Design And Optimization For Broadband Wireless Communication System

Wireless mesh network and OFDM technique as two important aspects of broadband wireless communication technology, has always been hotspot in research of communication. Wireless mesh network have serious capacity problem compare with wired network, so a large number of studies have been conducted to improve the capacity of the wireless mesh network. One of the most promising approaches for improving capacity of wireless mesh network is using of multiple radio interfaces. However, how to choose reasonable channel allocation scheme has always been the research hot spot. Usually, the number of radio interfaces is much more than the number of effective channel, which leads to the results that different links to operate on the same channels. This case severely affect the network overall performance.In this paper, at the beginning design the OFDM baseband communication system according to the protocol of IEEE802.11a. Then, the relationship between the lengths of route and traffic transmission and the relationship between the interference of route and throughput of the network were obtained by mathematical analysis. Draw a conclusion from analysis of above:shorter lengths of routing the greater probability of traffic successful transmission; Lengths of routing and the total number of interference links of routing are the two main factors influencing the network overall throughput. Last, collect the information in the wireless Mesh network using ant colony algorithm, and puts forward two kinds of channel allocation algorithm based the priority of the links. The main different of two kinds of channel allocation algorithm is that occupied channel respectively by using the greedy algorithm and routing interference channel allocation algorithm. At the same time, with MATLAB to validate the algorithm of above, compare it with ACI-DCA and CLCA respectively, and the result of the simulate show that the algorithms of above reduced the effect of interference and improved the throughput and decline the loss packet rate of the network. Then, validated and compared the property of above two kinds of algorithm, the compared result show that the property of routing interference channel allocation algorithm has an advantage over the greedy algorithm. Then, draw the final conclusion:The routes with less interference links had higher influence on whole network throughput, since during the channel allocation, according to the interference of the route to decide how much channel would be accessed by the link, which is benefit to improved the throughput of the network. At the same time, according to the route length of the link and the interference of the link to decide the priority of the link access channel, which is benefit to improvement the performance of the network.