METHOD AND APPARATUS FOR MITIGATING OSCILLATION BETWEEN REPEATERS

• US 20090290526A1
• Filed: 09/21/2007
• Published: 11/26/2009
• Est. Priority Date: 09/21/2006
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Lintelman, Ross L., LaMont, Lawrence Wayne, Puig, Carlos M., Otto, James C., Gainey, Kenneth M., Proctor, James A.
• Granted Patent: US 8,559,379 B2
• Time in Patent Office: Days
• US Class Current: 370/315
• CPC Class Codes: H04B 7/155 Ground-based stations H04B7/204 takes precedence
• CPC Class Codes: H04W 16/26 Cell enhancers or enhancement, e.g. for tunnels, building shadow

Abstract

A first repeater operating within a wireless network including a second repeater capable of communicating with the first repeater, and first and second wireless station devices capable of communicating with at least one of the first repeater and the second repeater, includes a reception device for receiving a wireless signal at a reception frequency; a detector for detecting if a predetermined portion of the received wireless signal includes a modified portion to thereby determine that the received signal is from the second repeater; and a transmission device for transmitting the wireless signal to one of the first and second wireless station devices at a transmission frequency to thereby repeat the wireless signal.

Claims

1. A first repeater operating within a wireless network, the wireless network including a second repeater capable of communicating with the first repeater, and first and second wireless station devices capable of communicating with at least one of the first repeater and the second repeater, the first repeater comprising:

a reception device for receiving a wireless signal at a reception frequency;

a detector for detecting if a predetermined portion of the received wireless signal includes a modified portion to thereby determine that the received signal is from the second repeater; and

a transmission device for transmitting the wireless signal to one of the first and second wireless station devices at a transmission frequency to thereby repeat the wireless signal.

2. The first repeater of claim 1, wherein if the predetermined portion of the received wireless signal includes the modified portion, the transmission device is configured to not repeat a substantial portion of the wireless signal.

3. The first repeater of claim 1, wherein if the predetermined portion of the received wireless signal includes the modified portion, the transmission device is configured to one of transmit the wireless signal at a frequency different from the transmission frequency, and transmit the wireless signal at a power level different from an original transmission power level.

4. The first repeater of claim 1, further including a signal modification device for modifying the wireless signal.

5. The first repeater of claim 1, further including a de-modification device for removing the modified portion from the predetermined portion of the wireless signal.

6. The first repeater of claim 1, wherein the transmission device is configured to transmit the wireless signal if the predetermined portion of the received wireless signal includes the modified portion and to not transmit the wireless signal if the predetermined portion of the received wireless signal does not include the modified portion.

7. The first repeater of claim 1, wherein the predetermined portion of the received wireless signal is a preamble of the wireless signal and the modified portion is a predetermined phase variation.

8. The first repeater of claim 1, wherein the detector is further configured to detect if the wireless signal was transmitted from one of the first and second wireless station devices by performing a qualifying detection process on the received wireless signal.

9. The first repeater of claim 8, wherein the qualifying detection process includes correlating a preamble of the received wireless signal to a predetermined signal pattern.

10. The first repeater of claim 8, wherein the qualifying detection process includes demodulating one of a predetermined information sequence, a pilot channel and a pilot carrier.

11. The first repeater of claim 1, further including a signal modification device configured to modify a predetermined portion of the received wireless signal to include a predetermined phase variation, thereby causing the second repeater to not repeat the wireless signal.

12. The first repeater of claim 1, wherein the repeater is one of a frequency translating repeater in which the reception frequency and transmission frequency are different, and a same frequency repeater in which the reception frequency and transmission frequency are same.

13. The first repeater of claim 1, wherein the detector is included within a notch processor configured to insert a notch pattern on the wireless signal to be transmitted and detecting a notch pattern inserted on a wireless signal as the modified portion.

14. The first repeater of claim 1, further comprising:

a processor; and

a memory coupled to the processor, the memory for storing a power adjustment routine for configuring the processor;

wherein the processor is configured to;

generate probe packets to be transmitted to the second repeater at the transmission frequency;

measure a received signal strength indication (RSSI) of a packet received in response to the probe packets;

determine if a path loss defined by a difference between a power level at which the probe packets were transmitted and the measured RSSI is less than a predetermined value; and

mark the transmission frequency as unavailable for use if the path loss is less than the predetermined value.

15. The first repeater of claim 14, wherein the processor is further configured to:

generate a group of packets to be transmitted to the second repeater at the transmission frequency if the path loss is not less than approximately the predetermined value;

determine an average RSSI for the group of packets;

if the average RSSI is less than a predetermined level, mark a current transmission power as acceptable.

16. The first repeater of claim 15, wherein the processor is further configured to:

adjust the current transmission power downward by a predetermined decibel level if the average RSSI is less not than the predetermined level;

regenerate the group of packets to be transmitted to the second repeater at the transmission frequency;

determine an average RSSI for the group of packets; and

if the average RSSI is less than a predetermined level, mark a current transmission power as acceptable.

