ENCODING BY TIME RATIO DISCRIMINATION

Time ratio discrimination (TRD) is also known as pulse width modulation (PWM). Despite coding taken as spacing between the pulses, the width of the pulses is taken here for identification of binary notation. Therefore, every bit of transmitted word is allocated a period of time within which the burst of ultrasound representing the bit must be transmitted. The actual duration of the transmitted bit is then expressed as a percentage of the allocated bit period, and the different percentages which result are used to represent binary-0 and binary-1.

The Philips SAA–05000A type remote-control transmitter is based on time ratio discrimination type of signal encoding. The principle of TRD is illustrated in Fig. ...

Get Consumer Electronics now with the O’Reilly learning platform.

O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.