A spectral method of digital I Q conversion

This paper develops a digital method of in phase (I) and quadrature (Q) conversion using techniques similar to those in the classical analog method. It uses a graphical method of representing the spectra of the processed signals that gives an intuitive feel for the process. It shows that while a sample rate of twice the bandwidth of the input signal is required, the computational complexity is reduced by a higher sample rate. The graphical technique gives insight into the filtering, IF frequency and sample rate requirements.