通信接收机性能退化手册

Defense SpectrumOrganization Joint Spectrum CenterAnnapolis, Maryland 21402 Consulting Report Communications Receiver PerformanceDegradation Handbook Document Control No. JSC-CR-10-004 11 August 2010 Prepared for: Joint Spectrum Center2004 Turbot LandingAnnapolis, MD 21402-5064 Approved for public release; distribution is unlimited. This page intentionally left blank. EXECUTIVE SUMMARY In May 2003, President Bush established the Spectrum Policy Initiative to promote the developmentand implementation of a United States spectrum policy for the 21st Century. In response to theSpectrum Policy Initiative, the Secretary of Commerce established a Federal Government SpectrumTask Force and initiated a series of public meetings to address policies affecting spectrum use by thefederal government, state and local governments, and the private sector. The recommendationsresulting from these activities were included in two reports released by the Secretary of Commercein June 2004. In November 2004, the President directed the federal agencies to develop a plan toimplement the 24 recommendations contained in the reports. One of the recommendations directedthe National Telecommunications and Information Administration (NTIA) to develop a handbookdocumenting best practices in spectrum engineering that will be recognized by all regulatoryauthorities in the United States. The “Best Practices Handbook” (BPH) will bring together a common set of approaches forconducting Electromagnetic Compatibility (EMC) analysis and will develop a common set ofInterference Protection Criteria (IPC) for performing technical studies to evaluate potentialinterference issues with emerging technologies. NTIA recognized that the communications receiverdegradation handbooks previously developed by the Joint Spectrum Center (JSC) have proven to bea valuable technical resource in establishing IPC values used in EMC analyses. Therefore, NTIArequested that the Defense Spectrum Organization/JSC expand and enhance the CommunicationsReceiver Performance Degradation Handbook and provide it to NTIA such that it could beincorporated into the BPH. The Communications Receiver Performance Degradation Handbook (henceforth referred to as theHandbook) provides Radio Frequency (RF) analysts with the capability to calculate the effects ofnoise and interference on RF communications receivers. This is accomplished by providing theHandbook user with a concise description of communications receiver theory, describing howinterference impacts communications systems, presenting a step-by-step interference evaluationmethod, and providing a catalog of Bit Error Rate (BER) performance data in the presence ofvarious interferers. The interference evaluation method presented in the Handbook is applicable not only for simpleinterference scenarios such as Continuous Wave (CW)-like and Additive White Gaussian Noise(AWGN)-like interference but also for complex interference scenarios such as pulsed interferenceand continuous interference which is not CW-like or AWGN-like. A key feature of the Handbookevaluation method is that it offers the RF analyst a means to quickly assess the potential performancedegradation effect of complex interference scenarios without having to perform extensive,complicated analysis or simulation. The techniques presented in the Handbook are applicable to RF communications systems regardlessof the specific frequency band of operation; that is, the techniques are applicable at L-band, S-band,X-band, and so on. Additionally, specific communications system parameters such as data rate andPseudorandom Noise (PN) chip rate are parameters within the analysis. The Handbook considers the modulation, coding and interferer types which are relevant in today’sRF environment and in emerging technologies. To the latter, consideration is given to theunderlying signal structures of WiFi, Worldwide Interoperability for Microwave Access (WiMax),Wireless Local Area Network (WLAN) and Ultra-Wideband (UWB). Section 1 provides general background and overview information. Section 2 describes the general procedures for performing a communications receiver performanceanalysis. It introduces the fundamental concepts and describes the receiver model. Section 3 provides a detailed description of the RF/Intermediate Frequency section. It also specifieshow interfering signals may be changed by the filters. Section 4 describes the despreader module in spread spectrum receivers. It specifies how the spreadspectrum processing gain can be calculated. It also provides information that can be used to analyzespread spectrum multiple-access systems. Sections 5 and 6 describe the demodulator module. They provide plots that characterizeperformance as a function of the input signal-to-interference power ratios. Analog voice andbroadcast television receivers are considered in Section 5 and digital receivers are considered inSection 6. Section 7 describes forward error correction (F