JP2011176743A - Communication quality estimating system, program, and estimated quality estimating method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a communication quality estimating system for sufficiently evaluating communication quality, in a first wireless communication system that includes a base station and a wireless terminal, one of which has at least one antenna and the other has a plurality of antennas, and establishes wireless communication between at least one antenna of one of the base station and the wireless terminal and the plurality of antennas of the other. <P>SOLUTION: A communication quality estimating system outputting communication quality in a first wireless communication system includes: an estimating unit that estimates throughput, as communication quality, an error rate or a block error rate at each predetermined estimating spot; and an output control unit that outputs an estimated communication quality and an estimated spot in association with each other. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a communication quality estimation system and a program.

Patent Document 1 and Patent Document 2 disclose a system for estimating a radio wave propagation characteristic for assisting in determining an installation position of a base station or the like in a wireless communication system. Patent Document 3 discloses a system that acquires received power, radio wave arrival direction, and radio wave arrival time for each multipath component of radio waves arriving at each observation point from a transmission source by the ray tracing method. Non-Patent Document 4 discloses a system that estimates propagation loss characteristics, radio wave delay characteristics, and radio wave arrival angle characteristics at each point.
Patent Document 1 Japanese Patent Application Laid-Open No. 2004-304400 Patent Document 2 Japanese Patent Application Laid-Open No. 2007-309709 Patent Document 3 International Publication No. 2005-088868 Non-Patent Document 4 Ota, Table, Fujii, “Space-Time in Next Generation Mobile Communication System Propagation Estimation System ", August 29, 2007, IEICE

  In the wireless LAN, standardization of the IEEE802.11n standard that realizes a higher transmission speed is underway. In IEEE 802.11n, the adoption of MIMO transmission technology has been decided as one of the technologies for realizing high speed. In a system that transmits and receives data between many-to-many or one-to-many antennas such as MIMO, for example, the throughput, error rate, or block error rate may change depending on the moving speed of the wireless terminal. Therefore, in the system that estimates the received power, radio wave arrival direction, radio wave arrival time, and the like as described above, communication quality may not be sufficiently evaluated. Therefore, a system capable of sufficiently evaluating communication quality in a system capable of transmitting and receiving data between many-to-many or one-to-many antennas such as MIMO is desired.

  A communication quality estimation system according to the present invention includes a base station and a radio terminal, and one of the base station and the radio terminal has at least one antenna, and the other of the base station and the radio terminal has a plurality of antennas. A communication quality estimation system for outputting communication quality in a first wireless communication system for performing wireless communication between at least one antenna on one side and a plurality of antennas on the other, wherein the throughput and error rate are as communication quality. Alternatively, an estimation unit that estimates the block error rate for each predetermined estimation point and an output control unit that outputs the estimated communication quality and the estimation point in association with each other are provided.

  In one aspect of the communication quality estimation system according to the present invention, the estimation unit includes an estimation formula for determining a propagation loss including a city structure parameter at an estimation point, an estimation formula for a propagation delay characteristic including a city structure parameter at the estimation point, and an estimation Communication quality may be estimated based on a radio wave arrival angle characteristic estimation formula including city structure parameters at a point.

  In one aspect of the communication quality estimation system according to the present invention, the estimation unit estimates the communication quality at each estimated point for each predetermined moving speed of the wireless terminal at the estimated point, and the output control unit The communication quality and the estimated point may be output in association with each other.

  One aspect of the communication quality estimation system according to the present invention further includes a display unit, and the output control unit superimposes a communication quality image indicating the communication quality in the first wireless communication system on each position corresponding to each estimation point. The first map image may be output to the display unit, and the display unit may display the first map image.

  In one aspect of the communication quality estimation system according to the present invention, the estimation unit estimates communication quality in a second radio communication system having a communication method different from that of the first radio communication system for each estimation point, and the output control unit One map image and a second map image in which a communication quality image indicating communication quality in the second wireless communication system is superimposed at each position corresponding to each estimated point are output, and the display unit outputs the first map image and the first map image. Two map images may be displayed.

