A Bi-objective Optimization Algorithm to extend the Clean Bandwidth of All Digital Transmitters

A novel bi-objective optimization algorithm to extend the clean bandwidth of radio frequency all digital transmitter(ADTx) is proposed and investigated in this paper. Owing to the inband quantization noise of pulse coding, a limited clean bandwidth (CBW) can be got. It will increase the design difficulty of the analog filter significantly. The bi-objective optimization algorithm can not only reduce the in band noise, but also achieve maximum bandwidth, using two point optimization. Simulation results show that for a carrier frequency of 345MHz, a symbol rate of 2Msps and a 16QAM signal with PAPR of 4.7dB, the CBW can be widely extended. And it should select the suitable ε to increase CBW and ensure the quality of the signal according to the system requirements. The experiment is carried out by Xilinx ZC706 FPGA. Experiment results show that the EVM of RF pulse signal is about 1.9%, and the CBW is about 25% bandwidth of the center frequency. As the level adopted is only two in this paper. If more levels are adopted, the CBW will be widely extended.