Radio propagation simulator and radio propagation characteristic estimation method used for the same, and program thereof

An electric wave propagation characteristic estimation method used for an electric wave propagation simulator and it, and its program

0001(Statement about related application) , This application claims a right of priority of previous Japanese patent application No. (November 28, 2007 application) 306701 [ 2007 to ]. It is considered that all the written contents of application of an above place are what has quotation in this book, and is rounded and indicated.

0002The present invention relates to the electric wave propagation characteristic estimation method used for an electric wave propagation simulator and it, and its program, and relates to the method for presuming the electric wave propagation characteristic in the evaluation area limited among the whole area taken into consideration especially at the time of presumption at high speed and with high precision.

0003In the electric wave propagation characteristic estimation method relevant to the present invention, in order to give arrangement of the base station in a radio communications system, etc., the electric wave propagation simulator (electric wave propagation characteristic presumption system) is used.

0004While this electric wave propagation characteristic estimation method estimates the received power in arbitrary stations, and a delay spread using an electric wave propagation simulator, it decides on setting positions, such as a base station, The increase in efficiency of suppressing the number of base stations arranged in order to secure the appropriate area which can be communicated to necessary minimum is attained.

0005An electric wave propagation simulation is divided roughly and there are what is depended on a statistical method, and a thing to depend on a deterministic approach.

0006A statistical method is the technique of determining the parameter of an estimate equation based on the propagation loss data of a large number which gave the estimate equation of the propagation loss which makes distance, frequency, etc. an argument, and were actually measured. In a statistical method, since the influence which an electric wave receives by the object which exists on the outskirts cannot be made to reflect correctly, high estimation precision is not acquired.

0007On the other hand, when a deterministic approach presumes the electric wave propagation situation of reaching a station from a transmission point, it is the technique of taking into consideration faithfully the influence of the object which exists on the outskirts. Since the influence of an object is faithfully taken into consideration, high-precision propagation presumption is possible.

0008One of the deterministic approaches has the ray tracing method. The ray tracing method is the technique of considering the electric wave emitted from an antenna to be a gathering on many electric wave lines (lei), compounding the lei which arrives at a station as what is spread while each lei repeats reflection and a penetration in geometric optics, and calculating a propagation loss and a delaying amount. The ray tracing method is further divided roughly into the imaging method and the lei loun Ting method.

0009The imaging method is the technique of determining reflection / penetration course of a lei of defining one pair of a transmission point and a station (receiving point), and connecting between the points concerned receiving [ transmit and ], in quest of the reflection point over a reflective surface. Since reflection / penetration course can be uniquely found when the point receiving [ transmit and ] and reflection / penetration thing are specified, it can search the imaging method for the propagation path of the strict lei from a transmission point to a receiving point.

0010However, in the imaging method, since search processing of a reflecting point or a diffracting point increases when many objects are in the field to presume, an operation throughput will increase. As a result, there is a problem that electric wave propagation presumption takes much time.

0011There is a technique indicated by nonpatent literature 1 as one technique for accelerating the imaging method. In a technique given in nonpatent literature 1, an object with a far distance from a receiving point is regarded as the contribution to propagation presumption being small, building quantity and building base area are deleted as a threshold, and propagation presumption is performed. Specifically space is divided into a plurality of zones according to the distance from a receiving point, a low building is deleted from a receiving point in a distant zone compared with circumference building quantity, and propagation presumption is performed.

0012On the other hand, the lei loun Ting method is the technique of considering that the lei which emitted the lei discretely at a given fixed angle from the transmitting antenna, carried out sequential search of the locus, and passed through near the station is the lei which arrived at the station concerned.

0013In this lei loun Ting method, it is concerned with the position of evaluation area, there is nothing, and in order to emit a lei in all directions, it will look even for the lei (lei which does not influence propagation presumption of evaluation area) which does not arrive at evaluation area. Therefore, in the lei loun Ting method, it cannot presume only the limited evaluation area at high speed. There is a technique indicated by nonpatent literature 2 as one of the techniques which presumes only the limited evaluation area at high speed.

