The Design And Implementation Of Dual-band Digital Predistorter Based On FPGA

From a long-term point of view,communication technology has never been stopped developing.Voice communication as lower speed data communication and web,audio,video as higher speed data communication will be coexisting for a long period in the future.The multi-standards coexisting situation make a higher application for multi-bands communication system,especially dual-band communication system.In order to achieve that one power amplifier transmit dual-band signals concurrently,the concept of concurrent dual-band power amplifier is proposed.The linearity technology of the concurrent dual-band power amplifier has been on the agenda.The technology of digital pre-distortion has been received the most attention and has become one of major solutions to linearize power amplifier for its prominent advantages which are lower complexity and cost,higher efficiency and flexibility,easier to implement and more effective of linearization.So,it get a jump and become the mainstream linearity technology among numerous power amplifier linearization technology.Therefore,this paper is constrained on the technology of the concurrent dual-band digital pre-distortion,and the pre-distortion algorithm is realized on FPGA hardware logic.1.A new concurrent dual-band digital pre-distortion structure which introduces a novel model complexity reduction technique into system,namely,time-division multiplexing for out-of-band lookup tables sharing is proposed.With the comparison of the conventional signal-band DPD structure and the conventional 2D-DPD structure,the advantages,disadvantages and the scope of application situations of the concurrent dual-band digital pre-distortion structure with time-division multiplexing for out-of-band lookup tables sharing are summarized.2.The DB-DDR model which is representative of polynomial memory form was converted into one-dimensional lookup table form.The concurrent dual-band digital pre-distorter structure which employs time-division multiplexing for out-of-band lookup table sharing as basis.The design and implementation of concurrent dual-band digital pre-distorter of DB-DDR model with one-dimensional lookup table form was completed on the FPGA hardware.3.The 2D-MP model which is representative of polynomial memory form was converted into one-dimensional lookup table form.Due to the special form of 2D-MP model,the out-of-band pre-distorter was optimized part in the concurrent dual-band digital pre-distorter with out-of-band lookup tables sharing.Three kinds of optional optimization structure was proposed.The design and implementation of concurrent dual-band digital pre-distorter of 2D-MP model was completed on the FPGA hardware.4.The two kinds of models which are DB-DDR model and 2D-MP model have tested on the FPGA hardware in the last.The experimental results confirm that the DB-DDR model and 2D-MP model implemented on the FPGA hardware both have higher model accuracy and better pre-distortion effects.