JP2010156572A - Antenna measuring method and system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technique for efficiently performing measurement using an echo chamber when measurement conditions set in an opposite device are changed sequentially. <P>SOLUTION: The measurement method determines, after acquiring the receiving signal quality information corresponding to a certain measurement condition, whether the receiving signal quality information corresponding to all the measuring conditions is acquired or not (Step 7), and if it is determined that the receiving signal quality information corresponding to all the measuring conditions is not obtained, sets the measurement conditions of which the receiving signal quality is not acquired yet to the opposite device (Step S1), to acquire the receiving signal quality information corresponding to the measurement condition. The above processing is repeated. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a technique for measuring the performance of an antenna of a portable wireless device or the like in a fading environment.

  As a conventional technique for measuring the performance of an antenna of a portable wireless device or the like in a fading environment, an antenna measurement device described in Patent Document 1 is known (for example, see Patent Document 1).

  The antenna measurement device described in Patent Document 1 is surrounded by a reflection wall that reflects electromagnetic waves, and includes an agitator that agitates an electromagnetic field. The device under measurement to be measured is placed inside the antenna measurement device. An antenna is provided on the reflection wall, and the opposing device performs wireless communication with the device under measurement via the antenna.

With this antenna measurement device, a fading environment can be simulated, and the antenna performance can be measured in consideration of the fading environment.
Special table 2003-529983 gazette

  However, there is a problem in that there is no known technique for efficiently performing measurement in the case where the measurement conditions set for the opposing device are sequentially changed using the antenna measurement device described in Patent Document 1.

  In order to solve the above problems, the present invention determines whether or not the received signal quality information corresponding to all measurement conditions has been acquired after acquiring the received signal quality information corresponding to a certain measurement condition, If it is determined that the received signal quality information corresponding to is not acquired, the measurement conditions for which the received signal quality has not yet been acquired are determined for the opposite device, and the received signal quality information corresponding to the measurement conditions is acquired. Repeat the process.

  The present invention has an effect that the measurement can be efficiently performed by sequentially changing the measurement conditions determined for the opposing device by repeating the above processing.

[Antenna measurement system]
An example of an antenna measurement system according to the present invention will be described with reference to FIG.
The box 1 is surrounded by a reflecting wall 1a that reflects electromagnetic waves. The box 1 is a so-called reverberation chamber and simulates a desired fading environment such as a three-dimensional uniform Rayleigh fading environment. Here, the term “wall” is used to describe the surfaces constituting the box 1 such as side walls, ceilings and floors. The reflection wall 1a is realized, for example, by attaching a metal foil or a metal plate to the inner wall of the box. In this example, the box 1 has a rectangular parallelepiped shape as a whole, but may have another shape. Although not shown, the box 1 is provided with a door for taking in and out the device 2 to be measured. The inner surface of the door is also constituted by a reflecting wall 1a that reflects electromagnetic waves.

  The box 1 includes antennas 1b, 1c, and 1d. In this example, three antennas 1b, 1c, and 1d are provided above the ceiling and two side walls of the box 1, respectively. The antenna 1 b radiates an electromagnetic wave corresponding to the applied electric signal into the box 1. Moreover, the electromagnetic wave which the to-be-measured apparatus radiated | emitted as needed is received.

  The box 1 includes stirrers 1e and 1f that stir the electromagnetic field emitted from the antennas 1b, 1c, and 1d. The stirrer 1e is a device that reciprocates the side wall of the box 1 to the left and right, and the stirrer 1f is a device that reciprocates the other side wall of the reflecting plate up and down. The reflector reflects incident electromagnetic waves.

  On the floor of the box 1, a turntable 1g is provided. The turntable 1g rotates what is placed around the rotation axis of the turntable 1g. The device under measurement 2 is disposed on the turntable 1g. The turntable 1g alternately repeats a right turn and a left turn in order to prevent the cord connected to the one placed on the turntable 1g from getting tangled. For example, 360 ° clockwise rotation and 360 ° counterclockwise rotation are repeated alternately. As the box 1, the antenna measurement system described in Patent Document 1 can be used.

  The device under test 2 is a wireless communication device including an antenna to be measured according to the present invention, and specifically a mobile phone. The device under measurement 2 includes a reception signal quality information generation unit that generates reception signal quality information that is information about the quality of the received signal.

  Specifically, the received signal quality information includes received signal strength (RSSI), received signal code power (RSCP), signal-to-noise ratio (SNR), Ec / No. ), Signal to Interference Signal (SIR), Signal to Interference and Noise Ratio (SINR), Carrier to Noise Ratio (CNR), Carrier-to-interference power ratio (CIR), carrier-to-interference and noise ratio (CINR), channel quality (CQI: Channel Quality Indicator), antenna under measurement 2 or more Is information relating to the received signal such as a correlation coefficient for the signal received by each antenna.

