KR20050004708A - Oscillation-Controlled Repeater in Wireless Communication System - Google Patents

Abstract

PURPOSE: An oscillation control repeater of a wireless communication system is provided to maintain a stable transmission quality even in a place where minute oscillations occur owing to a deficient isolation between antennas, thereby obtaining more isolations than those of existing RF repeater antennas. CONSTITUTION: A preprocessor(502) protects an overvoltage of a received RF signal, and branches the signal. The first band pass filter(503) filters a desired frequency band. An F-RFM(Forward-Radio Frequency Module)(504) controls a gain, and filters a frequency. An F-ICM(Forward-Interference Cancellation Module)(505) controls a phase of an inputted signal, and removes an oscillated signal. HPAs(High Power Amplifiers)(506,513) amplify a gain of an RF signal passing through the F-ICM(505). The second band pass filter(507) filters the amplified signal. An aftertreatment unit(508) protects an overvoltage while branching a signal. A conversion unit converts the signal of the aftertreatment unit(508). A controller(515) controls the F-RFM(504) and the F-ICM(505) during an oscillation, and displays a substantially inputted signal by using the converted value of the conversion unit.

Description

Oscillation control repeater in wireless communication system {Oscillation-Controlled Repeater in Wireless Communication System}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an oscillation control relay apparatus of a wireless communication system. In particular, the oscillation control of a wireless communication system for maintaining stable transmission quality even in a place where minute oscillation occurs due to lack of isolation between antennas. It relates to a relay device.

In general, the easiest way to relay a radio signal is to receive the radio signal, amplify it, and transmit it immediately. This type of repeater is a radio frequency (hereinafter simply referred to as 'RF') repeater.

1 is a schematic diagram for explaining a method of operation of a general RF repeater.

As shown in the figure, the conventional RF interface-based repeater operates by amplifying a radio signal transmitted from the base station 110 through the repeater 120, and then radiating to the terminal 130 in the shaded area. do.

Meanwhile, when the relay 120 emits a signal through the transmission antenna T _X , the signal may be transmitted to the base station 110 or the terminal 130, but the relay 120 itself may receive the reception antenna R _X. It can also be fed back.

FIG. 2 is a schematic diagram of a signal fed back to the repeater of FIG. 1 as a function of time.

As shown in the figure, the feedback signal includes not only a direct signal between antennas, but also signals coming through various paths by hitting various buildings and objects around. 2 illustrates a state of a signal channel, and each multipath signal may be expressed as a function of time.

The multipath signal is received with the same frequency component but with a different phase and magnitude of the signal. When this operation is repeated, the multipath signal is gradually fed back as the signal amplified by the repeater 120 continues to grow. A rash will occur.

3 is a schematic diagram illustrating a case where oscillation occurs in the signal of FIG. 2.

The above oscillation has a gain of 1 It is abnormal and arises from the point which is in phase.

The feedback oscillation of the RF repeater appears as a correlation between the isolation and system gain between the link antenna and the coverage antenna, and occurs when the difference is less than a certain value. do. This will be described with reference to FIG. 4.

4 is an exemplary diagram for explaining oscillation of a conventional RF repeater.

In FIG. 4, 'P _in ' is RF power input from the base station 110 and 'P _out ' is RF power output from the repeater 120 to the terminal 130. , 'g' is the amplification factor (amplification factor) of the repeater 120, 'f' is the feedback coefficient (feedback coefficient).

In the above case, when the isolation degree is larger than the system gain (ANT ISO> SYS Gain), P _out is as shown in Equation 1 below.

In this case, P _en is environmental noise. On the other hand, when the isolation is less than or equal to the system gain (ANT ISO ≤ SYS Gain), the output signal of the coverage antenna is increased as shown in Equation 2 below, and oscillation occurs.

On the other hand, in order to solve the increasing demand of subscribers, wireless communication providers are providing base station expansion and various kinds of relay devices. However, the optical relay device and the variable speed relay device is expensive, in particular, there is a problem that the optical line occupancy fee is separately required.

