KR20060055204A - Method and apparatus for independently controlling signal levels of forward signal and reverse signal of rf repeater - Google Patents

Abstract

The present invention relates to a method for adjusting a signal level by dividing a forward signal and a reverse signal of an RF repeater and an RF repeater using the same.

The present invention provides a method for adjusting a signal level by dividing a forward signal and a reverse signal in an RF repeater for relaying a signal between a base station and a terminal of a mobile communication system, the method comprising: (a) forwarding an RF signal transmitted to the RF repeater in the forward direction; Dividing the signal into the reverse signal; (b) adjusting a signal level using a forward variable attenuator and a reverse variable attenuator for the forward signal and the reverse signal classified in step (a), respectively; And (c) relaying the forward signal and the reverse signal whose signal levels are adjusted in step (b) to the terminal and the base station, respectively, in the RF repeater. To adjust the signal level.

According to the present invention, it is possible to optimize the relay performance of the RF repeater by dividing the forward signal and the reverse signal of the RF repeater and adjusting signal levels under different conditions.

RF repeater, mobile communication, signal level adjustment, variable attenuator

Description

Method to adjust the signal level by distinguishing the forward and reverse signals of the RF repeater and the applied RF repeater {Method and Apparatus for Independently Controlling Signal Levels of Forward Signal and Reverse Signal of RF Repeater}

1 is a flowchart showing a process of installing and testing a repeater;

Figure 2 is a block diagram showing the internal configuration of the RF repeater according to a preferred embodiment of the present invention,

3 is a flowchart illustrating a method of adjusting a signal level by dividing a forward signal and a reverse signal of an RF repeater according to a preferred embodiment of the present invention.

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

200: RF repeater 205: base station antenna

210, 230: duplexer 215, 240: low noise amplifier

220: forward variable attenuator 225, 250: high power amplifier

235 service antenna 245 reverse variable attenuator

The present invention relates to a method for adjusting a signal level by dividing a forward signal and a reverse signal of an RF repeater and an RF repeater using the same. More specifically, the RF signal transmitted to the RF repeater is divided into a forward signal and a reverse signal, and the forward and reverse signals are adjusted to a desired signal level using a forward variable attenuator and a reverse variable attenuator, respectively, and the signal level is adjusted. The present invention relates to a method for adjusting a signal level by dividing a forward signal and a reverse signal of an RF repeater for relaying a signal to a base station or a terminal, and an RF repeater using the same

As computer, electronic, and communication technologies have made rapid progress, various wireless communication services using wireless networks have been provided. Accordingly, a service provided by a mobile communication system using a wireless communication network is developing not only a voice service but also a multimedia communication service for transmitting data such as circuit data, packet data, and the like.

In order to provide such a service, a mobile communication service is an analog cellular advanced mobile phone system (AMPS) of a first generation mobile communication service, a digital cellular system of GSM (Global System for Mobile) and a CDMA of a second generation mobile communication service. Code Division Multiple Access (PCD), which has developed into a Personal Communication Service (PCS), a 2.5th generation mobile communication service, and recently, the International Mobile Telecommunication 2000, a third generation mobile communication service that has recently been standardized by ITU-R. ) Is commercially available.

IMT-2000 is a mobile communication that aims to implement various application services by combining global direct roaming including personal mobility and service mobility, the same level of call quality as wired telephone, high-speed packet data service and wired / wireless network. With the system, it is possible to provide various multimedia services (AOD, VOD, etc.) at a higher speed as well as improving existing voice and WAP service quality. The IMT-2000 is based on the 3GPP (Generation Partnership Project), and the asynchronous WCDMA (Wideband CDMA) system proposed by 3GPP2 and the synchronous CDMA-2000 (eg, CDMA 2000 1X, 3X, EV-DO) are proposed by 3GPP2 Etc.) are classified and provided.

In various wireless communication systems, a wireless communication service area is divided into a plurality of cells using a frequency reuse concept to expand coverage of a mobile communication network, and a wireless communication service near a center of each cell. Wireless base station (BS: Base Station) is being installed to process. Here, the radius of the cell is determined according to the signal strength of the region or the traffic amount of data. In other words, the cell radius is reduced in urban areas with high traffic volume, and the cell radius is increased in non-city areas with relatively low traffic volume. Do not exceed the.