0014<nplcit num="1"><text>Tetsuro Imai and Teruya Fujii: "city area compatible mobile communications propagation presumption system using lei trace", Shingaku Giho, RCS97-37-1997.</text></nplcit><nplcit num="2"><text>Masahiro Motoyoshi, Yoshinori Watanabe, Hiroto Sugawara, and Takashi Ono: "proposal of the seamless lei loun Ting method", Shinsaku general size, B-1-39-2006.</text></nplcit>

<p num="0015">The indication matter of the above-mentioned nonpatent literatures 1 and 2 shall have quotation in this book, and shall be rounded and indicated. The following analysis is given by the present invention.</p><p num="0016">When a designer utilizes an electric wave propagation simulator for actual design business, rearrangement of a base station, change of a parameter, etc. are considered based on the propagation estimation result in some conditions, and if required, there is a process in which propagation presumption is carried out again. When using the electric wave propagation characteristic estimation method relevant to the present invention mentioned above in this process, much presumed time is required for presuming the arranged whole circumference area of a base station.</p><p num="0017">On the other hand, if propagation presumption can be carried out in a short time to the limited area where a design top priority is high among whole area, without waiting for presumption of whole area, necessity, such as rearrangement of a transmitting station and parameter change, can be determined now, and efficient designing operation will become possible.</p><p num="0018">In order to realize this, the art of presuming an electric wave propagation situation at high speed and with high precision is needed only to some evaluation area in the whole area taken into consideration in the circumference of a base station at the time of presumption. However, no electric wave propagation characteristic estimation methods relevant to the present invention mentioned above can satisfy this demand. Below, the problem of the electric wave propagation characteristic estimation method relevant to the present invention is explained.</p><p num="0019">In the imaging method, evaluation area is narrow, when a station can represent with one point or a few points, it is using the high speed technique of a statement for the above-mentioned nonpatent literature 1 grade, and propagation presumption high-speed [ a certain grade ] is possible. However, since evaluation area needs to search it for a lei for every station to some extent when many stations are defined by the wide area in evaluation area, sufficient presumed speed is unrealizable.</p><p num="0020">On the other hand, in the lei loun Ting method, since it looks even for the lei (lei which does not influence propagation presumption of evaluation area) which does not arrive at evaluation area, it cannot presume only the limited evaluation area at high speed. As one of the techniques which presumes only this limited evaluation area at high speed, there is a technique indicated by the above-mentioned nonpatent literature 2.</p><p num="0021">In nonpatent literature 2, the direction which may arrive at evaluation area beforehand from the geometric structure of propagation environment is pinpointed, and the technique accelerated by emitting a lei only to the direction is indicated. However, nonpatent literature 2 is the method of limiting only a perpendicular radiation direction. A horizontal radiation direction cannot be limited. Therefore, in nonpatent literature 2, improvement in the speed of sufficient presumed time is unrealizable.</p><p num="0022">Then, it is in the object of the present invention providing the electric wave propagation characteristic estimation method used for the electric wave propagation simulator and it which can presume the electric wave propagation characteristic of the evaluation area limited among the whole area which cancels the above-mentioned problem and it takes into consideration at the time of presumption at high speed and with high precision, and its program.</p>

<p num="0023">The electric wave propagation simulator by the present invention is an electric wave propagation simulator which presumes the propagation situation of the electric wave which reaches the evaluation area where it was restricted of on the above-mentioned space from the transmission point using a plurality of objects defined on space, An extraction means to extract the path which arrives at the above-mentioned evaluation area using the geometric optics propagation presumption technique, It has the selecting means which chooses an object using the path extracted by the above-mentioned extraction means, and the geometric information on the above-mentioned evaluation area, and the estimation means which presumes the detailed electric wave propagation situation of reaching the inside of above-mentioned evaluation Eria from the above-mentioned transmission point only using the object selected by the above-mentioned selecting means.</p><p num="0024">A plurality of objects defined on space are used for the electric wave propagation characteristic estimation method by the present invention, It is an electric wave propagation characteristic estimation method which presumes the propagation situation of the electric wave which reaches the evaluation area where it was restricted of on the above-mentioned space from the transmission point. The 1st step that extracts the path which arrives at the above-mentioned evaluation area using the geometric optics propagation presumption technique, The 2nd step that chooses an object using the path extracted at the 1st above-mentioned step, and the geometric information on the above-mentioned evaluation area, It has the 3rd step that presumes the detailed electric wave propagation situation of reaching the inside of above-mentioned evaluation Eria from the above-mentioned transmission point only using the object selected at the 2nd above-mentioned step.</p><p num="0025">The program by the present invention is a program which the central processing unit in the electric wave propagation simulator which presumes the propagation situation of the electric wave which reaches the evaluation area where it was restricted of on the above-mentioned space from the transmission point using a plurality of objects defined on space is made to run, Extraction processing which extracts the path which arrives at the above-mentioned evaluation area using the geometric optics propagation presumption technique, Selection processing which chooses an object using the path extracted by the above-mentioned extraction processing, and the geometric information on the above-mentioned evaluation area, The presumed processing which presumes the detailed electric wave propagation situation of reaching the inside of above-mentioned evaluation Eria from the above-mentioned transmission point only using the object selected by the above-mentioned selecting means is included.</p>

