Intensity modulation with direct modulation (IM/DD) favors low duty cycle modulation schemes such as pulse position modulation (PPM) and multiple PPM(MPPM).In this paper,the channel model over IM/DD is introduced. Then, a brief summary is given about some of the modulation techniques used in this area. Finally, some of the pulse position based coded modulation techniques are rewiewed.

In underwater wireless optical communication links, pulse position modulation (PPM) and differential pulse position modulation (DPPM) are two typical modulation schemes. In this paper, we present an alternative modulation scheme to improve the communication performance compared with the traditional methods. As an improvement of DPPM, this new modulation scheme, which named as polarization diffe...

Wireless optical communication is the current research topic in high data rate data communication area.It is under research to utilize in under water sensor network communication and free space optical communication. Mainly PPM modulation scheme is used in FSO because of it high power efficiency ,transmission efficiency and strong anti jamming capability. One of the key difficulties of implemen...

The main purpose of Pulse-Width –Modulation (PWM) technique in power inverters is to control the output voltage. The most familiar techniques: uniform-pulse-width-modulation and sinusoidal-pulse-width-modulation. A Small Boundary-Pulse-Width (SBPW) technique for improving the inverter performance is proposed. The new method is based on pulse-width technique. Varied pulse-widths for the middle a...

Sinusoidal pulse width modulation is a popular modulation for most alternating current induction motor. It only requires fewer calculations and is easy to implement. However, the shortcomings of using it are low DC voltage utilization, and poor inverter transmission capability. In recent years, there is an increasing trend and more research concentration of using space vector pulse width modula...

In this paper we propose a suitable reference wave for Pulse Width Modulation (PWM) AC Drives. Staircase reference waves whose levels are calculated to eliminate certain harmonics are studied and a certain staircase reference waveform with L levels is constructed. When L is made very large in limit, this staircase waveform approaches a continuous one which is called Quasine (Quasi + Sine). This...