Method and system providing increased antenna functionality in a RF distribution system

• US 5,983,070 A
• Filed: 04/08/1997
• Issued: 11/09/1999
• Est. Priority Date: 04/19/1996
• Status: Expired due to Term

• Current Assignee: CommScope Technologies, LLC (CommScope Holding Company, Inc.)
• Original Assignee: LGC Wireless Incorporated (TE Connectivity Limited)
• Inventors: Cutrer, David M., Lau, Kam Y., Georges, John B.
• Primary Examiner(s): Miller, John W.
• Application Number:
  US08/841,941
• Time in Patent Office: 945 Days
• Field of Search: 455/3.1, 455/6.3, 455/14, 455/20, 455/22, 455/63, 455/66, 455/208, 455/209, 455/316, 455/317, 455/318, 455/319, 455/11.1, 455/12.1, 455/6.1, 455/69, 455/71
• US Class Current: 725/78
• CPC Class Codes: H03D 7/00 Transference of modulation from one carrier to another, e.g. frequency-changing H03D9/00, H03D11/00 take precedence; dielectric amplifiers, magnetic amplifiers, parametric amplifiers used as a frequency-changers H03F
• CPC Class Codes: H03D 7/163 the local oscillations of at least two of the frequency changers being derived from a single oscillator
• CPC Class Codes: H03L 7/07 using several loops, e.g. for redundant clock signal generation
• CPC Class Codes: H03L 7/23 with pulse counters or frequency dividers
• CPC Class Codes: H04B 1/0003 Software-defined radio [SDR] systems, i.e. systems wherein components typically implemented in hardware, e.g. filters or modulators/demodulators, are implented using software, e.g. by involving an AD or DA conversion stage such that at least part of the signal processing is performed in the digital domain digital baseband systems H04L25/00; digital modulation/demodulation H04L27/00; CDMA H04B1/707; TDMA H04B7/2643; image transmission H04N5/00
• CPC Class Codes: H04B 1/0007 wherein the AD/DA conversion occurs at radiofrequency or intermediate frequency stage
• CPC Class Codes: H04B 1/26 for superheterodyne receivers multiple frequency-changing H03D7/16
• CPC Class Codes: H04B 3/00 Line transmission systems combined with near-field transmission systems H04B5/00
• CPC Class Codes: H04B 7/2609 Arrangements for range control, e.g. by using remote antennas
• CPC Class Codes: H04W 84/14 WLL [Wireless Local Loop]; RLL [Radio Local Loop]

Abstract

A system and method for transmitting a radio frequency (RF) signal in a RF bandwidth over a low bandwidth medium, e.g., in-building unshielded twisted pair (UTP) cabling, which has a transmission bandwidth below the RF bandwidth. The system has a unit for receiving the RF signal and a global reference oscillator for distributing a global reference tone of high stability to the entire system. Local oscillators controlled by this global reference tone deliver RF reference tones of high stability required for mixing the RF signal to obtain an intermediate frequency (IF) signal which is fed through the low bandwidth medium to remote sites. A 10 base T cable network, often pre-existing in many building structures, provides a suitable, cost effective low bandwidth medium for such RF communication. Two of the four twisted pair cables of a UTP cable are sufficient to support bi-directional communication. The remaining twisted pair cables are used to control remote site antenna functions or support other types of communication services such as data LAN, video, wired voice, or other wireless services such as PCS or wireless LAN.

Claims

1. A method for transmitting a RF signal contained in a RF bandwidth over a low bandwidth medium having a transmission bandwidth below said RF bandwidth, said low bandwidth medium comprising a main cable, said main cable comprising a plurality of constituent cables, said method comprising the steps of:

a) receiving said RF signal;

b) providing a global reference tone of high stability at a frequency within said transmission bandwidth of said low bandwidth medium;

c) generating a first RF reference tone of high stability by using a first adjustment signal derived from said global reference tone to control the output of a first local oscillator, such that said first local oscillator generates said first RF reference tone;

d) mixing said first RF reference tone with said RF signal to produce an IF signal within said transmission bandwidth;

e) feeding said IF signal through a first constituent cable of said plurality of constituent cables;

f) generating a second RF reference tone of high stability by using a second adjustment signal derived from said global reference tone to control the output of a second local oscillator, such that said second local oscillator generates said second RF reference tone; and

g) mixing said second RF reference tone with said IF signal fed through said first constituent cable to recover said RF signal; and

h) re-transmitting said RF signal recovered from mixing said second RF reference tone with said IF signal.