<p num="0026">The effect that the electric wave propagation characteristic of the evaluation area limited among the whole area taken into consideration at the time of presumption can be presumed at high speed and with high precision by considering the present invention as above composition and operations is acquired.</p>

0027<figref num="1">It is a block diagram showing the example of composition of the electric wave propagation simulator by a 1st embodiment of the present invention.</figref><figref num="2">It is a flow chart which shows operation of the electric wave propagation simulator by a 1st embodiment of the present invention.</figref><figref num="3">It is a figure for explaining the technique of extracting the path which arrives at evaluation area using the geometric optics propagation presumption technique from the transmission point by a 1st embodiment of the present invention.</figref><figref num="4">It is a figure for explaining the technique of enforcing the imaging method between a transmission point and each peak of evaluation area for the virtual infinite plane by a 1st embodiment of the present invention which includes a reflective surface for every path, and a virtual infinite plane including a diffracting point, and obtaining a peak path.</figref><figref num="5">It is a figure for explaining the technique of defining the object selected area with the maximum width of the peak path by a 1st embodiment of the present invention.</figref><figref num="6">It is a block diagram showing the example of composition of the electric wave propagation simulator by a 4th embodiment of the present invention.</figref><figref num="7">It is a flow chart which shows operation of the electric wave propagation simulator by a 4th embodiment of the present invention.</figref>

Explanations of letters or numerals

002810 and 11 Object data 20 and 21 Path extraction part 30 and 31 Object selecting part 40, 41, and 51 Electric wave propagation characteristic estimating part 50 and 71 Control part 60 and 81 Memory 61 Indicator

0029Next, an embodiment of the invention is described with reference to drawings. Drawing 1 is a block diagram showing the example of composition of the electric wave propagation simulator (electric wave propagation characteristic presumption system) by a 1st embodiment of the present invention. In Drawing 1, the electric wave propagation simulator by a 1st embodiment of the present invention is constituted including object data 10, path extraction part 20, object selecting part 30, electric wave propagation characteristic estimating part 40, control part 50, and memory 60.

0030Object data 10 is the database with which the coordinate data in which the position and shape of a structure (object) outside indoor [, such as a building and indoor fixtures, ] are shown was stored. The data in which the position and shape of the actual structure were reproduced faithfully is stored in object data 10. For example, if it is an outdoor structure, commercial three-dimensional digital map data can be used.

0031Path extraction part 20 has the function to extract the path which arrives at evaluation area using the geometric optics propagation presumption technique. Object selecting part 30 has a function which chooses the object used for presumption using the path obtained by path extraction part 20, and the geometric information on evaluation area from the data in object data 10.

0032Electric wave propagation characteristic estimating part 40 has the function to presume the electric wave propagation characteristic in evaluation area using the object selected by object selecting part 30. Control part 50 is CPU (central processing unit) which controls above-mentioned each part, and it stores the program which CPU runs while memory 60 functions as a memory for work of this CPU.

0033Drawing 2 is a flow chart which shows operation of the electric wave propagation simulator by a 1st embodiment of the present invention. With reference to these figure 1 and Drawing 2, operation of the electric wave propagation simulator by a 1st embodiment of the present invention is explained. Operation shown in Drawing 2 is realized because control part 50 runs the program of memory 60.

