KR20120128411A - Wireless switching device for mobile communication and control method with PAPR detection - Google Patents

Abstract

PURPOSE: A wireless repeater for mobile communication and a control method using a PAPR(peak-to-average power ratio) detection method are provided to automatically control gains according to isolation degrees regardless of the kind of a signal. CONSTITUTION: When antenna isolation is converted, the different between the maximum voltage value and the minimum voltage value of a power value transferred from a second detection apparatus(186) to a second control unit(174) is converted. The second control unit compares the reference value and the stored value. A first control unit(129) increases the gain of a repeater by converting the control signal of voltage control attenuators(119,143) when wave quality is good. When wave quality is bad, the first control unit reduces the gain of the repeater. [Reference numerals] (129) Controller 1; (174) Controller 2

Description

Wireless switching device for mobile communication and control method with PAPR detection

The present invention relates to a wireless repeater for mobile communication and a control method thereof, and more particularly, a wireless repeater for mobile communication and its wirelessly capable of automatically selecting an FA for measuring antenna separation and automatically adjusting gain according to the degree of separation. It relates to a control method in the repeater.

When the wireless repeater with antennas installed in both directions receives the signal of the base station and the signal from the terminal and copies it to the shadow area, the repeater is of good quality according to the size of the antenna isolation between the antenna of the base station and the antenna of the terminal. The limit of gain that can amplify the signal is determined.

Specifically, the configurable gain of the repeater should be 10-15 dB lower than the antenna separation to enable communication with the terminal or the base station without error. The numerical value is expressed in terms of waveform quality (Rho) in a base station or a terminal. If the gain of the antenna is changed to 85dB and 65dB under the condition that the gain of the repeater is 60dB, the peak to average power ratio (PAPR) within the service frequency of the repeater is less than 15dB less than the antenna separation. If the characteristics of the signal input from the signal is maintained as it is (see FIG. 2), and the signal is measured using a measuring instrument, the quality of the waveform is measured to a value of 0.912 or more, which is required by the base station or the terminal. However, if the gain increases further and the antenna separation and the difference of about 0 ~ 4dB occur, the signal waveform in the service band of the repeater shows a distorted signal (ripple of in-band) that is different from the waveform of the signal sent from the base station or the terminal. If the signal is measured using the instrument to measure the quality of the waveform, it may be out of control standards, and the gain will increase and the repeater will start to oscillate if the gain of the repeater is greater than the antenna separation value. As a result, the output signal is gradually increased, and the signal output from the repeater becomes impossible to communicate with the terminal or the base station, resulting in deterioration of overall system performance such as system capacity.

For this reason, the repeater uses various methods to check and manage antenna separation in various ways.

As described above, there is no problem in the method of detecting the peak level, which varies depending on the degree of antenna separation, in the case of a small peak to average power ratio (PAPR) as described above. It is not applicable to the service of GSM signal. The reason is that in case of EVDO signal, EVDO signal shows different transmission envelope mask of active half-slot and idle half-slot, which shows very large PAPR unlike CDMA signal in 1.2288MHz. (See Figure 3). Due to the characteristics of these signals, the output voltage of the detector which detects the magnitude of the signal in the RF or IF band is different from that of the CDMA, CW, and WCDMA signals. This can be interpreted to be similar to applying AM modulation or gate to the CDMA signal. For this reason, the detection voltage using a narrow band filter within 1.2288 MHz, which is an index of antenna separation, can show a large difference. Even though the repeater transmits high quality signals due to the antenna separation, there is a case where the gain of the repeater needs to be reduced, and even if the gain is reduced, the antenna separation is continuously maintained in the case of a signal condition having a large PAR in the band. It will appear very small.

Next, in the case of the GSM signal, as shown in Fig. 3, the magnitude of power in the band of 500 KHz is also severely different from that of the CDMA or W-CDMA signal. For this reason, the PAPR of a signal within 1 MHz based on the center frequency of the signal in the service frequency band is the same as the two communication systems, CDMA and W-CDMA. Only in the case of waveforms in which PAPR appears very small (see FIG. 3), it is applicable.

Currently, SKDO, KTF in Korea, KDDI in Japan, and USPCS bands in the US provide EVDO and CDMA services simultaneously (see FIGS. 4 and 5), and the frequencies allocated by service companies and regions are not consistent. It is distributed differently, and according to the service company's purpose, it is possible to modify CDMA and EVDO by applying a small change of system (some modules). If the designed and manufactured repeater detects the PAPR in the EVDO signal band, malfunction is predicted as described above. In particular, the USPCS band in the United States may include GSM service, so the probability of a repeater malfunction in the region is even higher, so much improvement is required to actually service in the field.

