Concurrent dual-band digital predistortion

With a power amplifier (PA) being able to support widely separated frequency bands, dual-band digital predistortion techniques have been proposed as an efficient alternative to traditional wideband digital predistortion by only compensating nonlinear distortions around the signal bands of interest. In this paper, we provide theoretic analysis of the connection between wideband and dual-band memory polynomial models and propose two efficient implementation schemes based on lookup tables. Performance was evaluated with an experimental test setup using a symmetric Doherty PA and a dual-band signal (10 MHz LTE and 2-carrier WCDMA) with 97 MHz center separation. Drain efficiency of 31% was achieved with 41.2 dBm output power and both bands meeting −45 dBc ACLR requirement.