  As the received signal quality information, a control signal (so-called measurement report) used in cellular communication may be used. This control signal includes at least reception power RSCP and signal-to-noise power ratio Ec / No. In an environment where the device under test 2 is actually used, the device under test 2 periodically sends a control signal to the base station for control of the transmission output of the base station or handover. By using the control signal used in the environment where the device under test 2 is actually used as the received signal quality information, it is possible to perform measurement in consideration of the environment where the device under test 2 is actually used.

  The device under measurement 2 may include a single antenna, or may include two or more antennas (that is, multi-antennas). When two or more antennas are provided, a variable attenuator 22 may be provided on one of the antennas as illustrated in FIG. By changing the attenuation amount of the variable attenuator 22, it is possible to simulate a state in which there is a difference in performance between the antennas, and it is possible to perform measurement in consideration of the performance between the antennas. Further, as illustrated in FIG. 7B, the variable attenuators 221 and 222 may be provided for each antenna, and the antennas may be connected to each other by a line provided with the variable attenuators 222 and 223. By changing the attenuation amount of the variable attenuators 221, 222, 223, and 224, a desired antenna correlation can be realized. Therefore, measurement considering antenna correlation is possible.

  The opposite apparatus 3 is a pseudo base station apparatus that can communicate with the device under test 2, for example. The opposing device 3 is electrically connected to the antennas 1b, 1c, and 1d via the switch 4. The switch 4 selects one of the antennas 1b, 1c, and 1d as an antenna that is electrically connected to the opposing device 3. By switching the antennas 1b, 1c, and 1d with the switch 4, the antenna performance of the device under test 2 can be measured under various antenna conditions with different specifications, positions, and the like. If the antenna to be used is changed by switching the switch 4 during measurement, the antenna conditions change. Therefore, when it is desired to perform measurement under the same antenna conditions, the switch 4 is not switched. The opposing device 3 generates an electrical signal based on the determined measurement condition and applies it to the antenna selected by the switch 4 in the antennas 1b, 1c, and 1d. And the received signal quality information which the to-be-measured apparatus 2 produced | generated is acquired.

  The opposing device 3 can acquire the received signal quality information from the device under measurement 2 by wireless communication. That is, the device under test 2 radiates received signal quality information on its electromagnetic wave from its own antenna, and the opposing device 3 receives it via the antenna selected by the switch 4 in the antennas 1b, 1c, 1d. . On the other hand, when the device under measurement 2 and the opposite device 3 are connected by an electric wire, the opposite device 3 acquires the received signal quality information from the device under measurement 2 by wired communication through the electric wire. Also good.

  The control device 5 sets measurement conditions for the opposite device 3 and performs information processing on the received signal quality information received by the opposite device 3 corresponding to the measurement conditions. The measurement condition is, for example, at least one of the power of the desired signal and the power of the interference signal. Moreover, the control apparatus 5 controls operation | movement of the opposing apparatus 3, the stirrers 1e and 1f of the box 1, and the turntable 1g.

  As illustrated in FIG. 2, the control device 5 includes a measurement condition setting unit 51, a received signal quality information acquisition unit 52, a storage unit 53, an averaging unit 54, an end determination unit 55, a stop determination unit 56, a discard unit 57, Maximum value / minimum value acquisition means 58, first power range setting means 59, change determination means 510, and second power range setting means 511 are provided. Details of each means of the control device 5 will be described in the description of the antenna measurement method.

  The control device 5 and each means thereof can be realized, for example, by causing a personal computer to execute an antenna measurement program. Of course, all or part of the means of the control device 5 may be realized by hardware.

[Antenna measurement method]
Hereinafter, an example of the antenna measurement method will be described with reference to FIG.
First, the measurement condition setting means 51 of the control device 5 determines a measurement condition for the opposite device 3 for which the corresponding received signal quality information has not yet been acquired (step S1).

  The opposing device 3 generates an electrical signal based on the determined measurement conditions (step S2). The generated electric signal is applied to the antenna selected by the switch 4 in the antennas 1b, 1c, 1d of the box 1.

  The antenna to which the electric signal is applied radiates an electromagnetic wave corresponding to the electric signal into the box 1 (step S3). The electromagnetic wave is reflected by the reflection wall 1a of the box 1 and is stirred by the stirrers 1e and 1f, thereby fading fluctuations. That is, due to reflection and stirring, the electromagnetic waves arrive at the device under measurement 2 with a time difference, the electromagnetic waves whose phases are shifted interfere with each other, and the power of the electromagnetic waves that arrive at the device under measurement 2 varies over time.

