Multiple Transmitter System and Method

• US 20090225873A1
• Filed: 03/05/2008
• Published: 09/10/2009
• Est. Priority Date: 03/05/2008
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Davierwalla, Anosh, Wiley, George, Lee, Chulkyu
• Granted Patent: US 8,848,810 B2
• Time in Patent Office: Days
• US Class Current: 375/257
• CPC Class Codes: H04L 25/0272 Arrangements for coupling to multiple lines, e.g. for differential transmission
• CPC Class Codes: H04L 25/49 using code conversion at the transmitter; using predistortion; using insertion of idle bits for obtaining a desired frequency spectrum; using three or more amplitude levels ; Baseband coding techniques specific to data transmission systems spectral shaping H04L25/03828

Abstract

Systems and methods of data transmission are disclosed. In an embodiment, at least two transmitters are selectively activated and at least one transmitter is deactivated at a serial interface to transmit data via at least two distinct lines.

Claims

1. A system comprising,

a first transmitter coupled to a first transmission line;

a second transmitter coupled to a second transmission line; and

a third transmitter coupled to a third transmission line, wherein two of the three transmitters are conductive and wherein at least one of the three transmitters is not conductive.

2. The system of claim 1, wherein each transmitter is a tri-state device.

3. The system of claim 1, wherein a data encoder is coupled to each transmitter.

4. The system of claim 1, wherein the transmission lines have a Y-termination.

5. The system of claim 1, wherein the transmission lines have a common-mode termination.

6. The system of claim 1, wherein the transmission lines comprise flex cable.

7. The system of claim 1, wherein at least two of the transmission lines include a twisted pair.

8. The system of claim 1, wherein the transmission lines comprise a twisted trio.

9. An electronic device comprising:

a display;

a processing circuit; and

means for serial transmission coupled to the processing circuit and to the display, wherein the means for serial transmission includes at least three receivers configured to receive a signal via at least three wires from at least three transmitters, wherein at least two of the transmitters are active and at least one transmitter is inactive.

10. The electronic device of claim 9, wherein the at least three wires have a Y-termination.

11. The electronic device of claim 9, wherein the means for serial transmission includes a serial interface adapted to provide multimedia data to the display.

12. The electronic device of claim 9, further comprising:

a microphone;

a speaker;

a wireless transceiver coupled to the processing circuit; and

an antenna coupled to the wireless transceiver.

13. An electronic device comprising:

an image sensing device;

a data processing circuit; and

a serial interface coupled to the data processing circuit and to the image sensing device, wherein the serial interface includes at least two active transmitters and at least one inactive transmitter.

14. The electronic device of claim 13, wherein the image sensing device is remote from the data processing circuit.

15. The electronic device of claim 13, wherein the serial interface includes a coaxial cable coupled to at least two of the transmitters.

16. The electronic device of claim 13, wherein the serial interface is configured to transmit video data between the image sensing device and the data processing circuit.

17. A method, comprising:

selectively activating at least two transmitters and deactivating at least one transmitter at a serial interface to transmit data via at least two distinct lines.

18. The method of claim 17, further comprising:

encoding a received signal to at least one predefined state of multiple predefined states, each of the predefined states representing a different combination of a first polarity at a first transmitter, a second polarity at a second transmitter, and inactivity at a third transmitter.

19. The method of claim 18, wherein the multiple predefined states include:

a first state having the first polarity at the first transmitter, the second polarity at the second transmitter, and inactivity at the third transmitter;

a second state having the second polarity at the first transmitter, the first polarity at the second transmitter, and inactivity at the third transmitter;

a third state having inactivity at the first transmitter, the first polarity at the second transmitter, and the second polarity at the third transmitter;

a fourth state having inactivity at the first transmitter, the second polarity at the second transmitter, and the first polarity at the third transmitter;

a fifth state having the first polarity at the first transmitter, inactivity at the second transmitter, and the second polarity at the third transmitter; and

a sixth state having the second polarity at the first transmitter, inactivity at the second transmitter, and the first polarity at the third transmitter.

20. The method of claim 18, wherein the multiple predefined states further include a state where a fourth transmitter is inactive.

21. The method of claim 18, further comprising embedding a clock signal in the data that is transmitted via the at least two distinct lines by prohibiting a self-transition state.

22. A method, comprising:

receiving a data signal from a set of transmitters including a first transmitter driving a first line, a second transmitter driving a second line, and a third transmitter driving a third line, wherein the data signal comprises a first signal from the first transmitter and a second signal from the second transmitter, and wherein the third transmitter is inactive.

23. The method of claim 22, wherein the first signal includes a current having a first polarity and wherein the second signal includes a current having a second polarity.

24. The method of claim 22, further comprising:

determining a state transition between the data signal and a second data signal; and

decoding a data value based on the state transition.