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Digital Pre-distortion and Hardware Verification using SystemVue Application Note by Jinbiao Xu, Agilent Technologies Inc., EEsof EDA Introduction Power amplifier (PA) linearization using digital pre-distortion (DPD) techniques is critical for designers transitioning 3G systems to 3.9G and 4G. This application note introduces the concept behind DPD, as well as how to use the Agilent W1716 SystemVue DPD builder to do hardware verification. This software module implements memory polynomial algorithms to correct wireless components that have analog memory effects. Both simulation-based and test equipment-based extraction and verification are possible. For the purposes of this application note, SystemVue will be used with various Agilent test equipment, including the ESG/PSG/MXG family of signal sources and PSA/MXA/PXA family of analyzers. Digital pre-distortion Power amplifiers are essential components in the overall performance and throughput of communication systems, but they are inherently nonlinear. The nonlinearity generates spectral re-growth, which leads to adjacent channel interference and violations of the out-of-band emissions standards mandated by regulatory bodies. It also causes in-band distortion, which degrades the bit-error- rate (BER) and data throughput of the communication system. To reduce the nonlinearity, the power amplifier can be operated at a lower power (that is, "backed off") so that it operates within the linear portion of its operating curve. However, newer transmission formats, such as wideband code division multiple access (WCDMA) and orthogonal frequency division multiplexing (OFDM, 3GPP LTE), have high peak-to-average power ratios (PAPR); that is, large fluctuations in their signal envelopes. This means that the power amplifier needs to be backed off well below its maximum saturated output power in order to handle infrequent peaks, which result in very low efficiencies (typically less than 10%). With greater than 90% of the DC power being lost and turning into heat, the amplifier performance, reliability and ongoing operating expenses (OPEX) are all degraded. To maintain linearity and efficiency, one can apply linearization to the PA through