The present invention has been proposed to solve the above-mentioned conventional problems, and measures the antenna separation degree measured by the transmit / receive antenna separation applicable to any modulation system such as CDMA, W-CDMA, GSM, EVDO, etc. This is an implementation of automatic gain control that enables the transmission of high quality signals to the terminal and base station by using the CDMA, EVDO, and GSM signals. An object of the present invention is to provide a wireless repeater for mobile communication and a method of controlling the same, by implementing an output detection circuit that can be reduced to prevent overloading of components due to error detection.

In order to achieve the above object, in a wireless repeater according to a preferred embodiment of the present invention, all FAs in a band serviced by the repeater detect active FAs whose signal strength is greater than or equal to a predetermined magnitude, and the FA signal. If you need to determine whether the frequency components are CW, CDMA, EVDO, or GSM, and service the CDMA signal, measure the PAPR within the 450 KHz band from the center of the CDMA signal, or select an inactive adjacent FA to reduce the noise. Measure the PAPR of the level and adjust the gain of the repeater to the difference value.If you need to service an EVDO or GSM signal other than a CDMA signal, select an inactive adjacent FA to measure the PAPR of the noise level to the difference value. If you need to adjust the gain of the repeater and service EVDO, CDMA, and GSM simultaneously, the nearest non-active FA Selected by measuring the PAPR of the noise level and adjusting the gain of the repeater to the difference value. Finally, in order to detect the output power of GSM, EVDO, CDMA signal repeaters using one output signal detector, a delay circuit is applied to the output of the detector to detect the magnitude of the CDMA signal and GSM, EVDO signals. It prevents the overload and malfunction of the repeater termination amplifier (HPA) due to the malfunction of the repeater and accurately monitors and controls the power output by the repeater according to the signal, and the gain of the repeater is controlled by the value of antenna separation. It is to enable the control automatically in the changing mobile communication environment.

As described in detail above, according to the present invention, by applying an algorithm for selecting an FA to measure the isolation of the transmit / receive antenna, the PAPR is not measured based on the center frequency of the FA in which the waveform is present. If a FA with no signal is selected among adjacent FAs and periodically monitored, it is possible to transmit a good signal to a terminal, a base station or a repeater, and the repeater adapts itself and changes the waveform in the environment according to the change of surrounding conditions. Allows self-adjustment with the maximum gain allowed for Waveform Quality (Rho) and more accurate measurement of antenna separation even if the incoming signal is a signal of any type, even if the signal has a large PAPR or narrow BW in the serving FA To make it possible.

On the other hand, the present invention is not limited only to the above-described embodiments and can be carried out by modifications and variations within the scope not departing from the gist of the present invention, the technical idea that such modifications and variations are also within the scope of the claims Must see

1 is a diagram showing waveforms of a repeater output signal when the antenna separation is 15 dB or more than the set repeater gain;
2 is a diagram showing waveforms of a repeater output signal when the antenna separation is 5 dB or more than the set repeater gain;
3 is a diagram illustrating waveforms on a spectral screen according to signal types (CDMA, W-CDMA, EVDO, GSM);
4 is a diagram showing the service status by FA and region of the domestic mobile communication service provider 1;
5 is a diagram showing the status of services by FA of the domestic mobile communication service provider 2;
6 is a block diagram for output power detection according to the type of signal of the wireless repeater applied to the present invention;
7 is a waveform diagram of detection voltages at the front and rear ends of the delay circuit unit shown in FIG. 6;
8 is a block diagram for service frequency selection and signal type determination applied to the present invention;
9 shows FA (in case of A, B, C band of USPCS CDMA) within 15 MHz band,
FIG. 10 is a flowchart for finding an FA in which a signal having a predetermined intensity or more is detected among 11 FAs in an IF1 path; FIG.
11 is a flowchart for finding FA with low ripple among FAs having a signal in IF2 Path;
12 is a flow chart for finding an FA to measure the separation from among the CDMA signals in a repeater with a built-in CDMA modem,
13 is an overall flowchart for finding an FA to measure antenna isolation;
14 is an overall block diagram of a repeater to which the present invention is applied.
15 is a view illustrating a PAPR;
Description of the Related Art
101: repeater antenna in the direction of the base station 102, 127: duplex
126, 147: isolator 121, 145: directional coupler
119, 143, 164, 177: voltage controlled attenuator
110, 116, 140, 135, 166, 179: frequency up / down converter
113,138: seismic band pass filter 124,150: delay circuit part
129, 174 controller 127 repeater antenna in the terminal direction
122, 148, 173, 186 detector 170, 183 narrowband pass filter
108, 130, 165, 178,: local oscillator
107, 109, 131, 115, 151, 153, 157, 161: bidirectional separator
111, 136, 167, 180: low pass filter
105, 117, 134, 141, 154, 158, 162, 175: band pass filter

Hereinafter, a wireless repeater for mobile communication and a control method thereof according to an embodiment of the present invention will be described with reference to the accompanying drawings.

