基于FPGA的两种PPM调制对比分析

The Contrastive Analysis of Two PPM Modulations based on FPGA

为了分析调制系统效率与资源耗费的矛盾问题,设计了两种PPM调制系统,即系统A与系统B。系统A每次对两位二进制进行PPM调制,即先对输入的数据进行串并转换,每次并行输出两位数据,将输出的数据与时隙计数值进行比较,相等时输出一个脉冲。系统B则是对每位二进制进行独立的PPM调制,即先进行数值变换,用两位二进制代表一位数据信息,然后将转换后的两位二进制与时隙值进行比较,相等时输出一个脉冲。从时序仿真、功耗与资源占用结果对比可得:在50MHz的时钟下,本设计的两种调制系统均能对输入数据进行PPM调制,且系统B比系统A的总功耗少0.26mW,总逻辑单元少占用95个,但效率下降50%。

In order to analyze the contradiction between efficiency and resource consumption of modulation system, two kinds of PPM modulation systems, which are system A and system B, were designed in this paper. The System A carries out PPM modulation on two binaries at a time.That is to say, Firstly, the input data were performed serial to parallel converter and two bits of data were output in parallel each time, and the output data was compared with the time slot count value, and one pulse was output when they are equal. The System B carries out PPM modulation for each bit of binary, that is to say, Firstly, numerical transformation, which using two bits of binary representing a bit of data information, was performed, and then the two converted binary was compared with the time slot value,and then a pulse was output when they are equal. Through comparing the results of time series simulation, power consumption and resource occupancy, it can be concluded that the two modulation systems designed in this paper can achieve PPM modulation for the input data under the clock of 50 MHz, and for the system B, the total power consumption is 0.26 mw less and the total logic unit occupies 95 fewer than system A, but the efficiency decreases by 50%.