In order to solve this problem, an RF oscillation control relay apparatus is disclosed. The RF oscillation control relay apparatus receives a signal emitted from a base station antenna through a repeater link antenna, amplifies the signal, and radiates the signal back to a coverage antenna.

However, such a conventional RF relay device is, as described above, spaced apart from the link antenna and the coverage antenna due to an isolation problem between transmit and receive frequencies. Since the distance must be installed after the repeater gain + 10dB or more to ensure the isolation, there are many problems in installing the equipment. In addition, there is a problem that must be moved directly to the space where the equipment is installed in order to check the presence / absence of the relay device.

The present invention has been proposed to solve the above problems, and to provide an oscillation control relay apparatus of a wireless communication system for maintaining stable transmission quality even in a place where fine oscillation occurs due to lack of isolation between antennas. have.

1 is a schematic diagram for explaining a method of operation of a general RF repeater,

2 is a schematic diagram of a signal fed back to the repeater of FIG. 1 as a function of time;

3 is a schematic diagram illustrating a case where oscillation occurs in the signal of FIG. 2;

4 is an exemplary diagram for explaining oscillation of a conventional RF repeater;

5 is a structural diagram of an oscillation control relay apparatus of a wireless communication system according to the present invention;

6 is a detailed structural diagram of an embodiment of the band pass filter 1 of FIG. 5;

* Explanation of symbols for the main parts of the drawings

110: base station 120: repeater

130: terminal 501: link antenna

502: preprocessing unit 503: band filter unit 1

504: F-RFM 505: F-ICM

506, 513: HPA 507: band filter section 2

508: post-processing unit 509: coverage antenna

510: LNA 511: R-RFM

512: R-ICM 514: R-OSC

515: control unit 516: F-OSC

517: modem unit 518: power supply unit

According to an aspect of the present invention, there is provided an oscillation control relay apparatus of a wireless communication system for oscillating and controlling a forward radio frequency (RF) signal received through a link antenna and radiating it through a coverage antenna. Preprocessing means for protecting the overvoltage of the signal and branching the signal; First band filter means for filtering a desired frequency band; RF means for adjusting gain by filtering the control means and filtering the frequency; Interference canceling means for controlling the phase of a signal input by the control of said control means to remove the oscillated signal; Amplifying means for amplifying the gain of the RF signal passing through the interference canceling means; Second band filter means for filtering the signal amplified by the amplifying means; Post-processing means for branching the signal and protecting the overvoltage; Conversion means for converting the output signal of the post-processing means so that the control means can recognize the presence or absence of oscillation and its intensity; And the control means for controlling the RF means and the interference canceling means at the time of oscillation by using the value converted by the converting means, and controlling to display a signal actually input. To provide.

In addition, the present invention provides an oscillation control relay apparatus of a wireless communication system for oscillating and controlling a reverse RF signal received through a coverage antenna to radiate through a link antenna, wherein the overvoltage of the received RF signal is protected and the signal is branched. Pretreatment means for; First band filter means for filtering a desired frequency band; Low noise amplification means for minimizing noise figure; RF means for adjusting gain by filtering the control means and filtering the frequency; Interference canceling means for controlling the phase of a signal input by the control of said control means to remove the oscillated signal; Amplifying means for amplifying the gain of the RF signal passing through the interference canceling means; Second band filter means for filtering the signal amplified by the amplifying means; Post-processing means for branching the signal and protecting the overvoltage; Conversion means for converting the output signal of the post-processing means so that the control means can recognize the presence or absence of oscillation and its intensity; And the control means for controlling the RF means and the interference canceling means at the time of oscillation by using the value converted by the converting means, and controlling to display a signal actually input. To provide.