  The device under measurement 2 receives the electromagnetic wave and generates received signal quality information corresponding to the determined measurement condition (step S4). A plurality of pieces of received signal quality information corresponding to a certain measurement condition are generated as necessary. The received signal quality information is sent to the opposite device 3.

  The received signal quality information acquisition means 52 of the control device 5 acquires the generated received signal quality information from the opposite device 3 (step S5). The acquired received signal quality information is stored in the storage means 53 of the control device 5.

  When a plurality of reception signal quality information corresponding to a certain measurement condition is generated, the averaging means 54 of the control device 5 reads a plurality of reception signal quality information corresponding to the measurement condition from the storage means 53, and An average value of the received signal quality information is obtained (step S6).

  The end determination means 55 of the control device 5 determines whether or not the received signal quality information corresponding to all measurement conditions has been acquired (step S7). If it is determined that the received signal quality information corresponding to all measurement conditions has been acquired, the antenna measurement method processing ends. If it is determined that reception signal quality information corresponding to all measurement conditions has not been acquired, in other words, if there is a measurement condition for which reception signal quality information has not yet been acquired, the process returns to step S1. In step S1, the measurement condition setting means 51 determines a measurement condition for which reception signal quality information has not yet been acquired. For example, the measurement conditions set in advance are changed by a predetermined change width as the measurement conditions. The predetermined change width is appropriately determined depending on the performance and use required for the antenna measurement method and system. Through the processing in step S7, the processing from step S1 to step S5 (or from step S1 to step S6) is repeated until reception signal quality information corresponding to all measurement conditions is acquired.

  In the actual propagation environment in which the device under test 2 is used, conditions such as the power of the desired signal and the power of the interference signal vary in a wide range. For this reason, in order to measure the performance of the device under test 2 and its antenna, it is necessary to perform repeated measurement under various measurement conditions within a wide range assumed. By automating the setting of measurement conditions and the acquisition of received signal quality information, it is possible to efficiently perform measurement when the measurement conditions are sequentially changed.

[Appropriate number of samples]
The device under measurement 2 may generate a plurality of pieces of received signal quality information corresponding to the same measurement condition. The number of received signal quality information corresponding to the same measurement condition to be generated or the number of received signal quality information for which the averaging means 54 obtains an average value is referred to as “number of samples”.

  As the number of samples increases, the reliability of the measurement result obtained by the averaging means 54 of the control device 5 increases, but the measurement time increases. On the other hand, the smaller the number of samples, the lower the reliability of the measurement result obtained by the averaging means 54 of the control device 5, but the shorter the measurement time.

  Here, consider the number of samples required to achieve the required reliability. Specifically, the number of samples necessary for setting the measurement error on the basis of the average value when the number of samples is 350 to ± 1% is considered. As a result of the experiment, for example, as shown in FIG. 8, when the number of samples exceeds 50, the measurement error for the average values of the received power RSCP, the signal-to-noise power ratio Ec / No, and the channel quality CQI is within ± 1%. Thus, it was found that a highly reliable measurement result can be obtained to the extent that there is no practical problem. Therefore, it is desirable that the number of samples be 50 or more.

[Measurement considering the stop of the stirrer]
The reflectors of the stirrers 1e and 1f reciprocate left and right or up and down the side wall of the box 1, and there may be a slight time to stop when turning back. Further, the turntable 1g also repeats the right rotation and the left rotation alternately, and there may be a slight stop time when the rotation direction is reversed. If both the stirrers 1e and 1f and the turntable 1g are stopped, a desired Rayleigh fading environment is not generated, and thus there is a possibility that measurement under the desired Rayleigh fading environment cannot be performed. Further, if the averaging means 54 obtains the average value of the received signal quality information using the received signal quality information acquired during the stop time, the measurement accuracy is lowered. Increasing the number of samples improves the measurement accuracy, but has the disadvantage that measurement takes time.

  Therefore, in order to discard the received signal quality information acquired when the agitators 1e and 1f and the turntable 1g are stopped, the controller 5 may be provided with a stop determination unit 56 and a discard unit 57 as illustrated in FIG. .

The stop determination means 56 determines whether the stirrers 1e and 1f and the turntable 1g are stopped (step T1, FIG. 4). Information about whether or not the agitators 1e and 1f and the turntable 1g are stopped is sent to the discarding means 57. Whether or not the stirrers 1e and 1f and the turntable 1g are stopped can be determined, for example, by whether or not the received signal quality information has changed. Specifically, the received signal quality information Q _i at time _i and the received signal quality information Q _{i + 1 at} time i + 1 are compared, and if Q _i = Q _{i + 1} as illustrated in FIG. It can be determined that 1e, 1f and the turntable 1g are stopped.

