KR100579784B1 - Oscillation Control System and Method of Wireless Repeater Using Frequency Hopping Method - Google Patents

Abstract

The present invention relates to an oscillation control system and method for a wireless repeater using a frequency hopping method. The oscillation control system of the present invention filters only an intermediate frequency (IF) signal received from a base station and passes a signal of a specific frequency band. And a first local oscillator for generating a local frequency for frequency conversion. A mixing unit for mixing the signal filtered from the SAW filter unit with the frequency of the local oscillation unit to convert the signal into an RF signal, and then performing frequency hopping to an unused frequency band among the frequency bands of the repeater; A detection module unit for filtering a signal converted to an intermediate frequency (IF) after the signal transmitted to the outside through the transmission antenna through the frequency hopping is fed back to the reception antenna and detecting the signal as a DC component; And a microcomputer controlling the operation of the repeater after determining the oscillation degree of the repeater by measuring the degree of separation between the transmission and reception antennas by using the value output from the detection module unit, and comparing and analyzing the reference value stored in itself.

Repeater, Oscillation Control, Isolation, Frequency Hopping, Feedback

Description

Oscillation control system and method of radio repeater using frequency hopping method {OSCILLATION CONTROL SYSTEM OF RELAY STATION USING FREQUENCY HOPPING}

1 is a conceptual diagram illustrating the oscillation phenomenon of a wireless repeater;

2a and 2b are embodiments of a system for controlling oscillation in a conventional general wireless repeater,

3a is a schematic diagram of a wireless repeater according to the present invention;

3b is a block diagram of a system for controlling oscillation in a wireless repeater according to the present invention;

4 is a flowchart illustrating an oscillation control process of a wireless repeater using a frequency hopping method according to the present invention.

** Explanation of symbols for main parts of drawings **

1; wireless repeater 10; receiving antenna

20; transmitting antenna 11; input duplexer

12; low noise amplifier 13, 16; 1st, 2nd mixer

14; first filter unit 15; IF amplifier unit

17; first local oscillator 18; high power amplifier

19; output duplexer 30; oscillation control system

31; second filter unit 32; third mixer

33; second local oscillator 34; fourth mixer

35; third local oscillator 36; third filter

37; detection module 38; microcomputer

The present invention relates to oscillation control of a wireless repeater, and more particularly, by applying a frequency hopping method to a general mobile radio communication repeater method, using a frequency hopping method to suppress oscillation due to feedback by detecting a separation between transmission and reception antennas. An oscillation control system and method for a wireless repeater.

1 is a conceptual diagram illustrating an oscillation phenomenon of a wireless repeater. In the mobile communication, as shown in FIG. 1, in order to facilitate communication between the base station 200 and the mobile station 300 on the mobile terminal side, a wireless repeater is typically provided therebetween. 100 is installed.

The wireless repeater 100 is composed of a receiving antenna 110 for performing transmission and reception with the base station 200 and a transmission antenna 120 for performing transmission and reception with the mobile station 300, the signal received from the base station 200 To the mobile station 300 side or vice versa to transmit the signal received from the subscriber to the mobile station 300 to the base station 200 side. Therefore, the wireless repeater 100 is mainly installed in a radio shading area where radio waves are attenuated by natural or artificial obstacles. In some cases, the wireless repeater 100 may be installed by expanding the service area of the base station 200 or by other needs. At this time, the reception antenna 110 and the transmission antenna 120 of the wireless repeater 100 are installed adjacent to each other without securing the necessary separation distance due to the limitation of the installed space, so that the transmission and reception antennas 110 and 120 are separated from each other. There was a problem that is lowered.

As a result, a signal radiated to the mobile terminal through the transmission antenna 120 is fed back to the reception antenna 110 of the wireless repeater 100 and re-input as an input signal, thereby causing a signal to be oscillated. This oscillation generates signals in unwanted frequency bands and generates various spurious, which not only degrades call quality, but also prevents accurate signal processing, increases power consumption, and damages peripheral circuits and instruments. There is concern.