In addition, the present invention provides a radio communication system for oscillating the forward RF signal received through the link antenna to radiate through the coverage antenna, and to control the oscillation of the reverse RF signal received through the coverage antenna through the link antenna, An oscillation control relay apparatus, comprising: first processing means for protecting an overvoltage of a forward signal, branching a signal, branching a reverse signal, and protecting an overvoltage; First band filter means for filtering a desired frequency band; First RF means for adjusting the gain of the forward signal and filtering the frequency by the control means; First interference canceling means for controlling the phase of the input forward signal by controlling the control means to remove the oscillated signal; First amplifying means for amplifying the gain of the RF signal passing through the first interference canceling means; Second band filter means for filtering signals input from said first amplifying means and said second processing means; The second processing means for branching a forward signal, protecting an overvoltage, protecting an overvoltage of a reverse signal, and branching a signal; Low noise amplification means for minimizing the noise figure of the reverse signal received from the second band filter means; Second RF means for adjusting the gain of the reverse signal and filtering the frequency by the control means; Second interference removing means for controlling the phase of the reverse signal input by the control of the control means to remove the oscillated signal; Second amplifying means for amplifying the gain of the RF signal passing through the second interference canceling means; First and second conversion means for converting the output signals of the first and second processing means so that the control means can recognize the presence or absence of oscillation and its intensity; And the control means for controlling the RF means and the interference canceling means at the time of oscillation by using the values converted by the first and second converting means, and controlling to display a signal actually input. The oscillation control relay apparatus is provided.

The above objects, features and advantages will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. First of all, in adding reference numerals to the components of each drawing, it should be noted that the same components have the same number as much as possible even if displayed on different drawings. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

5 is a structural diagram of an oscillation control relay apparatus of a wireless communication system according to the present invention.

As shown in the figure, the relay apparatus of the present invention includes a link antenna 501, a preprocessor 502, a band filter unit 503, a forward-radio frequency module (hereinafter, simply referred to as 'F-'). RFM '504, forward-interference cancellation module (hereinafter, simply referred to as' F-ICM') 505, high power amplifier (hereinafter, simply referred to as' HPA ') 506, 513, band filter unit 2 507, post-processing unit 508, coverage antenna 509, low noise amplifier (hereinafter simply referred to as LNA) 510, reverse RF Reverse-radio frequency module (hereinafter simply referred to as 'R-RFM') 511, reverse-interference cancellation module (hereinafter referred to as simply 'R-ICM') 512, reverse A reverse-oscillation module (hereinafter, simply referred to as 'R-OSC') 514, a controller 515, a forward-oscillation module (hereinafter, simply referred to as 'F-OSC') 516, Modem unit 517 and power supply unit 518 It is configured to include).

The RF signal received from the base station 110 through the link antenna 501 is input to the preprocessor 502. The preprocessor 502 serves to protect the overvoltage and to couple the signal.

The band filter unit 1 503 is responsible for filtering a signal of a desired band. This will be described in detail with reference to FIG. 6.

FIG. 6 is a detailed structural diagram of an embodiment of the band filter unit 1 of FIG.

As shown in the figure, the band filter unit 1 503 of the present invention includes a duplexer 601 and a forward-band pass filter (hereinafter, simply referred to as 'F-BPF') 602. And a reverse-band pass filter (hereinafter, simply referred to as 'R-BPF') 603.

The duplexer 601 is responsible for separating or combining the forward signal and the reverse signal, and the F-BPF 602 is responsible for filtering a desired frequency band from the forward signal. Similarly, the R-BPF 603 is responsible for filtering the desired frequency band in the reverse signal. In the present invention, the BPF is applied separately from the duplexer 601 in order to have a bandpass performance of an intermediate frequency (IF) type relay device using the RF method.

The forward RF signal passing through the band filter unit 1 (503) is input to the F-RFM 504, and the F-RFM 504 adjusts gain under the control of the controller 515, and each operator They are responsible for filtering the desired frequency band.

Accordingly, the controller 515 is responsible for controlling gain control of the F-RFM 504 and monitoring the F-RFM 504. At this time, the control unit 515 may monitor the signal input level, output level, system internal temperature, gain adjustment according to the internal temperature of the F-RFM 504.