The comparator, agitator 1e, after 1f and turntable 1g was continued determination that has stopped, the received signal quality information Q _{j + 1} of the received signal quality information Q _j and time j + 1 at time j (j> i) If Q _j ≠ Q _{j + 1} as illustrated in FIG. 9, it can be determined that the stirrers 1e and 1f and the turntable 1g are not stopped at time j + 1.

Even if it is determined whether or not there is a change in the received signal quality information based on whether or not | Q _i −Q _{i + 1} | is within a predetermined threshold instead of whether or not Q _i = Q _{i + 1.} Good. This predetermined threshold is appropriately set based on the performance and specifications required for the antenna measurement method and system.

When it is determined in step T1 that the agitators 1e and 1f and the turntable 1g are stopped, the discarding unit 57 discards the received signal quality information in the stop time (step T2). Specifically, the received signal quality information at the stop time is erased from the storage means 53 of the control device 5. Alternatively, the information about the received signal quality information at the stop time is sent to the averaging means 54 so that the average means 54 can obtain the average value without using the received signal quality information at the stop time. In FIG. 9, the stop time is from time i to time j, but k ₁ and k ₂ are integers close to 0 including 0 (for example, each of k ₁ and k ₂ is -1, 0, or +1). The time from time i + k ₁ to time j + k ₂ may be defined as the stop time.

  Each time reception signal quality information is acquired, reception signal quality information at the stop time may be discarded as described above, or reception signal quality information at the stop time may be discarded after a plurality of reception signal quality information is accumulated. Alternatively, the reception quality information may be discarded immediately before the averaging means 54 obtains the average value.

  In this way, only the received signal quality information under the desired fading environment is obtained by discarding the received signal quality information in the stop time of the agitators 1e and 1f and the turntable 1g, and the desired fading environment Since the average value can be obtained using only the received signal quality information under, the measurement accuracy is improved.

[Setting of power range of desired signal 1]
Here, it is assumed that the measurement conditions include a condition regarding the power of the desired signal. When the opposing device 3 generates an electrical signal including a desired signal based on the measurement conditions determined by the measurement condition setting means 51, if the power of the desired signal is too high, the power of the electromagnetic wave received by the device under measurement 2 is reduced. There is a possibility that the upper limit of the power of the electromagnetic wave that can be received by the measuring device 2 is exceeded, and conversely, if the power of the desired power is too low, the power of the electromagnetic wave received by the device under measurement 2 can be received by the device under test 2. May be below the lower limit of power. In this case, the device under measurement 2 cannot receive electromagnetic waves normally, and there is a possibility that measurement cannot be performed with high accuracy. Therefore, it is necessary to set the power of the desired signal so that the power of the electromagnetic wave received by the device under test 2 falls within the range between the upper limit value and the lower limit value of the power of the electromagnetic wave that can be received by the device under test 2.

  For this purpose, prior learning is performed in advance, a desired signal power range determined for the opposing device 3 is determined in advance, and when the measurement is performed, the desired signal power is determined for the opposing device 3 within that range. You may do it.

  Hereinafter, a description will be given with reference to FIG. The measurement conditions include conditions for the power of the desired signal, and the received signal quality information includes the power of the electromagnetic wave received by the device under measurement 2. By performing A5 and steps A6 and A7, the maximum value and the minimum value of the power of the electromagnetic wave received by the device under test 2 when the opposite device 3 outputs a desired signal with a certain power are obtained.

  Specifically, the measurement condition setting means 51 of the control device 5 determines a certain power as the power of the desired signal in the opposite device 3 (step A1). The power with the desired signal determined here is preferably a power expected to be included in a range that can be received by the device under measurement 2, but is not limited thereto. The opposing device 3 generates and outputs a desired signal of the power (step A2). The antenna selected by the switch 4 of the antenna 1b, 1c, 1d of the box 1 radiates an electromagnetic wave corresponding to the desired signal into the box 1 (step A3). The device under measurement 2 receives the electromagnetic wave and generates information about the power of the received electromagnetic wave as reception signal quality information (step A4). Information about the power of the received electromagnetic wave is sent to the opposite device 3. The received signal quality information acquisition means 52 of the control device 5 acquires information about the power of the electromagnetic wave received from the opposing device 3 (step A5).

