A novel iterative digital down converter

The digital radio receivers often have fast analog to digital converters delivering vast amount of data. However, in many cases, the signal of interest represents a small proportion of that bandwidth. A digital down converter (DDC) is a filter that extracts the signal of interest from the incoming data stream. In this paper we first introduce an algorithm based on FFT which can be applied for simultaneous frequency shifting and decimating of intermediate frequency (IF) band signals, then a simplified iterative algorithm is suggested to improve the quality of reconstructed baseband signal.