Analysis of Out-of-Band Interference from UWB Signals to IRNSS Signals

IRNSS (Indian Regional Navigation satellite System), an innovation by ISRO has accuracy range of 20 meters in position and provides accurate Navigation. The standard Positioning service offered by IRNSS is an unauthorized service and it is transmitted on L5 and S bands respectively. IRNSS will be one of the most public availed applications and plays vital role in many technological advancements of India. MB-OFDM UWB has its wide applicative expansion in communications as indoor short-range high-speed wireless communication. It is more efficient, provided its high peak to average power ratio (PAPR) problem is optimized and distortions caused by non-linear components like high power amplifier (HPA) are eliminated. The technique used for PAPR reduction, the deliberate clipping causes spectral leakage, which in turn causes interference with other systems outside the frequency bands of UWB. Hence there is intense need to eliminate interference to IRNSS caused due to spectral leakage of UWB. In this paper, the interference to IRNSS signals from MB-OFDM UWB signals is analyzed and effect of filtering after clipping on the spectral leakage is evaluated using power spectral density as performance measure.