Accordingly, there is a need for a system for controlling the signal transmitted from the transmission antenna 120 on the mobile station 300 side to be prevented from being fed back to the reception antenna 110 on the base station 200 side.

2A and 2B illustrate embodiments of a system for controlling oscillation in a conventional wireless repeater. Referring to FIG. 2A, the conventional wireless repeater 100 receives a signal from a base station 110. And an input filtering unit 111 for filtering the received signal, a low noise amplifier 112 for amplifying the filtered signal to a good signal-to-noise ratio (S / N ratio), and an intermediate frequency circuit unit for increasing the selectivity of the signal. 113, a high output amplifier 114 for amplifying the signal component to a high output, an output filter 115 for filtering out a high output signal to remove a spurious signal, and radiating the output signal to the mobile terminal side The transmission antenna unit 120 is configured.

Accordingly, when the signal received from the base station is filtered by the reception antenna 110, only a signal corresponding to a desired frequency band is detected, and when the detected signal is amplified by the low noise amplifier 112, the amplified signal is an intermediate frequency circuit unit 113. Increase the selectivity of the signal. Subsequently, after passing through the high output amplifier 114 to amplify the signal component, various spurious signals are removed through the output filter 115 to transmit a signal by the transmission antenna 120.

In the conventional wireless repeater 100 configured as described above, as shown in order to control oscillation caused by a lack of separation (or separation) between the transmission and reception antennas 110 and 120, the transmission antenna unit 120 is installed to the transmission antenna. A signal generator 132 for generating a signal to the unit 120 and a spectrum analyzer 131 installed in the reception antenna unit 110 to measure the received signal. Therefore, when a signal generated from the transmission antenna 120 is fed back and received by the reception antenna 110, the signal level is detected by measuring the spectrum of the signal received through the spectrum analyzer 131, thereby between the transmission and reception antennas 110 and 120. The degree of separation has been measured.

However, such a conventional oscillation control method can be measured at the time of setup of the wireless repeater 100, there is a problem that can not be measured during operation of the wireless repeater 100 to transmit and receive signals between the base station and the mobile station.

Meanwhile, as shown in FIG. 2B, the system for detecting and controlling oscillation in the conventional wireless repeater 100 includes a pilot signal unit 141 for transmitting a pilot signal of a specific frequency to the high power amplifier 114, and an intermediate point. A detection module 142 for detecting a pilot signal fed back by detecting a signal output from the frequency circuit unit 113, and a microcomputer 143 for controlling the driving of the wireless repeater 100 according to the signal detected by the detection module 142. It can be composed of). That is, when the pilot signal of a specific frequency is transmitted to the high output amplifier 114 under the control of the microcomputer 143, the pilot signal is radiated to the free space through the transmission antenna 120 and fed back to the reception antenna 110. The input filtering unit 111, the low noise amplifier 112, and the intermediate frequency circuit unit 113 are sequentially applied. The pilot signal applied in this way was detected from the detection module 142 to measure the degree of separation.

However, unlike the oscillation control system illustrated in FIG. 2A, such a conventional oscillation control system has an advantage of measuring the degree of separation even when the wireless repeater 100 operates, but the frequency signal of the pilot radiated into the free space is G7W. However, there is a problem that violates the legal constraints beyond the frequency format of D7W.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and by applying the frequency hopping method to a general wireless mobile communication repeater method, the frequency radiated through the transmission antenna satisfies the conditions allowed by radio law by measuring the separation between transmitting and receiving antennas. It is an object of the present invention to provide an oscillation control system and method of a wireless repeater using a frequency hopping method to control the oscillation by detecting the oscillation degree by measuring the degree of separation with the measured separation degree.

The oscillation control system of the wireless repeater using the frequency hopping method of the present invention for achieving the above object is configured as follows.

