KR20000013066A - Optic relay device for cellular system and method therefor - Google Patents

Abstract

PURPOSE: An optic relay device for cellular system and a method therefor are provided to enhance receipt communication quality by the receipt diversity function provided by a remote base station. CONSTITUTION: The optic relay device for cellular system comprises: an optic matching unit distributing one frequency resource from a main base station providing telecommunication service to a mobile telephone and then connecting it to an optic line; an optic line connecting said optic matching unit and a remote base station; and a remote base station providing telecommunication service to the mobile telephone by using the frequency resource of the main base station connected via said optic line. Said optic matching unit includes the first optic/electric converter converting the high frequency transmission signal of the main base station into an optic signal.

Description

Optical repeater and method for cellular system

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical repeater and method for a cellular system, and in particular, in a digital cellular system (DCS) or a personal communication system (PCS), an ordinary base station and a remote base station are optically connected to the optical base station. An apparatus and method for connecting by using an optical line).

Cellular Mobile Communication System (Cellular Mobile Communication System) divides the entire coverage area into a plurality of wireless base station area composed of cells (cells), a small service area, and centralized control of these wireless base stations to the switching system This allows the subscriber to continue the call while moving from cell to cell.

1 illustrates a structural diagram of a cellular system using Code Division Multiple Access (CDMA) technology. As shown, a base station transceiver base system (BTS) 20, 30, 40 providing a mobile communication service to a mobile station (MS) 10, and a base station controlling a plurality of base stations A base station controller (BSC) 50 and a mobile switching center (MSC) 60 which connects a plurality of base station controllers to a public switched telephone network (PSTN).

Cellular mobile communication systems improve the efficiency of use of scarce frequencies, making them available to more users. A concept introduced to further increase frequency efficiency is a cell division technique, and one of such cell division techniques is a micro cell. Micro cell means a small remote base station (Remote BTS). The micro cell is connected to the main base station (Main BTS) using a micro waveguide or optical path. Remote base stations are mainly installed in underground shopping malls, large buildings, and radio-blocking areas, improving call quality and sharing the calls of the main base stations with high call volume.

The micro cell using the optical path requires a separate optical conversion device for connecting the main base station and the optical repeater. The optical relay includes an optical conversion device installed in the main base station and a remote base station incorporating the optical conversion device. The main base station for the micro cell is designed for remote base stations only. Therefore, the primary base station assigns all channels to the remote base station.

2 is a block diagram of a microcell according to the prior art. As shown, it consists of a primary base station 100 and a remote base station 200 connected to the primary base station using the optical path 1. The main base station 100 includes a digital unit 110 that modulates and demodulates a signal, a radio frequency unit 120 that converts a modulation / demodulation signal and a high frequency signal, and a high frequency signal. It includes an antenna unit 130 for amplifying and connecting to the antenna and the optical matching unit 140 for converting between the electrical signal and the optical signal of the main base station and connecting the main base station by the optical path. The remote base station includes an optical converter 210 for converting an optical signal from an optical path into an electrical signal, a high power amplifier (HPA) 220 for amplifying a signal to be transmitted to a mobile phone, and a mobile phone. Low noise amplifier (LNA) 230 for amplifying a signal received from the receiver, a duplexer 240 for connecting a transmission path and a reception path, and a transmission / reception function for connecting a signal from a remote base station to a mobile phone Antenna 250 is included.

As described above, the conventional optical distribution unit and the remote base station each have one transmission path and one reception path. A base station that is actually operated uses two receive antennas to obtain receive diversity. Therefore, the base station can select a good one of the two signals received from the two receiving antennas. However, since the remote base station has only one reception path, the reception diversity effect cannot be obtained.

The remote base station collects faults generated from internal devices (optical converter, high power amplifier, low noise amplifier, redundancy, filter, and antenna) and reports an alarm to the main base station. . But the operator of the system could not test the call quality of the remote base station when he wanted it. In addition, the remote base station according to the prior art had a problem that it was not possible to test the call quality using a high frequency transmission and reception path.

