KR20040085711A - Apparatus for measuring transmission VSWR amending call state of base station and method thereof - Google Patents

Abstract

PURPOSE: A method for measuring a transmission standing-wave ratio amending the call state of a base station is provided to exclude a maximum value and a minimal value from measured transmission standing-wave ratios, and to assign a weight to an overlapped value, thereby measuring a transmission standing-wave ratio without a service disconnection. CONSTITUTION: A system sequentially measures the first power and the second power corresponding to a forward power and a reverse power, respectively(S100,S110). The system measures a standing-wave ratio based on the first and second powers, and stores the measured standing-wave ratio in a memory with the first and second powers. The system checks the frequency of measuring the standing-wave ratio(S130). If the measuring and the storing are completed, the system erases a maximum value and a minimal value from stored standing-wave ratio data(S150), and detects an overlapped value from the data(S160). The system assigns a weight to a standing-wave ratio having the overlapped value(S170), and calculates an average in consideration of the weight of the standing-wave ratio and other standing-wave ratios(S180).

Description

Apparatus for measuring transmission VSWR amending call state of base station and method

The present invention relates to an apparatus and method for measuring a transmission standing wave ratio of an antenna in a communication equipment including a mobile communication base station or a repeater. More particularly, the present invention relates to a method for measuring a base station transmission standing wave ratio whose call state is corrected without interruption of transmission service.

1 is a diagram schematically illustrating a structure of a base station including a diversity antenna.

The base station 100 shown in FIG. 1 illustrates a base station including a diversity antenna among various base station types. Antenna diversity improves reception characteristics by separately receiving signals arriving by various paths of spatial or temporal propagation of RF propagation between the base station and the antenna. Diversity in the spatial sense is also referred to as antenna diversity because it is basically implemented by installing a plurality of transmitting and receiving antennas. This can be applied to the antenna transmission circuit and the reception circuit, but mainly considering the reception diversity in consideration of the economic and performance improvement effect of the system implementation.

The base station 100 largely includes a transmission / reception circuit 110, a diversity reception circuit 120, a first antenna 114, and a second antenna 123. In the base station shown in FIG. 1, the first antenna 114 is used for both transmission and reception, and the second antenna 123 is used for reception. The second antenna is a diversity antenna, and forms a diversity path and is used for antenna diversity.

The transmit / receive circuit 110 transmits a signal transmitted from a transmitter (not shown) to the first antenna 114 through a high power amplifier 111 and received by the first antenna 114. Is transmitted to a receiver (not shown) via a low noise amplifier 113. The duplexer 112 is used to connect the transmitting and receiving circuits so that the first antenna can be used for both transmitting and receiving. The transmission / reception circuit further includes a bandpass filter for selecting a desired channel band, and may be configured in various forms to further add as a separate antenna without the duplexer, and is not limited to the circuit shown in FIG. 1. .

The receiving circuit 120 includes a bandpass filter 121 and a low noise amplifier 122 for selecting a desired channel from the RF signal received from the second antenna.

The first antenna and the second antenna may constitute the same directional sector in pairs, and the base station antenna may be configured to transmit and receive a plurality of sectors.

Voltage standing-wave ratio (VSWR) refers to the ratio of voltages measured at adjacent fractures and breaks in a line or waveguide with standing waves, or to the maximum value of a wave that proceeds as a comparison of magnitude values of voltage waveforms. It means the minimum value of traveling wave. Hereinafter, for convenience, it is referred to as standing wave ratio (VSWR).

For example, in two mediums having two different impedances, traveling waves are divided into traveling waves and reflected waves by impedance mismatch, and the difference between the two waves is the standing wave ratio. Reflection coefficient In this case, the standing wave ratio VSWR may be defined as in Equation 1 below.

In other words, the standing wave ratio of 1 means that the incident wave passes through completely matched with the line impedance and the termination impedance, and as the larger than 1, the incident wave is reflected more, so the standing wave ratio checks whether there is an antenna abnormality. It is an important indicator.

2 illustrates a method of measuring the transmission standing wave ratio of the first antenna 114 according to the related art.

In order to measure the standing wave ratio of the transmitting antenna, the standing wave ratio detector 300 is used from the directional coupler 200 mounted to the transmitting circuit and the forward and reverse signals of the directional coupler.

