JP2004064221A - Interference testing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an interference testing apparatus for efficiently conducting repetitive tests by virtually reproducing a communication environment wherein a reception level is dynamically changed with the elapse of time in an interference test for intruding an interference wave to communication between a base station wireless apparatus and a moving mobile station wireless apparatus. <P>SOLUTION: In the interference testing apparatus, profile data denoting a change in an attenuation factor converted from a reception level measured in advance by means of a mobile test or the like are installed in a propagation path simulator 8 which changes the attenuation factor according to the elapse of time and data resulting from converting the reception level of an interference wave under a real environment into the attenuation factor are similarly installed to a propagation path simulator 9. Further, the propagation path simulator 8 is connected to a base station transmission apparatus 1 and the propagation path simulator 9 is connected to an interference signal source 5, respectively, and a composite unit 7 composes outputs of the propagation path simulators 8, 9 by operating them in the same timing and speed, and provides an output of the result to a mobile station reception apparatus 3 so that the interference testing apparatus conducts the interference test wherein the real environment is virtually reproduced. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a test apparatus for wireless equipment for mobile communication, and more particularly to an interference test apparatus for measuring and evaluating performance of a wireless system against frequency interference.
[0002]
[Prior art]
When evaluating and measuring the performance of wireless equipment for mobile communication, a radio wave propagation test in an actual running state or a state close to it is necessary. In the actual running state, the reception level dynamically fluctuates as the position changes due to the movement of the moving object.Therefore, when measuring the transmission characteristics for the static reception level, fully evaluate and measure the performance of the radio equipment including the communication procedure. It is difficult to do.
[0003]
Generally, a wireless device, a measuring device, or the like is installed on a test course, a moving body, or the like, and the transmission characteristics are measured while moving the moving body. However, it takes time and effort to prepare and execute a test. On the other hand, by applying a propagation path simulator that can change the attenuation over time, it is possible to simulate the radio wave propagation characteristics in a running state and to conduct efficient evaluation tests. (For example, JP-A-58-70653).
[0004]
On the other hand, in mobile communication, the wireless communication zone may be close to the wireless zone of another wireless system, and in order to evaluate the performance of wireless equipment, it is necessary to measure and evaluate the effects of interference waves in the same frequency band. .
[0005]
In general, in order to measure the influence of the interference wave on the transmission characteristics, the radio equipment to be evaluated and the radio equipment serving as the interference wave are combined via a variable attenuator, and the desired wave (D) level and the interference are measured. The interference resistance performance was measured by statically changing the wave (U) level ratio. Alternatively, similarly to the above, the radio transmission equipment, the measuring device, and the like are installed on a test course, a moving body, and the like, and the signal transmission characteristics are measured while moving the moving body.
[0006]
[Problems to be solved by the invention]
However, the conventional measuring method has the following problems. That is, the first problem is that it is difficult to sufficiently measure and evaluate the performance of the radio equipment including the communication procedure with a static change in the D / U ratio. The reason is that in an actual communication environment, the reception level dynamically fluctuates as the moving object moves, and the interference situation also fluctuates dynamically, so that the environment for evaluating the communication procedure is severe.
[0007]
The second problem is that preparation and execution of the test require time and effort as described above. The reason is that in order to measure and evaluate the performance of wireless equipment including the communication procedure, various changes in the moving speed of the mobile object, various changes in the interference wave level, and the distance to the interference source This is because it is necessary to repeatedly perform many similar measurements with various changes, and even a small change in the test conditions requires a great deal of labor and cost to change the test environment. Another problem is that an environment for the test is constructed every time the test is performed, and the test environment is disassembled when the test is completed.
[0008]
The present invention has been made in view of the above-described conventional problems, and an object of the present invention is to efficiently measure and evaluate the performance when wireless equipment receives interference from another wireless system in an environment close to a real environment. Accordingly, an object of the present invention is to provide an interference test apparatus capable of not only improving the productivity related to the test but also reducing the consumption of resources related to the test.
[0009]
[Means for Solving the Problems]
According to the present invention, in a downlink direction from a base station to a mobile station, an output signal of a base station transmitter is changed by a first channel simulator, and an output signal of a downlink interference signal source is changed by a second channel simulator. Then, the outputs of the respective propagation path simulators are combined and input to the mobile station receiver. Similarly, in the uplink direction from the mobile station to the base station, the output signal of the mobile station transmitter is changed by the first channel simulator, and the output signal of the uplink interference signal source is changed by the second channel simulator. Then, the outputs of the respective propagation path simulators are combined and input to the base station receiver.
