WO2008059486A2

WO2008059486A2 - System and method for cellular repeater antenna tuning

Info

Publication number: WO2008059486A2
Application number: PCT/IL2007/001388
Authority: WO
Inventors: Yoni Schiff
Original assignee: Cellvine Ltd.
Priority date: 2006-11-13
Filing date: 2007-11-12
Publication date: 2008-05-22
Also published as: WO2008059486A3

Abstract

A cellular repeater system (100B) that receives signals from a donor antenna (110) and transmits them to a coverage antenna (160) and vice versa including, a repeater unit (125) that repeats the signals from the donor antenna to the coverage antenna and vice versa, a feedback unit (147) that extracts indicative information regarding the quality of the signal that is repeated by the repeater unit (125), a remote receiving unit, that receives the indicative information from the feedback unit. The remote receiving unit is adapted to be positioned in the vicinity of the donor antenna to allow adjustment of the position of the donor antenna by a single person responsive to the indicative information provided there from.

Description

SYSTEM AND METHOD FOR CELLULAR REPEATER ANTENNA

TUNING

FIELD OF THE INVENTION The present invention relates generally to the field of antenna tuning and more particularly to a method and system for enabling the tuning of an antenna of a repeater by a single person.

BACKGROUND OF THE INVENTION The continuous growth of cellular phone utilization is accompanied by a collateral growth of cellular repeaters deployment.

A cellular repeater is a system that enables to improve the coverage of cellular communication network in areas where there are either coverage holes in the network or in places where the quality of service requires improvement. A cellular repeater system comprises a primary antenna referred to as a donor antenna, typically located on top of a roof or a high pole connected to a repeater unit that has two I/O ports, the first I/O ports connects the repeater with the donor antenna and a second I/O port connects the repeater with a secondary antenna, referred to as a coverage antenna, which is typically located at a central point within the area in which an improvement of communication is desired, such as a big building, terminal or an underground parking site.

During operation electromagnetic signals transmitted from an already existing antenna referred, to as a site antenna, are intercepted by the donor antenna, the signals are transferred, typically by a coaxial cable to the repeaters first I/O port. The repeater amplifies the signals and a coaxial cable carries the amplified signals from the repeaters second I/O port to the coverage antenna. Cellular phones in the vicinity of the coverage antenna receive signals from the coverage antenna. The repeater system functions similarly in the opposite direction, signals from cellular phones in the vicinity of the coverage antenna are intercepted by the coverage antenna, transferred to the repeater unit for amplification and transmitted by the donor antenna towards the site antenna.

One problem that constantly arises is the donor antenna tuning. This issue arises at the stage of installation and sometimes at later points in time when the system is already functioning, for example when the site antenna is relocated or if the environment around the site antenna undergoes significant changes.

The donor antenna, as opposed to the coverage- antenna, is a directional antenna that must be adjusted and tuned to receive signals from the site antenna. The traditional method for tuning the donor antenna includes sending one technician to connect a measuring device to the repeater unit to get indication on the signal level at the repeater unit. A second technician is located near the donor antenna and adjusts the donor antenna according to the feedback information that is provided by the first technician. Communication between the two technicians can be carried out by cellular phone. It should be noted that such a procedure may last a few hours and requires allocation of two technicians for each repeater installation or for any antenna tuning mission.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method and system for enabling antenna tuning in a repeater system by a single person. The antenna tuning is performed by adjusting the elevation and/or azimuth of the donor antenna.

It is another object of the present invention to provide a system that enables easy tuning of the donor antenna.

It is further an object of the present invention to provide a repeater system wherein results of measurement that are taken from the repeater unit are transmitted and available at the vicinity of the donor antenna. In an exemplary embodiment of the invention, the person tuning the donor antenna is aided by a device with a display that gives indication of the reception strength. Alternatively or additionally, the device gives indication by other methods that can be perceived by the human senses, for example by providing audio signals or tactile signals. Optionally, audio signals may include voice or non voice signals.