0034In the electric wave propagation simulator by this embodiment, first, control part 50 controls path extraction part 20, and extracts the path which arrives at evaluation area using the geometric optics propagation presumption technique (Drawing 2 step S100). The concrete path extraction method in this step S100 is mentioned below.

0035Next, control part 50 controls object selecting part 30, and chooses the object used for presumption using the path obtained at Step S100, and the geometric information on evaluation area (Drawing 2 step S110). The concrete object selection method in this step S110 is also mentioned below.

0036Finally, control part 50 controls electric wave propagation characteristic estimating part 40, and presumes the electric wave propagation characteristic in evaluation area using the object obtained at Step S110 (Drawing 2 step S120).

0037Drawing 3 is a figure for explaining the technique of extracting the path which arrives at evaluation area using the geometric optics propagation presumption technique from the transmission point by a 1st embodiment of the present invention. Drawing 4 is a figure for explaining the technique of enforcing the imaging method between a transmission point and each peak of evaluation area for the virtual infinite plane by a 1st embodiment of the present invention which includes a reflective surface for every path, and a virtual infinite plane including a diffracting point, and obtaining a peak path. Drawing 5 is a figure for explaining the technique of defining the object selected area with the maximum width of the peak path by a 1st embodiment of the present invention.

0038About the concrete path extraction method in the above-mentioned step S100, path extraction part 20 first presumes the electric wave which goes into evaluation area from a transmission point using the data stored in object data 10 using the geometric optics electric wave propagation presumption technique (refer to Drawing 3). As the geometric optics electric wave propagation presumption technique, the lei loun Ting method, the imaging method, etc. are applicable. As a result of presuming, when the lei emitted from the transmission point reaches in evaluation area, path extraction part 20 extracts the path, and memorizes it in memory 60.

0039About the concrete object selection method in Step S110, First, the field (reflective surface) of an object which object selecting part 30 reflected out of object data 10 based on the data of the path obtained at Step S100, and the neighborhood (diffraction edge) of the diffracted object are altogether extracted for every path obtained at Step S100.

0040When multiple paths with the reflective surface and diffraction edge from which object selecting part 30 was extracted at this time, and its same passage order exist, a reflective surface and diffraction edge are extracted to one path to represent. Next, object selecting part 30 obtains the path (peak path) corresponding to the peak of evaluation area. An example of the calculating method of this peak path is shown below.

0041A virtual infinite plane including the reflective surface where object selecting part 30 was extracted, and a virtual infinite plane including a diffracting point (For example, infinite plane which the incidence wave to the diffracting point concerned can reflect at the same angle as an angle of diffraction) A peak path is obtained by enforcing the imaging method for considering it as an object and taking only reflection into consideration between a transmission point and each peak of evaluation area (refer to Drawing 4). However, although a lei is strictly presumed from the combination of all the reflective surfaces in the usual imaging method, only the path obtained at Step S100 and the path of the same passage order are taken into consideration by this technique.

0042Next, object selecting part 30 defines the object selected area with the maximum width of the obtained peak path, and chooses the object which touches the object selected area. An example of the calculating method of this object selected area is shown below.

0043First, object selecting part 30 computes the solid that volume becomes large most among the solids which connect arbitrary points and are formed out of a transmission point and the reflecting point of the peak path on the first reflective surface. Next, object selecting part 30 computes the solid that volume becomes large most among the solids which connect arbitrary points and are formed out of the reflecting point of the peak path on the first reflective surface and next reflective surface. Henceforth, object selecting part 30 repeats the operation same to the last reflective surface.

0044Finally, object selecting part 30 computes the solid that volume becomes large most among the solids which connect arbitrary points and are formed out of the reflecting point of a peak path and the peak of evaluation area on the last reflective surface. Object selecting part 30 makes the solid on top of which all the these-computed solids and evaluation area were laid the object selected area (refer to Drawing 5). However, it is related with the path which arrived at evaluation area from the transmission point without reflecting once, The solid that volume becomes large most among the solids which connect arbitrary points and are formed out of the peak of a transmission point and evaluation area is computed, and let the solid on top of which the solid and evaluation area were laid be the object selected area.

