Frequency planning for multi-frequency sub-sampling receiver and its application for UMTS/WLAN and GNSS receivers

Communication devices market becomes more oriented to multi-purpose devices supporting multi-standards simultaneously. This market trend creates a demand for receivers with ability to receive multi-frequency signals. Besides, we need to save chip cost, area, and power consumption. Direct conversion sub-sampling receiver architecture is one of the most suitable candidates for multi-standard reception. However, Frequency planning of such receiver is an indirect and critical process. A proposed systematic methodology is presented to obtain the optimum sub-sampling frequency. Two specific case studies are highlighted. A UMTS/WLAN receiver is studied and the optimum sub-sampling frequency for reception is obtained to be 595MHz. The proposed technique is validated and compared to previously published work. A similar test case is applied to GNSS (GPS/Galileo) signals. The optimum sub-sampling frequencies are calculated and compared to other works.