SUMMARY OF THE INVENTION The present invention has been made to solve the problems of the prior art operating as described above, and implements a reception diversity function in an optical relay device of a base station that provides a communication service to a mobile phone using a code division multiple access technique. It is an object of the present invention to provide an optical relay device and a method for a cellular system.

It is an object of the present invention to provide an optical relay device and method for a cellular system for implementing a call quality test function in an optical relay device of a base station that provides a communication service to a mobile phone using code division multiple access technology.

Other objects and advantages of the present invention will become more apparent from the following detailed description of the invention and the accompanying drawings.

1 is a structural diagram of a cellular system using a code division multiple access technique.

2 is a block diagram of a microcell according to the prior art.

3 shows a configuration diagram of an optical repeater according to the present invention.

4 is a configuration diagram showing a maintenance apparatus of the optical relay device according to the present invention.

<Explanation of symbols for the main parts of the drawings>

10: mobile phone 20, 30, 40: base station

50: base station controller 60: mobile switching center

1,2,3,4: Optical path 100: Main base station

200: remote base station 110: digital unit

120: high frequency unit 130: antenna unit

140: optical matching unit 150: base station processor

160: alarm processing unit 210: light conversion unit

220: high power amplifier 230: low noise amplifier

240: redundant unit 250: dual transmit and receive antenna

300: light matching unit 310: first light / electric conversion unit

400: remote base station 410: second optical / electric conversion unit

420: high power amplifier 430, 440: low noise amplifier

450: redundant unit 460: receiving filter unit

470: dual transmit and receive antenna 480: receive only antenna

320: alarm monitoring and control unit 490: alarm collection unit

495: test phone 500: base station management system

In order to achieve the above object, a preferred embodiment of the optical relay device for a cellular system according to the present invention is a cellular system for providing a mobile communication service to a mobile telephone,

An optical matching unit for distributing one frequency resource in a primary base station providing a mobile communication service to the mobile telephone and connecting the optical link with an optical path;

An optical path connecting the optical matching unit and the remote base station; And

A remote base station that provides a mobile communication service to a mobile telephone by using frequency resources of a primary base station connected through an optical path.

In an embodiment of the present invention, the optical matching unit preferably includes a first optical / electric conversion unit for converting a high frequency transmission signal of the main base station into an optical signal,

The remote base station, the second optical / electrical conversion unit for converting the transmission optical signal transmitted through the optical path into an electrical signal;

An amplifier for amplifying the converted electrical signal to an output level;

A filter unit for removing an unnecessary band from the amplified signal; And

It is preferable to include an antenna for transmitting the filtered signal to the mobile telephone,

Preferably, the optical matching unit and the remote base station support reception diversity.

The remote base station includes: a first receiving antenna and a second receiving antenna for receiving a signal from a mobile telephone;

First and second filter units respectively removing unnecessary bands from two signals transmitted from the first and second receiving antennas;

First and second amplifiers for amplifying the two filtered signals, respectively; And

It is preferable to include a second optical / electrical conversion unit for converting the two amplified signals to an optical signal and transmitted to the optical path, respectively,

Preferably, the optical matching unit includes a first optical / electric conversion unit converting the first and second optical signals transmitted from the plurality of remote base stations through the optical path into electrical signals and transmitting the electrical signals to the main base station, respectively.

The remote base station preferably further includes a test telephone that attempts a test call with the remote base station.

Another preferred embodiment of an optical relay apparatus for a cellular system according to the present invention is a cellular system for providing a mobile communication service to a mobile telephone.

An optical matching unit connected to the main base station and supporting reception diversity;

An optical path connecting the optical matching unit and the remote base station to support reception diversity;

It includes a remote base station connected to the optical matching unit through an optical path and supporting receive diversity.

A preferred embodiment of the optical relay method for a cellular system according to the present invention includes an optical matching unit connecting a main base station and an optical path for providing a mobile communication service to a mobile phone, an optical path connecting the optical matching unit and a remote base station; An optical repeater comprising a remote base station connected to an optical matching unit through an optical path and connecting a mobile telephone in a micro cell to a main base station,

And a test phone for connecting a call through the transmit / receive antenna of the remote base station and diagnosing the radio call quality of the remote base station.

In an embodiment of the invention, the test telephone is preferably embedded in the remote base station and connects the call with the remote base station by the command of the primary base station.