0045According to this embodiment, in Step S110, object selecting part 30 chooses the object used for presumption using the path which arrives at evaluation area, and the geometric information on evaluation area. As a result, since the electric wave propagation characteristic in evaluation area can be presumed in this embodiment only using the object as which electric wave propagation characteristic estimating part 40 was chosen, The electric wave propagation characteristic of the evaluation area limited among the whole area taken into consideration at the time of presumption can be presumed at high speed and with high precision.

0046Next, a 2nd embodiment of the present invention is described. Although the electric wave propagation simulator by a 2nd embodiment of the present invention has the same composition as a 1st embodiment of the present invention mentioned above, the concrete object selection method in operation of the above-mentioned step S110 differs from a 1st embodiment of the present invention.

0047Since a 1st embodiment of the present invention can estimate the influence degree to estimation precision by a solid defining the object selected area also including the height direction, the effect that a building lower than a path can be excepted and presumed time can be shortened is acquired. However, in a 1st embodiment of the present invention, the processing which defines the object selected area becomes complicated, and also when the height of a transmission point is lower than a surrounding building, the effect of presumed time shortening by a solid defining the object selected area will become small.

0048So, in Step S110 in this embodiment, the plane on the two dimensions of X and the Y-axis defines the object selected area, and it chooses the object which touches the object selected area.

0049If it explains concretely, after obtaining the path (peak path) corresponding to the peak of evaluation area, by this embodiment, all the coordinate data will once be projected on a X-Y plane. Next, in this embodiment, the polygon that area becomes large most among the polygons which connect arbitrary points and are formed out of a transmission point and the reflecting point of the vertex path on the first reflective line is computed.

0050In this embodiment, the polygon that area becomes large most among the polygons which connect arbitrary points and are formed out of the reflecting point of the vertex path on the first reflective line and following reflective line is computed. Henceforth, in this embodiment, the operation same to the last reflective line as the above is repeated.

0051Finally, in this embodiment, the polygon that area becomes large most among the polygons which connect arbitrary points and are formed out of the reflecting point of a vertex path and the vertex of evaluation area on the last reflective line is computed. According to this embodiment, let the polygon which piled up these all computed polygons and evaluation area be the object selected area.

0052However, it is related with the path which arrived at evaluation area from the transmission point without reflecting once, The polygon that area becomes large most among the polygons which connect arbitrary points and are formed out of a transmission point and the vertex of evaluation area is computed, and let the polygon which piled up the polygon and evaluation area be the object selected area.

0053According to this embodiment, since the plane on the two dimensions of X and the Y-axis defines the object selected area in Step S110, the processing can be simplified rather than the processing which defines the object selected area in a 1st embodiment of the present invention mentioned above.

0054Next, a 3rd embodiment of the present invention is described. Although the electric wave propagation simulator by a 3rd embodiment of the present invention has the same composition as a 1st embodiment of the present invention mentioned above, the concrete object selection method in the above-mentioned step S110 differs from a 1st embodiment of the present invention.

0055In Step S110 in this embodiment, propagation presumption is carried out at high speed by reducing the number of processing steps of object selection processing compared with other embodiments.

0056If it explains to a concrete target, at this embodiment, it is the 1st embodiment and the appearance of the present invention, After extracting the field (reflective surface) of an object reflected for every path, and the neighborhood (diffraction edge) of the diffracted object, only an object including the reflective surface, the object containing diffraction edge, and the object in evaluation area are chosen, without performing the definition of the object selected area.

0057According to this embodiment, in Step S110, since it becomes possible to reduce the number of processing steps of object selection processing in order not to define the object selected area, compared with other embodiments, propagation presumption can be carried out at high speed.

0058Drawing 6 is a block diagram showing the example of composition of the electric wave propagation simulator by a 4th embodiment of the present invention. The electric wave propagation simulator according [ on Drawing 6 and ] to a 4th embodiment of the present invention, It is constituted including object data 11, path extraction part 21, object selecting part 31, electric wave propagation characteristic estimating part 41, electric wave propagation characteristic estimating part 51, indicator 61, control part 71, and memory 81.