There is thus provided according to an exemplary embodiment of the invention, a cellular repeater system that receives signals from a donor antenna and transmits them to a coverage antenna and vice versa comprising, a repeater unit that repeats the signals- from the donor antenna to the coverage antenna and vice versa, a feedback unit that extracts indicative information regarding the quality of the signal that is repeated by the repeater unit, a remote receiving unit that receives the indicative information from the feedback unit, and wherein the remote receiving unit is adapted to be positioned in the vicinity of the donor antenna or inside the donor antenna to allow adjustment of the position of the donor antenna by a single person responsive to the indicative information provided there from. Optionally, the feedback unit is integrated within the repeater unit. In an exemplary embodiment of the invention, the feedback unit includes a measuring unit and a modem unit. In some embodiments of the invention, the modem also serves as the measuring unit. Optionally, the feedback unit is controlled from the remote receiving unit. In an exemplary embodiment of the invention, the remote receiving unit is implemented by a mobile computer. Optionally, the remote receiving unit is implemented by an embedded controller with display capabilities. In an exemplary embodiment of the invention, the remote receiving unit is implemented by an embedded controller with audio capabilities. Optionally, the indicative information includes bit-error-rate (BER) information. In an exemplary embodiment of the invention, the indicative information includes information regarding signal intensity (e.g. power level). Optionally, the indicative information is transmitted by the feedback unit via wireless communication. In an exemplary embodiment of the invention, the indicative information on signal parameters in the repeater unit includes information of bit-error-rate (BER). Optionally, the feedback unit comprises a measuring unit with an electronic circuit that converts the measurements to DC voltages which are provided to a BIAS-T electronic circuit. In an exemplary embodiment of the invention, the BIAS-T electronic circuit provides a DC voltage output only at times when the BER falls below a predefined threshold level. Optionally, the monitoring unit comprises a LED-bar, which accepts the DC voltage from the BIAS-T and displays a representation of a value responsive to the indicative information.- - - - -^■■• -

There is additionally provided according to an exemplary embodiment of the invention, a cellular repeater system that enables antenna tuning by a single person, the system comprising, a donor antenna, a repeater unit that manipulates RF signals, being connected to the donor antenna by an RF conductor, a feedback unit that selectively samples the RF signal in the repeater unit, processes the sampled signal to create indicative information on parameters of the RF signal and transmits the indicative information on the parameters to the donor antenna; and a monitoring unit that is located at the vicinity of the donor antenna, receiving the transmission from the feedback unit and being responsive to the indicative information transmitted by the feedback unit. Optionally, the transmission from the feedback unit to the monitoring unit is passed through the RF conductor.

There is additionally provided according to an exemplary embodiment of the invention, in a cellular repeater system including a repeater unit, a feedback unit, and a remote receiving unit, a method for enabling antenna tuning by a single person, the method comprising the steps of, measuring and calculating parameters of the signals inside the repeater unit by the feedback unit, transmitting indicative information corresponding to the measured parameters by the feedback unit; and intercepting the transmitted indicative information by the remote receiving unit and displaying the indicative information.

There is additionally provided according to an exemplary embodiment of the invention, in a cellular repeater system including a donor antenna, a feedback unit, and an indication unit, a method for enabling donor antenna tuning by a single person, the method comprising, measuring parameters of the signals inside the repeater unit; processing the measured parameters by the feedback processing unit, transmitting the processed measured parameters to the donor antenna direction; and intercepting the transmitted measured parameters by the indication unit and providing a visual display or audio output responsive to the measured parameters.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be understood and appreciated more fully from the following detailed description taken in conjunction with the drawings, wherein:

Fig. IA is a schematic illustration of a repeater system that enables antenna tuning by a single person, using a laptop computer, according to an exemplary embodiment of the invention; Fig IB is a variation of the repeater system that is illustrated in Fig IA, wherein the measuring unit and the modem are integrated into a feedback unit;

Fig 1C is a variation of the repeater system that is illustrated in Fig IA, wherein the signal indication is sampled after being amplified by the repeater; and

Fig. 2 is a schematic illustration of a repeater system that enables antenna tuning by a single person, using a LED bar display located in the vicinity of the primary antenna, according to an exemplary embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION In order to understand the invention, four preferred embodiments according to the present invention are described with reference to Fig. IA, Fig lB, FiglC and Fig 2.

