TRANSMISSION LINE DIRECTIONAL COUPLING

• US 20090290650A1
• Filed: 04/09/2009
• Published: 11/26/2009
• Est. Priority Date: 04/09/2008
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Intellon Corporation (Qualcomm, Inc.)
• Inventors: Zyren, James
• Granted Patent: US 8,571,118 B2
• Time in Patent Office: Days
• US Class Current: 375/257
• CPC Class Codes: G06Q 50/06 Energy or water supply
• CPC Class Codes: H02J 2310/48 for electric vehicles [EV] or hybrid vehicles [HEV]
• CPC Class Codes: H02J 7/0013 acting upon several batteries simultaneously or sequentially H02J7/1423 takes precedence
• CPC Class Codes: H02J 7/0042 characterised by the mechanical construction
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y10S 307/01 Data transmitted over power lines

Abstract

Coupling signals to a transmission line over a plurality of taps includes coupling a first signal onto a transmission line at a first tap, coupling a second signal onto a transmission line at a second tap, and controlling a phase for at least a portion of the first signal relative to a phase for a corresponding portion of the second signal.

Claims

1. An apparatus, comprising:

multiple transmission line taps; and

a signal processing unit in communication with each of the taps, wherein the signal processing unit is configured to control a phase for at least a portion of a signal for at least a first of the taps relative to a phase for a corresponding portion of the signal for at least a second of the taps.

2. The apparatus of claim 1, wherein controlling the phase for the portion of the signal for the first of the taps comprises determining the phase based at least in part on a direction in which a signal is to be coupled between the taps and a transmission line.

3. The apparatus of claim 2, wherein controlling the phase for the portion of the signal for the first of the taps comprises determining a sign of the phase based at least in part on the direction.

4. The apparatus of claim 1, wherein controlling the phase for the portion of the signal for the first of the taps comprises controlling the phase to tune an amplitude of a combined signal from the taps that propagates away from the taps.

5. The apparatus of claim 4, wherein tuning the amplitude of the combined signal comprises reducing the amplitude of the combined signal in one direction away from the taps.

6. The apparatus of claim 4, wherein tuning the amplitude of the combined signal comprises increasing the amplitude of the combined signal in one direction away from the taps.

7. The apparatus of claim 1, wherein the signal processing unit is further configured to control an amplitude of the portion of the signal for the first of the taps relative to an amplitude of a corresponding portion of the signal for the second of the taps.

8. The apparatus of claim 1, wherein the signal comprises multiple subcarriers, and the signal processing unit is configured to determine a phase for each subcarrier for at least a first of the taps relative to a phase for a corresponding subcarrier for at least a second of the taps.

9. The apparatus of claim 8, wherein the corresponding subcarrier for the second of the taps has the same frequency as the subcarrier for the first of the taps.

10. The apparatus of claim 8, wherein the signal processing unit is configured to determine a phase and an amplitude for each subcarrier for the first of the taps relative to a phase and an amplitude of a corresponding subcarrier for the second of the taps.

11. The apparatus of claim 1, further comprising multiple transceivers each coupled to a respective one of the taps and coupled to the signal processing unit.

12. The apparatus of claim 1, further comprising a transceiver coupled to each of the taps and coupled to the signal processing unit.

13. The apparatus of claim 1, wherein controlling the phase for the portion of the signal for the first of the taps comprises controlling the phase to be approximately equal to a difference between a constant term and a term proportional to a frequency of the portion of the signal and a distance between the first and second taps.

14. The apparatus of claim 13, wherein the frequency of the portion of the signal corresponds to a frequency at a peak of a spectrum of the portion of the signal.

15. The apparatus of claim 13, wherein the portion of the signal comprises a subcarrier of the signal.

16. The apparatus of claim 13, wherein the distance between the first and second taps is proportional to a center wavelength corresponding to a center of a bandwidth over which a spectrum of the signal spans.

17. The apparatus of claim 16, wherein the distance between the first and second taps is approximately equal to the center wavelength divided by four.

18. The apparatus of claim 1, wherein controlling the phase for the portion of the signal for the first of the taps comprises determining a phase that provides at least a partial null in an array factor for signals coupled between a transmission line and first and second taps in one direction on the transmission line.

19. The apparatus of claim 18, wherein the determined phase provides gain in the array factor for signals coupled between the transmission line and the first and second taps in the opposite direction on the transmission line.

