Abstract
In conventional systems of pulse-code modulation (PCM), the signal is sampled at a constant frequency, and pulse groups representing the signal amplitude are transmitted. The sampling frequency has to be related to the highest frequency in the signal; consequently, the sampling frequency is higher than is necessary during those times when the signal contains low frequencies resulting in the under-utilization of the transmission bandwidth.A new system has been developed, "PULSE TIME-CODE MODULATION" (PTCM) in which the sampling frequency is varied to suit the requirements of the signal. As a result, the number of samples to be transmitted over a period is reduced and a narrower bandwidth can be used. In the system investigated, a time delay of the signal is inevitably introduced and this may be a disadvantage in some applications.
Date of Award | 1978 |
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Original language | English |
Awarding Institution |
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Keywords
- pulse time-code modulation system