JP3439396B2 - Electromagnetic environment design method and recording medium storing design program - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic environment design method for designing the number of base stations communicable with a communicable area of a base station of a wireless communication system by computer (computer) simulation, and a recording medium recording a design program. It is about.

[0002]

2. Description of the Related Art As a conventional simulation system used for designing the layout of base stations in a wireless communication system, there is known a system that analyzes the electric field strength distribution of a radio wave transmitted from a certain transmitting station based on the layout information of the communication environment. ing. As an analysis means, a geometrical optical method called a statistical method or a ray tracing method is often used.

Ray tracing is a method used for clarifying radio wave propagation characteristics in the design of a wireless communication system, and is described in, for example, "KR Schoubach,
N. J. Davis and T.M. S. Rappapo
rt, “A Ray Tracing Method”
for Predicting Path Lossa
nd Delay Spread in Microc
ellular Environments, “IEE
E Mechanical Technol. Con
f. , Pp. 932-935, May 1992. As described above, it is possible to analyze the electric field strength and the delay characteristic at any observation point regardless of the presence or absence of an obstacle.

The statistical method is a method of estimating the electric field strength distribution by utilizing the data of the radio wave propagation characteristics measured in various propagation environments, and a very large amount of data is required for more accurate estimation. It is necessary, and it is difficult to accurately estimate multiple communication environments such as offices.

In a radio communication system, in an environment where fading does not occur, if the reception electric field strength is higher than a certain threshold value (required reception strength), an automatic gain control (AGC) circuit keeps a constant communication quality. . However,
In the multipath environment used in the wireless communication system, even if the average received electric field strength satisfies the required received electric field strength,
Since the received electric field strength varies due to fading, the communication state may deteriorate. This tendency is particularly strong in offices and the like in recent years that form a complicated communication environment. Therefore, in the radio base station layout design for communication, a protection margin against fading is considered in the required received electric field strength in an environment without fading.

In the conventional base station design simulation, the transmission power of the base station, the required received electric field strength of the receiver,
The radius of the communication area (cell) of the base station is estimated from the margin of the fluctuation of the received electric field strength, and the base stations are arranged at the cell radius intervals. Also, if there is an area that cannot be covered by any means, a new base station was added.

[0007]

In the current wireless communication, large-capacity communication of images and the like is performed similarly to wired communication, so that a wireless communication system having a higher communication speed has been developed. As the speed of wireless communication systems increases, the effect of intersymbol interference on wireless communication quality increases. Intersymbol interference occurs because in a multipath environment, a received signal has a temporal spread and a 1-bit (symbol) communication signal interferes with preceding and following communication signals. The spread of the delay time of the delayed wave is 1 bit or 1 of the communication signal.
Intersymbol interference occurs except when it is sufficiently small with respect to the period of the symbol, and therefore an error unrelated to the electric field strength occurs, which greatly affects the communication quality and communicable area.

In the conventional wireless communication system, a mobile phone or PHS (Personal Handyphone) is used.
Voice communication by System etc. was the mainstream.
Therefore, the communicable area is basically whether or not it is possible to connect to the base station, and the communication signal is an area that reaches the required reception intensity or more. In mobile radio communication, a protection margin against fading is taken into consideration, but a design system regulated by communication quality and communication speed has not been developed so far.

In the design of a base station for a high-speed communication system such as a wireless LAN, since the communication speed is high and the cycle of 1 bit or 1 symbol is short, the communication quality and the communication speed are delays as parameters for determining the communicable area. It is necessary to consider the characteristics.

Further, the number of electronic devices operating at a high clock frequency has increased, and unnecessary radiation noise of electronic devices has spread to a high frequency band used for wireless communication. In addition, wireless communication systems that do not require a wireless station license are also used for wireless communication on the premises, and base station layout design that takes into consideration electromagnetic environments such as coexistence with electronic devices and coexistence with other wireless communication systems. Is needed.

A simulation system using ray tracing for base station design of a wireless communication system,
Although there are simulation methods for fading and noise in wireless communication systems, they support current and future high-speed wireless communication systems and comprehensively evaluate radio wave propagation characteristics and various communication characteristics (fading characteristics, delay characteristics, noise characteristics, etc.). Therefore, there is no design system for optimal base station layout design and optimal communication environment design.