  Since the electromagnetic wave inside the box 1 varies in fading, the power of the electromagnetic wave received by the device under measurement 2 varies over time. The maximum value / minimum value acquisition means 58 of the control device 5 obtains the maximum value and the minimum value of the power of the electromagnetic wave received by the device under measurement 2 (step A6).

  The first power range setting means 59 sets the power of the desired signal output from the opposite device 3 in step A2, the maximum value and the minimum value, and the upper limit value and the lower limit value of the electromagnetic wave power that can be received by the device under measurement 2. Is used to determine the range of power of the desired signal to be determined for the opposing device 3 (step A7).

  Here, as illustrated in FIG. 10, when the power of the desired signal output from the opposite device 3 increases, the power of the electromagnetic wave received by the device under test 2 increases by almost the same amount as the increase, and Even if the power of the desired signal output from the opposing device 3 changes, the property that the difference between the maximum value and the minimum value of the power of the electromagnetic wave received by the device under measurement 2 is substantially the same. That is, the property that the slopes of the line segment L1 and the line segment L2 in FIG.

  Specifically, the upper limit value of the power of the desired signal determined in the opposite device 3 = the power of the desired signal output from the opposite device 3 in step A2 + the upper limit value of the power of the electromagnetic wave receivable by the device under measurement 2−the device under measurement. 2 is the maximum value of the received electromagnetic wave power. Also, the lower limit value of the power of the desired signal determined for the counter device 3 = the power of the desired signal output from the counter device 3 in step A2 + the lower limit value of the power of the electromagnetic wave receivable by the device under test 2 -the device under test 2 receives The minimum value of the electromagnetic wave power.

  In step S <b> 1, the measurement condition setting unit 51 of the control device 5 determines power in the range between the upper limit value and the lower limit value as the measurement condition for the power of the desired signal generated by the opposite device.

  Thus, by obtaining the upper limit value and lower limit value of the power of the desired signal determined in the opposite device 3, it is possible to prevent disconnection due to excess or shortage of the electrolytic strength at the time of measurement and improve the measurement efficiency. .

[Setting of power range of desired signal 2]
Here, it is assumed that the measurement conditions include a condition regarding the power of the desired signal. The higher the power of the desired signal generated by the opposite apparatus 3, the higher the received signal quality information generated by the device under measurement 2 (for example, the power of the electromagnetic wave received by the device under measurement 2). However, there is received signal quality information in which the received signal quality information does not change when the power of the desired signal becomes higher than a certain value. For example, the higher the power of the desired signal, the higher the signal-to-noise power ratio SNR and the channel quality CQI, but the signal-to-noise power ratio SNR and the channel quality CQI are almost constant when the power of the desired signal is higher than a certain value. It becomes. Here, it is considered that the measurement is efficiently performed by omitting the measurement for the region R (FIG. 11) where the received signal quality information does not change.

Hereinafter, a description will be given with reference to FIG. First, in the state where the stirrers 1e and 1f and the turntable 1g of the box 1 are stopped, by performing the processing of steps B1 to B5 and B6 to B10 that perform the same processing as steps S1 to S5, the opposing device 3 The received signal quality information Q _i when the power of the desired signal generated by P _i is P _i and the received signal quality when the power of the desired signal generated by the opposite apparatus 3 is P _{i + 1} (P _{i + 1} <P _i ). Information Q _{i + 1} is acquired.

Specifically, first, the control device 5 stops the stirrers 1e and 1f and the turntable 1g of the box 1. As i = 1, the measurement condition setting means 51 of the control device sets _Pi to the counter device 3 as the power of the desired signal (step B1). The power P _i is preferably such that the received signal quality information generated when the power is P _i is included in the region R (FIG. 11) where the received signal quality information is constant. Not as long. Opposing device 3, power generating and outputting a desired signal is P _i (step B2). Selected antenna box 1 of the antenna 1b, 1c, the switch 4 1d, the power is radiated into the interior of the box 1 an electromagnetic wave corresponding to the desired signal is a P _i (step B3). The device under measurement 2 receives the electromagnetic wave and generates received signal quality information Q _i (step B4). The received signal quality information Q _i is sent to the opposite device 3. The reception signal quality information acquisition means 52 of the control device 5 acquires the reception signal quality information Q _i from the opposite device 3 (step B5).