  In one aspect of the communication quality estimation system according to the present invention, the estimation unit calculates the communication quality for each estimated point when the base station of the first radio communication system is installed at the installation position of the base station of the second radio communication system. The first control on which the output control unit superimposes the communication quality image indicating the communication quality at each estimated point when the base station of the first wireless communication system is installed at the installation position of the base station of the second wireless communication system. An image and a second map image may be output.

  A program according to the present invention includes a base station and a radio terminal, and one of the base station and the radio terminal has at least one antenna, the other of the base station and the radio terminal has a plurality of antennas, and at least one of the ones A program for causing a computer to function as a communication quality estimation system that outputs communication quality in a first wireless communication system that performs wireless communication between one antenna and a plurality of other antennas, and the throughput as communication quality The computer is caused to function as an estimation unit that estimates an error rate or a block error rate for each predetermined estimation point, and an output control unit that outputs the estimated communication quality and the estimation point in association with each other.

  A communication quality estimation method according to the present invention includes a base station and a radio terminal, and one of the base station and the radio terminal has at least one antenna, and the other of the base station and the radio terminal has a plurality of antennas, A communication quality estimation method for outputting communication quality in a first wireless communication system for performing wireless communication between the at least one antenna and the other plurality of antennas, wherein the communication quality includes a throughput and an error rate. Alternatively, an estimation step of estimating the block error rate for each predetermined estimation point and an output control step of outputting the estimated communication quality and the estimation point in association with each other are included.

  It should be noted that the above summary of the invention does not enumerate all the necessary features of the present invention. In addition, a sub-combination of these feature groups can also be an invention.

It is a figure which shows the functional block of the communication quality estimation system which concerns on this embodiment. It is a figure which shows the example of a display of the 1st map image displayed on a display part. It is a figure which shows the example of a display at the time of displaying a 1st map image and a 2nd map image side by side on a display part. It is a figure which shows the example of a display at the time of arranging the 1st map image at the time of installing a new base station, and a 2nd map image on a display part.

  Hereinafter, the present invention will be described through embodiments of the invention, but the following embodiments do not limit the invention according to the claims. In addition, not all the combinations of features described in the embodiments are essential for the solving means of the invention.

  FIG. 1 shows functional blocks of a communication quality estimation system that estimates communication quality of a first radio communication system including a base station and a radio terminal. In the present embodiment, in the first wireless communication system, one of the base station and the wireless terminal has at least one antenna. Furthermore, the other of the base station and the wireless terminal has a plurality of antennas. In such a first wireless communication system, wireless communication is performed between at least one antenna on one side and a plurality of antennas on the other side. The first wireless communication system may be a system using a MIMO (Multiple Input Multiple Output) wireless communication scheme.

  The communication quality estimation system in this embodiment estimates the throughput, error rate, or block error rate as communication quality based on propagation loss, radio wave delay, and radio wave arrival angle at each estimation point in the estimation target area.

The basic parameter storage unit 102 stores basic parameters necessary for estimating the communication quality at each estimated point. More specifically, the basic parameter storage unit 102 stores the height h _{b of} the base station antenna from the reference point, the distance d from the base station to the estimated point, and the base station transmission frequency f. Furthermore, the basic parameter storage unit 102 stores the number of transmitting side antenna elements, that is, the number of antenna elements N _{t included in} the base station, and the number of receiving side antenna elements, that is, the number of antenna elements N _{r included} in the wireless terminal. In addition, the basic parameter storage unit 102 stores a path number i indicating a delay time normalized by the transmission bandwidth B and the time resolution 1 / B.

