Linc System Efficiency Wilkinson Synthesizer-based Optimization To Achieve

Digital multi-level modulation techniques and multi-carrier technology are employed in all standards of the 3rd generation communication system to improve spectrum efficiency. These techniques cause a sharp increase in signal PAPR and have a high demand of power amplifier linearity. LINC (LInear amplification using Non-linear Components) is a linear transmitter architecture. By separated the phase- and magnitude-modulated signal into two constant envelopes, this architecture evade the high demand of amplifier linearity and can employ high efficiently PA. Therefore the theoretical efficiency of LINC amplifier can achieve 100%. However in practical application, the system efficiency is determined not only by amplifier but also by combiner, the working characteristics of combiner will led the system actual performance much lower than theoretical efficiency.This paper has analyzed the characteristics of Wilkinson power combiner and proposed a system efficiency improvement project based on PAPR (Peak to Average Power Ratio) reduction techniques and non-single threshold SCS architecture. After mathematical reasoning and simulation analysis, concrete implementation scheme and system data structure have been established.In the PAPR reduction module, polar clipping scheme and cascade interpolation filter has been employed to reduce system hardware resource consumption. Pipeline technology and simplified look-up-table improved the PAPR reduction module and non-single threshold SCS module's signal processing speed and saved the system hardware resource consumption further. This paper adopted Verilog HDL as module design language. By simulation and adaptation, this architecture improved system efficiency successfully. According to the simulation and experimental results, this scheme could improve the system efficiency from 9.8% to33.05%.For the shortage of system hardware resource and the complexity of design, there were still something else have not been finished completely, for example the signal peak regeneration created by filter and how to reduce this effect etc. The next work of this paper is to further optimize the PAPR reduction module's structure to improve its performance.