根据三基色(RGB)LED 合成白光的特点,提出一种改进的脉冲位置调制(CPPM)方式。首先从理论上对CPPM调制带宽进行分析,然后应用Optisystem软件分别对CPPM、OOK及脉冲位置调制(PPM)在平均功率相同的情况下的调制系统,在不同传输距离、速率及背景光条件下的误比特率和眼图进行了仿真,结果表明,CPPM调制比其它调制更有优势。
The paper propose an improved pulse position modulation (CPPM) according to the white source characteristic of red,green and blue(RGB) LED. Firstly, we theoretically analyze modulation bandwidth of the CPPM. Then using Optisystem software to make experiment simulation modulation system platform under the same average power for CPPM,OOK and pulse position modulation(PPM) to compare those system's bit error rate and eye diagram at different transmission distance、rates and background light. The results show that the CPPM modulation has more advantages than others.