Strong jamming signals from colocated transmitters can cause intermodulation and desensitization in receiver circuits. Cancellation circuits can remove interference but generate noise and distortion of their own. We analyze such a system using a signal-to-interference-and-noise ratio (SINR) measure. We show that the cancellation coupler can be optimized to maximize the SINR. The optimum coupler value is proportional to the expected level of the jammers. A hardware prototype reduced the jammers by 46 dB in a controlled experiment and by 25 dB in an over-the-air experiment. A convergence time of 8.4 ms was sufficient for this application.
展开▼