[0010]
Further, the control unit controls the change of the attenuation in the first propagation path simulator and the change of the attenuation in the second propagation path simulator to proceed at the same timing and speed (frequency).
[0011]
Here, in the first propagation path simulator, data obtained by actually measuring a reception level that changes with time as the mobile station moves by a running test or the like in a real environment and converting it into an attenuation amount is incorporated. In the second propagation path simulator, data obtained by actually measuring a reception level of an interference wave that changes with time as the mobile station moves by a running test or the like and converting the measured level into an attenuation amount is incorporated in advance.
[0012]
In such a configuration, by operating the first propagation path simulator and the second propagation path simulator at the same timing and speed, an environment in which the mobile station moves while receiving an interference wave is simulated. be able to.
[0013]
BEST MODE FOR CARRYING OUT THE INVENTION
Next, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing one embodiment of the interference test apparatus of the present invention. In the present embodiment, an example will be described in which an interference test is performed for a case in which a base station radio apparatus and a mobile station radio apparatus perform communication by a radio method using different frequencies in an uplink direction and a downlink direction. In FIG. 1, 1 is a base station transmitter, 2 is a base station receiver, 3 is a mobile station receiver, and 4 is a mobile station transmitter. Further, 5 is a downlink interference signal source, 6 is an uplink interference signal source, 7 is a combiner, 8 to 11 are propagation path simulators, and 12 is a control unit.
[0014]
Here, the propagation path simulators 8 to 11 have a function of storing attenuation data on the memory, sequentially reading data from the memory when a clock signal is input, and changing the attenuation of the variable attenuator. As shown in FIG. 2A, the memories of the propagation path simulators 8 and 10 store reception levels (reception levels corresponding to distances) measured in a real environment such as a running test on a test course as shown in FIG. As shown in (1), the profile data converted into the attenuation amount (the attenuation amount according to the distance) is stored. However, in the embodiment of FIG. 1, the propagation path simulators 8 and 10 correspond to the same propagation path in the down direction and the up direction, respectively, so that basically the same profile data can be applied. This is the same in the case of the propagation path simulators 9 and 11.
[0015]
On the other hand, in the propagation path simulators 9 and 11, similarly, profile data obtained by converting the reception level of the interference wave measured by running the mobile station in an actual environment into an attenuation amount is mounted. In the downlink direction, the output signal of the base station transmitter 1 via the propagation path simulator 8 and the output signal of the downlink interference signal source 5 via the propagation path simulator 9 are combined by the combiner 7, and the mobile station receiver Output to 3.
[0016]
The propagation path simulators 8 and 9 receive the clock signal from the control unit 12, and change the attenuation at the same timing and speed (frequency). The same configuration applies to the up direction. That is, the output signal of the mobile station transmitter 4 via the propagation path simulator 10 and the output signal of the uplink interference signal source 6 via the propagation path simulator 11 are combined by the combiner 7 and output to the base station receiver 2. Is done.
[0017]
Next, the operation of the present embodiment will be described. Taking the downlink direction as an example, when the control unit 12 starts to supply a clock signal, the outputs of the propagation path simulators 8 and 9 start to change in attenuation according to the profile data mounted thereon, and as the time elapses, the propagation path simulator 8 outputs a desired wave as shown in FIG. 3 (a), an unnecessary wave as shown in FIG. 3 (b) from the propagation path simulator 9, and a combiner 7 as shown in FIG. 3 (c). And a desired wave and an unnecessary wave are synthesized and output. This is to reproduce well a change in a signal input to the mobile station receiver 3 in an actual environment. The signal from the combiner 7 is received by the mobile station receiver 3, and for example, the signal transmission characteristics are evaluated by detecting the bit error rate of the received signal.
[0018]
The same operation is performed in the up direction, but by supplying a clock signal from the control unit 12 to both the up direction and the down direction at the same timing and speed (frequency), a more realistic communication environment is realized. Can be reproduced. That is, similarly in the uplink direction, the desired wave and the unnecessary wave from the propagation path simulators 10 and 11 are combined and output by the combiner 7 and received by the base station receiver 2. Also in this case, for example, the signal transmission characteristics are evaluated by detecting the bit error rate of the received signal.
