WCDMA uplink modulation scheme evolution and transmitter implementation

The evolution of a WCDMA uplink modulation scheme is presented. Modulation schemes are analyzed from the power amplifier implementation point of view by comparing the RF envelopes of various modulation schemes. The power amplifier linearity requirements of different modulation schemes are compared using a measured class AB power amplifier. One of the challenges in WCDMA is the implementation of the transmitter for a WCDMA terminal supporting both speech and high-speed data. This paper proposes a transmitter architecture for optimizing the current consumption of the WCDMA terminal in both modes.