Despite efforts to support better wireless communication services by appropriately adjusting the cell radius according to the frequency reuse concept and traffic volume, radio shadowing areas such as underground, interior, tunnel, etc. are difficult to reach in urban areas. This exists. Installing a number of new wireless base stations to address the radio shadows in these radio shadow areas is not only economically inefficient due to facility costs, installation costs, and maintenance costs, but can also be undesirable in cell design. There will be.

As a solution to this, it is possible to provide a wireless communication service using a repeater in such a radio shadow area. The repeater amplifies the base station signal and transmits it to the radio wave shadow area so that the signal of the base station can reach the radio wave shadow area, and amplifies and filters the terminal signal so that the signal of the terminal located in the radio wave shadow area can reach the base station. It transmits and solves the problem of radio wave shading.

1 is a flowchart illustrating a process of installing and testing a repeater.

As shown in FIG. 1, when the repeater is to be installed in the radio shadow area, the radio environment of the radio shadow area is measured prior to the installation of the repeater (S100). When it is determined that the signal level is low and it is necessary to install a repeater as a result of the radio wave environment measurement, construction for installing a repeater facility is started (S102). When the repeater is installed, the isolation between the transmitting and receiving antennas of the repeater is measured (S104), and the path loss of the signal between the base station and the repeater is measured (S106).

When the separation and path loss are measured, forward and reverse gains of the repeater are set in consideration of the measured separation and path loss values so that the relay can perform an effective relay (S108). After setting the gain of the repeater, it is checked whether the repeater affects the base station, such as whether the coverage of the base station and the repeater is overlapped to cause interference by the multipath signal (S110). When the repeater is installed, the call quality of the mobile communication service is measured within the coverage of the repeater to test the performance of the repeater (S112).

When the RF (Radio Frequency) repeater receives a radio signal from a base station as a radio type repeater, it transmits the radio signal amplified by the signal to a terminal within the coverage of the RF repeater. In the conventional RF repeater, the same amplification degree is applied without distinguishing a forward signal transmitted from the base station to the terminal and a reverse signal transmitted from the terminal to the base station. In other words, if the amplification degree is increased or decreased to adjust the signal level of the RF repeater, the signal level increases or decreases with the same amplification of the forward signal and the reverse signal.

Conventionally, a mobile communication service is provided by installing an RF repeater in an underground space among radio shadow areas, but recently, a mobile communication service is provided through an RF repeater even in an in-building environment of the ground. In the ground in-building environment, unlike the underground space, there are many complex structures inside the building, so it is necessary to relay signals by adjusting the signal level of the forward signal and the reverse signal differently according to the location of the RF repeater.

However, in the conventional RF repeater as described above, since the signal level of the forward signal and the reverse signal changes together at the same ratio according to the adjusted amplification degree, the desired forward signal level can be precisely optimized to optimize the repeater performance of the RF repeater. There was a problem that the signal cannot be adjusted to the reverse signal level.

In order to solve this problem, the present invention divides an RF signal transmitted to an RF repeater into a forward signal and a reverse signal, and adjusts the forward signal and the reverse signal to a desired signal level using a forward variable attenuator and a reverse variable attenuator, respectively. It is an object of the present invention to provide a method for adjusting a signal level by dividing a forward signal and a reverse signal of an RF repeater relaying a signal whose signal level is adjusted to a base station or a terminal, and an RF repeater using the same.

According to a first object of the present invention, a method for adjusting a signal level by dividing a forward signal and a reverse signal in an RF repeater that relays a signal between a base station and a terminal of a mobile communication system, comprising: (a) Dividing the RF signal transmitted to the RF repeater into the forward signal and the reverse signal; (b) adjusting a signal level using a forward variable attenuator and a reverse variable attenuator for the forward signal and the reverse signal classified in step (a), respectively; And (c) relaying the forward signal and the reverse signal whose signal levels are adjusted in step (b) to the terminal and the base station, respectively, in the RF repeater. To adjust the signal level.

