KR20060094550A - Wireless switching device for mobile communication and control method threrof - Google Patents

Abstract

The present invention is a wireless communication environment (eg, US USPCS Band (CDMA, EVDO, GSM), Korea CDMA & PCS Band (824 ~ 894 MHz: CDMA, EVDO, 800) in which various signal services are mixed in the frequency to be serviced. ~ 1900MHZ: CDMA, EVDO), Japan CDMA Band (CDMA, EVDO)) repeater automatically finds the service frequency, classifies the signal type by checking the signal to service and automatically adjusts the gain of the repeater The present invention relates to a wireless repeater for mobile communication and a method of controlling the same, wherein the signal characteristics of various FA signals are narrow-band-blocked according to a change in voltage value detected by a signal detector using a part of a signal input to the repeater. Analysis of the transmit / receive antennas in the FA band or the nearest FA of the active FA, which is analyzed using a filter and also finds the FA to be serviced. By measuring the ripple according to the size of the isolation between the new antennas, the gain can be automatically controlled based on the value, so that the repeater can provide high quality signals in any mixed signals of EVDO, GSM, CDMA, W-CDMA, CW. An implementation of a repeater and its operation algorithm that controls transmission and reception to a terminal and a base station. To this end, two local oscillators, two narrowband filters, and a frequency change and a detected voltage are determined by separating a part of a signal. The control algorithm is implemented and the control algorithm is illustrated.

Description

Wireless repeater for mobile communication and its control method {Wireless switching device for mobile communication and control method threrof}

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 the IF1 path;

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.

<Description of Symbols for Major Parts of Drawings>

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

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 when the gain of the repeater is 60dB, and the repeater gain is 15dB or less than the antenna separation, the ripple within the service frequency of the repeater is the signal input from the base station or the terminal. When the signal quality is measured using a measuring instrument, the signal is measured to a value of about 0.98 to 0.99, which is equal to or greater than 0.912, which is a standard required by a base station or a terminal. However, if the gain increases further and the difference between antenna separation and 4-7dB occurs, the waveform of the signal in the service band of the repeater shows a distorted signal (in-band ripple) that is different from the waveform of the signal sent from the base station or the terminal. When measuring the quality of the waveform by using the signal (see Fig. 1), it is out of the management standard of 0.85 ~ 0.93, and the gain is increased, and when the gain of the repeater is larger than the antenna separation value, the repeater The oscillation starts to increase and the output signal gradually increases, 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.

To summarize the technical methods applied in the conventional repeaters,

1) How to use the Shutdown function to remove the power of the amplifier at the end when the output of the repeater is over the specified value

2) How to use ALC, AGC function that automatically adjusts gain of attenuator or AGC Amp in order to detect amplitude of output signal and maintain constant output value of repeater at all times.

3) When the repeater is installed and the power is applied, adjust the gain of the repeater 10 ~ 15dB larger than the operating gain to detect whether the output signal is detected by the detector and oscillate. How to check if it is obtained

4) Minimize the gain when installing the repeater and apply power, or use the switch to turn off the path of the repeater, and use the local oscillator to apply the continuous wave (CW) to the antenna in the direction of the base station. Local oscillator after detecting the magnitude of the signal inputted to the antenna in the terminal direction and using the difference to determine the antenna separation degree, and after the repeater and the antenna are installed in the environment where the repeater can check the quality of the good signal How to operate the gain of the repeater by turning off the power supply, turning the path back on and setting the signal of good quality to the gain that can be transmitted

5) In the FA (800KHz ~ 1.2288MHz) where the signal exists by using additional local oscillation circuit, narrow band filter and detector, divide the signal at the place where it is easy to process before amplifying and outputting the signal input to the repeater. By dividing the signal into narrow bands and changing the frequency finely, it detects the ripple of the in-band and continuously monitors the antenna separation, and automatically adjusts the gain of the repeater based on this ripple to prevent oscillation and transmit high quality signals. How to

6) Method of outputting a test signal (CW or Pilot) to the transmitting antenna along with the frequency signal to be serviced to the immediate neighbor of the serving frequency (FA) and detecting the strength of the test signal coming into the receiving antenna to check the antenna separation.

