Asynchronous Sampling Rate Conversions in Digital Communications Systems

Abstract

The problem of resampling digital signals at an output sampling rate that is incommensurate with the inputsampling rate is the topic of this paper. This problem is often encountered in practice, as for example in the multiplexingof video signals from different sources for the purpose of distribution. There are basically two approaches to resamplethe signals. Both approaches are thoroughly described and practical circuits for hardware implementation are provided.A comparison of the two circuits presented in the paper shows that one circuit requires a division to compute the newsampling times. This time scaling operation adds complexity to the implementation with no performance advantage overthe other circuit, and makes the division free circuit the preferred one for resampling.