Feedforward power amplifier linearization for 4G basestation

Currently Third and Fourth Generation (3G/4G) cellular communication and broadband wireless systems (WiMax) are emerging as the universal standard for mobile telecommunications. These systems provide anytime anywhere wireless data and voice coverage. Since these systems rely on wide bandwidth to accommodate the required high data rate, the hardware and signal processing involved in the transmitter equipment becomes a challenge. One particular challenge is the design of the 3G/4G base-station transmitters and its associated non-linear power amplifier. These amplifiers are highly non-linear, thus to overcome the stringent linearity requirements, various hardware and signal processing linearization schemes have been used. This paper presents one method for linearizing the transmitter power amplifier by means of digital baseband signal processing. This method boosts the power amplifier efficiency using baseband feed forward linearization. The proposed transmitter hardware architecture and the digital signal processing algorithms proposed here are analyzed analytically first, then their performance is verified using computer simulations.