Digital two-level PAM and analogue PWM hybrid optical fiber transmission systems for TV and data applications

We propose a novel optical fiber transmission system for supporting both digital and analogue communications in a very cost-effective fashion. The proposed system simultaneously uses a 2-level pulse amplitude modulation (PAM) for data communications and an analogue pulse width modulation (PWM) for TV applications. The principle of the 2-level PAM and analogue PWM hybrid scheme is presented, and its some distinguishing features are explained. Moreover, this proposed technique requires the same transmission bandwidth as a conventional analogue PWM scheme. Consequently, two different types of communication services can be transmitted over a common optical fiber channel by using the 2-level PAM and analogue PWM technique, without the use of wavelength- or frequency- or time-division multiplexing