WiMAX System-Level Simulation Research Based On Ns2

WIMAX is a broadband wireless access technology for broadband wireless access metropolitan area network (BWAMAN) based on the IEEE 802.16 standard. The basic objection of WiMAX is to provide a broadband wireless access mean with effective interoperability in the multi-vendor environment of the point-to-multipoint metropolitan area network.The farthest transmission distance of the WiMAX wireless signal can reach 50km, the coverage area of the network is ten times of that of the base station of 3G (3rd Generation, the third-generation mobile communications). As the driving of the social informatization, WiMAX, which is a kind of broadband access scheme for wireless metropolitan area network, is payed more and more attentions with its perfect performance and the wide market prospect. The satisfaction of the QoS for services, which is influenced by the access control, scheduler, resource allocation, channel condition etc., is more and more different. It becomes the key point in current that how to advance the performance of the whole WiMAX system.This subject aims to the system-level simulation of WiMAX and provides a whole WiMAX system-level simulation platform based on ns2 .The platform includes the physical layer of WiMAX, the MAC layer and the traffic generator which is used to simulate the generator of multi-kind of sevices.Then we consummate and optimize the management module of the dynamic services, the scheduler module in MAC layer, the resource allocation module, the ARQ module, the channel module and the cross-layer feedback module. This paper provides the details of the module design of the improved WiMAX system module which aims to improve the performance of the whole WiMAX system.It is needed to understand the technology to analyze and improve the performance of the system. This paper focused on the key technologies of the physical layer and MAC layer of the WiMAX system and their impacts on the performances of system before expatiating on the design of the system-level platform. At the same time, this paper also introduces the relevant algorithms and their performances.Also, this paper proposes a whole scheduling and resource allocation algorithm strategy which can make the WiMAX system meet the QoS requirements of variety service flows and make the throughoutput of the WiMAX system maximize. The improvements of the algorithm aim at the MAC layer and the physical layer at the same time. It adjusts the resource allocation scheme considering the impaction of the channel conditions and the modulation/demodulation of the physical layer on the transmission rate and the resources allocation. Finally, we provide the simulation results of the performance of the WiMAX system. The results of experiment demonstrate that the proposed scheduling and resource allocation algorithm strategy is more efficient than the existent algorithm strategies and also demonstate the validity of the improved WiMAX system module for the performance evaluation of the whole WiMAX system.