A new hierarchical beam search algorithm for wireless ad hoc networks in multipath channel scenario

摘要

For the beam search algorithms proposed by some existing literatures cannot always find the global optimal beam in multipath channel and the single communication link may easily be broken, the node at the edge of a wireless ad hoc network will encounter a temporary outage problem, which means it will be isolated from the network. To solve this problem, We propose a new hierarchical beam search algorithm which can be performed on some marginal nodes. The algorithm will take advantage of the multipath channel and find some available communication beams together with the global optimal beam. The main idea of our algorithm is to increase the opportunity to find multiple local optimal beams. The selected number of beams at each level is greater than or equal to the number of paths. In last level, we selectively delete beams and then obtain a plurality of local optimal beams which can be alternative communication beams for the marginal node. Furthermore, we can also get the global optimal beam simultaneously, which are included in these local optimal beams. The simulation results show that, comparing With the exhaustive search algorithm, it has almost the same success rate, but lower search complexity to get a number of alternative beams. Comparing with binary search algorithm, the proposed algorithm has higher success rate to find the global optimal communication beam in multipath environment. (C) 2016 Published by Elsevier B.V.