The directional coupler 200 is mounted on a transmission antenna line. In the measuring method, the output signal of the transmitter itself is used without using a separate transmitting circuit. The directional coupler 200 includes a forward port 201 and a reverse port 202, and can extract the forward and reverse signals, respectively. The extracted power signal is input to the standing wave ratio detector 300 through the path 10 and the path 20 and used to calculate the standing wave ratio. The reflection coefficient Can be calculated from the delivered signal power (forward power) / reflected signal power (reverse power). As described above, the forward power is measured from the signal detected through the path 10, and the reverse power is measured from the signal detected through the path 20. The detector measures forward power and reverse power at regular time intervals.

However, in the above-described transmitter, the output range of 36 to 45 dBm varies depending on the call connection and call release states. That is, since the output signal changes by a large difference due to the call state of the transmitter, the standing wave ratio obtained by measuring the transmission signal power and the reflected signal power at a time interval by the above-described prior art is very inferior in reliability. This problem makes it difficult to measure the standing standing wave ratio without interruption of service in a transmitter whose call state changes, and finally, it is possible to satisfy the reliability only by measuring the standing wave ratio through a separate transmission circuit by separating the transmitting antenna in the state of stopping service. .

An object of the present invention is to provide a method and apparatus for measuring a transmission standing wave ratio of a base station whose call state is corrected without interrupting service in order to solve the above-mentioned problems of the prior art.

1 is a diagram illustrating a structure of a base station having a diversity antenna.

2 is a diagram illustrating a conventional method of measuring the transmission standing wave ratio.

3 is a block diagram showing the configuration of a transmission standing wave ratio detector according to an embodiment of the present invention.

4 is a block diagram illustrating a specific configuration of an optimum standing wave ratio calculator according to an exemplary embodiment of the present invention.

5 is a flowchart illustrating a standing wave ratio measurement flow according to an embodiment of the present invention.

In order to achieve the above object of the present invention, a method for measuring the transmission standing wave ratio according to the present invention,

(a) measuring a first power signal output from the transmitter to the antenna;

(b) measuring a second power signal reflected from the antenna;

(c) measuring a standing wave ratio based on the first power signal and the second power signal by a predetermined number of times;

(d) storing standing wave ratio data relating to the measured standing wave ratios;

(e) detecting an overlapping value of standing wave ratios based on the stored standing wave ratio data;

(f) weighting standing wave ratios corresponding to the detected overlap values;

(g) calculating an average value of the standing wave ratios in consideration of the weight.

The step (d) may further include removing the maximum value and the minimum value of the measured standing wave ratios.

Also, in the step (e), the overlap value may be detected based on the ratio of the first power signal and the second power signal.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention.

In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention. Like parts are designated by like reference numerals throughout the specification. (When a part is connected to another part, this includes not only a directly connected part but also an electrically connected part with another element in between.)

Now, a transmission standing wave ratio measuring method according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

3 is a block diagram showing an internal configuration of a transmission standing wave ratio detector according to an embodiment of the present invention.

The standing wave ratio detector according to the embodiment of the present invention includes a first power measuring unit 311, a second power measuring unit 312, a standing wave ratio calculating unit 313, a memory unit 320, and an optimum standing wave ratio calculating unit ( 330, a control unit 340.

As shown in FIG. 2, when the specification of the directional coupler is -40 dBm, the output power is X, and the reflected power is X-transmission power, the forward power is X-40 dBm, and the reverse power is (X-transmission power. )-40dBm. Since the ratio between the transfer power and the reflected power can be obtained from the difference in dB, the reflection coefficient can be obtained regardless of the value of the output power X.

A forward power signal and a reverse power signal are received through the first power measurement unit 311 and the second power measurement unit 312, respectively. The first power measuring unit 311 and the second power measuring unit 322 may be configured separately as shown, but the single power measuring unit is implemented by alternately receiving forward and reverse power signals at regular time intervals. It is economical.

The received forward power and the reverse power are calculated by the standing wave ratio calculation unit using the above-described equation, and stored in the memory unit 320 together with the calculated standing wave ratio. The controller 340 controls the standing wave ratio calculation unit to repeat the forward and reverse power measurement and the standing wave ratio calculation repeatedly for a predetermined number of times, and calculates the optimum standing wave ratio based on the data stored in the memory unit 320. The unit 330 outputs a high standing wave ratio.

Hereinafter, an algorithm for calculating an optimum standing wave ratio according to an embodiment of the present invention will be described in more detail with reference to FIG. 4.

4 is a functional block diagram showing in more detail the configuration of the optimum standing wave ratio calculation unit of the present invention.

The standing wave ratio calculated by the standing wave ratio calculator and the first power and the second power corresponding thereto are sequentially stored in the memory unit 320 as standing wave ratio data. The counter included in the controller 340 transmits the standing wave ratio calculated for a predetermined number of times (for example, 20 times) to the maximum / minimum value canceling unit 331. The maximum / minimum value canceling section erases the maximum and minimum values of the transmitted standing wave ratios and sets 18 standing wave ratio data in this case.