An object of the present invention is to solve the above-mentioned problems of the conventional technique by setting arbitrary evaluation parameters for the electric field strength distribution, delay characteristic distribution, error rate characteristic distribution and transmission rate distribution which determine the communicable area. Electromagnetic environment design that enables easy and automatic visualization of the communication environment, can specify threshold values for any evaluation parameters, and performs base station layout design of the optimum wireless communication system and optimum communication environment design It is to provide a recording medium in which a method and a design program are recorded.

[0013]

In order to achieve the above object, the present invention provides an electromagnetic environment design method for designing the number of base stations communicable with a communicable area of a wireless communication system by computer simulation. Radio wave propagation based on the input information stored in the storage device in the first step, the first step of inputting the layout information, the base station arrangement information, and the target wireless communication system information and storing the information in the storage device. The second step of analyzing the characteristics to obtain the electric field strength distribution and the delay characteristic distribution and storing the distribution in the storage device, and analyzing the communication characteristics based on the information stored in the storage device, the error rate distribution and the effective transmission rate A third step of obtaining a distribution and storing it in a storage device, and setting a predetermined threshold value for the electric field strength, delay characteristic, error rate, and effective transmission rate stored in the storage device. Characterized by comprising a fourth step of the constant to determine the number of communicable base station communicable area of the base station of a wireless communication system.

Further, the present invention is characterized in that, in the electromagnetic environment designing method, ray tracing is used for analysis of radio wave propagation characteristics.

Further, the present invention is characterized in that, in the electromagnetic environment designing method, a signal processing analysis system is used for communication characteristic analysis.

Further, the present invention is characterized in that, in the electromagnetic environment designing method, a storage means for automatically creating a database of calculated communication characteristics is provided to shorten an analysis time.

In the electromagnetic environment design method according to the present invention, the position information of the noise / interference wave source and the characteristic parameters for the noise / interference wave source are input in the electromagnetic environment design method, and radio wave propagation characteristic analysis and communication characteristic analysis are used. Noise
It is characterized by analyzing the electric field strength distribution, delay characteristic distribution, error rate distribution, and effective transmission rate distribution in the presence of an interference wave source.

According to the present invention, in a recording medium in which a design program for designing the number of base stations communicable with a communicable area of a wireless communication system by using computer simulation is recorded, the layout information of the communication environment and the base station arrangement information are stored. And a target radio communication system information to be input and stored in the storage device, the radio wave propagation characteristics are analyzed based on the input information stored in the storage device in the first procedure, and the electric field strength distribution and the delay are analyzed. A second procedure for obtaining a characteristic distribution and storing it in a storage device, and a third procedure for analyzing a communication characteristic based on the information stored in the storage device to obtain an error rate distribution and an effective transmission rate distribution and storing it in the storage device. The base station of the wireless communication system can communicate by setting a predetermined threshold for the procedure, the electric field strength, the delay characteristic, the error rate, and the effective transmission rate stored in the storage device. It is intended to execute the fourth step of obtaining the number of available communication base station with the rear to the computer.

The present invention is also characterized in that, in the recording medium in which the design program is recorded, ray tracing is used for analysis of radio wave propagation characteristics.

The present invention is also characterized in that a signal processing analysis system is used for communication characteristic analysis in a recording medium in which the design program is recorded. .

Further, the present invention is characterized in that the recording medium in which the design program is recorded is provided with a storage means for automatically converting the calculated communication characteristics into a database to shorten the analysis time.

In the recording medium having the design program recorded thereon, the present invention is a noise / interference wave source (a noise source is an electronic device or the like that is an unintentional electromagnetic wave generation source, and the interference wave source intentionally generates electromagnetic waves. Other wireless communication systems using the same frequency band, etc.) position information and noise / interference wave source characteristic parameters are input, and using the radio wave propagation characteristic analysis and communication characteristic analysis, the noise / interference wave source exists. It is characterized by analyzing the electric field strength distribution, delay characteristic distribution, error rate distribution and effective transmission rate distribution in the case of

According to the present invention, the electric field strength distribution, the delay characteristic distribution,
We propose an electromagnetic environment design system that enables optimal base station layout design and optimal communication environment design for arbitrary communication environments by using error rate characteristic distribution and transmission rate distribution evaluation parameters.

[0024]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a diagram showing a system configuration of an electromagnetic environment design system used in the present invention. 1-1 is an input device, 1-2 is a display device, and 1-3 is a central processing unit. Reference numerals 1-4 are storage devices. FIG. 2 is a diagram showing a design flow of the electromagnetic environment designing method of the present invention. Figure 2 below
The design procedure based on is explained.

