A Direct IQ-Regeneration Technique for Five-Port Digital Receiver

Many papers have been proposed in order to demonstrate that the multi-port system. The main advantage of the multi-port system is the frequency direct conversion. However, this kind of system must be calibrated for each frequency in order to demodulate the exact inphase (I) and quadrature (Q) signal transmitted and further be compensated to the path errors of multi-port. But, this paper is to show the new method to recover the wanted signals without calibration and iteration procedure to update the information. This technique uses the least square solution using pseudo inverse caused to the singular value decomposition (SVD) receiving matrix of multi-ports. The pseudo-inverse operation can separate desired branches from the observation of multi-port output and this method is introduced in this paper. Also, this paper shows the full digital five port receiver which uses the only digital processor applied the down sampling conception to be low the carrier frequency sampling rate. Except the antenna and low noise amplifier of the analog signals at front-end of the system, this system is consists of the digital five-port network and digital signal processing (DSP) sections. Ultimately, the target of this system is on software defined radio (SDR) system implemented down sampling method and regeneration skill of I and Q signals.