Digital Predistortion of Power Amplifiers for Spectrally Agile Wireless Transmitters

There is a "Digital Divide" between rural and non-rural residents. A major initiative in bridging this gap is the approval of rules for the use of television white spaces (TVWSs) by the Federal Communications Commission (FCC). The IEEE 802.22 standard provides guidelines for utilizing these TVWS channels while protecting the incumbent user's rights. However, due to the high peak-to-average-power ratio (PAPR) of orthogonal frequency division multiplexing (OFDM)-based IEEE 802.22 signals, the power amplifier (PA) in the transmitter RF chain is operated in its saturation region, causing signal clipping and hence, spectral leakage in the adjacent channels. To combat this issue, we propose a novel, computationally fast approach for digital predistortion (DPD) of the PA in spectrally agile wireless transmitters such that the RF mask is complied with.