Compensation of timing offset and frequency offset in multi-band receiver based on RF sub-sampling

Abstract

In software defined radio, the analog-to-digital converter (ADC) should be placed as close to antenna as possible. But current technique actually can't do analog-to-digital conversion from RF band signals. So, one method has been studied to sample RF band signals to IF band. As one of the ways, sub-sampling technique can convert signals from RF band to IF band without oscillator. If sub-sampling technique is used, multiple bands can be converted from RF band to IF band. But due to the filter performance in RF band, it is possible that interference is generated between signals that are converted in low frequency band. The effect degrades performance. In this paper, we propose one method that uses time division multiplexing (TDM) method as a solution to avoid interference between signals. By doing TDM and sub-sampling at the same time the method can get signals without large changes from the existing structures.