In a system where different sample rates are running, there are times a Sampling Rate Converter is needed to convert one sampling rate to another. The idea of SRC is using the sequence of discrete time sampled at a certain input sampling frequency, and with some conversion technique, create a new sequence of discrete sampled at a different rate from the input. There are Synchronous and Asynchronous converters. Synchronous converters are those with a known input sampling frequency and conversion factor, where as Asynchronous converters are systems where the exact sampling frequencies are not known. The conversion process interpolates or decimates the input signal sampled at the input signal sampling rate to the desired signal at output sample rate. Figure 1-1 shows a Sampling Rate Converter model.

Figure 1-1 Sampling Rate Converter Model