'PREDISTORTION FOR POWER AMPLIFIER LINEARIZATION IN FULL-DUPLEX TRANSCEIVERS WITHOUT EXTRA RF CHAIN'

FERNANDO GREGORIO; GUSTAVO GONZALEZ; JUAN COUSSEAU; TANELI RIIHONEN; RISTO WICHMAN

New orleans

Conferencia; ICASSP 2017; 2017

Genuine full-duplex operation requires effective mitigation of selfinterference(SI) due to simultaneous transmission and reception atthe same frequency band. In addition to its well-known harmful effecton signals of high peak-to-average power ratio, nonlinear behaviorof a power amplifier (PA) complicates SI cancellation andinduces spectral regrowth. We introduce a digital predistortion architecturethat linearizes the response of the PA in a full-duplextransceiver. Specifically, we propose a two-step procedure to estimatethe predistorter parameters and the SI canceller coefficients.Different from a direct application of conventional predistorters, theproposed architecture does not need an extra RF chain to estimatethe PA response and exploits the inherent SI signal instead. Finally,simulation results show that the proposed scheme is able to increasesignificantly the signal-to-interference-plus-noise ratio at thetransceiver output and to reduce out-of-band emissions when comparedto linear and nonlinear cancellation without predistortion.