The analysis and design of RF sub-sampling frontend for SDR

Radio frequency (RF) sub-sampling theory enables one to convert the RF frequency down to baseband, which is a significant technique in software defined radio (SDR). Based on this, a RF sub-sampling frontend for SDR is designed and verified by hardware platform. The effect of jitter, ADC resolution and folding noise which are the dominating error sources degrading signal-to-noise ratio (SNR) in digital frontend (DFE) were considered. A method of SNR measurement is presented and performed. The results of experiment indicate that the three noise sources are sufficient to estimate the performance of RF sub-sampling frontend and matches with theoretical analysis with reasonable accuracy.