Chapter 3 introduces the other three modulation schemes , including OOK , DPPM and DH-PIM , their performance are compared , simulated and analyzed .

第三章介绍了其它三种调制方式：开关键控调制OOK、差分脉冲位置调制DPPM、双头脉冲间隔调制DH-PIM，并对这几种不同调制方式的性能进行了比较和仿真分析。

The hardware sub-system of the transmitter and the receiver includes the modules of FEC coding and decoding , DPPM modulation and demodulation , signal deserialization module and time slot synchronization .

发射机和接收机硬件子系统的包括FEC编解码，DPPM调制解调，信号的串并转换模块以及时隙同步等模块。

Six Sigma with statistical tools is valuable for quality improvement and together with the Six Sigma vision of “ Customer Loyalty ” and3.4 dppm quality goals forms an effective company quality policy .

六西格玛的数据分析工具对提高质量工作是相当有效的，而且通过用户至上的原则和每百万产品3.4件残次品的标准可以有效建立全员质量意识。

Simultaneously , a theoretical analyses and research of the implementations of an Forward Error Correction ( FEC ) sub-system and a Differential Pulse Position Modulation ( DPPM ) sub-system are done in this paper .

同时本文对前向纠错（FEC）编码和差分脉冲位置调制（DPPM）子系统的实现做了详细理论分析研究。

3 ) By the description on the PPM theory of the atmosphere laser emergency communication system and the comparison to the L-PPM , DPPM and multiple pluse PPM , the thesis proposes the scheme of the L-PPM modulator and demodulator .

并对L-PPM、DPPM、多脉冲PPM这三种脉冲位置调制进行了比较，给出了大气激光通信系统中单脉冲PPM调制器和解调器的设计方案。