Wireless repeater implementing low-level oscillation detection and protection for a duplex communication system

• US 20050272367A1
• Filed: 05/26/2005
• Published: 12/08/2005
• Est. Priority Date: 05/26/2004
• Status: Active Grant

• Current Assignee: zBoost Incorporated (Wilson Electronics Holdings LLC)
• Original Assignee: Wireless Extenders (Wilson Electronics Holdings LLC)
• Inventors: Rodgers, Michael W., Kim, Stephen W.
• Granted Patent: US 7,706,744 B2
• Time in Patent Office: Days
• US Class Current: 455/11.100
• CPC Class Codes: H04B 7/15564 Relay station antennae loop interference reduction
• CPC Class Codes: H04B 7/2606 Arrangements for base station coverage control, e.g. by using relays in tunnels

Abstract

A modular wireless repeater typically deployed with a roof-mounted tower-signal antenna and a base unit with a base unit antenna located within the building, to which the tower-signal antenna and the base unit are connected by the user or a satellite TV installer using a 75 Ω coaxial cable. The system allows a customer to purchase a unit for all wireless service providers in a given frequency band, such as Cellular, PCS, GSM900, or DCS, etc., and then add on modules for additional types of service that the customer may desire in the future. The system also detects and prevents low-level oscillations. The wireless repeater also performs intelligent power control allowing it to function properly with near and far base unit antennas as well as near and far mobile stations.

Claims

1. A wireless repeater comprising:

a base unit antenna;

a tower-signal antenna;

a bi-directional amplifier;

an oscillation detection circuit configured to detect oscillations caused by feedback from the tower-signal antenna to the base unit antenna while discriminating these oscillations from pulsed signals, full duplex signals, and amplitude modulated signals; and

an oscillation protection circuit configured to decrease or disconnect power to at least one of the amplifiers in response to oscillations detected by the oscillation detection circuit.

2. The wireless repeater of claim 1, wherein:

the pulsed signals are characteristic of TDMA and GSM signals;

the full duplex signals are characteristic of AMPS signals; and

the amplitude modulated signals are characteristic of CDMA signals.

3. The wireless repeater of claim 1, further comprising an isolation management circuit configured to periodically increase an uplink gain of the bi-directional amplifier to trigger the low-level oscillations.

4. A wireless repeater comprising:

a base unit antenna;

a tower-signal antenna;

a bi-directional amplifier; and

an oscillation detection and protection circuit including an isolation management circuit configured to periodically increase an uplink gain of the bi-directional amplifier to trigger oscillations caused by feedback from the tower-signal antenna to the base unit antenna; and

a shutdown circuit configured to decrease or disconnect power to at least one of the amplifiers in response to an oscillation detected in response to the operation of the isolation management circuit.

5. A wireless repeater for providing improved wireless communications service through a wireless base station located a significant distance away from the customer premises, the wireless repeater configured to improve the communication service in a poor reception area within customer premises that experiences poor communication service through the base station, comprising:

a wireless repeater comprising an enclosure that houses a bi-directional amplifier, and which is configured for location within the customer premises;

a base unit antenna located proximate to the enclosure and configured for bi-directional communications with wireless communication terminals located within the poor reception area;

a tower-signal antenna located within the customer premises remotely from the enclosure and configured for bi-directional communications with the wireless base station; and

a communication link connecting the tower-signal antenna from the enclosure whereby the tower-signal antenna may be strategically located within the customer premises for communication with the base station while the base unit antenna may be strategically located within the customer premises for communication with the wireless communication terminals located in the poor reception area.

6. The wireless repeater of claim 5, wherein the base unit antenna is attached to the enclosure.

7. The wireless repeater of claim 5, wherein the communication link between the enclosure and the tower-signal antenna comprises 75 ohm satellite coaxial cable.

8. The wireless repeater of claim 5, further comprising an oscillation detection circuit configured to detect oscillations caused by feedback from the tower-signal antenna to the base unit antenna.

9. The wireless repeater of claim 8, further comprising an oscillation protection circuit configured to lower or eliminate a gain setting associated with the bi-directional antenna in response to detected oscillations caused by feedback from the tower-signal antenna to the base unit antenna.

10. The wireless repeater of claim 8, wherein the oscillation detection circuit comprises a pulse detection circuit configured to discriminate between oscillations caused by feedback from the tower-signal antenna to the base unit antenna and a pulsed communication characteristic of TDMA and GSM signals.

11. The wireless repeater of claim 8, wherein the pulse detection circuit comprises a peak to average circuit.

12. The wireless repeater of claim 8, wherein the oscillation detection circuit comprises a modulation frequency threshold detection circuit configured to discriminate between oscillations caused by feedback from the tower-signal antenna to the base unit antenna and a communication signal modulation containing high frequency content associated with a communication signal.