7) Method of verifying antenna separation by encrypting signature signal to service signal and outputting with frequency signal and detecting the strength of test signal coming into receiving antenna

8) After dividing the signal in a place where it is easy to process the signal before it is amplified and output, process the signal by using the QPSK demodulator, and then check the antenna separation by making the parameter of the signal change as a parameter. Has been reported and applied.

The most commonly used method among the various technical methods described above is the method of 5), which is easy to apply and relatively inexpensive to implement.

However, the problem with this scheme is that the size of the FA (Frequency Allocation, hereinafter FA) band in which the signal to be serviced, like the CDMA or W-CDMA signal, must be greater than or equal to a predetermined size (600 to 800 KHz) In the modulation method in which no large ripple occurs, there is no difficulty in determining the size of antenna separation. This is because the in-band ripple of the service signal is very small in CDMA and W-CDMA, and the band size is 1.2288 MHz (for CDMA) and 3.84 MHz (for W-CDMA), which is more than 500 to 800 KHz. .

As described above, there is no problem in a method of detecting a magnitude of a ripple that varies according to the degree of antenna separation in a small ripple situation as described above, but it is not applicable to a service of an EVDO or GSM signal. The reason is that in case of EVDO signal, EVDO signal has different transmission envelope mask of active half-slot and idle half-slot, and shows very large ripple value unlike CDMA signal in 1.2288MHz. (See FIG. 3). Due to the characteristics of these signals, the output voltage of the detector that 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 when the repeater transmits a good signal, it is necessary to reduce the gain of the repeater, and even if the gain is reduced, the antenna separation is continuously maintained in the case of a signal condition with large ripple 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. Therefore, the method of measuring the ripple of the signal within 1MHz based on the center frequency of the signal in the service frequency band is the same as the two communication systems of CDMA and W-CDMA. Only in the case of waveforms in which ripple 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 ripple 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 it is necessary to determine whether CW, CDMA, EVDO, or GSM are unwanted frequency components and service the CDMA signal, measure the ripple within the 450 KHz band from the center of the CDMA signal, or select an inactive adjacent FA to reduce noise. Measure the ripple of the level and adjust the gain of the repeater to the difference value.If it is necessary to service EVDO or GSM signals other than the CDMA signal, select the inactive adjacent FA to measure the ripple of the noise level to the difference value. If you need to adjust the repeater's gain and service EVDO, CDMA, and GSM at the same time, the nearest neighbor is not active. Select FA to measure the ripple of the noise level and adjust the gain of the repeater to that 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.

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 FA with low ripple among the signals (FA which is a CDMA signal or FA without signal) is searched among the signals using the IF2 path, which is another signal of the output of DIV2. 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 continuously measuring the ripple 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 where a FA for measuring ripple is selected as a FA for measuring ripple in a CDMA modem using a CDMA modem, and FIG. 13 includes the respective 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 the base station signal within the band serviced by the repeater. Can be seen getting bigger and bigger. As the ripple increases, as described above, the Rho value, which is the quality of the waveform, gradually decreases to a value of 0.912 or less. If the antenna separation degree is changed by changing the position of the person, the car, and the antenna in the environment where the repeater is installed and storing the ripple value of which the Rho value is 0.912 in the controller, the detector 2 (186) of FIG. The ripple of the voltage value sent from the controller to the controller (the difference between the maximum and minimum of the 15 voltages) is also changed. This ripple is a reference value to determine how much antenna separation is and the quality of the waveform is good. When 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.

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 ripple is measured based on the center frequency of the FA where the waveform exists, 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 ripple 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 embodiment, but can be modified and modified within the scope not departing from the gist of the present invention, the technical idea to which such modifications and variations are also applied to the claims Must see

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 ripple and the quality of the waveform in a frequency allocation in which no signal is present, thereby automatically adjusting the gain of the wireless repeater so that the quality of the waveform 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 ripple in 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 ripple in the frequency allocation and if the frequency allocation is determined to be valid, the power supply is stopped or A control method for a wireless repeater, characterized in that the ripple is measured periodically in the frequency allocation unless 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. A wireless repeater for mobile communication, in which a frequency allocation in which a signal is present and a frequency allocation in which a signal is not found are used, and an accurate frequency selection is performed using a 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.

Images