An adaptive weaver architecture radio with spectrum sensing capabilities to relax RF component requirements

This paper presents an architecture that utilizes spectrum sensing with a Weaver architecture receiver to ease the requirements on the RF front-end components. With the ability to sense the environment, large interferers that overwhelm small desired signals can be avoided. The learning and adapting capabilities are enabled by means of a flexible receiver architecture employing variable local oscillators (LOs) at RF and intermediate frequency (IF). Avoiding large interferers can reduce image rejection ratio (IRR) requirements for a given performance and results in a greater tolerance to the Q of filters and receiver mismatches. The design approach is applied to an IEEE 802.11a receiver and the results show that for a given performance level, the proposed design requires an IRR that is 40 dB less than that required for conventional Weaver receivers