The F-ICM 506 is responsible for moving the oscillation waveform to a desired position under the control of the controller 515. That is, the F-ICM 506 is responsible for controlling the phase of the input signal, thereby adjusting the phase of the input signal and the output signal, and is responsible for preventing the in-phase condition that is the condition of the oscillation. will be. This can be set by the operator for each field environment to suit the radio environment that changes according to the field environment. Accordingly, the relay device of the present invention maintains stable transmission quality (EVM-Modulation Accuracy) even in a long road where fine oscillation occurs due to lack of isolation between antennas, thereby improving the isolation between existing antennas. It can provide the same effect as the situation with ~ 10dB more.

The HPA 506 is responsible for amplifying the gain of the RF signal passing through the F-ICM 505, and the band filter unit 2 (507) is a third party to the RF signal amplified by the HPA (506) It is responsible for filtering the radio waves without affecting the service band. The configuration is the same as that of the band filter unit 1 (503).

Finally, the post processor 508 serves to couple the signal and protect the overvoltage. The post-processed RF signal may be radiated through the coverage antenna 509.

The F-OSC 514 is responsible for converting the transmission signal into a value recognizable by the controller 515. That is, for example, the F-OSC 514 lowers the carrier frequency band of the mobile communication that is 800MHz or more to the baseband (for example, 45MHz (± 10MHz)), and to the baseband The control unit 515 can recognize the presence of the oscillation and the strength of the input signal with respect to the lowered signal.

Accordingly, the controller 515 may control the oscillation of the signal actually input using the corresponding value, and may display the signal actually input through the display unit (not shown) in a graphic form. That is, the controller 515 controls the F-RFM 504 during oscillation, so that the F-RFM 504 controls oscillation by adjusting gain, and controls the F-ICM 505 during oscillation. Thus, by allowing the F-ICM 505 to change the phase of the signal, it is possible to maintain the best quality (EVM).

In the above, the forward direction has been described, and the reverse direction may be operated in the same concept as the forward direction. However, in the reverse direction, the preprocessor 502 may be referred to as a post processor, and the post processor 508 may be referred to as a preprocessor. In addition, the LNA 510 is responsible for minimizing the noise figure of the system of the reverse signal passing through the preprocessor.

The display unit is operated by a separate personal computer (PC), and the control may be performed on a separate program (GUI) that is in charge of the control of the controller 515.

The modem unit 517 is responsible for enabling the operator to monitor the state of the relay device of the present invention in real time using a wireless modem such as a CDMA method, and to remotely control the power supply unit 518. ) Is responsible for supplying power required for each component of the relay device of the present invention, and reporting its status to the controller 515.

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and various substitutions, modifications, and changes are possible in the art without departing from the technical spirit of the present invention. It will be clear to those of ordinary knowledge.

As described above, the present invention maintains stable transmission quality even in a place where fine oscillation occurs due to insufficient antenna isolation in the RF relay, thereby securing 5 to 10 dB more than the isolation between the existing RF relay antennas. It has the effect of making it possible.

In addition, the present invention has the effect of ensuring the modulation accuracy (EVM) at the time of oscillation, by performing the oscillation control and spectrum, it is very useful in the installation / operation / management of the relay device in the field.

Therefore, the present invention has the effect of eliminating the difficulty in selecting the antenna installation location caused by the existing RF relay and antenna installation, enabling the call at low power, and to provide a stable and uniform quality This has the effect of making the installation and operation convenient.

Furthermore, the present invention has an effect of reducing the economic burden caused by the installation of optical repeaters by expanding a large number of installable areas of the RF relay device that have been used so far and limited to a part of the city outside the city. .

