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A BROADCAST DATA TRANSMISSION AND DISPLAY SYSTEM

IP.com Disclosure Number: IPCOM000006304D
Original Publication Date: 1991-Dec-01
Included in the Prior Art Database: 2001-Dec-21
Document File: 2 page(s) / 109K

Publishing Venue

Motorola

Related People

Juan C. Santiago: AUTHOR

Abstract

This publication describes a system which provides the means for transmitting digital data to a large num- ber of radio receivers using existing commercial broad- cast stations and existing radio channels. The system embeds digital data on to regular analog commercial radio programming, which has substantial coverage in most commercial and consumer markets. The digital encoding is done at sub-audible frequencies, which makes the system compatible with existing technology and radio receiving equipment.

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MOTOROLA INC. Technical Developments Volume 14 December 1991

A BROADCAST DATA TRANSMISSION AND DISPLAY SYSTEM

by Juan C. Santiago

  This publication describes a system which provides the means for transmitting digital data to a large num- ber of radio receivers using existing commercial broad- cast stations and existing radio channels. The system embeds digital data on to regular analog commercial radio programming, which has substantial coverage in most commercial and consumer markets. The digital encoding is done at sub-audible frequencies, which makes the system compatible with existing technology and radio receiving equipment.

  The system consists of a computer, a low-pass filter, and an audio summer on the transmitting end, and a special receiver on the receiving end. The information is generated by either the station itself or a separate infor- mation or news service, and entered into the computer at the station site. The purpose of the computer is to buffer the data and to provide the flexibility of special software features. These features might include message repeat at pre-defined time intervals, station identifica-

tion, and for the case of a news service, to insert a spon- sor's message between news items.

  After the data is buffered and perhaps rearranged by the computer, it is low-pass filtered, added to the regular analog voice information from the station, and sent over the air. The digital information from the computer is encoded as a ten (IO)-bit-per-second data stream and passed through an analog filter with a cutoff frequency of twenty (20) hertz. This fre- quency is below the human audible range, therefore making this system compatible with existing radio receivers tuned to the transmitting station. A ten (IO)-bit-per-second stream will allow the transmis- sion of a ten (IO)-bit character every second. Out of these, eight (8) bits could be used for the character itself (ASCII), and the remaining two bits could be used for error correction or control information. Figure I highlights the main components of the sys- tem at the transmitting site.

Analog Voice Audio From Station

1

Existing Equipment 14 *I

~-jL-i

(( 1)
.-A

Low-Pass Audio AMorFM Power Broadcast Filter Summer Modulator Amplifier Antenna

Figure 1.

Data Entry

c- Motorola. 1°C. ,991 67

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MOTOROLA INC. Technical Developments Volume 14 December 1991

  The Receiver/Display consists of a radio recei...