20. The apparatus of claim 18, wherein the signal processing unit is configured to determine a signal strength for each subcarrier for a specified direction on the transmission line and to determine amplitudes and phases for each subcarrier for each of the taps that provide at least a partial null in the array factor for the specified direction.

21. The apparatus of claim 20, wherein the signal processing unit is configured to determine a signal strength for each subcarrier for a specified direction on the transmission line and to determine amplitudes and phases for each subcarrier for each of the taps that provide at least some gain in the array factor for the specified direction.

22. The apparatus of claim 20, wherein the determined signal strength is provided as feedback based on a signal strength received from a device coupled to the transmission line in the specified direction.

23. The apparatus of claim 22, wherein the signal processing unit is configured to use the feedback to adaptively control subcarrier amplitudes and phases to compensate for changes in characteristics of the transmission line.

24. The apparatus of claim 18, wherein the signal processing unit is configured to transmit signals from the first and second taps to the transmission line according to the array factor.

25. The apparatus of claim 18, wherein the signal processing unit is configured to receive signals from the transmission line to the first and second taps according to the array factor.

26. The apparatus of claim 1, wherein the signal processing unit is configured to:

determine a first set of amplitude values for modulating each subcarrier of a first signal to be transmitted from the first tap, and determine a first set of phase values for modulating each subcarrier of the first signal; and

determine a second set of amplitude values for modulating each subcarrier of a second signal to be transmitted from the second tap based on the first set of amplitude values, and determine a second set of phase values for modulating each subcarrier of the second signal based on the first set of phase values.

27. The apparatus of claim 26, wherein each phase value in the second set of phase values is approximately equal to the phase value of the same subcarrier in the first set of phase values offset by a relative phase shift that is controlled by the signal processing unit.

28. The apparatus of claim 26, wherein each amplitude value in the second set of amplitude values is approximately equal to the amplitude value of the same subcarrier in the first set of amplitude values.

29. The apparatus of claim 26, wherein each amplitude value in the second set of amplitude values is approximately equal to the amplitude value of the same subcarrier in the first set of amplitude values scaled by a factor that at least partially compensates for an amplitude taper over a bandwidth over which the multiple subcarriers span, where the amplitude taper corresponds to a difference between a frequency of a subcarrier and a center frequency of the bandwidth.

30. The apparatus of claim 26, wherein processing the signal comprises transmitting the first signal from the first tap and transmitting the second signal from the second tap at approximately the same time.

31. The apparatus of claim 1, wherein the signal processing unit is configured to:

determine a first set of phase values for processing each subcarrier of a first signal received from the first tap; and

determine a second set of phase values for processing each subcarrier of a second signal received from the second tap based on the first set of phase values.

32. The apparatus of claim 31, wherein the signal processing unit is configured to receive the first signal from the first tap and receive the second signal from the second tap at approximately the same time.

33. The apparatus of claim 32, wherein the signal processing unit is configured to process a subcarrier of the first signal using a phase value from the first set of phase values to recover a first vector, process a corresponding subcarrier of the second signal using a phase value from the second set of phase values to recover a second vector, and combine the first and second vectors according to a relative phase to recover a data value.

34. The apparatus of claim 33, wherein the signal processing unit is configured to control the relative phase according to a direction in which the data value is being received from a transmission line coupled to the taps.

35. The apparatus of claim 1, wherein the signal processing unit is configured to simultaneously transmit a first signal in one direction on a transmission line coupled to the taps and transmit a second signal different from the first signal in another direction on the transmission line.

36. The apparatus of claim 1, wherein the signal processing unit is configured to simultaneously receive a first signal from one direction on a transmission line coupled to the taps and receive a second signal different from the first signal from another direction on the transmission line.

37. A method for coupling signals to a transmission line over a plurality of taps, comprising:

coupling a first signal onto a transmission line at a first tap;

coupling a second signal onto a transmission line at a second tap; and

controlling a phase for at least a portion of the first signal relative to a phase for a corresponding portion of the second signal.

38. A method, comprising:

transmitting a payload bearing packet in a first direction on a transmission line; and

transmitting a packet in a different direction on the transmission line that includes information about the payload bearing packet.

39. The method of claim 38, wherein the information about the payload bearing packet comprises one or more of a source address, a destination address, and a time duration of transmission.

40. The method of claim 38, wherein the packet that includes information about the payload bearing packet is prioritized below acknowledgement packets and above payload bearing packets for accessing the transmission line according to a medium access protocol.

41. The method of claim 38, wherein the packet that includes information about the payload bearing packet is combined with a different payload bearing packet being transmitted in the different direction on the transmission line.