CELLULAR REPEATER WATERMARKING SYSTEM AND METHOD

• US 20080020705A1
• Filed: 05/04/2007
• Published: 01/24/2008
• Est. Priority Date: 07/21/2006
• Status: Active Grant

• Current Assignee: Wilson Electronics LLC (Wilson Electronics Holdings LLC)
• Original Assignee: Wilson Electronics
• Inventors: MacConnell, John
• Granted Patent: US 7,917,084 B2
• Time in Patent Office: Days
• US Class Current: 455/15
• CPC Class Codes: H04B 7/15535 Control of relay amplifier gain amplifier gain control in general H03G3/00; gain control reducing self - or loop interference H04B7/15578
• CPC Class Codes: H04W 16/26 Cell enhancers or enhancement, e.g. for tunnels, building shadow
• CPC Class Codes: H04W 76/20 Manipulation of established connections
• CPC Class Codes: H04W 88/08 Access point devices
• CPC Class Codes: H04W 92/16 Interfaces between hierarchically similar devices

Abstract

A method and system for providing a watermark by amplitude modulating data onto signals being repeated from and/or to a cellular telephone handset without degrading the performance of the cellular telephone system. An exemplary cellular repeater system may include a first communication device configured to receive a cellular telephone signal from a handset. The cellular telephone signal is amplified by a variable gain amplifier configured to create an adjusted signal. The amplification factor applied by the variable gain amplifier is controlled by a message encoder configured in accordance with a predetermined encoding scheme. The adjusted signal is then transmitted to a base station by a second communication device.

Claims

1. A cellular repeater system comprising:

a first communication device configured to receive a cellular telephone signal from a handset;

a variable gain amplifier configured to apply a variable amplification factor to the uplink signal to create an adjusted signal;

a message encoder configured to control the variable amplification factor in accordance with a predetermined encoding scheme; and

a second communication device configured to transmit the adjusted signal to a base station.

2. The cellular repeater system as recited in claim 1, wherein the message encoder configured to control the variable amplification factor in accordance with a predetermined encoding scheme is further configured to apply a watermark to the cellular telephone signal for identifying at least one property of the cellular repeater system.

3. The cellular repeater system as recited in claim 2, wherein the watermark is decodable by the base station and is used by the base station to account for one or more effects of the cellular repeater system or for an operating mode of the cellular repeater system.

4. The cellular repeater system as recited in claim 1, wherein the cellular telephone signal is an uplink signal or a downlink signal.

5. The cellular repeater system as recited in claim 1, wherein at least one of the first communication device and the second communication device is a wired connection or an antenna.

6. The cellular repeater system as recited in claim 1, wherein the message encoder controls the variable amplification factor using amplitude modulation.

7. The cellular repeater system as recited in claim 1, further comprising at least one low-pass data filter for filtering out the high frequencies of signals produced by the at least one message encoder.

8. In a cellular repeater system, a method for watermarking a cellular telephone signal, the method comprising:

receiving an uplink signal from a handset;

applying a first watermark identifier to the uplink signal by modulating the uplink signal in accordance with a first predetermined encoding scheme; and

transmitting the modulated uplink signal to a base station.

9. The method as recited in claim 8, wherein the watermark identifier identifies at least one property of the cellular repeater system and is decodable by a recipient of the uplink signal to be used to account for effects introduced by the cellular repeater system.

10. The method as recited in claim 9, wherein the first watermark identifier identifies a delay time introduced to the uplink signal by the cellular repeater system.

11. The method as recited in claim 8, further comprising amplifying the uplink signal prior to transmitting to the base station.

12. The method as recited in claim 8, further comprising:

receiving a downlink signal from the base station;

modulating the downlink signal in accordance with a second predetermined encoding scheme for applying a second watermark identifier to the downlink signal; and

transmitting the modulated downlink signal to the handset.

13. The method as recited in claim 12, wherein the first predetermined encoding scheme and the second predetermined encoding scheme are the same, and the first watermark identifier and the second watermark identifier are the same.

14. In a cellular telephone system, a cellular repeater system with watermarking capabilities comprising:

a first antenna for communicating signals to and from a base station;

a second antenna for communicating signals to and from a handset;

a first variable gain module having an input coupled to the first antenna and an output coupled to the second antenna, the first variable gain module applying a first amplification factor to the signals received from the base station;

a second variable gain module having an input coupled to the second antenna and an output coupled to the first antenna, the second variable gain module applying a second amplification factor to the signals received from the handset; and

at least one message encoder configured to control at least one of the first amplification factor and the second amplification factor in accordance with a predetermined encoding scheme, wherein the signals received from the handset or from the base station are modulated according to the predetermined encoding scheme without affecting a performance of the cellular telephone system.

15. The cellular repeater system as recited in claim 14, wherein the at least one message encoder applies a watermark identifier to the signals received from the base station using amplitude modulation.

16. The cellular repeater system as recited in claim 14, wherein the at least one message encoder applies a watermark identifier to the signals received from the base station and to the signals received from the handset using amplitude modulation.

17. The cellular repeater system as recited in claim 16, wherein the at least one message encoder utilizes an identical watermark data rate for the signals received from the base station and the signals received from the handset.

18. The cellular repeater system as recited in claim 16, wherein the at least one message encoder utilizes a first watermark data rate for the signals received from the base station and a second watermark data rate for the signals received from the handset, wherein the first and second watermark data rates are different.

19. The cellular repeater system as recited in claim 14, wherein the at least one message encoder applies a first watermark identifier to the signals received from the base station and a second watermark identifier to the signals received from the handset, wherein the first and second watermark identifiers are different.

20. The cellular repeater system as recited in claim 14, wherein the at least one message encoder further comprises a first message encoder for controlling the first amplification factor and a second message encoder for controlling the second amplification factor.

21. The cellular repeater system as recited in claim 14, further comprising at least one low-pass data filter for filtering out the high frequencies of signals produced by the at least on message encoder.

22. At a base station, a method for processing an uplink mobile telephone signal, the method comprising:

receiving an uplink signal that has been amplified and retransmitted by a cellular repeater system;

extracting a watermark identifier applied to the uplink signal by the cellular repeater system in accordance with a predetermined encoding scheme, the watermark identifier identifying at least one property of the cellular repeater system;

executing a predefined task in response to the at least one property of the cellular repeater system to account for effects introduced by the cellular repeater system.

23. The method as recited in claim 22, wherein the at least one property of the cellular repeater system includes a delay introduced into the uplink signal by the cellular repeater system.

24. The method as recited in claim 22, wherein extracting the watermark identifier further comprises demodulating the uplink signal in accordance with a predetermined modulation scheme to extract the watermark identifier.