That is, in a mobile communication repeater that receives an RF signal from a base station, converts it into an IF signal, amplifies the IF signal, converts it back into an RF signal, and transmits the signal to a mobile station. And a first local oscillator for generating a local frequency for frequency conversion. A mixing unit for mixing the signal filtered from the SAW filter unit with the frequency of the local oscillation unit to convert the signal into an RF signal, and then performing frequency hopping to an unused frequency band among the frequency bands of the repeater; A detection module unit for feeding back a signal transmitted to the mobile station by the frequency hopping to filter a signal received through a reception antenna of the base station to detect a DC component; And a microcomputer controlling the operation of the repeater after determining the oscillation degree of the repeater by measuring the degree of separation between the transmission and reception antennas by using the value output from the detection module unit, and comparing and analyzing the reference value stored in itself.

On the other hand, the oscillation control method of the radio repeater using the frequency hopping method according to the present invention, by measuring the separation between the transmission and reception antennas of the instrument of the mobile communication radio which is provided to enable smooth communication between the base station and the mobile station to detect and control the oscillation of the signal In the method, the first step of the frequency hopping to the unused frequency band of the radio repeater and radiating through the transmission antenna; And, the signal radiated from the transmission antenna is fed back to the reception antenna and received And converting the feedback signal amplified and converted into an IF signal into a signal of a low frequency band by mixing with a local oscillation frequency; A third step of filtering only a continuous wave component by filtering a signal converted into a signal of the low frequency band by a narrow band filter; A fourth step of detecting a DC component from the continuous wave component and converting the DC component into a voltage value; A fifth step of comparing the converted voltage value with a reference value embedded in the microcomputer to measure the separation degree of the wireless repeater and determine the degree of oscillation; And a sixth step of controlling the operation of the wireless repeater according to the oscillation degree.

Hereinafter, with reference to the accompanying drawings will be described a preferred embodiment of the present invention;

Figure 3a is a schematic diagram of a wireless repeater according to the present invention, Figure 3b is a block diagram of a system for controlling the oscillation in a wireless repeater according to the present invention, Figure 4 is an oscillation of a wireless repeater using a frequency hopping method according to the present invention A flowchart showing the control process.

First, referring to FIG. 3A, the wireless repeater 1 according to the present invention is a general RF mobile communication method, including a reception antenna unit 10 for receiving a signal from a base station, an input duplexer 11, and a low noise amplifier 12. , First mixer 13, first filter unit 14, IF amplifier 15, second mixer 16, first local oscillator 17. A high output amplifier 18, an output duplexer 19, and a transmission antenna unit 20.

In more detail, the receiving antenna unit 10 receives the RF signal from the base station, and the input duplexer 11 functions to separate only the receiving frequency received from the receiving antenna 10 by filtering the input RF signal. The low noise amplifier 12 amplifies the filtered signal into a signal having a good signal to noise ratio. The first mixer 13 converts the signal amplified based on the local oscillation frequency into an intermediate frequency signal (hereinafter referred to as an IF signal) by a downlink mixer, and outputs the frequency. A SAW (surtace acoustic wave) filter that detects only a signal of a desired frequency band within a band is filtered through a signal output from the first mixer 13 to detect an IF signal of a specific frequency band. The IF amplifier 15 amplifies the detected IF signal to adjust the size of the signal, and the second mixer 15 converts the amplified IF signal back to the RF signal through an uplink mixer. At this time, the first mixer 13 and the second mixer 16 are connected to the first local oscillator 17 for generating a local oscillation frequency in order to convert the RF signal into an IF signal and convert the RF signal back into an RF signal. The high output amplifier 18 amplifies the signal converted into the RF signal, and the output duplexer 19 filters the signal amplified by the high output amplifier 18 to remove the unwanted signal, and the transmission antenna unit 20 ) Transmits a signal output from the output duplexer 19 to the mobile terminal to enable signal transmission and reception between mobile stations.

