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Fundamental Theory Framework On Software Radio

Posted on:2001-05-17Degree:DoctorType:Dissertation
Country:ChinaCandidate:J ZhangFull Text:PDF
GTID:1118360002451585Subject:Signal and Information Processing
Abstract/Summary:PDF Full Text Request
After the migration from analog to digital, and from fixed to mobile, radio systems are undergoing the third revolution from hard-wired radios to software-defined radios. Software Radios (SR) is one kind of digital signal processing system, which greatly expand the areas of digital signal processing. There has been considerable research on SR. but the systematic theory study has not been found. Centering on the topic of all-digital or all-software communication signal processing, it's an unsolved problem to form the theory of communication signal producing and processing. In this report, we have a try and propose a fundamental theory framework on SR. which consists of five parts. i) digital IF (RE) theory-includes sampling and quantization of wideband IF signal, digital waveform synthesis, multirate signal processing, digital channelizer, digital up (down) conversion between baseband-modulated and bandpass modulated signal through orthogonal modulating (demodulating). ii) Multimode mo-dem theory based on signal space mapping-baseband implementation of mo-dem is one of the features of SR. With orthogonal basis-function to express the modulated signal, the basis-function waveform synthesizer and the basis-function correlating demodulator are obtained. Then we can discuss digital signal detection and analog waveform estimation. iii) Channel estimation and supervision-includes parameters estimation (such as channel delay, carrier frequency & phase, degradation) and waveform estimation. An important feature of SR is that direct-computing method based on soft-clock is used to accomplish channel estimation instead of feedback loop methods. Because SR is one kind of multiband multimode system interfaced with various networks, it's important to analyze and supervision channel environment. iv) Adaptive beamforming and smart antenna-includes estimation of space vector and digitally forming of antenna beam, which can implement adaptive multi-target tracking, interference rejection and smart transmitting. Smart antenna consists of antenna arrays and digital signal processing networks. v) Architecture of SR-it's the core theory on the realization of SR. The aim of SR is to implement multiband, multimode, multipersonaIit~ multiservice into an open, expandable, reusable, modular hardware and software architecture, which need a mathematical models and theory description. This report studies most of above content except for adaptive antenna. At last the application schemes of SR in PCMIFM telemetering receiver and CDMA multi-target telemetering receiver are discussed.
Keywords/Search Tags:Software Radio, Theory Framework, Digital Signal Processing
PDF Full Text Request
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