A circuit for finding an active FA (FA having a signal of a certain power or higher) among the signals input to the wireless repeater implemented in the present invention, and finding a CDMA signal and a non-CDMA signal among the found FAs Is shown in FIG. 8 and is mentioned.

As shown in FIG. 8, FAs requiring amplification are found in signals input to the repeater, and FAs with the maximum power are selected from valid FAs (FAs in which a value above a certain power is detected in the service frequency band of the repeater). It was configured as shown in Figure 8 to select the FA for measuring the antenna separation.

When explaining the function of each block, the IF signal (IF: band intercepted by the size of the bandwidth (BW, Bandwidth (BW)) that the repeater can service through the main path of the FWD path of the repeater) The intermediate frequency is separated and mixed with the reference frequency of the local oscillator (typically using 10 MHz) and input to PAD7, the input part of the measurement frequency search block. This signal is separated in two directions so that one signal leaves only the reference frequency component in BPF4, and the signal changed from the base station to the intermediate frequency is removed. The reference frequency signal is appropriately amplified so that it can be used as the reference frequencies of the local oscillators PLL1 and PLL2, and is divided into two signals and input to the respective local oscillators PLL1 and PLL2. This is to select the correct FA by synchronizing using the same signal as the reference frequency used for the down conversion and up conversion of the main path.

Another signal separated from DIV1 removes the reference frequency component from BPF1, leaving only the signal transmitted purely from the base station. This signal can vary in frequency and BW according to the design of the repeater. In this description, the center frequency of the intermediate frequency is 140MHz and 15MHz BW, which is a wide frequency band of the USPCS band, will be described.

Like the FA of the USPCS band of FIG. 9, the FA is divided into 11 FAs in the 15 MHz BW band. One of the two intermediate frequency signals divided in DIV2 is input to the following IF1 path, which band-stops into a narrow band of 300 KHz to determine which of the 11 FAs is used by the base station. The controller sends a control signal to change PLL1 11 times. This signal passes only the band of 300KHz BW, and the rest of the band is blocked, so only the signal within 300KHz BW is input to Detector1. Depending on the magnitude of this signal, Detector1 outputs as a voltage, and this voltage is input to Detector1. Appears in proportion to the magnitude of the signal. The center frequency is changed at 1.25MHz intervals from 133.75MHz to 146.25MHz in order by the signal of PLL1 changed 11 times in the IF2 path, so it is possible to detect the strength of the signal input to the repeater for each FA. In the process, the controller stores FAs having a high input signal using the voltage output from the detector 1. The detailed sequence in which the controller operates is shown in the flowchart of FIG.

When the FAs with the signal are found as described above, the IF2 path, which is another signal of DIV2, is used to search for FAs with low PAPR (FA which is a CDMA signal or FA without signal) among them. Find. The IF2 path uses a 30KHz narrowband BPF1, with 30KHz narrow band blocking to measure ripple within 500kHz BW, and the controller changes PLL2 15 times to the maximum and minimum of the magnitude of the signal measured at detector2. Read to find the FA with less difference. In this process, FAs with CDMA signals can be found.

FIG. 11 illustrates a process of finding a CDMA signal. When a FA with a small ripple is found within 500 KHz BW in the IF2 path by searching for an FA having no signal in the IF1 path, a FA for selecting an antenna separation is selected and the controller 2 is selected. By measuring the PAPR at this FA, the gain of the repeater can be automatically controlled while monitoring the antenna separation in real time.

FIG. 12 is a flowchart illustrating a case in which a FA for measuring PAPR is selected as a FA for measuring PAPR in a repeater using a CDMA modem, and FIG. 13 includes all of the sequences, that is, from the beginning. This is the overall flow chart for finding the FA to measure antenna isolation (if it is the highest FA in CDMA).

