Simultaneous analog and digital communication applications

• US 5,537,436 A
• Filed: 06/14/1993
• Issued: 07/16/1996
• Est. Priority Date: 06/14/1993
• Status: Expired due to Fees

• Current Assignee: Rembrandt Communications LP (Rembrandt IP Management, LLC)
• Original Assignee: AT&T Corporation (AT&T, Inc.)
• Inventors: Davis, William R., Roberson, D. Randy, Bremer, Gordon, Chapman, Joseph Q., Ko, Kenneth D., Smithwick, Luke J., Smith, Richard K., Bottoms, Stanley
• Primary Examiner(s): Chin, Stephen
• Assistant Examiner(s): GHEBRETINSAE, TEMESGHEN
• Application Number:
  US08/076,520
• Time in Patent Office: 1,128 Days
• Field of Search: 375/8, 375/5, 375/39, 375/38, 379/93, 379/97, 379/98, 379/99
• US Class Current: 375/222
• CPC Class Codes: H04J 7/00 Multiplex systems in which the amplitudes or durations of the signals in individual channels are characteristic of those channels
• CPC Class Codes: H04L 27/18 Phase-modulated carrier systems, i.e. using phase-shift keying H04L27/32 takes precedence
• CPC Class Codes: H04L 27/3483 using a modulation of the constellation points

Abstract

A number of arrangements and methods that achieve concurrent communication of analog information and digital information. In general terms, when the communication channel is viewed as a multi-dimensional space, the digital information signal is divided into symbols, and the symbols are mapped onto the signal space with a preset distance between them. The analog signal, generally limited in magnitude to less than half the distance separating the symbols, is converted to component signals and added (i.e., vector addition) to the symbols. The sum signal is then transmitted to the receiver where the symbols are detected and subtracted from the received signal to yield the analog signal components. The transmitted analog signal is recreated from those components. Arrangements utilizing the above principles are applications where systems that include a digital port can benefit from an analog communication channel, and conversely, where systems that include an analog port can benefit from a digital communication channel.

Claims

1. A modem system comprising:

a signal mapper having digital symbols applied to the mapper at a digital port and analog signal samples applied to the mapper at an analog port, for developing mapper output signals that represent the digital symbols and the analog samples;

a modulator, responsive to the signal mapper output signals, for developing a modulated output signal at an output port of the modulator representable by a N-dimensional signal space that is composed of a plurality of N-dimensional sub-spaces, where

N is an integer greater than 1,

the sub-spaces are areas when N is 2 and volumes when N is greater than 2,

a predetermined point in each of the sub-spaces being associated with a predetermined digital symbol applied to said mapper in each of the N dimensions, with a zero level analog sample in each of the N dimensions, and other points in each of the volumes associated with the predetermined digital symbols in each of the N dimensions and a non-zero level analog sample in at least one of the N dimensions, and

the analog samples in each of the N dimensions form a mutually exclusive set; and

means for coupling the output port of the modulator to an output port of the modem.

2. The modem of claim 1 further comprising a user appliance connected to the digital port.

3. The modem of claim 1 further comprising a PBX connected to the output port of the modem.

4. The modem of claim 3 wherein the analog port of the modem is connected to said PBX.

5. The modem of claim 3 wherein the digital port of the modem is connected to said PBX.

6. The modem of claim 1 further comprising a wireless base station coupled to the analog port.

7. The modem of claim 6 wherein said wireless base station is a cordless telephone base station, further comprising digital user apparatus connected to the digital port.

8. The modem of claim 1 further comprising electronic game apparatus coupled to the digital port of the modem, with the analog port adapted for connecting a telephone instrument thereto.

9. The modem of claim 8 further comprising visual display means coupled to the game apparatus.

10. The modem of claim 1 further comprising a television system coupled to the analog port.

11. The modem of claim 10 wherein the television system is also connected to the digital port.

12. The modem of claim 10 wherein the television system is also coupled to a band-splitting means that is responsive to a signal applied at a wide-band port and wherein the modem output port is also responsive to the band-splitting means.

13. The modem of claim 1 incorporated in a pluggable assembly consonant with the PCMCIA standard.

14. The modem of claim 1 having a portable computer connected to the digital port thereof.

15. The modem of claim 14 further comprising wireless transmission and receiving circuitry connected to the output port thereof.

16. The modem of claim 1 further comprising:

first means, for implementing telephone functions, coupled to the analog port, and

second means, including visual display means, coupled to the digital port.