守恒技术固定微波系统7125 8500mhz

ROBERTL.HINKLEANDREWFARRAR U.S.DEPARTMENTOFCOMMERCERobert A.Mosbacher, Secretary Alfred C.Sikes, Assistant SecretaryforCommunications and Information MAY1989 ABSTRACT Since the spectrum is a limited natural resource, the spectrum managementcommunity has a major interest in identifying spectrum conservation techniques thatwill provide more efficient spectrum utilization. Advances in new technology for fixedmicrowave systems in antennas, modulation schemes and signal processing techniquesoffer increased efficiency in spectrum utilization. This report analyzes the spectrumconserving properties of the various new technologies for fixed microwave systemsapplying the concepts in CCIR Report 662-2, and was defined as the spectrumconservation factor (SCF). The report concludes that the SCF technique is aneffective indicator of the spectrum conserving properties of technologies which can beusedtodevelopnewspectrumstandards. KEYWORDS Spectrum EfficiencySpectrum Conservation Factor (SCF)Fixed Microwave System7125-8500 MHz Band TABLEOFCONTENTS Subsection SECTION1INTRODUCTION BACKGROUND1-1OBJECTIVE.1-3APPROACH1-3 SECTION 2CONCLUSIONS AND RECOMMENDATIONS INTRODUCTION2-1GENERAL CONCLUSIONS.2-2SPECIFICCONCLUSIONS2-22-2Antennas2-3ModulationSignal Processing.2-3RF Filters.2-4RECOMMENDATIONS.2-4 INTRODUCTION3-1ANALYSIS APPROACH3-1MICROWAVE REFERENCE SYSEM CHARACTERISTICS3-3 vi 3-34 PageSECTION 3(Continued)3-33-33-63-93-113-113-123-133-143-153-153-173-183-183-203-253-263-303-303-323-323-32 TABLE OF CONTENTS(Continued) TablePage LIST OF TABLES 3-1SPECTRUM CONSERVATION DESIGN FACTORS3-23-2HYPOTHETICAL HOP CHARACTERISTICS3-43-3DIGITAL SYSTEM PARAMETERS.3-143-4ANALOG SYSTEM PARAMETERS3-163-5MAXIMUMPERMISSIBLEINTERFERENCE LEVELSFORDIFFERENT MODULATION TYPES.3-193-6SPECTRUMCONSERVATIONFACTOR FOR ANALOG ANDDIGITAL MODULATIONS3-213-7SPECTRUM CONSERVATION FACTOR COMPARISON OF64-AND256-QAMFORSHDANTENNAS.3-223-8SPECTRUM CONSERVATION FACTOR IMPROVEMENT FORSHROUDED DISHANDCONICAL HORN REFLECTOR ANTENNASAS AFUNCTIONOFMODULATIONTYPE.3-233-9SPECTRUM CONSERVATION FACTOR FOR ANALOG ANDDIGITALMODULATIONS3-243-10 PROCESSING GAIN SUMMARY.3-273-11 CORRECTION/CODING (64-QAM MODULATION)3-293-12 SPECTRUM CONSERVATION FACTOR FOR ERRORCORRECTION/CODING (64-QAM MODULATION).3-29EQUALIZER (64-QAM MODULATION)3-273-13 SPECTRUM CONSERVATION FACTOR FORADAPTIVE EQUALIZER (64-QAM MODULATION)3-313-14 SPECTRUM CONSERVATION FACTOR FOR ERRORCORRECTION/CODING AND ADAPTIVEEOUALIZER (64-QAM MODULATION)3-31 BACKGROUND The National Telecommunications and Information Administration (NTIA) isresponsible for managing the Federal Government's use of the radio frequencyspectrum.NTIA's responsibilities include establishing policies concerning spectrumassignment, allocation and use, and providing the various departments and agencieswith guidance to ensure that their conduct of telecommunications activities.'isconsistent with these policies.1 In discharging these responsibilities, NTIA assessesspectrum utilization, identifies existing and/or potential compatibility problems amongthe telecommunications systems that belong to various.departments'and agencies,provides recommendations for resolving any compatibility conflicts that may exist inthe use of the frequency spectrum,'and recommends changes.to promote spectrumefficiency and improve spectrum management procedures. The radio spectrum is a limited natural resource that must be carefully managedto ensure its availability to accommodate spectrum requirements for newtelecommunication systems.Therefore, NTIA has established a long-range plan formanagement and use of the radio spectrum.2 One of NTIA's major policy initiativesoutlined in the plan is the establishment of procedures to ensure the efficient andeffective use of the spectrum. However, because of the economic burden that can beadopts regulatory controls only where necessary to ensure the continued availability ofthe spectrum.This encourages effective and economical use of the spectrum,development of new technologies in a less restrictive regulatory environment, and the 1-2. MEMORANDUM TO: Deputy Associate Administrator, Office of SpectrumManagement; FROM:Executive Secretary IRAC; SUBJECT:SpectrumResource Assessment of the Federal Government Fixed Service Bands (Above400 MHz.) NTIA Technical Memorandun 87-127, IRAC Doc. 25498/2. Mayher, R.J; Haines, R.H.; et al, The Sum Data Base: A New Measure of 1.the development of methods to identify heavily used geographical areas in aband,the evaluation of available radiocommunication technologies with respect totheir ability to conservethe spectrum. OBJECTIVE The objective of this task was to evaluate spectrum conservation techniques forfixedservicepoint-to-pointmicrowavesystemstoidentifysystem-designconsiderations that promote more effective and efficient spectrum use. APPROACH The following approach was taken to accomplish the above objective Identify major fixed microwave system design factors tha