Claims (7)

An oscillation control relay apparatus of a wireless communication system for oscillating and controlling a forward radio frequency (RF) signal received through a link antenna through a coverage antenna, Preprocessing means for protecting the overvoltage of the received RF signal and for branching the signal; First band filter means for filtering a desired frequency band; RF means for adjusting gain by filtering the control means and filtering the frequency; Interference canceling means for controlling the phase of a signal input by the control of said control means to remove the oscillated signal; Amplifying means for amplifying the gain of the RF signal passing through the interference canceling means; Second band filter means for filtering the signal amplified by the amplifying means; Post-processing means for branching the signal and protecting the overvoltage; Conversion means for converting the output signal of the post-processing means so that the control means can recognize the presence or absence of oscillation and its intensity; And The control means for controlling the RF means and the interference canceling means at the time of oscillation by using the converted value by the converting means, and controlling to display a signal actually input; Oscillation control relay device of a wireless communication system comprising a. An oscillation control relay apparatus of a wireless communication system for oscillating and controlling a reverse RF signal received through a coverage antenna to radiate through a link antenna, Preprocessing means for protecting the overvoltage of the received RF signal and for branching the signal; First band filter means for filtering a desired frequency band; Low noise amplification means for minimizing noise figure; RF means for adjusting gain by filtering the control means and filtering the frequency; Interference canceling means for controlling the phase of a signal input by the control of said control means to remove the oscillated signal; Amplifying means for amplifying the gain of the RF signal passing through the interference canceling means; Second band filter means for filtering the signal amplified by the amplifying means; Post-processing means for branching the signal and protecting the overvoltage; Conversion means for converting the output signal of the post-processing means so that the control means can recognize the presence or absence of oscillation and its intensity; And The control means for controlling the RF means and the interference canceling means at the time of oscillation by using the converted value by the converting means, and controlling to display a signal actually input; Oscillation control relay device of a wireless communication system comprising a. An oscillation control relay apparatus of a wireless communication system for oscillating and controlling a forward RF signal received through a link antenna to radiate through a coverage antenna, and controlling and oscillating a reverse RF signal received through a coverage antenna to radiate through a link antenna. In First processing means for protecting an overvoltage of the forward signal, branching the signal, branching the reverse signal, and protecting the overvoltage; First band filter means for filtering a desired frequency band; First RF means for adjusting the gain of the forward signal and filtering the frequency by the control means; First interference canceling means for controlling the phase of the input forward signal by controlling the control means to remove the oscillated signal; First amplifying means for amplifying the gain of the RF signal passing through the first interference canceling means; Second band filter means for filtering signals input from said first amplifying means and said second processing means; The second processing means for branching a forward signal, protecting an overvoltage, protecting an overvoltage of a reverse signal, and branching a signal; Low noise amplifying means for minimizing the noise figure of the reverse signal received from the second band filter means; Second RF means for adjusting the gain of the reverse signal and filtering the frequency by the control means; Second interference removing means for controlling the phase of the reverse signal input by the control of the control means to remove the oscillated signal; Second amplifying means for amplifying the gain of the RF signal passing through the second interference canceling means; First and second conversion means for converting the output signals of the first and second processing means so that the control means can recognize the presence or absence of oscillation and its intensity; And The control means for controlling the RF means and the interference canceling means at the time of oscillation by using the converted values by the first and second converting means, and controlling to display a signal actually input; Oscillation control relay device of a wireless communication system comprising a. The method according to any one of claims 1 to 3, Display means for displaying the input signal according to the control of the control means, to display the presence or absence of the oscillation to the operator Oscillation control relay device of the wireless communication system further comprising. The method according to any one of claims 1 to 3, Modem means for operator to monitor in real time and remote control Oscillation control relay device of the wireless communication system further comprising. The method according to any one of claims 1 to 3, Power supply means for supplying power Oscillation control relay device of the wireless communication system further comprising. The method of claim 3, wherein The first and second band filter means, A duplexer for separating / combining forward signals; A first bandpass filter for filtering signals of a desired frequency band in the forward signal; And Second bandpass filter for filtering signals of a desired frequency band from the reverse signal Oscillation control relay device of a wireless communication system comprising a.