Another preferred embodiment of the optical relay method for a cellular system according to the present invention includes an optical matching unit connecting a main base station and an optical path for providing a mobile communication service to a mobile telephone, and an optical path connecting the optical matching unit and a remote base station. And a remote base station connected to an optical matching unit through an optical path and configured to connect a mobile telephone in a micro cell to a main base station.

Receiving, by the remote base station, two high frequency signals from the mobile telephone respectively through the two receiving antennas;

Filtering each of the two high frequency signals received;

Amplifying each of the two filtered high frequency signals;

Converting the two amplified received signals into optical signals, respectively;

Transmitting the converted two optical signals to the primary base station through the receiving optical path, respectively;

Receiving, by the optical matching unit of the main base station, two optical signals transmitted from the remote base station through the receiving optical path; And

Converting the received two optical signals into electrical signals, respectively, and forwarding them to the main base station.

Another preferred embodiment of the optical relay method for a cellular system according to the present invention includes an optical matching unit connecting a main base station and an optical path for providing a mobile communication service to a mobile telephone, and an optical linking unit between the optical matching unit and a remote base station. An optical repeater comprising a remote base station connected to an optical matching unit through a furnace and an optical path and connecting a mobile telephone in a micro cell to a main base station,

The system operator instructing the primary base station to test the remote base station;

Transmitting, by the main base station, the test signal to the optical matching unit;

Transmitting, by the optical relay unit, a test signal to a remote base station through an optical path;

The remote base station forwarding the test signal to the test telephone;

The test telephone receiving the test signal and consequently forwarding the signal to a remote base station;

Transmitting, by the remote base station, the resulting signal to the optical relay via the optical path;

Transmitting, by the optical relay, the resultant signal to the primary base station; And

Diagnosing the wireless environment of the remote base station using the resultant signal.

In the following description of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted. In addition, terms to be described below are terms defined in consideration of functions in the present invention, and may vary according to the intention or custom of a user or an operator. Therefore, the definition should be made based on the contents throughout the specification.

The optical relay apparatus according to the present invention includes an optical matching unit connecting the high frequency path and the optical path of the main base station, and a remote base station connected to the optical matching unit of the main base station through the optical path and the optical path connecting the optical matching unit to the remote base station. . The optical relay is assigned one sector / one frequency (sub-cell) of the primary base station. Since the optical repeater supports a relatively narrow area compared to the main base station, it is possible to provide a service with only one sub-cell.

The optical relay device according to the present invention supports the reception diversity. The optical matching unit includes one transmission path connecting the transmission path of the base station with the transmission optical path, and two reception paths connecting the two reception paths of the base station with the two reception optical paths, respectively. The remote base station also includes one transmit path and two receive paths. Therefore, the optical matching unit and the remote base station provide receive diversity.

3 shows a configuration diagram of an optical repeater according to the present invention. As shown, the optical matching unit 300 includes a first optical / electric converter 310 connected to one frequency channel of the main base station 100. The first optical / electric converter 310 performs conversion between the high frequency electric signal of the main base station 100 and the optical signal transmitted from the optical paths 2, 3, and 4.

The remote base station 400 includes a second optical / electric converter 410 for converting an optical signal and an electrical signal transmitted through the optical paths 2, 3, and 4 to amplify a transmission signal. A power amplifier (HPA) 420 and two low noise amplifiers 430 and 440 to amplify the received signal. The remote base station uses one transmit / receive antenna 470 and one receive-only antenna 480 to support receive diversity. In other words, the remote base station uses one transmit antenna and two receive antennas. The dual transmit / receive antenna is connected to the high power amplifier 420 and the low noise amplifier 430 through the duplexer 450. The duplexer 450 performs a filtering function to remove the unwanted wave from the signal received through the dual transmit and receive antennas. The reception only antenna is connected to the low noise amplifier through the reception filter 460.

Hereinafter, the transmission operation of the optical matching unit 300 and the remote base station 400 will be described. The main base station 100 transmits a high frequency transmission signal to the first optical / electric converter 310. The first optical / electric converter 310 converts a high frequency transmission signal into an optical signal and transmits the converted optical signal to the remote base station 400 through an optical path.

