【作者】 张在兴；

【导师】 焦淑红；

【作者基本信息】 哈尔滨工程大学 ， 通信与信息系统， 2009， 硕士

【摘要】 随着通信技术飞速发展,移动用户对数据业务的需求不断提高,新一代的移动通信系统期望能提供更高的数据传输率、更好的通信质量、支持更快的终端移动速度。WiMAX(微波接入全球互操作性)即IEEE 802.16系列标准,是宽带移动化的重要里程碑,其中的IEEE 802.16e标准更被称为移动WiMAX,促进了移动宽带的演进和发展。WiMAX系统以正交频分复用(OFDM)或正交频分多址接入(OFDMA)技术作为其基带信号的调制方式,但是这种技术一直存在着一个固有缺陷,就是峰均功率比(PAPR)过高。这就要求系统中的功率放大器等内部器件具有很大的动态范围和高度线性,以避免传输信号的非线性失真和频谱扩散,然而这么做会导致系统成本和实现难度的增加。围绕此问题,本论文首先简略地介绍了WiMAX通信技术及其基带子系统的基本原理和关键技术；在此基础上,分析了基带子系统高峰均功率比产生的原因及其分布；然后依次描述了目前国内外降低PAPR的三大主流技术中的各种主要算法及其优缺点,并对这些算法的性能进行了比较,包括是否造成信号线性失真、是否增加系统的发射功率和误比特率(BER)、是否造成系统数据传输速率的损失及计算复杂度和发射接收端实现复杂度；根据IEEE 802.16e标准对降低峰均功率比的要求,再综合考虑硬件实现的复杂度、占用芯片资源等情况,在原有预留子载波算法基础上提出了一种改进算法——受控修剪算法,并根据仿真确定了算法应用的关键参数；最后,基于FPGA实现了该算法,得到比较好的削峰效果,通过对处理时间、硬件资源占用率等性能分析证明本方案在WiMAX基带系统实现中有较大优势。更多还原

【Abstract】 With the rapid development of communication technology, users of mobile data services as demand increases, so the new wireless communication systems are expected to provide higher transmission rate, offer better quality and support faster moving terminals. WiMAX(Worldwide Interoperability for Microwave Access), namely the series of IEEE 802.16 standards is an important milestone of mobile broadband. The IEEE 802.16e standard is known as mobile WiMAX, it makes the promotion of the mobile broadband evolution and development.WiMAX system uses orthogonal frequency division multiplexing (OFDM) or orthogonal frequency division multiple access (OFDMA) as the modulation of baseband signal. But the technology has an inherent flaw which is the high Peak to Average Power Ratio (PAPR). This requires the PA system, and other internal device with a large dynamic range and high linearity in order to avoid non-linear distortion of the signal transmission and spread of the spectrum. But to do so will lead to an increase in system cost and more difficult to achieve.Around this problem, this paper briefly introduces WiMAX communication technology and its basebond subsystem and the basic principles of key technologies firstly; on this basis, it analyzes the causes and distribution of high peak to average power ratio in basebond system; then it descripts the three current domestic and foreign mainstream technologies to get lower PAPR in the variety of algorithms and their main advantages and disadvantages, also the performances of different algorithms are compared, including whether or not caused by linear distortion signal, whether or not to increase the transmitting power system and the bit error rate (BER), whether caused by data transfer rate and the loss of computational complexity and the launch of the receiving end to achieve complexity; according to the IEEE 802.16e standard to reduce PAPR requirements, and considering the complexity of hardware, resources taken up of the chip, an improved method-controlled clipper algorithm is presented based on the original Tone Reservation method, and the key parameters of the algorithm application is determined by simulation; finally, the algorithm is achieved based on the FPGA, and it gained an ideal effect, we can see that this scheme has great advantage in program of WiMAX baseband system from the performance analysis of processing time, occupancy rate of hardware resources.更多还原