Time Division Pulse Modulation
Original Publication Date: 1986-Jun-01
Included in the Prior Art Database: 2005-Mar-09
This article describes a time division pulse modulation (TDPM) method for infrared packet transmission. Several known methods exist for encoding data bits for transmission on various physical media. Among these techniques are the Manchester, non-return to zero (NRZ), NRZ inverted (NRZI) and group encoding. The method disclosed herein lowers the power consumption and increases the distance and data rate of infrared packet switched transmissions. With TDPM one light pulse encodes 4 bits (a nibble) of information by measuring the time between adjacent pulses. Referring to the pulse illustration of Fig. 1, given that the last pulse already occurred and used up 1000 ns for the LEDs to turn on and off, the next pulse begins at one of 16 allotted slot times.