Therefore, the wireless repeater 1 according to the present invention modulates an RF signal received from a base station into an IF signal and performs frequency conversion first, and modulates an IF signal into an RF signal and secondarily performs frequency conversion. It is configured to suppress crosstalk and interference between signals.

Referring to the oscillation control system provided to control the oscillation by measuring the separation between the transmitting and receiving antennas in the wireless repeater 1 configured as described above is shown in Figure 3b.

That is, the oscillation control system 30 of the present invention is provided with a second filter unit 31, a third mixer 32, and a second local oscillation unit 33 for applying a frequency hopping method, and also provide a feedback signal. A fourth mixer 34 for detection, a third local oscillator 35 connected to the fourth mixer 34, a third filter unit 36 for filtering a signal output from the fourth mixer 34, and filtering And a microcomputer 38 for controlling the IF amplifier 25 of the wireless repeater 1 according to the detected result value.

The second filter unit 31 is a SAW filter connected to the rear end of the first mixer 13 and filters the IF signal converted from the first mixer 13 to filter the IF signal of a specific FA frequency band different from that of the first filter unit 14. Only the signal is detected, and the third mixer 32 converts the IF signal detected from the second filter unit 31 back to an RF signal based on the local oscillation frequency of the second local oscillator 33.

The fourth mixer 34 is connected to the first mixer 13 to mix the IF signal applied from the first mixer 13 and the local oscillation frequency described later to convert to the low frequency band, and the third local oscillator 35. Supplies a local oscillation frequency necessary for the conversion in the fourth mixer 34, and the third filter unit 36 outputs only continuous wave components by filtering the low frequency converted signal as a narrowband filter. In addition, the detection module 37 detects the signal (that is, the continuous wave component) filtered by the third filter unit 36, detects the DC component, converts the DC component into a voltage value, and the microcomputer 38 converts the detection module ( 37, the separation degree of the wireless repeater 1 is measured using the detected DC component, and the voltage value corresponding to the DC component is analyzed and compared with the reference voltage value in itself to determine the oscillation state of the wireless repeater 1, and accordingly The operation of the radio repeater 1 is controlled. In the microcomputer 38 for this purpose, a program for measuring the degree of separation of the wireless repeater 1 and a reference voltage value for determining the degree of separation and oscillation should be stored as a voltage value. As described above, the operation of the wireless repeater 1 according to the control of the microcomputer 38 controls the gain of the IF amplifier 15 as described below so that the IF signal amplified during transmission and reception is not weak or excessively large. And a method of temporarily stopping the operation of the wireless repeater 1 so that the output of the wireless repeater 1 is temporarily stopped.

As described above, when the radio repeater 1 using the frequency hopping method hops a frequency into an unused FA band among the frequency bands of the mobile communication repeater and radiates it through the transmission antenna 20, the output signal is fed back to the reception antenna 10. The received and received signal is passed back to the input duplexer 11, the low noise amplifier 12, the first mixer 13 and converted into an IF signal. The oscillation degree is detected by measuring the degree of separation between the transmitting and receiving antennas 10 and 20 by filtering and filtering the low frequency signal. The degree of separation of the radio repeater 1 even when transmitting and receiving signals between the base station and the mobile station while satisfying the conditions permitted by radio law. Can be measured easily.

Hereinafter, a method of controlling oscillation of the wireless repeater 1 using the oscillation control system 30 that performs separation measurement and oscillation detection will be described in detail with reference to a flowchart.