The city structure parameter storage unit 104 stores city structure parameters related to the city structure of each estimated point necessary for estimating the communication quality of each estimated point with higher accuracy. In the present embodiment, urban structure parameter storage unit 104, as a city structural parameters, average building height at each putative point <H>, road width W, and stores the average building height h _s roadside. Note that the city structure parameter storage unit 104 may store a city structure parameter for each estimated area including at least one estimated point.

  Here, each parameter stored in the basic parameter storage unit 102 and the city structure parameter storage unit 104 may be input in advance by a user via an input unit such as a keyboard.

  The estimation formula storage unit 106 stores an estimation formula for estimating communication quality using each parameter. The estimation formula may be a formula defined based on actual measurement values. In the present embodiment, as estimation formulas, an estimation formula for determining propagation loss including urban structure parameters at the estimated location, an estimation formula for propagation delay characteristics including urban structure parameters at the estimated location, and radio wave arrival including urban structure parameters at the estimated location An angular characteristic estimation formula is stored.

The following equation shows an example of an estimation equation for propagation loss characteristics.

The following formula shows an example of the propagation delay characteristic estimation formula.

The following formula shows an example of the estimation formula of the radio wave arrival angle characteristic on the base station side.

However, a and (beta) are defined by following Formula.

The following formula shows an example of an estimation formula for specifying the radio wave arrival angle on the wireless terminal side.

However, η is defined by the following equation.

  In addition, each said estimation formula is only an example. Each estimation formula is based on, for example, the contents described in Chapter 1.4 “Extension module” of “Report ITU-R M.2135“ Guidelines for evaluation of radio interface technologies for IMT-Advanced ”.

  Now, the estimation unit 110 uses each estimation formula stored in the estimation formula storage unit 106 based on each parameter stored in the basic parameter storage unit 102 and the city structure parameter storage unit 104, thereby estimating each estimated point. The propagation loss, propagation delay, and radio wave arrival angle are calculated. Further, the estimation unit 110 calculates the throughput, error rate, and block error rate, respectively, using system level simulation and theoretical formulas. The system level simulation may be a system level simulation based on 3GPP or a system level simulation based on IMT-Advanced.

  Here, the estimation unit 110 may calculate each communication quality for each predetermined movement speed of the estimation target of the wireless terminal. Further, the estimation unit 110 may calculate the throughput, error rate, and block error rate at each estimation point for each of the uplink and the downlink.

  The output control unit 120 acquires a map image including the estimation target area from the map image stored in the map image storage unit 122. Furthermore, the output control unit 120 generates a first map image in which a communication quality image indicating communication quality in the first wireless communication system is superimposed on each position corresponding to each estimated point with respect to the map image, and the display unit 130 Output to. When the estimation unit 110 calculates communication quality for each moving speed of the wireless terminal, the output control unit 120 may generate a first map image for each moving speed and output the first map image to the display unit 130. The display unit 130 displays the first map image. The display unit 130 may display a first map image corresponding to the moving speed v specified by the user, for example. Instead of displaying the map image output from the output control unit 120 on the display unit 130, for example, the map image may be output to a printer, and the map image may be printed on the printer.

  FIG. 2 shows a display example of the first map image displayed on the display unit 130. A 1st map image shows distribution of the throughput in each presumed point of the signal transmitted from wireless base station B1, B2, for example. In the figure, they are indicated by a straight line, an alternate long and short dash line, and a broken line in descending order of throughput.

  As described above, according to the present embodiment, in a wireless communication system in which data is transmitted / received between many-to-many or one-to-many antennas such as MIMO, throughput, error rate, or block error rate is also estimated as communication quality. can do. Therefore, the communication quality can be evaluated from a wider viewpoint as compared with the conventional case. Moreover, according to this embodiment, a throughput, an error rate, or a block error rate can be estimated according to the moving speed of a wireless terminal. Therefore, for example, the communication quality at each point can be evaluated in consideration of the average moving speed of the wireless terminal at each point.

