The Complete Guide to Troubleshooting and Fine-Tuning Digital Predistortion (Download)
Digital predistortion (commonly known as DPD) is an algorithm widely used in wireless communication systems. DPD’s purpose is to suppress the spectral regrowth on the wideband signal that’s passed through the radio-frequency power amplifier (PA),1 thereby improving the PA’s overall efficiency.
In general, PAs have nonlinear effects and inefficiency when dealing with high-power input signals. The nonlinear effect and the spectral interferences are caused by the spectral regrowth to the neighbor bands. Figure 1 shows spectrum regrowth before and after DPD correction using the TETRA1 standard on the ADRV9002 platform. The ADRV9002 offers an internal, programmable, and power-optimized DPD algorithm that can be customized to correct the nonlinear effect of the PA, thus improving the overall adjacent channel power ratios (ACPR).