Next, the measurement condition setting means 51 of the control device sets _{Pi + 1} as the power of the desired signal in the opposite device 3 (step B6). The electric power P _{i + 1} is smaller than the electric power P _i . In the actual measurement in steps S1 to S7, the power of the desired signal is changed within a certain width, but it is desirable that the difference between the power P _{i + 1} and the power P _i is larger than the change width. This pre-measurement is intended to detect whether or not there is a change in the received signal quality information, and it is not necessary to make the change width of the power of the desired signal as fine as the actual measurement performed in steps S1 to S7. In this pre-measurement, the measurement time of the pre-measurement can be shortened by widening the change width (= | P _i −P _{i + 1} |) of the power of the desired signal.

Opposing device 3, power generating and outputting a desired signal is P _i (step B7). The antenna selected by the switch 1 of the antennas 1b, 1c, 1d of the box 1 radiates an electromagnetic wave corresponding to a desired signal whose power is _{Pi + 1} into the box 1 (step B8). The device under measurement 2 receives the electromagnetic wave and generates reception signal quality information Q _{i + 1} (step B9). The received signal quality information Q _{i + 1} is sent to the opposite device 3. The reception signal quality information acquisition means 52 of the control device 5 acquires reception signal quality information Q _{i + 1} from the opposite device 3 (step B10).

The change determination means 510 of the control device 5 compares the absolute value of the difference between the received signal quality information Q _i and the received signal quality information Q _{i + 1} with a predetermined threshold value, thereby obtaining the received signal quality information Q _i and the received signal quality. It is determined whether or not there is a change in the information Q _{i + 1} (step B11). For example, determines that the absolute value of the difference between the received signal quality information Q _i and the received signal quality information Q _{i + 1} is equal to or less than a predetermined threshold value, there is no change in the received signal quality information Q _i and the received signal quality information Q _{i + 1} can do. Further, determining that the absolute value of the difference between the received signal quality information Q _i and the received signal quality information Q _{i + 1} is equal to or greater than a predetermined threshold value, there is a change in the received signal quality information Q _i and the received signal quality information Q _{i + 1} can do. The predetermined threshold value is appropriately set based on performance, specifications, and the like required for the antenna measurement method and system.

When it is determined that the received signal quality information Q _i and the received signal quality information Q _{i + 1} are not changed, the second power range setting unit 511 of the control device 5 determines the power of the desired signal determined in the opposite device 3. The power _Pi is removed from the range (step B12). Thereafter, i is incremented by 1, that is, i = i + 1 (step B13), and the process returns to step B1. At this time, since the received signal quality information Q _i corresponding to the power P _i (power P _{i + 1 in} the notation before incrementing i by 1) has already been acquired, steps B1 to B5 are omitted, and steps B1 to B1 are omitted. By performing B10, received signal quality information Q _{i + 1} corresponding to the power P _{i + 1} (power P _{i + 2 in} the notation before incrementing i by 1) (received signal quality information Q _{i + 2 in} the notation before incrementing i by 1) You may get only.

When it is determined that there is a change between the received signal quality information Q _i and the received signal quality information Q _{i + 1} , the preliminary measurement process is finished and the process of step S1 is performed.

The measurement condition setting means 51 of the control device 5 uses the power within the range of the power of the desired signal determined for the counter device 3 thus determined as the condition for the power of the desired signal generated by the counter device 3 in step S1. To the opposite device. The measurement condition setting means 51 supplies the power within the range of the power of the desired signal determined in the counter device 3 thus determined at an interval narrower than the absolute value of the difference between the power P _{i + 1} and the power P _i. It is desirable to set

  Thus, the measurement can be efficiently performed by omitting the measurement for the region where the received signal quality information does not change.

[Reference antenna]
As illustrated in FIG. 12, the reference antenna 6 disposed at the position of the device under measurement 2 may be used as the reception antenna of the device under measurement 2 instead of the device under measurement 2. As the reference antenna 6, an arbitrary antenna such as a half-wave dipole antenna or a sleeve antenna, which is the most basic antenna, can be used. The reference antenna 6 and the device under test 2 are connected by a connection cable 7, and the device under test 2 uses the reference antenna 6 as a receiving antenna instead of its own antenna.

  The gain of the reference antenna 6 and the loss of the connection cable 7 are measured in advance. By correcting the gain of the reference antenna 6 and the loss of the connection cable 7 from the measurement result obtained using the antenna measurement system using the reference antenna 6, the wireless device excluding the antenna of the device under test 2 itself is corrected. Performance can be measured.

  Also, the measurement result obtained using the antenna measurement system using the reference antenna 6 is compared with the measurement result obtained without using the reference antenna 6 and without using the antenna measurement system. The difference between the two measurement results is caused by whether the reference antenna 6 is used as the receiving antenna or whether the antenna of the device under measurement 2 itself is used. Therefore, by comparing both measurement results, it is possible to extract a difference in performance between the reference antenna 6 and the antenna of the device under test 2 itself. This makes it possible to measure the performance of the antenna of the device under test 2 itself, which is independent.

