摘要
为了驱动后级开关功放,全数字发信机需要利用数字射频调制器将输入信号转换为相应的脉冲序列信号.针对现有脉宽调制(PWM)和Delta-Sigma调制(DSM)策略在调制性能及系统实现方面存在的不足,本文利用面积等效原理提出一种新的数字射频调制策略.理论分析和仿真结果表明,本文策略相比PWM和DSM,不仅简化了硬件实现难度,而且能够获得更优的带内SNR和编码效率性能.
In order to drive the switched mode power amplifier(SMPA) for full-digital transmitter,the input Radio Frequency(RF) signal of full-digital transmitter first needs to be transformed into pulse sequences by using the digital RF modulator.Considering the disadvantages in modulation performance and system realization of existing digital RF modulation strategies,especially the Pulse Width Modulation(PWM) and Delta-Sigma Modulation(DSM),a digital RF modulation strategy was proposed and analyzed in this paper by using the area equivalent theory.The theoretical analysis and simulation results show that,compared to the PWM and DSM,the proposed modulation strategy not only reduces the hardware implementation difficulty,but also achieves better performance of the SNR and coding efficiency.
引文
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