KR200199766Y1 - Radio relay apparatus having a turnaround wave sense circuit - Google Patents

Abstract

Disclosed is a circuit for detecting a return input between transmission and reception in order to maintain a constant distance between transmission and reception antennas (or RF cables) of a wireless repeater and a carrier detection circuit for automatically adjusting the gain of the wireless repeater. It relates to a wireless repeater having a.

The present invention is a wireless repeater for receiving and amplifying a signal transmitted from the base station through the base station direction antenna, and transmits the amplified signal through the mobile station direction antenna to establish a communication connection between the base station and the mobile station, A low noise amplifier for amplifying only a low noise region by receiving a signal input from the base station and a signal input from the base station and a signal output from the base station, and detecting a return input signal among the signals output from the low noise amplifier, It is possible to secure the stability of the wireless network design by automatically performing the output control by using the up / down converter including a carrier detection section for adjusting the overall loop gain in response to the input signal.

Description

Radio relay apparatus having a turnaround wave sense circuit

The present invention relates to a wireless repeater having a carrier detection circuit.

More specifically, a carrier wave detection circuit for automatically adjusting the gain of the radio repeater by detecting a return input level between the transmitter and the receiver in order to maintain a constant interval between the transceiver antennas (or the RF cable) of the radio repeater. It relates to a wireless repeater having a.

The global telecommunications market is changing rapidly. Wired and wireless communication is the field where the daily changes in quantity and quality are different from those in other industries or technologies.

In particular, in the field of wireless communication, many countries around the world are making bold and active investments in order to accelerate the construction of the world's single communication network in the 21st century. Many years ago, pagers and city phones have changed the perception of wireless to many people and have been enough to unlock the potential of the future wireless mobile market.

In the wireless communication field described above, large companies have entered the mobile communication market with the introduction of cellular and PCS as the CDMA (code division multiplex) technology has been announced in the late 20th century and the digital revolution has spread rapidly. Since then, the market of data communication, wireless subscriber network (WLL) and TRS (frequency public communication) has emerged, and new concept of mobile communication that can overcome regional and spatial limitations by using satellite called IMT-2000, called next-generation mobile communication, is emerging. Reached the flag.

Therefore, general subscribers use the wireless communication method described above to make a call with the other party. Basically, in order to be able to do this, a base station, a wireless repeater, a mobile station and a mobile terminal should be provided.

At this time, the configuration and operation of a general wireless repeater is shown in the accompanying drawings, the base station transmits a signal having a predetermined frequency, and the base station direction antenna provided in the wireless repeater receives the above-described predetermined signal received duplex filter Output as (10).

Then, the duplex filter 10 filters only the preset frequencies among the above-described signals and outputs them to the low noise amplifier 20, and the low noise amplifier 20 amplifies only the low noise region among the signals having the filtered frequency.

The signal amplified by the low noise amplifier 20 is input to the up / down converter 30, and the up / down converter 30 is up to a frequency sufficient to transmit the frequency of the input signal through the mobile station antenna. Or down convert.

The signal having this up or down converted frequency is amplified to the maximum output through the driving amplifier 40 and the HPA 50, and the signal thus amplified to the mobile station through the duplex filter 10a and the mobile station direction antenna. It is sent out.

Conversely, the signal sent from the mobile station is again received through the mobile station directional antenna, and the signal filtered through the duplex filter 10a is linearly amplified by the low noise amplifier 20a.

The amplified signal is input to the up / down converter 30a, the up / down converter 30a upconverts the frequency of the input signal, and the upconverted signal is driven. The amplified part 40a and the HPA 50a are amplified to have the maximum output, and the signal thus amplified to the maximum is transmitted to the base station through the base station direction antenna, so that the mobile station and the base station are mutually connected.

All the above operations are performed according to the control signal of the controller 60.

In other words, the above-mentioned wireless repeater is a device for amplifying the signal received from the base station to allow a call to the subscriber in the shadowed area and sending it to the subscriber. The wireless repeater has a close relationship with the surrounding environment. There is a problem that the input signal can not maintain a constant value by the surrounding environment.

That is, the received signal from the base station to the wireless repeater is a transmission signal amplified by the wireless repeater and output to the subscriber side. When the received signal is re-received by the base station antenna, the strength of the retransmitted return input signal is determined by the surrounding environment. Is changed by.