17. A first repeater operating within a wireless network, the wireless network including a second repeater capable of communicating with the first repeater, and first and second wireless stations capable of communicating with at least one of the first repeater and the second repeater, the first repeater comprising:

a reception device receiving a wireless signal from one of the second repeater, first wireless station, and second wireless station;

a detection device coupled to the reception device, the detection device detecting if a received signal strength indication (RSSI) of the wireless signal is greater than a predetermined RSSI threshold;

a digital demodulator coupled to the reception device, the digital demodulator configured to demodulate the wireless signal if the detected RSSI is greater than the predetermined RSSI threshold;

a signal modification device coupled to the reception device, the signal modification device configured to modify a predetermined portion of the wireless signal; and

a transmission device coupled to the signal modification device for transmitting the modified wireless signal to one of the second repeater, first wireless station, and second wireless station.

18. The first repeater of claim 17, wherein the signal modification device includes a bi-phase modulation device configured to modulate a phase of the predetermined portion of the wireless signal.

19. The first repeater of claim 18, wherein the bi-phase modulator is further configured to modulate the predetermined portion of the wireless signal to have a unique signature recognizable by the second repeater upon receiving the modified wireless signal.

20. The first repeater of claim 18, further comprising a surface acoustic wave (SAW) filter coupled to the output of the bi-phase modulator to remove spectral splattering from the modified wireless signal.

21. The first repeater of claim 18, further comprising a timing circuit coupled to the bi-phase modulator, the timing circuit controlling an amount of time during which the bi-phase modulator modulates the phase of the predetermined portion of the wireless signal, the timing circuit being activated when the detected RSSI is greater than the predetermined RSSI threshold.

22. The first repeater of claim 18, wherein the bi-phase modulator includes a transfer switch coupled to a linear oscillator (LO), the transfer switch switching positive and negative terminals of the LO at a predetermined frequency to modulate the phase of the predetermined portion of the wireless signal.

23. The first repeater of claim 17, wherein the digital demodulator is further configured to:

detect if a predetermined portion of the wireless signal has gain modulation; and

to not demodulate a substantial portion of the wireless signal if the predetermined portion of the wireless signal received has gain modulation, thereby causing the first repeater to not repeat a substantial portion of the wireless signal.

24. The first repeater of claim 17, wherein the digital demodulator is further configured to not demodulate the wireless signal if a predetermined portion of a preamble of the wireless signal received has gain modulation and the digital demodulator is in a wireless local area network (WLAN) only configuration, thereby causing the first repeater to not repeat a substantial portion of the wireless signal.

25. The first repeater of claim 17, wherein:

the digital demodulator is further configured to determine if a preamble of the wireless signal received has phase modulation; and

the transmission device is configured to one of transmit the modified wireless signal at a frequency different from the second frequency, and transmit the wireless signal at a different power level if the preamble of the received wireless signal is determined to have the phase modulation.

26. The first repeater of claim 17, wherein the digital demodulator is further configured to determine if a preamble of the received wireless signal has phase modulation and to remove the phase modulation.

27. The first repeater of claim 17, wherein the wireless signal includes one or more packets defined according to the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard, wherein the predetermined portion of the wireless signal is an initial portion of a preamble of the one or more packets.

28. The first repeater of claim 27, wherein the initial portion of the preamble is a portion of the wireless signal that is not recovered by the first and second wireless stations.

29. The first repeater of claim 27, wherein the initial portion of the preamble is a first four symbols of a packet in the wireless signal.

30. The first repeater of claim 17, wherein the signal modification device includes a notch processor for inserting a notch pattern on the wireless signal to be transmitted and detecting a notch pattern inserted on a wireless signal received from the second repeater.

31. The first repeater of claim 27, wherein the modified wireless signal conforms to a spectral mask defined by the IEEE 802.11g standard.

32. The first repeater of claim 18, wherein the bi-phase modulator includes a transfer switch coupled to an amplifier on a signal path of the wireless signal.

33. A first repeater operating within a wireless network, the wireless network including a second repeater capable of communicating with the first repeater, and first and second wireless stations capable of communicating with at least one of the first repeater and the second repeater, the first repeater comprising:

a reception device receiving a wireless signal including one or more packets at a reception frequency;

a signal modification and detection device coupled to the reception device, the signal modification and detection device configured to modify a predetermined portion of the packet to thereby generate a modified wireless signal and to detect if a predetermined portion of the packet includes a modified signal pattern;

a transmission device coupled to the signal modification and detection device for transmitting the modified wireless signal to one of the second repeater, first wireless station, and second wireless station at a predetermined power level and a transmission frequency;

a processor controlling the reception device and the transmission device; and

a memory coupled to the processor, the memory for storing a power adjustment routine for configuring the processor to;

generate probe packets to be transmitted to the second repeater at the transmission frequency;

measure a received signal strength indication (RSSI) of a packet received in response to the probe packets; and

adjust one of the power level or the transmission frequency in accordance with the measured RSSI.

34. The first repeater of claim 33, wherein the signal modification and detection device coupled to the reception device comprises a notch processor configured to insert a notch pattern on the wireless signal to be transmitted and detect a notch pattern inserted on a wireless signal received from the second repeater.

35. The first repeater of claim 33, wherein the signal modification and detection device coupled to the reception device comprises:

a bi-phase modulation device configured to modulate a phase of the predetermined portion of the wireless signal; and

a digital demodulator coupled to the reception device, the digital demodulator configured to determine if the wireless signal includes a modulated phase pattern as the modified portion.