Computer system incorporating an infrared link for reduced interference communication with a radio transceiver

• US 5,734,487 A
• Filed: 07/29/1996
• Issued: 03/31/1998
• Est. Priority Date: 06/30/1994
• Status: Expired due to Term

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Compaq Computer Corporation (HP Inc.)
• Inventors: Rossi, Markku J.
• Primary Examiner(s): Robertson, David L.
• Application Number:
  US08/681,670
• Time in Patent Office: 610 Days
• Field of Search: 455/41, 455/89, 455/90, 455/575, 359/124, 359/145, 359/146, 359/172, 359/133
• US Class Current: 398/115
• CPC Class Codes: G06F 13/385 for adaptation of a particular data processing system to different peripheral devices
• CPC Class Codes: H04B 1/38 Transceivers, i.e. devices in which transmitter and receiver form a structural unit and in which at least one part is used for functions of transmitting and receiving

Abstract

Two units are disclosed, one of which is installed in the computer and one of which is located remotely and includes the antenna and radio frequency transmitter and receiver elements. The two units communicate over an infrared (IR) link. The data is transmitted between the two units as real and imaginary components using separate IR signals. By using real and imaginary digitized signals, great flexibility is provided as to the actual contents and protocols capable of being utilized and serial digital data can be provided from the computer and received in the computer using only simple table look-ups. The antenna unit includes personalization byway of differing filters and software to allow it to operate with a plurality of radio channels and protocols. Each unit has a serial number to identify itself and to keep a communication link secure once established. The IR link is established by hitting an initialization switch on each of the two units, at which time they commence transmitting their serial numbers and an acknowledgement process occurs. Once this initialization has occurred and both units have registered the other unit, only communications from the proper serial number provider are accepted. After the initialization phase, data and commands are sent between the two units in a packetized structure which allows error checking as necessary.

Claims

1. A computer system communicating by infrared light with a remote radio frequency transceiver, the computer system comprising:

a data bus;

a serial communication interface device coupled to said data bus;

a microcomputer, coupled to said serial communication interface device, for providing and receiving serial data streams; and

a computer system transceiver circuit coupled to said microcomputer for infrared communication with the remote radio frequency transceiver, said computer system transceiver circuit comprising;

first and second infrared (IR) light emitting diodes (LEDs) having different IR wavelengths from each other for sending digital data streams to the remote radio frequency antenna;

first and second IR photodetectors responsive to received wavelengths of infrared fight from the remote radio frequency transmitter and forming signals therefrom;

transmitter conversion circuitry for converting a data stream received from said microcomputer to real and imaginary component digitized streams for provision to said first and second IR LEDs, respectively; and

receiver conversion circuitry converting signals formed by said first and second IR photodetectors into real and imaginary digitized streams, respectfully, of digital data for provision to said microcomputer.

2. The computer system of claim 1, wherein said transmitter conversion circuitry converts said digital data stream to said real and imaginary component digitized streams representative of an analog waveform sent by an analog modem.

3. The computer system of claim 1, wherein said computer system is assigned a serial number and wherein said real and imaginary component digitized streams are provided to the remote radio frequency transmitter in a packet including said serial number.

4. The system of claim 3, wherein said computer system further includes initialization circuitry that provides said serial number to the remote radio frequency transmitter during initialization of said digital transceiver circuit, said initialization circuitry also cooperating with the remote radio frequency transmitter to receive a second serial number identifying the remote radio frequency transmitter, and wherein said receiver conversion circuitry converts said real and imaginary component digitized streams only if the serial number of a received packet matches said second serial number.

5. The system of claim 4, wherein said initialization circuitry includes a switch operable to commence operation.

6. The computer system of claim 1, wherein said serial communication interface device is a universal asynchronous receiver and transmitter (UART).

7. The computer system of claim 1, further comprising a memory device coupled to said microcomputer for providing minimal operating routines to the microcomputer during system initialization and for receiving additional operating routines from other portions of the computer system.

8. The computer system of claim 1, further comprising a memory device coupled to said digital transceiver circuit for receiving and storing information for controlling the conversions of the real and imaginary component digitized streams.

9. The computer system of claim 1, wherein said microcomputer and said computer system transceiver circuit are incorporated on an expansion bus card.

10. A computer system communicating by infrared light with a remote radio frequency transceiver, the computer system comprising:

a data bus;

a serial communication interface device coupled to said data bus;

a microcomputer, coupled to said serial communication interface device, for providing and receiving serial data streams; and

a computer system transceiver circuit coupled to said microcomputer for infrared communication with the remote radio frequency transceiver, said computer system transceiver circuit comprising;

first and second infrared (IK) light emitting diodes (LEDs) having different IR wavelengths from each other for sending digital data streams to the remote radio frequency antenna;

first and second IR photodetectors responsive to received wavelengths of infrared light from the remote radio frequency transmitter and forming signals therefrom;

transmitter conversion circuitry for converting a data stream received from said microcomputer to digital data streams representative of real and imaginary components of analog signals sent by an analog modem, said digital data streams being provided to said first and second IR LEDs, respectively; and

receiver conversion circuitry converting signals formed by said first and second IR photodetectors into real and imaginary digitized streams, respectfully, of digital data for provision to said microcomputer.