Complex gain and fixed-point digital predistorters for CDMA power amplifiers

Two digital baseband predistortion techniques, one based on the complex gain digital predistorter (CGDP) approach and the other based on the fixed-point predistorter (FPPD) approach, are used to compensate a nonlinear high-power amplifier (HPA) in an IS-2000 system. Forward-link performance for a perfectly linear HPA, nonlinear HPA, and compensated HPA using both a CGDP and an FPPD are compared using an IS-2000 forward-link simulator. Both predistortion techniques are shown to provide similar forward-link performance and reduction in spectral regrowth of the sidebands for the wide-band compensated HPAs utilized by IS-2000 systems.