According to a second object of the present invention, in the RF repeater for adjusting the signal level by dividing the transmission signal between the base station and the terminal of the mobile communication system into a forward signal and a reverse signal, the transmission signal received through the antenna of the RF repeater A duplexer (210, 230) for separating the forward signal and the reverse signal; Low Noise Amplifiers (215, 240) for reducing noise components of the transmitted signal and amplifying the signal components; A high power amplifier (225, 250) for amplifying the effective power for wirelessly transmitting the transmission signal; A forward variable attenuator 220 for adjusting a variable step to adjust a signal level of the forward signal received from the low noise amplifier 215 to transmit the signal to the high output amplifier 225; And a reverse variable attenuator 245 that adjusts a variable step to adjust a signal level of the reverse signal received from the low noise amplifier 240 and transmits the signal level to the high output amplifier 250. The present invention provides an RF repeater for adjusting a signal level by dividing a transmission signal between a base station and a terminal into a forward signal and a reverse signal.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. First of all, in adding reference numerals to the components of each drawing, it should be noted that the same reference numerals are used as much as possible even if displayed on different drawings. In addition, in describing the present invention, when it is determined that the detailed description of the related well-known configuration or function may obscure the gist of the present invention, the detailed description thereof will be omitted.

Figure 2 is a block diagram showing the internal configuration of the RF repeater according to a preferred embodiment of the present invention.

As shown in FIG. 2, the RF repeater 200 according to the preferred embodiment of the present invention includes a base station antenna 205, a duplexer 210 and 230, and a low noise amplifier (LNA) 215. 240, forward variable attenuator 220, high power amplifier (HPA) 225, 250, service antenna 235, reverse variable attenuator 245, and the like. can do.

The forward variable attenuator 220 and the reverse variable attenuator 245 adjust the variable levels to adjust signal levels of the forward signal relayed from the base station to the terminal and the reverse signal relayed from the terminal to the base station, respectively. Here, the forward variable attenuator 220 is positioned between the low noise amplifier 215 and the high output amplifier 225, and the reverse variable attenuator 245 is positioned between the low noise amplifier 240 and the high output amplifier 250. Accordingly, the forward variable attenuator 220 and the reverse variable attenuator 245 adjust the signal levels of the forward signal and the reverse signal independently without affecting other direction signals.

On the other hand, the reverse signal transmitted from the terminal to the RF repeater 200, since the strength of the received signal may vary according to the region where the terminal is located, it is necessary to finely adjust the level of the signal rather than the forward signal transmitted from the base station. For example, the forward variable attenuator 220 may include a three-stage variable function to adjust the signal level in three stages, and the reverse variable attenuator 245 may adjust the signal level more precisely than the forward variable attenuator 245. It can be equipped with a five-stage variable function for adjusting the signal level in five steps. However, the variable stage is not limited to the above-described three or five stages, and the variable attenuator having the multi-stage variable function according to the propagation environment between the base station and the terminal may be used as the forward variable attenuator 220 or the reverse variable attenuator 245. It is available.

The forward variable attenuator 220 and the reverse variable attenuator 245 have a rotary switch and can turn a rotary switch to set a variable step, and adjust the signal level of the forward signal or the reverse signal according to the set variable step. do. In addition, the forward variable attenuator 200 and the reverse variable attenuator 245 of the present invention may be mounted on the RF repeater 200 as a built-in type, and may be mounted on an existing RF repeater 200 so as to be mounted on an external type forward variable. Attenuator 220 and reverse variable attenuator 245 may be used.

The duplexers 210 and 230 serve as filters for separating the RF signal transmitted to the RF repeater 200 into a forward signal and a reverse signal. Since the mobile communication system using the frequency division duplex (FDD) method allocates different frequencies to the forward signal and the reverse signal, it is possible to separate the RF signal into the forward signal and the reverse signal using the duplexers 210 and 230. . Although not illustrated in the drawings, a first band pass filter (BPF) is included between the duplexer 210 and the low noise amplifier 215 to pass a signal of a frequency band used in a forward signal, and the duplexer A second band pass filter may be included between the 230 and the low noise amplifier 240 to pass a signal of a frequency band used in the reverse signal.

On the other hand, in the case of using a time division duplex (TDD) scheme in a mobile communication system, since the same frequency is used for the transmission of the forward signal and the reverse signal, the forward signal and the reverse direction are used by using a switch (not shown) instead of the duplexers 210 and 230. The signal can be separated.

The transmission of the signals in the forward and reverse channels using the above-described components of the RF repeater 200 will be described in detail as follows.

