Systems and methods for maintaining operation of a receiver co-located with a transmitter and susceptible to interference therefrom by desensitization of the receiver

• US 6,442,375 B1
• Filed: 07/14/1999
• Issued: 08/27/2002
• Est. Priority Date: 07/14/1999
• Status: Expired due to Term

• Current Assignee: Ericsson, Inc. (Telefonaktiebolaget LM Ericsson)
• Original Assignee: Ericsson, Inc. (Telefonaktiebolaget LM Ericsson)
• Inventors: Parmentier, Jack D.
• Primary Examiner(s): Nguyen, Lee
• Application Number:
  US09/353,238
• Time in Patent Office: 1,140 Days
• Field of Search: 455/78, 455/250.1, 455/278.1, 455/295, 455/296, 455/310, 455/311, 455/317, 455/552, 455/553
• US Class Current: 455/78
• CPC Class Codes: G01S 19/21 Interference related issues ; Issues related to cross-correlation, spoofing or other methods of denial of service
• CPC Class Codes: H04B 1/109 by improving strong signal performance of the receiver when strong unwanted signals are present at the receiver input
• CPC Class Codes: H04B 1/3805 with built-in auxiliary receivers

Abstract

Systems and methods can be used to maintain operation of a receiver co-located with a transmitter in a communication device and susceptible to interference therefrom by anticipating the intervals during which the transmitter is active (i.e., transmitting) and then desensitizing the receiver during that interval. Although the receiver may operate in a reduced capacity due to periodic desensitization, the adverse effects of interference generated by the transmitter can be avoided. For example, interference from the transmitter can cause variables, such as the gain applied by an automatic gain control module at the receiver input, to deviate from a normal operating or steady state value, which must then be recovered when the interference from the transmitter ceases.

Claims

1. A system for maintaining operation of a communication device, comprising:

a transmitter that implements a communication protocol having active and inactive transmission intervals;

a receiver that is susceptible to interference from the transmitter during active transmission intervals;

control logic that anticipates the active transmission intervals and generates a control signal; and

an automatic gain control, responsive to the control signal, which maintains during an active transmission interval a gain applied at an input of the receiver during a preceding inactive transmission interval.

2. A system as recited in claim 1, further comprising:

a rectifier, responsive to the transmitter, that generates a direct current signal; and

an analog to digital converter that generates a digital signal in response to the direct current signal and provides the digital signal to the control logic.

3. A system as recited in claim 1, wherein the control logic comprises:

a computer readable storage medium having computer readable program code means that anticipate the active transmission intervals; and

a processor, responsive to th e computer readable program code means, that generates the control signal.

4. A system as recited in claim 1, further comprising:

a switch, responsive to the control signal that electrically isolates the receiver from the transmitter.

5. A system as recited in claim 4, wherein the switch is connected in series between the receiver and an antenna.

6. A system as recited in claim 4, wherein the switch is connected between an antenna that is electrically connected to the receiver and ground.

7. A system as recited in claim 1, wherein the receiver is a global positioning system (GPS) receiver.

8. A system as recited in claim 1, wherein the receiver is a Bluetooth receiver.

9. A system as recited in claim 1, wherein the communication protocol is based on TDMA wireless access technology.

10. A method of maintaining operation of a communication device, comprising the steps of:

providing a transmitter that implements a communication protocol having active and inactive transmission intervals;

providing a receiver that is susceptible to interference from the transmitter during active transmission intervals;

anticipating the active transmission intervals; and

maintaining during an active transmission interval a gain applied at an input of the receiver during a preceding inactive transmission interval in response to the anticipating step.

11. A method as recited in claim 10, wherein the maintaining step comprises:

preventing a gain applied at an input of the receiver from being reduced.

12. A method as recited in claim 10, wherein the maintaining step comprises:

electrically isolating the receiver from the transmitter.

13. A method as recited in claim 12, wherein the isolating step comprises:

disconnecting the receiver from an antenna electrically connected thereto.

14. A method as recited in claim 12, wherein the isolating step comprises:

grounding an antenna electrically connected to the receiver.

15. A method as recited in claim 10, wherein the anticipating step comprises:

converting an analog signal generated by the transmitter to a digital signal; and

generating a control signal in response to the digital signal that identifies the active transmission intervals.

16. A method as recited in claim 10, wherein the communication protocol is based on TDMA wireless access technology.

17. A system for maintaining operation of a communication an device, comprising:

means for providing a transmitter that implements a communication protocol having active and inactive transmission intervals

means for providing a receiver that is susceptible to interference from the transmitter during active transmission intervals;

means for anticipating the active transmission intervals; and

means, responsive to the means for anticipating, for maintaining during an active transmission interval a gain applied at an input of the receiver during a preceding inactive transmission interval.

