Digital cancellation technique to mitigate receiver desensitization in cellular handsets operating in carrier aggregation mode with multiple uplinks and multiple downlinks

Abstract

Recent explosive growth in uplink and downlink carrier aggregation in cellular networks is leading to severe desense in receivers for deployment of certain band combinations. In this paper, we studied receiver desense caused by 2nd order nonlinearity of components in the signal chain. A practical case of two (bands 3 and 8) uplink aggregation and three (bands 3, 8 and 26) downlink carrier aggregation was considered to demonstrate greater than 20dB desense in band 26 receiver despite using state of the art frontend components including linear diplexer with IIP2 greater than +90dBm. We developed a digital cancellation technique that is capable of achieving greater than 20dB improvement in signal-to-interference-plus-noise ratio for 10MHz LTE signals.