[0019]
As described above, in the present embodiment, since the interference test is performed using the propagation path simulator storing the profile data of the reception attenuation amount of the real environment measurement data, the signal change in the real environment can be well reproduced, and the signal can be reproduced in a state close to the real environment. Testing can be performed.
[0020]
In addition, by applying a pseudo interference wave using a propagation path simulator for each of the signal transmission from the base station to the mobile station and the signal transmission from the interference source to the mobile station, the test can be easily and repeatedly performed under the same conditions. This eliminates the need to perform the test while moving the moving body as compared with the measurement on the test course, thus making it possible to easily construct and disassemble the test equipment. Therefore, many tests can be easily performed when a repeated test is required.
[0021]
Further, for example, as shown in FIG. 4A, the change of the ratio between the desired wave (D) level and the interference wave (U) level is shifted so as to increase or decrease the attenuation data of the interference wave propagation path simulator. This is possible. Similarly, as shown in FIG. 4B, changing the positional relationship between the base station and the interference source (the mobile station and the interference source) involves temporally shifting the attenuation data of the interference wave propagation path simulator. Is possible.
[0022]
Also, since the moving speed of the moving object can be changed by changing the speed (frequency) of each clock signal of the propagation path simulator for the desired wave and the propagation path simulator for the interference wave, the operation related to the propagation path simulator is performed. The interference condition can be easily set by setting various conditions. Since a slight change in the interference condition can be easily set as described above, the interference test can be efficiently performed.
[0023]
【The invention's effect】
As described above, according to the present invention, by performing an interference test using a propagation path simulator that stores profile data of the reception attenuation amount of the actual environment measurement data, the test can be performed in a state close to the actual environment. . In addition, the test can be performed easily and at a low cost. In particular, even when a repetitive test is required, the test can be performed easily, and it is easy to make minor changes in interference conditions. It can be done efficiently.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating an embodiment of an interference test apparatus according to the present invention.
FIG. 2 is a conceptual diagram illustrating an example of profile data implemented in a propagation path simulator.
FIG. 3 is a conceptual diagram showing the operation of the present invention.
FIG. 4 is a conceptual diagram showing an example of a method for changing test conditions.
[Explanation of symbols]
REFERENCE SIGNS LIST 1 base station transmitter 2 base station receiver 3 mobile station receiver 4 mobile station transmitter 5 downlink interference signal source 6 uplink interference signal source 7 combiners 8 to 11 propagation path simulator 12 controller

Claims (6)

An interference test apparatus for performing an interference test by adding an interference wave to the communication between a base station radio apparatus and a mobile station radio apparatus, comprising: a downlink direction from the base station radio apparatus to a mobile radio apparatus; A first propagation simulator having profile data obtained by converting a reception level in a real environment into an attenuation amount in each of the uplink directions to the wireless device, and a second propagation simulator having profile data obtained by converting the reception level of an interference wave in the real environment into an attenuation amount And synthesizes an output signal of the base station radio apparatus output via the first propagation path simulator and an interference signal output via the second propagation path simulator in the downstream direction. An output signal of the mobile station radio apparatus, which is output to the mobile station radio apparatus and output through the first propagation path simulator in the uplink, And the interference signal output via the propagation path simulator is combined and output to the base station radio apparatus, and the attenuation amounts of the first and second propagation path simulators in the down direction and the up direction are calculated at the same timing and speed, respectively. An interference test apparatus characterized in that an interference test is performed by changing the interference test. The said 1st and 2nd propagation path simulator has profile data which converted the reception level according to the distance measured in the real environment while driving | running | working a mobile station into the amount of attenuation, The claim 1 characterized by the above-mentioned. Interference test equipment. The said 1st propagation path simulator of an up direction and the down direction, and the 2nd propagation path simulator of an up direction and a down direction have the same profile data, respectively, The Claims 1 and 2 characterized by the above-mentioned. Interference test equipment. A control unit for supplying a clock signal to the first and second propagation path simulators; the control unit supplies the first and second propagation path simulators with the same timing and speed to the first and second propagation path simulators; The interference test apparatus according to claim 1, wherein a clock signal is supplied. The interference test apparatus according to claim 1, wherein a moving speed of the mobile station wireless device is equivalently changed by changing a frequency of a clock signal from the control unit. The positional relationship between the base station radio apparatus and the interference signal source or the mobile station radio apparatus and the interference signal source is changed by temporally shifting attenuation profile data in the second propagation path simulator. The interference test apparatus according to claim 1.

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