802. 16 WiAX 物理层模型实现与分析MATLAB - 0412.doc

摘 要 WIMAX(Worldwide Interoperability for Microwave Access，全球微波互联接入)是一项新兴的宽带无线接入技术，能提供面向互联网的高速连接。随着4G网络、移动互联网和物联网等高新技术的飞速发展，作为其中重要支撑的WIMAX技术也发挥着巨大的推动作用。而LDPC码和OFDM作为WIMAX中的核心关键技术，如何通过深入研究以求更好的发挥其优势，将是无线通信研究领域需要重点研究讨论的热点。 本文首先就WIMAX物理层有关技术展开研究，对其中的OFDM技术原理、LDPC码原理、MIMO技术及WIMAX标准下的参数配置等深入学习研究，讨论了基于OFDM的WIMAX物理层仿真。根据系统框图中的加扰、级联编码、交织、符号映射、OFDM调制等各个部分，分别通过对每个部分进行模块化编程来实现。 针对WiMAX物理层基带仿真模型未采用SUI信道的问题，在理想同步情况下，综合考虑影响系统性能的各种因素，包括SUI信道、循环前缀(CP)长度、RS+CC编码和信道估计，运用Simulink对其进行评估。仿真结果表明。采用自适应调制编码或改变CP长度能平衡BER和数据速率。 关键字：WIMAX；物理层仿真；LDPC；OFDM；SUI信道 ABSTRACT WIMAX is an emerging broadband wireless access technology which can provide high-speed Internet connection.With rapid development of the high-tech such as 4G network,mobile internet and the Internet of Things,WIMAX as one of the important support technology also plays a huge role in promoting.LDPC codes and OFDM as the core technology in WIMAX in order to deeply study and fully exert its advantage,which need to focus on discussion in Wireless Communication. This paper focuses on some technologies related with the WiMAX Physical Layer,including the principle of OFDM technology,the principle of the LDPC codes and MIMO technology and configuration parameters based on WiMAX standard.We discussed the Performance of the OFDM System Based on WiMAX Physical Layer.The analysis accord to the diagram of the scrambling, concatenated coding,interleaving,symbol mapping and OFDM modulation. through each section for carry out the modularization programming. The baseband simulation model ofWiMAX PHY-Layer does not take SUI channel into consideration．Aiming at this problem and under the conditions of perfect synchronization,this paper considers the factors effects the system performance synthetically,including SUI channel，the length of Cyclic Prefix(CP)，RS+CC encoding,channel estimation，and evaluates them based on Simulink。Simulation results show that by changing the length ofCP and using Adaptive Modulation and Coding(AMC)，the balance betwee