When the primary base station 100 operates one or more remote base stations 400, the optical matching unit should further include an optical signal distribution unit that distributes the optical signals to one or more remote base stations. The optical signal distribution unit distributes the optical signal transmitted from the main base station and transmits the optical signal to the plurality of remote base stations through the transmission optical path, or combines the optical signals transmitted through the reception optical path from the plurality of remote base stations to the main base station.

The connection between the optical matching unit 300 and the remote base station 400 uses a single mode optical path when the distance is relatively short (for example, 4 km or less). I use it. In this case, the optical matching unit 300 further includes a wavelength division multiplexing matching unit (WDM Interface Unit) that supports a Wavelength Division Multiplexing (WDM) scheme. Unlike the time division multiplexing method, the wavelength division multiplexing method bundles and transmits signals of various wavelengths to an optical fiber. The wavelength division multiplexing matching unit multiplexes and transmits an optical signal when the remote base station is located at a long distance. The optical matching device can then transmit and receive the optical signal using a single optical path without separating the transmission optical path and the reception optical path.

The second optical / electric converter 410 of the remote base station 400 converts the optical signal received from the transmission optical path 2 into a high frequency electrical signal. The large power amplifier 420 amplifies the converted high frequency electric signal and transmits the converted high frequency electric signal to the transmission antenna 460 through the duplexer 450.

Hereinafter, the reception operation of the optical matching unit and the remote base station will be described. The remote base station 400 receives a high frequency signal through two receive antennas 460 and 470. The received high frequency signal is transmitted to the low noise amplifiers 430 and 440 through the duplexer 450 and the filter 460, respectively. The low noise amplifiers 430 and 440 amplify the received signals and transmit the amplified signals to the second optical / electric converters 430 and 440, respectively. The second optical / electric converters 430 and 440 convert the amplified received signals into optical signals, respectively. The receiving optical beams 3 and 4 transmit the converted optical signals to the optical matching section of the main base station.

The first optical / electric converter 310 of the optical matching unit 300 converts the two received optical signals into electrical signals and transfers them to the high frequency reception path of the main base station 100. The primary base station processes the received signal.

The operator of the system uses the base station management system to maintain the main base station and the optical relay. 4 is a configuration diagram showing a maintenance apparatus of the optical relay device according to the present invention. As shown, the optical matching unit 300 includes an Alarm Monitoring and Controlling Unit 320 for processing alarms reported by the remote base station, and the remote base station 400 includes each device (second). An alarm gathering unit 490 collects the faults generated by the optical / electrical converting unit, the amplifying unit, and the filter unit and reports an alarm on the fault to the control unit.

The alarm monitoring and control unit 320 monitors whether an alarm has been reported from the remote base station and transmits the alarm to the alarm processing unit 160 of the main base station. The alarm processor 160 reports the corresponding alarm to the processor 150 of the base station or the base station management system 500. The operator of the system can know whether the remote base station has failed through the base station processor or the base station management system.

The system operator may also instruct the remote base station to attempt a test call through the base station management system 500 or the base station. The base station controller generates a test signal and delivers it to the remote base station 400 through the main base station 100. The remote base station forwards the remote test signal to a test mobile (TM) 495. The test phone 495 receives the test signal through the transmit antenna of the remote base station and passes the result signal to the receive antenna of the remote base station. The remote base station passes the received result signal over the optical path to the primary base station.

The primary base station collects the result signal of the test call and forwards it to the base station controller. The base station controller determines the call environment of the remote base station by calculating a frame error rate (RER) for the test call. If the frame error rate is lower than the predetermined threshold, the base station controller adjusts the output of the large power amplifier of the remote base station. The system operator can collect the resulting signal directly from the primary base station and determine the call environment of the remote base station.

The present invention can be variously modified and can take various forms and only the specific embodiments thereof are described in the detailed description of the invention. It is to be understood, however, that the present invention is not limited to the specific forms mentioned in the detailed description of the invention, but rather includes all modifications, equivalents, and substitutions within the spirit and scope of the invention as defined by the appended claims. It should be understood to do.