Fig. IA shows a repeater system IOOA including a donor antenna

110, the donor antenna being a directional antenna that should be tuned to receive electromagnetic signals from a site antenna 105, the donor antenna is typically located on top of the roof of a building in a location that provides a line of sight with the site antenna 105, this condition is not a must but usually guarantees optimal receiving conditions.

The signals that are received by the donor antenna 110 are passed through a first coaxial cable 115 to the location of a repeater unit 125 which is typically located in the vicinity of a coverage antenna 160. The location of the coverage antenna is defined according to coverage requirements that the repeater ^""system^{"' "}is expected^' tor satisfy; The coverage^~antenna^~46θ~is— typically- -a— non- directional antenna, thus providing equal coverage around the coverage antenna 160. The repeater unit 125 includes a repeater circuit 140 which amplifies signals in both directions, i.e. signals that arrive from the primary antenna 110 through I/O port 130, are amplified and transmitted through I/O port 135 and a second coaxial cable 155 towards the coverage antenna 160. In the opposite direction, signals from a cellular phone 165 operated by a user 180, are received by the coverage antenna 160 and arrive at I/O port 135 are amplified by the repeater circuit 140 and transmitted through I/O port 130 and the first coaxial cable 115 to the donor antenna 110.

At the stage of installation or later when tuning of the donor antenna 110 is needed, a measuring unit 145 is activated. The measuring unit connects to the repeater via a directional coupler 133. The directional coupler is a standard device that enables the sampling of an RP signal without attenuation of the signal while it is being sampled.

The measuring unit 145 serves for providing indication of the signal level that is being received by the donor antenna 110. While there are various protocols and transmission methods, the measuring unit is specific according to the transmission method, for example in a CDMA cellular system the measuring unit will provide parameters such as the EC/IO ratio and the SQE parameter for IDEN, which give indication relating to the quality of the signal. Optionally, the measuring unit may measure the signal level as well as other parameters such as bit-error-rate (BER) which also provides an indication of the quality of the signal that was received by the donor antenna 110.

The indication on the signal level is provided to a modem unit 150 which transmits the data to a laptop 170 which is used by a technician 175 that is conducting the antenna tuning while getting continuous feedback through the laptop display. The wireless connection link 152 between the modem 150 and the laptop— 170 requires -the- -installation— of— a- -software- application— to— enable-- interpretation of the indication on the signal level to a visual display or audio output at the laptop 170. Optionally the technician 175 is enabled to adjust the antenna while viewing the display of laptop 170 or by listening to an audio signal (e.g. a series of beeps at different rates) produced by laptop 170.

In an exemplary embodiment according to the present invention the modem 150 is bidirectional, thus is able to receive commands that are being sent from the laptop 170 and convert them into operating command to the measuring unit 145, e.g. commands to start sampling the signal, configuration commands to define which parameters should be extracted like BER/FER or signal intensity (RSSI), noise to signal ratio (SQF, S/N) etc. This feature of remotely controlling the measuring unit 145 saves the technician the need to physically access repeater unit 125 while adjusting the antenna. In another exemplary embodiment according to the present invention the measuring unit 145, the modem 150 and the directional coupler are located at another point along the first coaxial cable 115, for example external to repeater 125.

