Simulator to Produce Narrowband Multipath Effects on L-Band Aircraft-to-Satellite Signals

Final report: Mar 1972 - Jun 1973PDFTech ReportDOT-TSC-OST-76-44DOT-TSC-372OS219/R7106AircraftCommunications satellitesL bandMultipath transmissionRadio frequency interferenceRadio linksRadio relay systemsRadio signalsSimulationTraining simulatorsUltrahigh frequencyUnited StatesUnited States. Dept. of Transportation. Office of the SecretaryGetchell, Edward H.Mahoney, Paul F.John A. Volpe National Transportation Systems Center, (U.S.)NTL-AVIATION-Air Traffic ControlNTL-AVIATION-Aviation Safety/AirworthinessNTL-AVIATION-AVIATIONVolpe National Transportation Systems Center, Technical Reference CenterThe purpose of the program was to study the aircraft-to-satellite communications channel and to develop instrumentation to accurately simulate the effects of the multipath, Doppler and additive noise effects of such channels. Such a device which simulates aircraft-to-satellite communication channels has been designed and fabricated. The simulator provides capability for test and evaluation of communications and navigation equipment under controlled and repeatable conditions without the need for extensive, costly, time-consuming and nonrepeatable field experiments. The basic approach to channel simulation is to split up the signal into several parts, delay each path differently then multiply the delayed signals by a set of complex noise waveforms and sum the results. Both additive and multiplicative noise signals are exactly reproducible; thus the channel conditions may be reset and repeated. The channel bandwidth is 10 MHz; the relative delay between direct path and multipath signals may be selected to be 5, 30 or 55 microsec. The multipath delay spread is 8 microsec with a 2 microsec resolution