In the present invention operating as described above, the effects obtained by the representative ones of the disclosed inventions will be briefly described as follows.

The remote base station according to the present invention further provides a reception diversity function provided by the primary base station to further improve received call quality. In addition, since the test terminal is built in, the call state of the remote base station can be properly monitored.

Claims (12)

A cellular system for providing a mobile communication service to a mobile telephone, An optical matching unit for distributing one frequency resource in a primary base station providing a mobile communication service to the mobile telephone and connecting the optical link with an optical path; An optical path connecting the optical matching unit and a remote base station; And And a remote base station providing a mobile communication service to a mobile telephone by using a frequency resource of a primary base station connected through the optical path. The optical relay apparatus of claim 1, wherein the optical matching unit comprises a first optical / electric conversion unit for converting a high frequency transmission signal of a main base station into an optical signal. The method of claim 2, wherein the remote base station, A second optical / electric converter for converting a transmission optical signal transmitted through the optical path into an electrical signal; An amplifier for amplifying the converted electrical signal to an output level; A filter unit for removing an unnecessary band from the amplified signal; And An optical repeater for a cellular system comprising an antenna for transmitting a filtered signal to a mobile telephone. The optical relay apparatus of claim 1, wherein the optical matching unit and the remote base station support reception diversity. The method of claim 4, wherein the remote base station, A first receiving antenna and a second receiving antenna for receiving a signal from the mobile telephone; First and second filter units respectively removing unnecessary bands from two signals transmitted from the first and second receiving antennas; First and second amplifiers for amplifying the two filtered signals, respectively; And And a second optical / electric converter for converting the two amplified signals into optical signals and transmitting the optical signals to the optical paths, respectively. The optical matching unit of claim 4, wherein the optical matching unit includes a first optical / electric conversion unit converting the first and second optical signals transmitted from the plurality of remote base stations through the optical path into electrical signals and transmitting the electrical signals to the main base station, respectively. Optical repeater for cellular systems. 10. The apparatus of claim 1, wherein the remote base station further comprises a test telephone attempting a test call with the remote base station. A cellular system for providing a mobile communication service to a mobile telephone, An optical matching unit connected to the main base station and supporting reception diversity; An optical path connecting the optical matching unit and a remote base station to support reception diversity; And And a remote base station connected to the optical matching unit via the optical path and supporting receive diversity. An optical matching unit connecting the optical base station and the optical path to provide a mobile communication service to the mobile telephone; In the optical repeater consisting of a remote base station connected to the And a test telephone for connecting a call via a transmit / receive antenna of the remote base station and for diagnosing the radio call quality of the remote base station. 10. The apparatus of claim 9, wherein the test telephone is embedded in a remote base station and connects a call with a remote base station by command of a primary base station. An optical matching unit connecting the optical base station and the optical path to provide a mobile communication service to the mobile telephone, and an optical matching unit through the optical path and optical path connecting the optical matching unit and the remote base station, and the mobile telephone in the micro cell In the optical repeater consisting of a remote base station connected to the Receiving, by the remote base station, two high frequency signals from the mobile telephone respectively through the two receiving antennas; Filtering each of the two high frequency signals received; Amplifying each of the two filtered high frequency signals; Converting the two amplified received signals into optical signals, respectively; Transmitting the converted two optical signals to the primary base station through the receiving optical path, respectively; Receiving, by the optical matching unit of the main base station, two optical signals transmitted from the remote base station through the receiving optical path; And And converting the received two optical signals into electrical signals, respectively, and forwarding them to a primary base station. An optical matching unit connecting the optical base station and the optical path to provide a mobile communication service to the mobile telephone; In the optical repeater consisting of a remote base station connected to the The system operator instructing the primary base station to test the remote base station; Transmitting, by the main base station, the test signal to the optical matching unit; Transmitting, by the optical relay unit, a test signal to a remote base station through an optical path; The remote base station forwarding the test signal to the test telephone; The test telephone receiving the test signal and consequently forwarding the signal to a remote base station; Transmitting, by the remote base station, the resulting signal to the optical relay via the optical path; Transmitting, by the optical relay, the resultant signal to the primary base station; And Diagnosing the wireless environment of the remote base station using the resultant signal.