Advanced Measurement Techniques Study for Digital Systems.
Quarterly progress rept. no. 3, 1 Jan-1 Apr 72,
GEORGIA INST OF TECH ATLANTA ENGINEERING EXPERIMENT STATION
Pagination or Media Count:
This report summarizes the investigations conducted during the third quarter of effort on a program whose overall purpose is to establish limits for electromagnetic emissions from digitally modulated transmitters. Efforts during the third quarter contributed to this overall purpose by 1 defining the manner in which established limits may be imposed at both the equipment and system levels, 2 providing interference-to-noise ratio calculations and plots for a number of different transmitter modulation structures and receiver types of concern, and 3 utilizing the interference-to-noise ratio calculations to reveal receiver performance degradation in a manner relatable to the limits which must be imposed on transmitter emissions. A procedure based on a tier arrangement of design and test activities at the equipment and system levels is defined as a means of imposing the established limits. Calculated interference-to-noise ratios, based on computed transmitter spectra, are provided for Frequency Shift Keying FSK, Four Phase Differential Phase Shift Keying 4PhiDPSK, and Pulse Code Modulation-Frequency Modulation PCM-FM modulation structures. These ratios are plotted as a function of the bandwidth of receivers whose performance may be degraded. Normalizations and generalizations are developed in order to reduce the required number of initial calculations and to enhance the use of the calculated data. Representative examples of how the calculated results may be used to reveal necessary equipment and system level limits on transmitter emission are discussed. Author
- Radiofrequency Wave Propagation
- Non-Radio Communications