In particular, in Korea, which has a distinct four seasons with a severe temperature difference in each season, it is more sensitive to the above-mentioned return input signal. This return input signal has a great influence on the operation of the communication network, and not only disables the subscriber's call. In addition, the wireless repeater, of course, affects the base station, causing several base stations to cause anomalies or oscillations, saturating the base station, and severely interrupting the service of the base station.

Therefore, an object of the present invention is to maintain a constant interval between the transmitting and receiving antennas (or RF cable) of the radio repeater to solve the above problems. To provide a wireless repeater having a carrier detection circuit for automatically adjusting the gain of the wireless repeater by detecting the return input level between the transmission and reception.

1 is a block diagram schematically illustrating the configuration of a wireless repeater according to the prior art;

2 is a block diagram for schematically illustrating a configuration of a wireless repeater according to the present invention;

3 is a block diagram schematically illustrating a configuration of a carrier wave detection circuit unit applied to FIG. 2;

4 is a graph showing the detection level of the output and the return input signal of the wireless repeater.

* Description of Signs of Main Parts of Drawings *

110: gain control unit

111: carrier detector 112: controller

113: variable attenuator 114: local oscillator

115: frequency converter

In order to achieve the above object, a radio signal received from the base station according to the present invention is received and amplified through a base station directional antenna, and the amplified signal is transmitted through a mobile station directional antenna to establish a communication connection between the base station and the mobile station. A repeater comprising: a low noise amplifier for amplifying only a low noise region by receiving a signal inputted from a base station antenna and a signal inputted from a base station antenna and a signal output from the base station to a mobile station; And an up / down converter including a carrier detection unit for detecting a signal and adjusting an overall loop gain in response to the detected return input signal.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Figure 2 is a block diagram for schematically illustrating the configuration of a wireless repeater according to the present invention, in the present invention is shown that the carrier detection circuit 110 is included in the inside of the wireless repeater, in particular up / down converter 100 Although limited to, but described, the carrier wave detection circuit 110 may be variously configured externally or separately from the wireless repeater according to the use range and characteristics of the above-described wireless repeater.

Meanwhile, components except for the carrier wave detection circuit 110 are similar to those of FIG. 1, and thus a detailed description thereof will be omitted.

As shown in FIG. 3, the carrier wave detection circuit 110 detects a loop gain by receiving a return input signal from a signal transmitted through a mobile station direction antenna (or a base station direction antenna), and detects loop gain. Gain control is performed so as not to exceed 1 and then amplified to maximum output.

3 is a block diagram schematically illustrating a configuration of a carrier wave detection circuit 110 applied to FIG. 2.

As shown, the carrier detector 111 measures the loop gain by measuring the level of the feedback input signal among the signals input from the low noise amplifier 20 described above.

The controller 112 compares the loop gain measured by the carrier wave detector 111 described above with a preset loop gain, and outputs a control signal for adjusting the loop gain according to the comparison result.

The controller 112 includes the same components as the control unit 60 of FIG. 2 when the carrier detection circuit 110 is provided inside the wireless repeater, or the control unit 60 when provided outside the wireless repeater. It is a component that can be configured separately.

Therefore, in the detailed description of the present invention will be described limited to the controller (112).

The variable attenuator 113 attenuates the input signal so that the loop gain of the signal input through the antenna can be maintained below a predetermined value in response to the control signal input from the controller 112 described above.

The frequency converter 115 is a frequency of the signal input from the variable attenuator 113 described above. The number is shifted to have a frequency preset by the local oscillator 114 to obtain a signal having the desired frequency.

The above-described local oscillator 114 inputs different frequencies to the frequency converter 115 according to frequencies allocated to cellular phones, PCS, and the like.

With reference to the accompanying drawings, the operation of the wireless repeater having the carrier detection circuit according to the present invention configured as described above will be described in more detail.

First, the carrier detection technique of the carrier detector 111 is a method for measuring a coupling loss between a base station direction antenna and a mobile station direction antenna in an operating state of a wireless repeater, and offsets the frequency of the transmission signal from the received signal to receive the received signal. As a technique for detecting the bit of P, it is described using a formula as follows.

In order to operate the wireless repeater in a stable condition, Similarly, the return signal loop gain should be less than one.

According to the above equation, the carrier detector 111 detects the loop gain of the transmitted signal, and the detected loop gain is input to the controller 112. The above-described controller 112 compares the loop gain detected by the carrier wave detector 111 with the preset loop gain, and outputs a control signal according to the comparison result.