18. A system as recited in claim 17, wherein the means for maintaining comprises:

means for preventing a gain applied at an input of the receiver from being reduced.

19. A system as recited in claim 17, wherein the means for maintaining comprises:

means for electrically isolating the receiver from the transmitter.

20. A system as recited in claim 19, wherein the means for isolating comprises:

means for disconnecting the receiver from an antenna electrically connected thereto.

21. A system as recited in claim 19, wherein the means for isolating comprises:

means for grounding an antenna electrically connected to the receiver.

22. A system as recited in claim 17, wherein the means for anticipating comprises:

signal means for converting an analog signal generated by the-transmitter to a digital signal; and

means, responsive to the digital signal, for generating a control signal that identifies the active transmission intervals.

23. A system as recited in claim 17, wherein the receiver is a global positioning system (GPS) receiver.

24. A system as recited in claim 17, wherein the receiver is a Bluetooth receiver.

25. A system as recited in claim 17, wherein the communication protocol is based on TDMA wireless access technology.

26. A system for maintaining operation of a communication device, comprising:

a transmitter that implements a communication protocol having active and inactive transmission intervals;

a receiver that is susceptible to interference from the transmitter during active transmission intervals;

a rectifier, responsive to the transmitter, that generates a direct current signal;

an analog to digital converter that generates a digital signal in response to the direct current signal; and

control logic that anticipates the active transmission intervals and generates a control signal in response to the digital signal to desensitize the receiver during the active transmission intervals.

27. A system as recited in claim 26, further comprising:

an automatic gain control, responsive to the control signal that prevents a gain applied at an input of the receiver from being reduced during the active transmission intervals.

28. A system as recited in claim 26, further comprising:

a switch, responsive to the control signal that electrically isolates the receiver from the transmitter.

29. A system as recited in claim 28, wherein the switch is connected in series between the receiver and an antenna.

30. A system as recited in claim 28, wherein the switch is connected between an antenna that is electrically connected to the receiver and ground.

31. A system as recited in claim 26, wherein the receiver is a global positioning system (GPS) receiver.

32. A system as recited in claim 26, wherein the receiver is a Bluetooth receiver.

33. A system as recited in claim 26, wherein the communication protocol is based on TDMA wireless access technology.

34. A method of maintaining operation of a communication device, comprising the steps of:

providing a transmitter that implements a communication protocol having active and inactive transmission intervals;

providing a receiver that is susceptible to interference from the transmitter during active transmission intervals;

generating a direct current signal responsive to operation of the transmitter;

converting the direct current signal to a digital signal;

generating a control signal in response to the digital signal that identifies the active transmission intervals; and

desensitizing the receiver in response to the control signal.

35. A method as recited in claim 34, wherein the desensitizing step comprises:

preventing a gain applied at an input of the receiver from being reduced.

36. A method as recited in claim 34, wherein the desensitizing step comprises:

electrically isolating the receiver from the transmitter.

37. A method as recited in claim 36, wherein the isolating step comprises:

disconnecting the receiver from an antenna electrically connected thereto.

38. A method as recited in claim 36, wherein the isolating step comprises:

grounding an antenna electrically connected to the receiver.

39. A method as recited in claim 34, wherein the communication protocol is based on TDMA wireless access technology.

40. A system for maintaining operation of a communication device, comprising:

means for providing a transmitter that implements a communication protocol having active and inactive transmission intervals

means for providing a receiver that is susceptible to interference from the transmitter during active transmission intervals;

means, responsive to operation of the transmitter, for generating a direct current signal;

means for converting the direct current signal to a digital signal;

means, responsive to the digital signal, for generating a control signal that identifies the active transmission intervals; and

means, responsive to the control signal, for desensitizing the receiver.

41. A system as recited in claim 40, wherein the means for desensitizing comprises:

means for preventing a gain applied at an input of the receiver from being reduced.

42. A system as recited in claim 40, wherein the means for desensitizing comprises:

means for electrically isolating the receiver from the transmitter.

43. A system as recited in claim 42, wherein the means for isolating comprises:

means for disconnecting the receiver from an antenna electrically connected thereto.

44. A system as recited in claim 42, wherein the means for isolating comprises:

means for grounding an antenna electrically connected to the receiver.

45. A system as recited in claim 40, wherein the receiver is a global positioning system (GPS) receiver.

46. A system as recited in claim 40, wherein the receiver is a Bluetooth receiver.

47. A system as recited in claim 40, wherein the communication protocol is based on TDMA wireless access technology.