In the case of the forward channel, the forward signal transmitted from the base station to the RF repeater 200 is transmitted to the duplexer 210 through the base station antenna 205, and the duplexer 210 transmits the forward signal to the low noise amplifier 215. The low noise amplifier 215 reduces the noise component of the forward signal, amplifies the signal component, and delivers it to the forward variable attenuator 220. The forward variable attenuator 220 adjusts the variable level to adjust the signal level of the forward signal, and forwards the forward signal to the high output amplifier 225. The high output amplifier 225 amplifies the effective power for transmitting the forward signal wirelessly and transmits it to the duplexer 230, and the duplexer 230 transmits the forward signal to the service antenna 235 and transmits it to the terminal.

In the reverse channel, the reverse signal transmitted from the terminal to the RF repeater 200 is transmitted to the duplexer 230 through the service antenna 235, the duplexer 230 transmits the reverse signal to the low noise amplifier 240. The low noise amplifier 240 reduces the noise component of the reverse signal, amplifies the signal component, and transmits the signal component to the reverse variable attenuator 245. The reverse variable attenuator 245 adjusts the variable level to adjust the signal level of the reverse signal, and transmits the reverse signal to the high output amplifier 250. The high output amplifier 250 amplifies the effective power for transmitting the reverse signal wirelessly and transmits it to the duplexer 210. The duplexer 210 transmits the reverse signal to the base station antenna 205 and transmits it to the base station.

3 is a flowchart illustrating a method of adjusting a signal level by dividing a forward signal and a reverse signal of an RF repeater according to a preferred embodiment of the present invention.

As shown in FIG. 3, the forward variable attenuator 220 and the reverse variable attenuator 245, respectively, to allow the RF repeater 200 to adjust the forward and reverse signals to a desired signal level before operating the RF repeater 200. In step S300, a variable step of the control unit is set. The variable step setting may select a desired variable step by rotating the rotary switches provided in the forward variable attenuator 220 and the reverse variable attenuator 245 as described above with reference to FIG. 2.

When the RF repeater 200 is operated after the variable step is set, the RF repeater 200 receives an RF signal between the base station and the terminal (S302). The received RF signal is separated into a forward signal and a reverse signal at the duplexers 210 and 230 and is transmitted to the forward variable attenuator 220 and the reverse variable attenuator 245, respectively (S304). The forward variable attenuator 220 and the reverse variable attenuator 245 adjust the signal levels of the forward signal and the reverse signal, respectively, according to the variable step set in step S300 (S306). The forward signal and the reverse signal whose signal levels are adjusted are transmitted to the air through the service antenna 235 and the base station antenna 205, respectively, and the terminal and the base station receive the forward and reverse signals whose signal levels are adjusted, respectively ( S308).

Therefore, in the RF repeater 200 of the present invention, the variable steps of the forward variable attenuator 220 and the reverse variable attenuator 245 are set according to the propagation environment of the area where the RF repeater 200 is installed, and according to the set variable step. The RF signal is relayed by adjusting the signal levels of the forward and reverse signals.

The above description is merely illustrative of the present invention, and those skilled in the art to which the present invention pertains may various modifications without departing from the essential characteristics of the present invention. Accordingly, the embodiments disclosed herein are not intended to limit the present invention but to describe the present invention, and the spirit and scope of the present invention are not limited by these embodiments. It is intended that the scope of the invention be interpreted by the following claims, and that all descriptions within the scope equivalent thereto shall be construed as being included in the scope of the present invention.

As described above, the present invention enables the relay to adjust the forward signal and the reverse signal to a desired signal level using the forward variable attenuator and the reverse variable attenuator of the RF repeater, respectively, thereby optimizing the relay performance of the RF repeater. It has an effect.

Therefore, even in an in-building environment where there are many complex structures inside the building, it is possible to effectively relay wireless signals by adjusting the signal level of the forward signal and the reverse signal to be suitable for the area where the RF repeater is installed.

Claims (18)

