Digital I&Q demodulation in array processing: Theory and implementation

Following the IF sampling strategy, a receiver is able to overcome inherent limitations of conventional I&Q demodulators, performing this operation in a completely digital manner. In this paper, IF sampling is analyzed both from theoretical and implementation points of view for the case of an antenna array based receiver. Both analysis are complementary and provide useful guidelines for the design of Software-Defined Radio receivers. The foundations of IF sampling strategy are presented and the design of all-digital I&Q demodulators is covered. Finally, an application to the design of a S-DMB receiver is also presented and FPGA implementation issues discussed.