Spread-Spectrum In-Band Interference Mitigation Techniques using N-Path Mixer-First Designs

Mixer-first N-path filters have shown significant success in rejecting out-of-band jammers before entering the active receiver signal path. In this talk we will focus on the use of mixer-first N-path filters for in-band jammer rejection. In particular, we will explore the use of spread-spectrum N-path filter based systems to reject in-band jammers. In one implementation, Walsh code domain N-path filters have been used to provide close to 40dB of self-interference rejection. We also consider implementations of direct-sequence spread spectrum techniques to provide over 20dB of high-power jammer rejection using the inherent processing gain of such a system. Finally, we will focus on the use of N-path filters for ultra-fast hopping transceiver that provide processing gain and jammer rejection of in-band jammers.