13. The wireless repeater of claim 12, wherein the modulation threshold frequency is below a frequency characteristic of CDMA signals.

14. The wireless repeater of claim 8, wherein the oscillation detection circuit comprises a full duplex detection circuit configured to discriminate between oscillations caused by feedback from the tower-signal antenna to the base unit antenna and a full duplex communication characteristic of wireless telephone communication signals.

15. The wireless repeater of claim 14, wherein the full duplex detection circuit comprises a frequency detection circuit configured to detect signal components having significant amplitudes occurring in downlink and uplink communication channels associated with AMPS communication signals.

16. The wireless repeater of claim 14, wherein the full duplex detection circuit comprises a frequency detection circuit configured to detect signal components having significant amplitudes occurring in downlink and uplink communication channels associated with CDMA communication signals.

17. The wireless repeater of claim 8, wherein the oscillation detection circuit comprises a continuous wave detection circuit configured to detect a signal component occurring at an analog continuous wave frequency.

18. The wireless repeater of claim 17, wherein the analog continuous wave frequency is characteristic of AMPS signals.

19. The wireless repeater of claim 14, wherein the full duplex detection circuit comprises:

a mixing circuit configured to combine uplink and downlink signals to create a mixed duplex signal;

a filter configured to receive the mixed duplex signal and produce a filtered mixed duplex signal by band-pass filtering the mixed duplex signal; and

a power detection circuit configured to determine a power level associated with a valid full duplex signal.

20. The wireless repeater of claim 8, wherein the oscillation detection circuit comprises an isolation management circuit configured to periodically increase an uplink gain of the bi-directional amplifier to trigger oscillations caused by feedback from the tower-signal antenna to the base unit antenna.

21. A wireless repeater comprising a base unit antenna, a tower-signal antenna, a bi-directional amplifier, and an oscillation detection and protection circuit comprising:

a pulse detection circuit configured to discriminate between oscillations caused by feedback from the tower-signal antenna to the base unit antenna and pulsed communication signals;

a modulation frequency threshold detection circuit configured to discriminate between oscillations caused by feedback from the tower-signal antenna to the base unit antenna and a signal comprising a significant component occurring above a modulation frequency threshold associated with a communication signal;

a full duplex detection circuit configured to discriminate between oscillations caused by feedback from the tower-signal antenna to the base unit antenna and full duplex communications characteristic of full duplex communication signals;

a logic circuit configured to detect oscillation occurring above a threshold level that has been distinguished from a pulsed signal by the pulse detection circuit, distinguished from a full duplex signal by the full duplex detection circuit, and distinguished from communications occurring above a threshold frequency by the modulation frequency threshold detection circuit; and

a shutdown circuit configured to decrease gain or disconnect power to at least one of the amplifiers in response to an oscillation detected by the logic circuit.

22. The oscillation detection and protection circuit of claim 21, further comprising a continuous wave detection circuit configured to detect a signal component occurring at an analog continuous wave frequency.

23. The oscillation detection and protection circuit of claim 22, further comprising an isolation management circuit configured to periodically increase an uplink gain of the bi-directional amplifier to trigger the occurrence of oscillations caused by feedback from the tower-signal antenna to the base unit antenna.

24. The oscillation detection and protection circuit of claim 22, wherein the pulse detection circuit comprises a peak to average circuit.

25. The oscillation detection and protection circuit of claim 24, wherein the pulsed communication signals are characteristic of TDMA and GSM signals.

26. The oscillation detection and protection circuit of claim 22, wherein the full duplex detection circuit comprises a frequency detection circuit configured to detect signal components having significant amplitudes occurring in downlink and uplink communication channels.

27. The oscillation detection and protection circuit of claim 26, wherein the downlink and uplink communication channels are characteristic of AMPS and CDMA signals.

28. The wireless repeater of claim 22, wherein the full duplex detection circuit comprises:

a mixing circuit configured to combine uplink and downlink signals to create a mixed duplex signal;

a filter configured to receive the mixed duplex signal and produce a filtered mixed duplex signal by band-pass filtering the mixed duplex signal; and

a power detection circuit configured to determine a power level associated with a valid full duplex communication signal.

29. The wireless repeater of claim 28, wherein the analog continuous wave frequency is characteristic of AMPS signals.

30. A wireless repeater system comprising:

a base unit antenna,

a tower-signal antenna, and

a first wireless repeater module configured to engage in duplex communications with a first type of wireless communication system and having an output port for connecting to another a second wireless repeater module configured to engage in duplex communications with a first type of wireless communication system.

31. The wireless repeater system, wherein the first wireless repeater module comprises a diplexer configured to

receive communication signals from the first and second types of wireless communication systems;

route signals received from the first type of wireless communication system to internal circuitry; and

route signals received from the second type of wireless communication system to the output port.