A method of adjusting signal levels by dividing a forward signal and a reverse signal in an RF repeater that relays a signal between a base station and a terminal of a mobile communication system, (a) dividing the RF signal transmitted to the RF repeater into the forward signal and the reverse signal; (b) adjusting a signal level using a forward variable attenuator and a reverse variable attenuator for the forward signal and the reverse signal classified in step (a), respectively; And (c) relaying the forward signal and the reverse signal whose signal levels are adjusted in step (b) to the terminal and the base station, respectively; Method for adjusting the signal level by separating the forward signal and the reverse signal in the RF repeater comprising a. The method of claim 1, In step (b), And adjusting a signal level by dividing a forward signal and a reverse signal in the RF repeater, wherein the signal level of the forward signal is adjusted using the forward variable attenuator having a three-stage variable function. The method of claim 1, In step (b), And adjusting a signal level by dividing a forward signal and a reverse signal in the RF repeater using the reverse variable attenuator having a 5-step variable function. The method of claim 1, And the forward variable attenuator and the reverse variable attenuator include a rotary switch for adjusting a variable step. The method of claim 1, And the forward variable attenuator and the reverse variable attenuator are built in or externally mounted to the RF repeater. The method of claim 1, The forward variable attenuator and the reverse variable attenuator respectively adjust the signal level of the forward signal and the reverse signal according to a predetermined variable step. How to adjust. The method of claim 1, When the mobile communication system uses a frequency division duplex (FDD) scheme, in the step (a), the RF signal is divided into the forward signal and the reverse signal by using a duplexer. A method of adjusting the signal level by separating the forward and reverse signals. The method of claim 1, When the mobile communication system uses a time division duplex (TDD) scheme, the RF signal is divided into the forward signal and the reverse signal by using a switch in the step (a). A method of adjusting the signal level by dividing up the reverse signal. In the RF repeater for adjusting the signal level by dividing the transmission signal between the base station and the terminal of the mobile communication system into a forward signal and a reverse signal, A duplexer (210, 230) for separating the transmission signal received through the antenna of the RF repeater into the forward signal and the reverse signal; Low Noise Amplifiers (215, 240) for reducing noise components of the transmitted signal and amplifying the signal components; A high power amplifier (225, 250) for amplifying the effective power for wirelessly transmitting the transmission signal; A forward variable attenuator 220 for adjusting a variable step to adjust a signal level of the forward signal received from the low noise amplifier 215 to transmit the signal to the high output amplifier 225; And Reverse Variable Attenuator 245 for adjusting the signal level of the reverse signal received from the low noise amplifier 240 by adjusting the variable step and transmitting the signal to the high output amplifier 250. RF repeater for adjusting the signal level by dividing the transmission signal between the base station and the terminal characterized in that the forward signal and the reverse signal. The method of claim 9, The forward variable attenuator has a three-stage variable function, and the three-stage variable function adjusts the variable level to adjust the signal level of the forward signal. RF repeater that adjusts the signal level by dividing it into signals. The method of claim 9, The reverse variable attenuator has a five-stage variable function, and the five-stage variable function adjusts the signal level of the reverse signal by adjusting a variable step. RF repeater that adjusts signal level by dividing into reverse signal. The method of claim 9, The forward variable attenuator and the reverse variable attenuator include a rotary switch for adjusting a variable step. An RF repeater for dividing a transmission signal between a base station and a terminal into a forward signal and a reverse signal to adjust a signal level . The method of claim 9, And the forward variable attenuator and the reverse variable attenuator are internally or externally mounted to the RF repeater. The RF repeater adjusts a signal level by dividing a transmission signal between a base station and a terminal into a forward signal and a reverse signal. The method of claim 9, The duplexers 210 and 230 operate so that the forward signal received from the base station to the RF repeater is transmitted to the terminal via the low noise amplifier 215, the forward variable attenuator 220, and the high power amplifier 225. RF repeater for adjusting the signal level by dividing the transmission signal between the base station and the terminal into a forward signal and a reverse signal. The method of claim 9, The duplexers 210 and 230 operate so that the reverse signal received from the terminal to the RF repeater is transmitted to the base station through the low noise amplifier 240, the reverse variable attenuator 245, and the high power amplifier 250. RF repeater for adjusting the signal level by dividing the transmission signal between the base station and the terminal into a forward signal and a reverse signal. The method of claim 9, The RF repeater includes a first band pass filter (BPF) for passing a signal in a frequency band used in the forward signal and a second band pass filter for passing a signal in a frequency band used in the reverse signal. RF repeater for adjusting the signal level by dividing the transmission signal between the base station and the terminal into a forward signal and a reverse signal. The method of claim 16, The first band pass filter is located between the duplexer 210 and the low noise amplifier (215) RF repeater for adjusting the signal level by dividing the transmission signal between the base station and the terminal into a forward signal and a reverse signal. The method of claim 16, The second band pass filter is positioned between the duplexer (230) and the low noise amplifier (240), RF repeater for adjusting the signal level by dividing the transmission signal between the base station and the terminal into a forward signal and a reverse signal.

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