  Further, by using the reference antenna 6 in place of the device under measurement 2, it is possible to perform measurement in a state where the influence of noise generated from the device under measurement 2 is eliminated.

[Adaptive modulation means]
The opposing device 3 may include adaptive modulation means. The adaptive modulation means selects an optimal modulation method and coding rate in accordance with the propagation environment from the opposite apparatus 3 to the device under test 2, that is, the received signal quality information received by the opposite apparatus 3. In this case, the device under measurement 2 needs to include an adaptive demodulation unit corresponding to the adaptive modulation unit of the opposite device 3. Thereby, it is possible to more faithfully simulate the communication state generated by the actual counter device 3 having the so-called adaptive modulation / demodulation function and the device under test 2. It is possible to measure the performance of the device under test 2 and its receiving antenna in a more realistic situation.

  For example, if the received signal quality information indicated by the received signal quality information acquired from the device under test 2 is good, the adaptive modulation means uses a modulation method having a large multi-level number, and further sets the coding rate to a high value. When the received signal quality information indicated by the information is poor, a modulation scheme with a small multi-level number is used, and the coding rate is set to a low value. In addition, in order to determine whether the received signal quality information is good or bad, the counter device 3 or the device under measurement 2 includes a communication speed measuring unit that measures the communication speed in the path from the counter device 3 to the device under test 2. It may be.

[Other variations]
The device under measurement 2 may generate a plurality of types of received signal quality information different from each other. For example, the device under test 2 may generate a received signal RSCP, a noise-to-signal power ratio Ec / No, and a channel quality CQI for the same received signal. When a plurality of received signals RSCP, noise-to-signal power ratio Ec / No, and channel quality CQI are generated, the averaging means 54 of the control apparatus 5 receives the received signal RSCP, noise-to-signal power ratio Ec / No, and An average value is obtained for each of the channel quality CQIs.

  In the above example, the box 1 is provided with a plurality of antennas 1b, 1c, 1d and the antennas 1b, 1c, 1d used in the switch 4 are selected. However, the box 1 may be provided with one antenna. . In this case, the switch 4 can be dispensed with by directly connecting the antenna and the opposing device 3.

  In the above example, the control device 5 includes the measurement condition setting means 51, the received signal quality information acquisition means 52, the storage means 53, the averaging means 54, the end determination means 55, the stop determination means 56, the discarding means 57, the minimum maximum value. The value acquisition unit 58, the first power range setting unit 59, the change determination unit 510, and the second power range setting unit 511 are provided. At least one of these units is provided in the counter device 3 and / or the box 1. Also good.

  In the above example, the average value calculation (step S6) of the received signal quality information is performed before the determination (step S7) whether the received signal quality information corresponding to all the measurement conditions has been acquired. After that, the average value of the received signal quality information may be calculated.

  Needless to say, other modifications are possible without departing from the spirit of the present invention.

The functional block diagram of the example of an antenna measurement system. Functional block diagram of a control device example The flowchart of the example of an antenna measuring method. The flowchart of the example of step T. The flowchart of the example of step A. The flowchart of the example of step B. (A) is a figure which illustrates the structure for evaluating the performance between antennas. (B) is a figure which illustrates the structure for evaluating antenna correlation. The figure for demonstrating the appropriate number of samples. The figure for demonstrating the stop time of a stirrer. The figure for demonstrating the upper limit and lower limit of the range of the power of the desired signal defined in an opposing apparatus. The figure for demonstrating the area abbreviate | omitted from the range of the electric power of the desired signal defined to an opposing apparatus. The functional block diagram of the example of the antenna measurement system using a reference | standard antenna.

Explanation of symbols

1 Box 1a Reflecting wall 1b, 1c, 1d Antenna 1e, 1f Stirrer 1g Turntable 2 Device under test 22, 221, 222, 223, 224 Variable attenuator 3 Counter device 4 Switch 5 Controller 51 Measurement condition setting means 52 Reception Signal quality information acquisition means 53 Storage means 54 Averaging means 55 End determination means 56 Stop determination means 57 Discard means 58 Maximum value minimum value acquisition means 59 First power range setting means 510 Change determination means 511 Second power range setting means 6 Reference Antenna 7 connection cable

Claims (8)

