Digital Data Transmission in a Pulse Amplitude Modulation (PAM) Communication System

摘要

This report presents the results of an experimental evaluation of the effectiveness of digital data transmission in a pulse-amplitude modulation (PAM) communication system. Some sources of PAM system errors are discussed to clarify the nature of the problem. A PAM communication system was simulated and equipment was developed to obtain experimental results indicative of PAM's effectiveness in transmission of digital data. The results consist of word channel, and bit error probability curves for different numbers of digital bits per PAM channel. The digital bits are converted to analog voltage levels selected PAM channels. After decommutation, the digital bits are recovered from the analog voltage levels. The data indicates that the number of bits per channel should be 4 or less with 4 being marginal depending upon the digital data quality requirements. The error probability curves can be used to determine whether or not a specific PAM communication system can telemeter digital data within given constraints. In addition, the results provide guidelines for the implementation of digital data in a PAM system. (Author)