As shown in FIG. 4, an IF signal is first fed back to the receiving antenna 10 from the transmitting antenna 20 and sequentially applied to the input duplexer 11, the low noise amplifier 12, and the first mixing unit 13. The feedback signal is converted into the fourth mixer 31, mixed with the local oscillation frequency signal of the third local oscillator 32, and then converted into a low frequency signal (S1). The converted signal is filtered by the narrow-band filter of the third filter unit 33 to detect only continuous wave components, and the detected continuous wave components are detected by the detection module 34 to be output as current components and converted into voltage values. (S2, S3). Subsequently, the converted voltage value is applied to the microcomputer 35 and used to measure the degree of separation of the wireless repeater 1. First, the magnitude of the converted voltage value and the reference value built in the microcomputer 35 are analyzed and compared ( S4, S5). As a result of analysis, if the converted voltage value is smaller than the reference value, the microcomputer 35 determines that the radio repeater 1 has a high degree of separation, and loops back to the first step, and if the converted voltage value is larger than the reference value, the wireless repeater 1 It is determined that the separation is low to operate the attenuator (S6). That is, by changing the gain of the wireless repeater 1 through the attenuator so that the IF signal amplified during transmission and reception does not become large, it is preferable to change the gain in the direction of reducing the gain of the IF amplifier 15 in the wireless repeater 1 ( S7).

As described above, the process of detecting and controlling the oscillation is repeated in real time. When oscillation is not suppressed even if the gain is changed, the output of the radio repeater 1 is paused to prevent oscillation ( S10).

As described above, according to the present invention, a frequency hopping to an unused frequency band of a wireless mobile communication repeater is radiated through a transmitting antenna, and when the radiated signal is fed back to a receiving antenna and received, it detects and transmits and receives an antenna. By checking the degree of separation and the degree of oscillation, it is effective to increase the separation of the repeater and control the oscillation.

Furthermore, the oscillation of the repeater is prevented in advance so that the base station communication system can be stably driven, and the subscriber can be provided with improved call quality service.

Claims (5)

In a mobile communication wireless repeater for receiving an RF signal from a base station through a receiving antenna, converts it into an IF signal, amplifies the IF signal, converts it back to an RF signal, and transmits the signal to a mobile station through a transmitting antenna. SAW filter unit for filtering the IF signal to pass only a signal of a specific frequency band; And, A first local oscillator for generating a local frequency for frequency conversion; A mixing unit for mixing the signal filtered from the SAW filter unit with the frequency of the first local oscillation unit and converting the signal into an RF signal, and then performing frequency hopping to an unused frequency band of the wireless repeater; A second local oscillator for frequency conversion, a mixer for mixing the IF signal and a signal generated from the second local oscillator and converting the signal into a low frequency band, a narrow band filter for filtering only the converted signal from the mixer and outputting only continuous wave components; A detection circuit converts the continuous wave component outputted from the narrowband filter into a DC component and converts the voltage into a voltage value. The signal transmitted to the mobile station by the frequency hopping is fed back to the receiving antenna of the base station. A detection module unit filtering the DC component; And And a microcomputer for controlling the operation of the repeater after determining the oscillation degree of the repeater by measuring the degree of separation between the transmission and reception antennas with the value output from the detection module unit and comparing and analyzing the reference value stored therein. Oscillation control system of a repeater using a frequency hopping scheme. delete In the method for detecting and controlling the oscillation of the signal by measuring the separation between the transmission and reception antennas of the mobile communication wireless repeater provided to enable smooth communication between the base station and the mobile station, A first step of hopping a frequency to an unused frequency band among the frequency bands of the wireless repeater and radiating it through the transmission antenna; A second step of converting a signal radiated from the transmission antenna into a reception antenna, received, amplified, and converted into an IF signal by mixing with a local oscillation frequency to a low frequency band signal; A third step of filtering only a continuous wave component by filtering a signal converted into a signal of the low frequency band by a narrow band filter; A fourth step of detecting a DC component from the continuous wave component and converting the DC component into a voltage value; A fifth step of comparing the converted voltage value with a reference value embedded in the microcomputer to measure the separation degree of the wireless repeater and determine the degree of oscillation; And And reducing the gain of the IF amplifier so as to reduce the output signal of the wireless repeater according to the oscillation degree, or stopping and controlling the operation of the wireless repeater to temporarily stop the output of the wireless repeater. Oscillation control method of a repeater using a frequency hopping scheme. delete delete

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