track the location information of neighbor nodes.When the number of neighbor nodes is too large,there is a high complexity caused by tracking a large number of neighbor nodes.While the number of neighbor nodes is too small,the throughput of the network will be reduced,and the topology is not robust enough.Based on this,this thesis studied the topology control technology based on narrow beam directional antenna.Under the condition of ensuring network topology connectivity,the number of neighbor nodes was reasonably limited,so that the network has a large throughput.The main work is as follows:Firstly,a directional antenna topology control algorithm based on traffic demand is proposed.The wireless Ad hoc network based on directional antennas needs to meet the traffic demand between nodes.However,the traffic transmission capability of the network is constrained by factors such as link capacity,the structure of topology,and the maximum number of beams that a node can use.This thesis considers three factors of channel modeling,link scheduling and traffic demand,and models the topology control problem as an optimization problem,which achieved the goal that under the premise of guaranteeing the degree of the nodes in the topology,an optimal link scheduling and routing strategy can be found to maximize the throughput of the network.Specifically,the algorithm studied the topology control algorithm of nodes under different maximum beam quantity constraints and the MATLAB+CPLEX tool was used to simulate the topology control algorithms under the single-beam and multi-beam.The simulation results show that,when each node using 2 times the maximum node degree of the number of beams,the network can achieve the maximum throughput.Then,a distributed algorithm based on directional antenna beam cluster rotation is proposed.The algorithm can quickly build a network that meets the node's degree limit while enabling the network to achieve near-optimal throughput.In order to avoid the problem of too many neighbors in the topology generated by the distance-based distributed algorithm,a beam cluster rotation algorithm is proposed,which can effectively reduce the number of neighbors in the generated topology.However,because the topology generated by the algorithm is sparse,this thesis proposes an augmented beam cluster rotation algorithm,which makes the final topology increase the number of links in the topology and improve the throughput of the network.Finally,the proposed algorithm is simulated by MATLAB software.The simulation results show that the augmented beam cluster rotation algorithm not only limits the number of neighbors that generate topology nodes,but also enables the network to have a large traffic transmission capability.When the path loss is large,the traffic transmission capability of the topology generated by the enhanced beam cluster rotation algorithm can approach the centralized optimal situation.