Interference robust SDR FE receiver

Abstract

Research on Dynamic Spectrum Access (DSA) has focused to a large extent on the reliable detection of signals at very low power levels, possibly even under the noise floor. However, many of those channels that are detected to be free are adjacent to used channels, with possibly very large power levels. As a result, the true DSA problem is not only reliable detection of free bands, but also robust operation next to used bands. In this demo we demonstrate an SDR RFIC which is robust against outof-band interference. This robustness is achieved by improving the linearity of the SDR receiver significantly. The need for robustness is demonstrated in real time by showing the received constellation diagram of an 802.11af-like OFDM signal in the presence of a large out-of-band interferer. The wanted and interfering signal are received simultaneously by two generations of SDR RFIC's, showing both the performance degradation caused by interference from adjacent bands and the improvement enabled by the robust receiver.I.