PROJECT TITLE :

Digital Mitigation of Transmitter-Induced Receiver Desensitization in Carrier Aggregation FDD Transceivers

ABSTRACT:

Carrier aggregation transmissions in frequency division duplexing devices reduce the duplexing distance between the transmitter (TX) and receiver (RX) bands. As a consequence, the spurious intermodulation distortion product created by the nonlinear RF front-end of the TX could easily extend over to the RX band, potentially inflicting own RX desensitization. In this paper, we propose an efficient and computationally possible adaptive digital identification and cancellation technique to mitigate the RX desensitization. We initial show that the spurious leakage signal at own RX band depends on a similar leakage channel that models the signal leakage path as well as the TX nonlinearities, duplexer filter responses, and RX path. The parameters of the equivalent leakage channel can be efficiently estimated with the smallest amount squares or the recursive least squares algorithm, using the particular digital transmit knowledge as a reference, and then used to regenerate and cancel the leakage interference from the received signal. The performance of the proposed technique is evaluated with extensive laptop simulations, furthermore as with practical real-world RF measurements, demonstrating excellent calibration properties with up to 19-dB improvement in singal-to-interference plus noise ratio of the required received signal.