The overlap value processor 332 obtains a difference (ie, reflection coefficient) between the first power and the second power among the 18 standing wave ratio data, rounds it to 0 decimal places, and selects the overlapping value. In addition to the above-described method, the overlap value processor may select the overlap value based on the standing wave ratio.

The standing wave ratio corresponding to the selected superimposed value is given a suitable weight in the weight calculator 333. The weight may be a function of the number of overlap values, or may be derived from empirical data obtained by experiments.

The 18 standing wave ratios including the weighted standing wave ratios are calculated by the average value calculator 334 in consideration of the weights. The average value of the calculated standing wave ratio is a reliable standing wave ratio excluding the maximum / minimum value and weighted the overlapping value, and is a standing wave ratio value correcting a change in the call state of the transmitter.

5 is a flowchart illustrating a flow of a transmission standing wave ratio calculation method according to an embodiment of the present invention.

In steps S100 and S110, the first power and the second power corresponding to the forward power and the reverse power, respectively, are sequentially measured. In operation 120, the standing wave ratio is measured based on the measured first power and the second power and stored together with the first power and the second power in the memory unit 320. In step S130, the number of times of standing wave ratio measurement is examined, and the above-described steps are repeated until a predetermined number (for example, 20 times) is reached.

When 20 standing wave ratio measurements and storage are completed, the maximum value and the minimum value of the stored standing wave ratio data are erased (S150). In step S160, the overlapping value is detected from the standing wave ratio data from which the maximum / minimum value is erased. As described above, the method of calculating the overlap value may be performed after rounding the decimal point to zero decimal places of the difference between the first power and the second power.

When the overlapping value is detected, the standing wave ratio having the overlapping value is given a predetermined weight (S170), and an average value considering the weights of the weighted standing wave ratio and other standing wave ratios is calculated and outputted (S180).

With the above-described configuration, the variation of the standing wave ratio due to the transmitter output that varies depending on the call state can be corrected by weighting the overlapped values by excluding the maximum / minimum value with severe deviation.

In the above description, the case of measuring the standing wave ratio data 20 times has been described as an example, but it may be appropriately adjusted according to the performance or environment of the transmitting antenna.

Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of right.

The apparatus for measuring transmission standing wave ratio and the measuring method according to the above-described configuration of the present invention compensates for a change in call state and provides an accurate transmission standing wave ratio without interrupting service. Therefore, it has a remarkable effect that the performance of the transmitting antenna can be measured with high reliability using the calculated standing wave ratio.

Claims (8)

A method for measuring the transmission standing wave ratio with the corrected call state: (a) measuring a first power signal output from the transmitter to the antenna; (b) measuring a second power signal reflected from the antenna; (c) measuring a standing wave ratio based on the first power signal and the second power signal by a predetermined number of times; (d) storing standing wave ratio data relating to the measured standing wave ratios; (e) detecting an overlapping value of standing wave ratios based on the stored standing wave ratio data; (f) weighting standing wave ratios corresponding to the detected overlap values; (g) calculating an average value of the standing wave ratios in consideration of the weight. The method of claim 1, The step (d) further comprises the step of removing the maximum and minimum of the measured standing wave ratio. The method of claim 1, The step (e), the transmission standing wave ratio measuring method for detecting the overlap value based on the ratio of the first power signal and the second power signal. The method of claim 3, wherein The method of claim 1, wherein the overlapping value is selected from values having the same result of rounding the difference in dBm units of the first power signal and the second power signal to 0 decimal places. The method of claim 1, The standing wave ratio data includes a measured standing wave ratio and first and second powers corresponding thereto. The method of claim 1, And said weights are determined from predetermined experimental data. In the apparatus for measuring the transmission standing wave ratio of the base station: A first power measuring unit measuring a first power signal output from the transmitter to the antenna; A second power measurement unit measuring a second power signal reflected from the antenna; A standing wave ratio calculator configured to calculate a standing wave ratio a plurality of times based on the first power and the second power; A memory unit which stores the standing wave ratios calculated the plurality of times; An overlap value processor for detecting an overlap value of standing wave ratios stored in the memory unit; A weight calculator for weighting the overlap value; And a mean value calculating unit for calculating an average value of the measured standing wave ratios in consideration of the weight. The method of claim 7, wherein And a maximum / minimum value removing unit for removing a maximum value and a minimum value among the standing wave ratios calculated a plurality of times.