  By the way, when moving an existing wireless communication system to a new wireless communication system, we want to evaluate the communication quality when a base station of a new wireless communication system is installed at a place where the base station of the existing wireless communication system is installed. There is a case. In some cases, it is desired to evaluate the communication quality of an existing radio communication system and the communication quality of a new radio communication system.

  Therefore, the communication quality estimation system may estimate, for each estimation point, the communication quality of a second wireless communication system using, for example, a W-CDMA system that is different from the communication system of the first wireless communication system. Furthermore, the communication quality estimation system displays, together with the first map image, a second map image in which a communication quality image indicating communication quality in the second wireless communication system is superimposed on each position corresponding to each estimated point with respect to the map image. May be.

  In this case, the estimation formula storage unit 106 stores each estimation formula for the second wireless communication system. The estimation part 110 estimates the communication quality for every estimated point in a 2nd radio | wireless communications system using each estimation formula with respect to a 2nd radio | wireless communications system based on each parameter. The city structure parameter may be a common value in each of the first and second wireless communication systems. The output control unit 120 displays the second map image obtained by superimposing the communication quality image indicating the communication quality in the second wireless communication system at each position corresponding to each estimated point on the map image together with the first map image. Output to. The display unit 130 displays the first map image and the second map image side by side, for example.

  FIG. 3 shows a display example when the first map image and the second map image are displayed side by side on the display unit 130. The first map image and the second map image show the distribution of throughput at each estimated point of the signal transmitted from each of the radio base stations B1 and B2. By displaying in this way, it is easy to visually evaluate a change in communication quality when a base station of a new wireless communication system is installed at a location where a base station of an existing wireless communication system is installed, for example. become.

  For example, as shown in FIG. 3, it can be visually seen that, for example, the area A1 that could be covered without any problem as communication quality in the existing second wireless communication system is not sufficiently covered by the new first wireless communication system. Can be easily evaluated.

  Furthermore, the communication quality estimation system according to the present embodiment is configured so that the first and second wireless communications when a base station is installed at a new installation location in addition to the existing base station to cover an area where the communication quality is not sufficient. Each communication quality of the system may be displayed in the first map image and the second map image. In this way, a new communication quality image indicating the communication quality of each estimated point when the base station is set at a new location for each of the first map image and the second map image is displayed in a new manner. A change in communication quality at each estimated point of the first and second wireless communication systems when a base station is installed can be visually confirmed. In this case, the user may register the basic parameters for the new base station in the basic parameter storage unit 102 via the input unit.

  FIG. 4 shows a case where the first map image and the second map image when the base station B3 is installed at a new location are displayed side by side on the display unit 130 in order to improve the communication quality of the area A1 in the first wireless communication system. A display example is shown. In addition, the 2nd map image shown in FIG. 4 has shown the example of a display containing the communication quality at the time of setting the base station B3 in said new place also about a 2nd radio | wireless communications system. In this way, the respective communication qualities when the base station is added at the same location for each of the first and second wireless communication systems are displayed side by side as the first map image and the second map image. Therefore, it is possible to visually evaluate a change in communication quality when a new base station is added to each of the first and second wireless communication systems.

  The communication quality estimation system according to the present embodiment may be configured by installing a program for performing various processes related to the above-described communication quality estimation and causing the computer to execute the program. That is, the basic parameter storage unit 102, the city structure parameter storage unit 104, the estimation formula storage unit 106, the estimation unit 110, the output control unit 120, the map are executed by causing a computer to execute programs for performing various processes related to communication quality estimation. A communication quality estimation system may be configured by causing a computer to function as the image storage unit 122 and the display unit 130.

  The computer has various memories such as a CPU, ROM, RAM, and EEPROM (registered trademark), a communication bus, and an interface. The CPU reads out processing programs stored in the ROM as firmware in advance and sequentially executes them to estimate communication quality. Functions as a system.