In determining the FA to measure the antenna separation in the same way as above, if all FAs have signals, select the FA of the highest signal among the CDMA signals, and if there is no FA, select the FA to select the antenna separation. Select the FA to measure, adjust PLL1 and change PLL2 periodically to measure antenna isolation. As shown in Figs. 1 and 2, the antenna separation is shown to be the same size in both the FA and the non-FA in which the base station signal exists in the band serviced by the repeater. Can be seen getting bigger and bigger. As the PAPR increases, the Rho value, which is the quality of the waveform, gradually decreases as described above, and becomes 0.912 or less. If the antenna separation degree is changed by changing the position of a person, a car, and an antenna in an environment in which a repeater is installed and storing a PAPR value having a Rho value of 0.912 in the controller, the detector 2 (186) of FIG. The minimum maximum difference (the difference between the maximum and the minimum of 15 voltages) of the voltage value sent to the controller is also changed. This PAPR is a reference value to determine how much antenna separation is and the quality of the waveform is good. If it is determined that the waveform quality is good compared to the value stored in the controller 2 (174), the controller 1 (129) changes the control signal of the voltage control attenuator (119, 143) of the FWD to gain the repeater If the quality of the waveform is judged to be poor, the repeater's gain is decreased to monitor the quality of the waveform according to the change in the surroundings of the repeater in real time, and the antenna transmits a good signal no matter what kind of signal is input to the repeater. The gain can be automatically adjusted according to the degree of separation.

In addition, in FIG. 14, 106, a band pass filter 107, a low pass filter 180, a bidirectional separator 153, a band pass filter 154, 155, 156, and a bidirectional separator 157, which are reference blocks, are used. The controller 1 129 and the controller 2 174 are divided for convenience of the drawings, and can be implemented by the controller 1 129 alone, and the IF1 path and the IF2 path are simply applicable. The frequency up / down converter 166 and the voltage-controlled attenuator 177 are for inputting the appropriate signal size to the detector 1 173 and the detector 2 186, but similar performance can be realized even when not applied. Looks very complex but can be simplified if implemented as mentioned above.

Claims (7)

In the wireless communication repeater for transmitting and receiving signals between the base station and the mobile station,
Automatically selecting the frequency allocation (FA) to measure the antenna separation by separating the intermediate frequency or RF frequency signal from the relay signal between the base station and the mobile station and automatically adjusts the gain of the wireless repeater based on the selected degree of separation. Control method of a wireless repeater for mobile communication, characterized in that.
The method of claim 1,
When the frequency allocation is automatically selected, a control method of a wireless repeater, characterized in that the antenna separation is measured regardless of the type of signal to be selected by relaying a frequency allocation in which no signal exists.
The method of claim 2,
A function of the PAPR and the waveform quality value in a frequency allocation in which no signal exists, and automatically adjusts the gain of the wireless repeater such that the waveform quality value is within a predetermined range (about 0.912 to 0.998). Repeater control method.
In the wireless communication repeater for transmitting and receiving signals between the base station and the mobile station,
In selecting the frequency allocation to measure the antenna separation by separating the intermediate frequency or RF frequency signal from the relay signal between the base station and the mobile station, in measuring the PAPR at the frequency allocation, two narrowband filters, two local oscillators, and Using two detectors, one local oscillator is used to find the frequency allocation to measure antenna isolation, then the other local oscillator measures the PAPR within that frequency allocation and if the frequency allocation is determined to be valid, the power supply is stopped or A control method of a wireless repeater, characterized in that the PAPR is periodically measured at the frequency allocation unless there is a specific command to the control unit.
In the wireless communication repeater for transmitting and receiving signals between the base station and the mobile station,
When selecting a frequency allocation (FA) to measure the antenna separation by separating the intermediate frequency or RF frequency signal from the relay signal between the base station and the mobile station, two kinds of narrowband filters, two local oscillators, and two detectors are used. A wireless repeater for mobile communication, characterized by finding a frequency assignment where a signal is present and a non-existent frequency assignment.
In the wireless communication repeater for transmitting and receiving signals between the base station and the mobile station,
When selecting a frequency allocation (FA) to measure the antenna separation by separating the intermediate frequency or RF frequency signal from the relay signal between the base station and the mobile station, two kinds of narrowband filters, two local oscillators, and two detectors are used. The wireless repeater for mobile communication, characterized in that the frequency allocation is found and the non-existent frequency allocation to find the correct frequency using the reference frequency together.
In order to minimize the error of the detector for various types of signals input to the repeater, a delay circuit is added to the next stage of the detector to improve the accuracy of the power output from the repeater by applying different detection characteristics for different signal types. Control method of a wireless repeater for mobile communication, characterized in that.

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