It should be noted that the division as shown in Fig. IA between measuring unit 145 and modem unit 150 shown in Fig. IA is a logical division which does not necessarily reflect a physical division, for example both may be located in the same encasement or in different encasements. Fig. IB shows another exemplary embodiment according to the present invention, very similar to the embodiment shown in Fig IA but where the measuring unit 145 and the modem 150 are integrated in a feedback unit 147 that integrates both functions of sampling the RF signal via the directional coupler 133, and sending indicative information regarding the sampled signal level and BER by wireless communication link 152 to the laptop 170.

Fig. 1C shows another exemplary embodiment according to the present invention, similar to the embodiment shown in Fig IB except that the feedback unit 147 samples the RF signal via a directional coupler 133 that is located in the ^* vicinity of-the second-I/θ-port~135, after-the-signal-was-amplified-by-the-repeater- circuit 140.

In another exemplary embodiment according to the present invention the laptop 170 is replaced with a modem and a simple embedded controller that is capable to provide visual display or audio output.

In yet another exemplary embodiment according to the present invention, the measurement unit 145 may be activated and controlled by remote commands that are issued by the laptop 170 and intercepted by the modem 150 that serves to transmit these commands to the measurement unit 145.

In another exemplary embodiment according to the present invention, the modem 150 or alternatively the feedback unit 147 does not transmit any data to the laptop 170 whenever the BER values exceed a predefined threshold, since the data is meaningless if the error rate is too large. Fig. 2 shows another preferred embodiment of a repeater system 200 according to the present invention. The repeater system 200 includes a directional donor antenna 210 that receives electromagnetic waves from a site antenna 205. The electromagnetic signals are transferred from the primary antenna 210 through a first coaxial cable 215 to a repeater unit 225. The electromagnetic signals pass through the first I/O port 230 of the repeater unit and after amplification by the repeater unit circuit 240 the signals passes through the second I/O port 235 of the repeater unit 225 and through a second coaxial cable 255 to a coverage antenna 260. The signals that are transmitted by the coverage antenna 260 are received by a cellular phone 265 operated by a user 280. As previously described the electromagnetic signals pass also in the opposite direction from the cellular phone 265 through the coverage antenna and the repeater unit 225 until the donor antenna 210.

When tuning of donor antenna 210 is required, the signals that are transmitted from the repeater unit 225 to the coverage antenna 260 are measured at the vicinity of the first I/O port 230. The signals are sampled via a directional coupler 243 and measured by a measuring unit 245. The measuring unit measures

DC voltage level that gives an indication proportional to the strength of the RF signal or alternately proportional to the BER values and provides the DC output to a BIAS-T circuit 250. The BIAS-T circuit 250 sends the indicative DC signal (e.g. that gives an indication proportional to the strength of the sampled RF signal or alternatively to the BER values) to the donor antenna. The DC signal is carried on the electromagnetic signals that are transferred from the repeater unit 225 through the first coaxial cable 215 to the donor antenna 210. A LED bar 270 is provided to display the BER results (or alternatively other signal level parameters) according to the DC level that is provided by the BIAS-T circuit 250. Optionally, other means may be used to display the BER results, for example an LCD display or LEDs.

In another exemplary embodiment of the invention the BIAS-T circuit 250 provides a DC level only when the BER measurement results are below a predefined threshold, thus the technician 275 that performs the antenna tuning gets a clear indication whenever the BER is falling below the predefined threshold, simplifying the task of tuning the primary antenna.

In another exemplary embodiment of the invention the measuring unit 250 provides other parameters that characterize the signal quality according to the specific cellular system and protocols being used.

It should be noted that the functionality of repeater unit 225 is not limited to just amplification of the signals in both direction but typically deals with other parameters, for example traffic measurements however for describing the present invention the detailed functionality of the repeater unit was ignored apart from its amplification functionality.

