【作者】 林华杰；

【导师】 史浩山；

【作者基本信息】 西北工业大学 ， 电路与系统， 2004， 博士

【摘要】 软件无线电(Software Radio)中心思想是:构造一个具有开放性、模块化、标准化、可重构的通用硬件平台,将各种功能,如工作频段、调制解调类型、数据格式、加解密模型、通信协议等用软件来完成,并通过软件加载来实现各种无线通信功能的开放式的体系结构。它是以现代通信理论为基础,以数字信号处理为核心,以微电子技术为支撑的崭新的通信体制。 在软件无线电通信体制中,模数、数模转换器(ADC/DAC)尽可能地靠近天线,原有无线通信体制中尽可能多的功能希望被数字化,采用软件实现,所以软件无线电的提出不仅对微电子技术提出了更高的要求,也对无线通信体系结构以及数字信号处理算法提出了新的课题。所以当前人们对软件无线电的研究主要集中在以下三个方面:一、以目前的技术水平理想的软件无线电体系结构还远不能实现,那么目前软件无线电应采用何种体系结构,不仅最大程度地满足软件无线电开放性、模块化、标准化的要求,而且要求具有可实现性、高性能、低功耗、高集成度等特点;二、软件无线电要求尽可能实现数字化、软件化,其所涉及的内容包括了现代通信理论的方方面面,如宽带天线理论、调制解调、信道的编译码、信道均衡、加解密等,极大地扩展了数字信号处理的研究领域并且提出了更高的要求;二、软件无线电的应用,软件无线电概念最初的提出来源于军事通信的要求,然而其在个人通信领域应用的研究是当前的研究热点。 针对以上三方面,本论文进行了研究,所做的创造性工作和取得的成果如下: 1.阐述了软件无线电的三种体系结构,由于中频带通采样软件无线电结构是目前较为可行的方案,所以对几种典型的中频接收机——超外差中频接收机、零中频接收机、双正交变换宽带中频接收机和低中频接收机——做了详细的论述和比较,并以此为基础提出了一种数字化镜像抑制低中频接收机结构。 2.讨论了软件无线电的关键技术——模数转换器、数字信号处理器(DSP)以及现场可编程逻辑阵列(FPGA)的现状及发展。在模数转换器方面通过比较指出∑-△ADC更适合于软件无线电在移动通信系统中的应用。 3.对软件无线电的数字信号处理理论及算法做了有限的研究,包括多速率信号处理、更多还原

【Abstract】 The term "Software Radio" stands for "radio functionalities defined by software", it refers to configurate an opened, modularized, standardized and reused hardware platform, realize almost all of the functions of transceiver by software such as working frequency, modulation and demodulation, data format, encryption and decryption, communication protocol and so on, and use over-the-air (OTA) download. The software radio communication system is based on modern communication theory, digital signal processing and micro-electronics technologies.Compared the software radio to the old radio communication system, most of the function should be realized by digital and software, so we face new technical challenges not only on micro-electronics technology but also on radio communication system architecture theory and digital signal processing technologies. Therefore, software radio is mainly studied on three aspects: 1) Radio Communication System Architecture Theory—the ideal software radio cannot be realized with present technique advancement, the realized structure is studied which has high performance, low power, high-integration, and satisfy as much requirement of software radio as possible; 2) Digital Signal Processing Theory—software radio is one kind of digital signal processing system, which greatly expand the areas of digital signal processing; 3) Application of Software Radio—software radio originates form the development of military radio, but now its application in the 3rd generation mobile communication has been a research hot spot.In this report, we have a try on software radio theory of architecture and digital signal processing, which consists of six parts. Section Ⅰ is preface, which introduces the concept of software radio and its development. Section Ⅱ discusses three software radio architectures, compares the structures of IF receiver, and gives a new kind architectures of low IF receiver for digital image-rejection. Section Ⅲ discusses the key techniques of software radio—ADC, DSP and FPGA. Our analysis of ADC shows that the sigma-delta converter is a more perfect fit to the application in software radio. Section IV’ studies some digital signal processing algorithm of software radio, which includes multirate signal processing, digital channelizer, carrier synchronization and timing recovery, modulation and demodulation, and channel error monitoring. In this section we stress on a kind of time-variable CIC filter based on CIC filter for fraction radio sample rate conversion, a timing error detection algorithm for all digital receivers, and a bit error rate detection algorithm base on re-encode of forward error correction. Section Vdescribes the scheme of digital microwave transceiver which has some characteristic of software radio; Section VI is conclusion of this dissertation.更多还原