  As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. It will be apparent to those skilled in the art that various modifications or improvements can be added to the above-described embodiment. It is apparent from the scope of the claims that the embodiments added with such changes or improvements can be included in the technical scope of the present invention.

  The order of execution of each process such as operations, procedures, steps, and stages in the apparatus, system, program, and method shown in the claims, the description, and the drawings is particularly “before” or “prior to”. It should be noted that the output can be realized in any order unless the output of the previous process is used in the subsequent process. Regarding the operation flow in the claims, the description, and the drawings, even if it is described using “first”, “next”, etc. for convenience, it means that it is essential to carry out in this order. It is not a thing.

102 basic parameter storage unit 104 urban structure parameter storage unit 106 estimation formula storage unit 110 estimation unit 120 output control unit 122 map image storage unit 130 display unit

Claims (8)

A base station and a radio terminal, wherein one of the base station and the radio terminal has at least one antenna, the other of the base station and the radio terminal has a plurality of antennas, and the at least one of the one A communication quality estimation system that outputs communication quality in a first wireless communication system that allows wireless communication between an antenna and the other plurality of antennas,
An estimation unit that estimates a throughput, an error rate, or a block error rate as the communication quality for each predetermined estimation point;
An output control unit for outputting the estimated communication quality and the estimated point in association with each other;
A communication quality estimation system comprising: The estimation unit includes a propagation loss identification estimation formula including a city structure parameter at the estimation point, a propagation delay characteristic estimation formula including a city structure parameter at the estimation point, and a radio wave arrival angle including a city structure parameter at the estimation point. Estimating the communication quality based on a characteristic estimation formula;
The communication quality estimation system according to claim 1. The estimation unit estimates the communication quality at each estimated point for each predetermined moving speed of the wireless terminal at the estimated point,
The output control unit outputs the communication quality and the estimated point in association with each movement speed, respectively.
The communication quality estimation system according to claim 1 or 2. A display unit;
The output control unit outputs a first map image in which a communication quality image indicating the communication quality in the first wireless communication system is superimposed on each position corresponding to each of the estimated points to the display unit,
The display unit displays the first map image;
The communication quality estimation system according to any one of claims 1 to 3. The estimation unit estimates the communication quality in a second wireless communication system having a communication method different from that of the first wireless communication system for each estimation point,
The output control unit outputs the first map image and a second map image in which a communication quality image indicating the communication quality in the second wireless communication system is superimposed on each position corresponding to each estimated point. ,
The display unit displays the first map image and the second map image;
The communication quality estimation system according to claim 4. The estimation unit estimates the communication quality for each of the estimated points when the base station of the first radio communication system is installed at the installation position of the base station of the second radio communication system,
The output control unit is configured to superimpose a communication quality image indicating the communication quality at each estimated point when the base station of the first wireless communication system is installed at the installation position of the base station of the second wireless communication system. Outputting a first map image and the second map image;
The communication quality estimation system according to claim 5. A base station and a radio terminal, wherein one of the base station and the radio terminal has at least one antenna, the other of the base station and the radio terminal has a plurality of antennas, and the at least one of the one A program for causing a computer to function as a communication quality estimation system that outputs communication quality in a first wireless communication system that performs wireless communication between an antenna and the other plurality of antennas,
An estimation unit that estimates the throughput, error rate, or block error rate as the communication quality for each predetermined estimation point; and
An output control unit that outputs the estimated communication quality and the estimated point in association with each other;
A program for causing the computer to function as A base station and a radio terminal, wherein one of the base station and the radio terminal has at least one antenna, the other of the base station and the radio terminal has a plurality of antennas, and the at least one of the one A communication quality estimation method for outputting communication quality in a first wireless communication system for performing wireless communication between an antenna and the other plurality of antennas,
Estimating to estimate the throughput, error rate or block error rate as the communication quality for each predetermined estimation point;
An output control stage for outputting the estimated communication quality and the estimated point in association with each other;
A communication quality estimation method including:

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