It should be appreciated that the above described system and methods may be varied in many ways, including omitting or adding elements or steps, changing the order of steps and the type of devices used. It should be appreciated that different features may be combined in different ways. In particular, not all the features— shown— above— m- a— particular— embodiment— are-neeessary— in— every- embodiment of the invention. Further combinations of the above features are also considered to be within the scope of some embodiments of the invention. It will be appreciated by persons skilled in the art that the present invention is not limited to what has been particularly shown and described hereinabove. Rather the scope of the present invention is defined only by the claims, which follow.

Claims

1. A cellular repeater system that receives signals from a donor antenna and transmits them to a coverage antenna and vice versa comprising:

(a) a repeater unit that repeats the signals from the donor antenna__ — ___ ^. — to-the-coverage-antenna-and-viee-versaj— — — - — — - — - — —

(b) a feedback unit that extracts indicative information regarding the quality of the signal that is repeated by said repeater unit; (c) a remote receiving unit that receives the indicative information from said feedback unit; and wherein said remote receiving unit is adapted to be positioned in the vicinity of the donor antenna or inside the donor antenna to allow adjustment of the position of the donor antenna by a single person responsive to the indicative information provided there from.

2. A system according to claim 1, wherein said feedback unit is integrated within said repeater unit.

3. A system according to claim 1, wherein said feedback unit includes a measuring unit and a modem unit.

4. A system according to claim 1, wherein said feedback unit is controlled from said remote receiving unit.

5. A system according to claim I₅ wherein said remote receiving unit is implemented by a mobile computer.

6. A system according to claim I₅ wherein said remote receiving unit is implemented by an embedded controller with display capabilities.

7. A system according to claim I₅ wherein said remote receiving unit is implemented by an embedded controller with audio capabilities.

8. A system according to claim I₅ wherein said indicative information includes bit-error-rate (BER) information.

9. A system according to claim 1, wherein said indicative information includes information regarding signal intensity.

10. A system according to claim 1, wherein said indicative information is transmitted by said feedback unit via wireless communication.

11. A cellular repeater system that enables antenna tuning by a single person, the system comprising: _ tø — A-donorantenna,— — — — - — — —

(b) a repeater unit that manipulates RF signals, being connected to said donor antenna by an RF conductor; (c) feedback unit that selectively samples the RF signal in said repeater unit, processes said sampled signal to create indicative information on parameters of said RF signal and transmits said indicative information of said parameters in the direction of said donor antenna; and (d) a monitoring unit that is located at the vicinity of said donor antenna that receives the transmission from said feedback unit and responds to the indicative information transmitted by said feedback unit.

12. The system according to claim 11, wherein the transmission from said feedback unit to said monitoring unit is passed through said RF conductor.

13. The system according to claim 11, wherein said indicative information on signal parameters in said repeater unit includes information of bit- error-rate (BER).

14. The system according to claim 11, wherein said feedback unit comprises a measuring unit that is adapted to convert the measurements to a DC signal and provide them to a BIAS-T connected to the donor port of the repeater.

15. The system according to claim 14, wherein, said BIAS-T electronic circuit provides a DC voltage output only at times when the BER falls below a predefined threshold level.

16. The system according to claim 11, wherein said monitoring unit comprises means for displaying a value responsive to said indicative information.

15.1n-axellular^eρeater system4neluding-a-repeater--unitra-feedbaΘk unit_τ- and a remote receiving unit, a method for enabling antenna tuning by a single person, the method comprising the steps of: (a) measuring and calculating parameters of the signals inside the repeater unit by said feedback unit;

(b) transmitting indicative information corresponding to said measured parameters by said feedback unit; and

(c) intercepting said transmitted indicative information by the remote receiving unit and displaying said indicative information.

18. In a cellular repeater system including a donor antenna, a feedback unit, and an indication unit, a method for enabling donor antenna tuning by a single person, the method comprising:

(a) measuring parameters of the signals inside the repeater unit; processing said measured parameters by the feedback processing unit; (b) transmitting said processed measured parameters to the donor antenna direction; and (c) intercepting said transmitted measured parameters by the indication unit and providing a visual display or audio output responsive to said measured parameters.