• Journal of the Korea Institute of Information and Communication Engineering
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• v.22 no.12
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• pp.1684-1690
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• 2018

A new digital pre-distortion (DPD) technique for closely spaced dual-band signals is proposed. In the system under consideration, dual-band signals are amplified by a single broadband power amplifier (PA) at a transmitter. The PA output is distorted by cross-modulation between the two bands as well as their own inter-modulation distortion. Especially, if the two bands are placed in close proximity to each other, their spectral regrowths due to in-band intermodulation overlap with each other, which degrades DPD performance. To solve this problem, we propose a new DPD technique where the dual-band PA characteristics are estimated first, and then the DPD parameters are obtained from the estimated PA characteristics. By finding the DPD parameters through two steps, pre-distortion can perform well for the closely-spaced dual band signals. The proposed technique is verified through computer simulation. Simulation result shows that the proposed method performs better than the conventional method for closely-spaced dual band signals.