Digital compensation in IF modulated upconversion software radio architecture

In the transmitter path of software radios a relevant problem is the upconversion of the baseband or IF signal with high image frequency suppression. For this purpose an up-converter based on a quadrature modulator has been developed utilizing a signal processing method for increasing the image sideband supression. A simplified system has been built to test this new method. For extending the posibble modulation types and bandwidth the development of digital modulation approach using a direct digital synthesizer is in progress.