MULTI-CHANNEL INFRARED CABLELESS COMMUNICATION SYSTEM

A system for simultaneously transmitting a plurality of audio signals into a transmission space from at least one transmission point to one or more reception points. The plurality of audio signals is inputted to an encoder. The encoder time-division multiplexes and samples the audio signals to generate an encoded pulse amplitude modulated signal. The encoded pulse amplitude modulated signal is converted into a corresponding encoded pulse position modulated signal. A sync pulse is then added to the encoded pulse position modulated signal to form an encoded composite signal. The encoded composite signal is broadcast into the transmission space as an optical signal, preferably in the infrared portion of the spectrum. The optical signal is received by at least one receiver located in the transmission space. Each of the receivers receives the optical signal and generates a received pulse position modulated signal. A portion of the pulse position modulated signal which contains a selected one of the plurality of audio signals is converted into a pulse amplitude modulated signal. The pulse amplitude modulated signal is then converted into a corresponding audio signal which is presented to a user. Preferably each receiver is completely portable and may be carried about by the user. The user preferably hears the selected audio signal by way of headphones included with the receiver. One particular application of the disclosed system is where verbal translation of a speaker's words must simultaneously occur in several languages and all of those translations are conveyed to listeners who individually select one of the translations to listen to.