0059Object data 11 is the database with which the coordinate data in which the position and shape of a structure (object) outside indoor [, such as a building and indoor fixtures, ] are shown was stored. The data in which the position and shape of the actual structure were reproduced faithfully is stored in object data 11. For example, if it is an outdoor structure, commercial three-dimensional digital map data can be used.

0060Path extraction part 21 has the function to extract the path which arrives at evaluation area using the geometric optics propagation presumption technique. Object selecting part 31 has a function which chooses the object used for presumption using the path obtained by path extraction part 21, and the geometric information on evaluation area from the data in object data 11. Electric wave propagation characteristic estimating part 41 has the function to presume the electric wave propagation characteristic in evaluation area using the object selected by object selecting part 31.

0061Electric wave propagation characteristic estimating part 51 has the function to presume the electric wave propagation characteristic in whole area using object data 11 with the general electric wave propagation characteristic estimation method which makes the start the electric wave propagation characteristic estimation method relevant to the present invention mentioned above. Indicator 61 has a function which displays an electric wave propagation characteristic. Control part 71 is CPU which controls these each part 21-61. Memory 81 stores a program which CPU runs while functioning as a memory for work of this CPU.

0062Drawing 7 is a flow chart which shows operation of the electric wave propagation simulator by a 4th embodiment of the present invention. With reference to these figure 6 and Drawing 7, operation of the electric wave propagation simulator by a 4th embodiment of the present invention is explained. Operation shown in Drawing 7 is realized because control part 71 runs the program of memory 81.

0063In the electric wave propagation simulator by this embodiment, control part 71 presumes the electric wave propagation characteristic of evaluation area first using one method of the embodiments of the 1st to 3 of the present invention mentioned above (Drawing 7 step S101). Next, control part 71 displays the electric wave propagation characteristic estimation result of the evaluation area obtained at Step S101 by indicator 61 (Drawing 7 step S111).

0064Control part 71 controls electric wave propagation characteristic estimating part 51, and presumes the electric wave propagation characteristic in whole area using object data 11 (Drawing 7 step S121). When it is possible to perform processing of Step S111 and processing of Step S121 in parallel, it may carry out such.

0065Then, control part 71 displays the electric wave propagation characteristic estimation result of the whole area obtained at Step S121 by indicator 61 (Drawing 7 step S131).

0066In the process in which this embodiment considers rearrangement of a base station, change of a parameter, etc. based on the propagation estimation result in conditions with a designer, and propagation presumption will be again carried out if required, The propagation estimation result in evaluation area is displayed to the limited evaluation area where a design top priority is high among whole area, without waiting for the end of propagation presumption of whole area. Therefore, in this embodiment, more efficient designing operation becomes possible.

0067As mentioned above, the present invention has realized the electric wave propagation characteristic estimation method for presuming the propagation situation of the electric wave which reaches the evaluation area where it was restricted of on space from the transmission point using a plurality of objects defined on space.

0068In the present invention, the path which arrives at evaluation area is first extracted using the geometric optics propagation presumption technique, and an object is chosen using the extracted path and the geometric information on evaluation area.

0069In the present invention, the electric wave propagation characteristic of the evaluation area limited among the whole area taken into consideration at the time of presumption can be presumed at high speed and with high precision by presuming the detailed electric wave propagation situation of reaching the inside of evaluation Eria from a transmission point only in consideration of the selected object.

0070The electric wave propagation simulator of the present invention is an electric wave propagation simulator which presumes the propagation situation of the electric wave which reaches the evaluation area where it was restricted of on the above-mentioned space from the transmission point using a plurality of objects defined on space, The path extraction part which extracts the path which arrives at the above-mentioned evaluation area using the geometric propagation presumption technique, The object selecting part which chooses an object using the path extracted by the above-mentioned path extraction part, and the geometric information on the above-mentioned evaluation area, It shall have an electric wave propagation characteristic estimating part which presumes the detailed electric wave propagation situation of reaching the inside of above-mentioned evaluation Eria from the above-mentioned transmission point using the object selected by the above-mentioned object selecting part. That is, since an electric wave propagation situation is presumed using the object selected among a plurality of objects defined on the above-mentioned space by the above-mentioned object selecting part, the electric wave propagation characteristic of the area limited among the whole area taken into consideration at the time of presumption can be presumed at high speed and with high precision.