That is, as a result of the comparison, when the loop gain detected by the carrier detector 111 is greater than the preset gain, the controller 112 controls the control signal to attenuate the magnitude of the signal input through the base station direction antenna (or mobile station direction antenna). Will print

The control signal of the controller 112 is input to the variable attenuator 113, and the variable attenuator attenuates the signal input through the base station direction antenna (or mobile station direction antenna) by the above-described control signal to the frequency converter 115. Output

Then, the frequency converter 115 shifts the input signal by the frequency input from the local oscillator 114 and outputs it to the mobile station through the amplifier 116. The loop gain at this time is obtained by Equation 2 to be described later. Can be.

In addition, when double detection of a neighboring signal input through the base station direction antenna (or mobile station direction antenna) described above, a bit is generated, and the carrier detector 111 compares the DC component and the AC component of the bit described above. The loop gain can be measured.

In addition, as described later, the carrier detector 111 compares the DC and AC components of the bit to measure the loop gain.

As described above, the loop gain detected by the carrier wave detector 111 and the output characteristics of the detector and the output characteristics of the wireless repeater will be described with reference to an example illustrated in FIG. 4. There is usually no change at -10dB, and increases rapidly around 0dB to reach oscillation.

Therefore, the inspection of the output of the existing radio repeater alone can not identify the signs until just before the oscillation, the call quality degrades the loop gain below -5dB, and rapidly deteriorates near the oscillation point.

Therefore, the carrier wave detector 111 performs gain control by adjusting the gain of the oscillation preventing radio repeater 113 with the variable attenuator 113 so that the return signal does not increase and the loop gain does not exceed 1 when there is a risk of oscillation.

The above-described carrier detection unit 110 is the front end, the rear end, or each circuit of the up / down converter. It can be inserted and operated in the middle of a cow. It can also be installed separately on the outside of the wireless repeater.

As described above, the present invention can provide stable communication service by preventing oscillation of the device by first measuring gain of the transmission input level between the base station direction antenna and the mobile station direction antenna and automatically adjusting the gain.

Second, the present invention is applicable to all wireless communication fields including cellular, PCS, IMT-2000, and TRS, and by applying the present invention, the failure rate of equipment can be reduced to ensure reliability.

Third, the wireless repeater to which the present invention is applied has an effect that the maintenance and reinvestment costs are significantly reduced.

Although described above with reference to a preferred embodiment of the present invention, those skilled in the art various modifications of the present invention without departing from the spirit and scope of the present invention described in the utility model registration claims below And can be changed.

Claims (4)

In the wireless repeater for receiving and amplifying a signal transmitted from the base station through the base station direction antenna, and transmits the amplified signal through the mobile station direction antenna to establish a communication connection between the base station and the mobile station, Receives a signal input to the mobile station through the mobile station direction antenna and a signal transmitted from the base station through a base station direction antenna to detect the return input signal, and adjust the overall loop gain in response to the detected return input signal Wireless repeater having a carrier detection circuit comprising a carrier detection. The method of claim 1, wherein the carrier detection unit A carrier detector for measuring a loop gain by measuring a level of a transmission input signal among signals input through the base station directional antenna; A controller for comparing the loop gain measured by the carrier detector with a preset loop gain and outputting a control signal for adjusting the loop gain according to the comparison result; A variable attenuator configured to attenuate the signal in response to a control signal input from the controller so that the loop gain of the signal input through the antenna is kept below a predetermined value; And And a frequency converter configured to shift the frequency of the signal input from the variable attenuator to have a preset frequency by a local oscillator. The method of claim 1, And a controller for checking a loop gain of the wireless repeater through the return input signal input from the carrier detection unit and outputting a control signal for increasing or decreasing the total loop gain of the wireless repeater according to the check result. The carrier detection unit receives a signal output from the mobile station through the mobile station direction antenna and a signal transmitted from the base station through a base station direction antenna, detects the transmission input signal, and sends the detected signal to the controller. And a total wave gain adjustment in response to a control signal input in response to the return input signal from the control unit. The method of claim 3, wherein the carrier detection unit A carrier detector for measuring a loop gain by measuring a level of a transmission input signal among signals input through the base station directional antenna; A variable attenuator configured to attenuate a signal such that a loop gain of a signal input through an antenna is maintained below a predetermined value in response to a control signal input from the controller; And And a frequency converter configured to shift the frequency of the signal input from the variable attenuator to have a preset frequency by a local oscillator.