(A) a measurement condition setting means for determining a measurement condition for the opposing device;
(B) the opposing device generates an electrical signal based on the determined measurement conditions;
(C) An antenna that radiates electromagnetic waves corresponding to an applied electric signal, a reflection wall that reflects the electromagnetic waves, a stirrer that stirs the electromagnetic waves, and a turntable on which a device to be measured is placed. An electromagnetic wave corresponding to the electrical signal is radiated through the transmitting antenna inside the box;
(D) the device under test receives the electromagnetic wave and generates received signal quality information;
(E) a received signal quality information obtaining unit obtaining the received signal quality information;
(F) determining whether the end determination means has acquired the received signal quality information corresponding to all measurement conditions;
(G) If it is determined in step (F) that the received signal quality information corresponding to all the measurement conditions has not been acquired, the measurement condition setting unit has not yet acquired the received signal quality. The steps defined in the opposing device;
An antenna measurement method including: The antenna measurement method according to claim 1,
The step (E) includes (E-1) a step in which the stop determining means determines whether the stirrer and the turntable are stopped, and (E-2) a discarding means in the step (E-1). The received signal quality information at the stop time is discarded when it is determined that
An antenna measurement method. The antenna measurement method according to claim 1 or 2,
The measurement condition includes a condition regarding power of a desired signal generated by the opposing device, and the received signal quality information includes power of electromagnetic waves received by the device under measurement, and power of electromagnetic waves that can be received by the device under measurement. The upper and lower limit values are predetermined,
(H) The maximum value of the electromagnetic wave power received by the device under test when the maximum value / minimum value acquisition unit outputs the desired signal of the power with the opposite device in steps (A) to (E). Determining a value and a minimum value;
(I) The first power range setting means adds the upper limit value to the power of the desired signal output from the opposing device and subtracts the maximum value to determine the power range of the desired signal for the opposing device. A value obtained by adding the lower limit value to the power of the desired signal output from the opposing device and subtracting the minimum value as a lower limit value of the power range of the desired signal determined in the opposing device. Including
The step (A) and the step (F) are steps for determining the power within the above range in the counter device as a measurement condition for the power of the desired signal generated by the counter device.
An antenna measurement method. In the antenna measuring method in any one of Claim 1 to 3,
The measurement conditions include a condition for the power of the desired signal generated by the opposite device, and i is a positive integer.
(J) while the stirrer and the above rotary table is stopped, in step (D) from step (A), the reception signal quality when the power of the desired signal in which the opposing device generates is P _i Obtaining the received signal quality information Q _{i + 1} when the information Q _i and the power of the desired signal generated by the opposite device is P _{i + 1} (P _{i + 1} <P _i );
(K) The change determining means compares the absolute value of the difference between the received signal quality information Q _i and the received signal quality information Q _{i + 1} with a predetermined threshold value, whereby the received signal quality information Q _i and the received signal quality information are compared. Determining whether there is a change in the signal quality information Q _{i + 1} ;
(L) If the second power range setting means determines that there is no change in the received signal quality information Q _i and the received signal quality information Q _{i + 1 in the} step (K), the desired power set in the opposite device Removing power P _i from the range of power of the signal,
In the step (A) and the step (F), the condition regarding the power of the desired signal generated by the opposing device is an interval smaller than the absolute value of the difference between the power P _{i + 1} and the power P _i. Determining power within range to the opposing device;
An antenna measurement method. The antenna measurement method according to any one of claims 1 to 4,
The step (D) is a step of generating a plurality of received signal quality information under the same measurement conditions,
(M) The averaging means calculates an average value of the plurality of received signal quality information or an average value of the received signal quality information remaining in the plurality of received signal quality information without being discarded by the step (E-2). Further comprising the step of determining
An antenna measurement method. The antenna measurement method according to claim 5, wherein
The step (D) is a step of generating 50 or more received signal quality information under the same measurement conditions.
An antenna measurement method. In the antenna measuring method according to any one of claims 1 to 6,
The received signal quality information is a control signal used in cellular communication.
An antenna measurement method. A box having a device under test disposed therein, a transmission antenna that radiates an electromagnetic wave corresponding to an applied electrical signal, a reflection wall that reflects the electromagnetic wave, and a stirrer that stirs the electromagnetic wave;
An opposing device that applies an electrical signal based on a predetermined measurement condition to the transmitting antenna and obtains received signal quality information from the device under measurement;
A controller for controlling the stirrer and the opposing device,
The control device sets measurement conditions for the counter device, confirms that the counter device has acquired the received signal quality information corresponding to the measurement conditions from the device under test, and then receives reception signals corresponding to all measurement conditions. If it is determined whether the signal quality information has been acquired and it is determined that the received signal quality information corresponding to all the measurement conditions has not been acquired, the measurement conditions for which the received signal quality has not yet been acquired are set in the counter device. Define
An antenna measurement system.

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