0071The above-mentioned path extraction part can use the lei loun Ting method as the above-mentioned geometric propagation presumption technique.

0072The above-mentioned path extraction part can use the imaging method as the above-mentioned geometric optics propagation presumption technique.

0073The above-mentioned object selecting part shall choose an object including the route in the path which arrives at the above-mentioned evaluation area, and the object in the above-mentioned evaluation area from the above-mentioned transmission point obtained by the above-mentioned path extraction part.

0074The above-mentioned object selecting part shall choose the object which touches the object selected area defined using the path extracted by the above-mentioned path extraction part, and the geometric information on the above-mentioned evaluation area.

0075The above-mentioned object selecting part shall define the above-mentioned object selected area by the two-dimensional plane of X and the Y-axis.

0076The above-mentioned object selecting part enforces the imaging method from the above-mentioned transmission point between the above-mentioned transmission point and each peak of the above-mentioned evaluation area for an infinite plane including the route in the path which arrives at the above-mentioned evaluation area, The maximum width and the evaluation area of a peak path which were obtained shall define the above-mentioned object selected area.

0077When the above-mentioned electric wave propagation simulator makes the above-mentioned electric wave propagation characteristic estimating part the 1st electric wave propagation characteristic estimating part, The 2nd electric wave propagation characteristic estimating part that presumes the electric wave propagation characteristic of whole area using a general electric wave propagation characteristic estimation method is further included, The electric wave propagation characteristic estimation result of the above-mentioned evaluation area by the 1st above-mentioned electric wave propagation characteristic estimating part shall be displayed ahead of the electric wave propagation characteristic estimation result of the whole above-mentioned area by the 2nd above-mentioned electric wave propagation characteristic estimating part.

0078A plurality of objects defined on space are used for the electric wave propagation characteristic estimation method of the present invention, The 1st step that extracts the path which is an electric wave propagation characteristic estimation method which presumes the propagation situation of the electric wave which reaches the evaluation area where it was restricted of on the above-mentioned space from the transmission point, and arrives at the above-mentioned evaluation area using the geometric optics propagation presumption technique, The 2nd step that chooses an object using the path extracted at the 1st above-mentioned step, and the geometric information on the above-mentioned evaluation area, It has the 3rd step that presumes the detailed electric wave propagation situation of reaching the inside of above-mentioned evaluation Eria from the above-mentioned transmission point using the object selected at the 2nd above-mentioned step. Since a detailed electric wave propagation situation is presumed with a described method using the object selected among a plurality of objects defined on space at the 2nd step, the electric wave propagation characteristic of the area limited among the whole area taken into consideration at the time of presumption can be presumed at high speed and with high precision.

0079The program of the present invention is a program which the central processing unit in the electric wave propagation simulator which presumes the propagation situation of the electric wave which reaches the evaluation area where it was restricted of on the above-mentioned space from the transmission point using a plurality of objects defined on space is made to run, Extraction processing which extracts the path which arrives at the above-mentioned evaluation area using the geometric optics propagation presumption technique, The selection processing which chooses an object using the path extracted by the above-mentioned extraction processing and the geometric information on the above-mentioned evaluation area, and the presumed processing which presumes the detailed electric wave propagation situation of reaching the inside of above-mentioned evaluation Eria from the above-mentioned transmission point using the object selected by the above-mentioned selecting means are included. The above-mentioned program is installable in a computer via a well-known recording medium. The above-mentioned program can also be used as a program product.

0080The present invention is applicable to uses, such as a base station design in mobile communications. Since especially the present invention can check the estimation result of the limited area where a design top priority is high in a short time, it can carry out designing operation efficiently.

0081In within the limit [ of all the indications (the range of a claim is included) of the present invention ], change and adjustment of an embodiment thru/or an example are still more possible based on the fundamental technical thought. In within the limit [ of the range of the claim of the present invention ], combination thru/or selection with various various indication elements is possible. That is, as for the present invention, it is needless to say that the various modification which can be made according to all the indications and technical idea containing the range of a claim if it is a person skilled in the art, and correction are included.