2. The method of claim 1 wherein said RF signal is received at a remote coverage site in step (a) and re-transmitted at a base station in step (h).

3. The method of claim 1 wherein said RF signal is received at a base station in step (a) and re-transmitted by an antenna at a remote coverage site in step (h).

4. The method of claim 3 wherein the voltage on a second constituent cable contained in said plurality of constituent cables controls the strength of said RF signal re-transmitted by said antenna.

5. The method of claim 4 wherein the voltage on said second constituent cable is adjusted at a centralized location.

6. The method of claim 1 wherein said main cable is cable selected from the group of cable consisting of 10 base T cable, telephone wire cable, and unshielded cable.

7. The method of claim 1 wherein said plurality of constituent cables comprises twisted pair cables.

8. The method of claim 1 wherein a second constituent cable supports a communication service selected from the group of communication services consisting of data local area network, video, wired voice, wireless personal communications system, and wireless local area network.

9. The method of claim 1 wherein said RF bandwidth is selected from the group of RF bandwidths used for cellular communications, cordless telephony, local RF communications, satellite television, interactive multi-media video, and high-bit rate local area networks.

10. In a system for bi-directional communication, a communication station for transmission of RF signals contained in a RF bandwidth over a low bandwidth medium having a transmission bandwidth below said RF bandwidth, said system comprising a global reference oscillator for providing said system with a global reference tone of high stability at a frequency within said transmission bandwidth of said low bandwidth medium, wherein said communication station comprises:

a) a receiving means for receiving a first RF signal;

b) a local oscillator controlled by an adjustment signal derived from said global reference tone, such that said local oscillator generates a RF reference tone of high stability;

c) a down-conversion means comprising a first mixing means connected to said receiving means and to said local oscillator for mixing said RF reference tone with said first RF signal to produce a first IF signal within said transmission bandwidth, said first mixing means being further connected to said low bandwidth medium for feeding said first IF signal through said low bandwidth medium;

d) an up-conversion means comprising a second mixing means connected to said local oscillator and to said low bandwidth medium for receiving a second IF signal, said second IF signal being produced with a second RF signal and a second down-conversion means at a distant location, said second mixing means further mixing said second IF signal with said RF reference tone to recover said second RF signal; and

e) a transmitting means for transmitting recovered second RF signal.

11. The system of claim 10 wherein said low bandwidth medium is an element of the group of low bandwidth media consisting of 10 base T cable, telephone wire, unshielded twisted pair cable, power cable.

12. The system of claim 10 wherein said low bandwidth medium comprises main cable, said main cable comprises a plurality of constituent cables.

13. The system of claim 12 wherein said constituent cables comprise twisted pair cables.

14. The system of claim 12 wherein said down-conversion means feeds said first IF signal through a first constituent cable of said plurality of constituent cables and said up-conversion means receives said second IF signal through a second constituent cable of said plurality of constituent cables.

15. The system of claim 14 wherein said global reference tone is fed simultaneously with said second IF signal through said second constituent cable to said up-conversion means.

16. The system of claim 14 wherein a second up-conversion means at said distant location receives said first IF signal from said first constituent cable and recovers said RF signal from said IF signal.

17. The system of claim 12 wherein a subset of said constituent cables carry electrical signals from a centralized location to said communication station for controlling said transmitting means.

18. The system of claim 17 wherein said main cable is 10 base T cable and said plurality of constituent cables is four twisted pair cables.

19. The system of claim 12 wherein the voltage on a constituent cable of said subset of constituent cables controls the gain of said transmitting means.

20. The system of claim 12 wherein a subset of said constituent cables carry electrical signals from said communication station to a centralized location for monitoring said communication station from said centralized location.

21. The system of claim 20 wherein said main cable is 10 base T cable and said plurality of constituent cables is four twisted pair cables.

22. The system of claim 20 further comprising an operation test means for testing the operability of said communication station wherein the outcome of said test is carried over said subset of constituent cables to said centralized location.

23. The system of claim 22 wherein said test means is initiated at said centralized location by sending a signal over a second subset of said constituent cables to said communication station.

24. The system of claim 20 wherein the voltage on one constituent cable of said subset indicates that said communication station is drawing power.

25. The system of claim 12 wherein said global reference tone is fed to said communication station through one constituent cable of said plurality of constituent cables.

26. The system of claim 10 wherein said receiving means and said transmitting means of said communication station comprise a diplexer for frequency duplex communication.

27. The system of claim 26 wherein said communication station further comprises an antenna connected to said diplexer.