In steps 101 to 103, the analysis environment layout information / base station layout information / wireless communication system information of the communication environment is input from the input device 1-1 and stored in the storage device 1-4 via the central processing unit 1-3. Remember. In step 104, the presence / absence of a noise / interference source is selected,
When there is noise / interference source (Yes), position information of the noise / interference source, characteristic parameters such as frequency / amplitude for the noise / interference source, etc. are selected or input (step 105) and stored in the storage device 1-4. . If there is no noise / interference source (No), step 106 and step 10
Proceed to 7.

In step 106, the storage device 1-
Radio wave propagation characteristic analysis is performed based on the input information stored in 4. In the radio wave propagation characteristic analysis, the electric field strength distribution within the analysis range, the delay characteristic distribution, the signal-to-noise / interference wave ratio distribution, etc. are calculated. The analyzed result is stored in the storage device 1-4.

In step 107, it is judged whether or not there is a database of communication characteristics with respect to thermal noise of the target wireless communication system, error rate characteristics with respect to delay spread, and if the database does not exist (No), it is stored in the storage device 1-4. Communication characteristic analysis based on the stored information (step 108)
Then, an error rate distribution and an effective transmission rate distribution are obtained and a communication characteristic database to be stored in the storage device 1-4 is created (step 109). If the database has been created (Yes), the process proceeds to the selection of evaluation parameters in step 110.

When both the radio wave propagation characteristic analysis (step 106) and the communication characteristic database creation (step 109) are completed, an evaluation parameter is selected (step 110).

In step 110, the communicable area of the base station and the number of receivable channels (the number of communicable base stations)
If is not selected, the selected information is extracted from the information stored in the above-mentioned storage device 1-4, and the electric field strength distribution,
Evaluation parameters such as delay spread distribution (delay characteristic distribution), error rate distribution, and effective transmission rate distribution are displayed on the display device 1-2 and stored in the storage device 1-4 (step 111). When evaluating all base stations, it is possible to select the minimum value, the maximum value, the average value, the median value or the like for each evaluation parameter.

When the communicable area of the base station is selected in step 110 (step 112), predetermined values are set for the electric field strength, delay spread, error rate, and effective transmission rate stored in the storage device 1-4. The threshold value is set and input or selected, the communicable area of the base station of the wireless communication system is obtained, stored in the storage device 1-4 (step 113), and the communicable area is displayed on the display device 1-2. It is displayed and stored in the storage device 1-4 (step 114). In step 114, it is determined whether communication is possible or not depending on whether or not the threshold value set in advance in the central processing unit 1-3 is satisfied. The threshold can be selected both when it is prepared in advance and when a predetermined value is input. In this case, it is possible to set threshold values for all the evaluation parameters and judge by logical sum, or to define by a part of the evaluation parameters.

When the number of receivable channels is selected in step 110 (step 115), step 1
In step 16, a predetermined threshold value is set and input or selected, the number of receivable channels is calculated, the number of receivable channels is displayed on the display device 1-2, and stored in the storage device 1-4 (step 117). ). As with the communication area, the number of receivable channels is evaluated based on the number of base stations that satisfy the threshold value set in advance in the central processing unit 1-3 for the observation points within the analysis range. Parses
It is evaluated based on the number of channels per base station.

Next, when reselecting the evaluation parameter (step 118), the process returns to step 110, and each information is initialized, re-input, re-stored, and re-evaluated. When the initial input information (communication environment layout information / base station arrangement information / wireless communication system information) stored in the storage device 1-4 is reset (step 119), step 10 is performed.
Return to 1 and evaluate again. Further, in step 119, when the base station arrangement and the communication environment satisfy the requirements, the design is completed.

As described above, in the design method of the present invention, the communicable area is evaluated based on the evaluation parameters such as the electric field strength distribution, the delay spread distribution, the error rate distribution, the effective transmission rate distribution, and each observation. Since the number of receivable channels at each point can also be evaluated, it is possible to perform sufficient base station layout design and communication environment design in consideration of communication quality such as transmission rate required for wireless communication systems, traffic, and obstacles due to noise and interference. .

(First Embodiment) FIG. 3 is a diagram showing a design flow of the first embodiment of the present invention. FIG. 4 is a top view of floor layout information and base station arrangement information of a building according to the first embodiment of the present invention. In the analysis target layout information input (step 301), the three-dimensional coordinates of the wall or ceiling used for the radio wave propagation characteristic analysis and the material (including the physical constants used for the analysis) are stored in the storage device. Further, the three-dimensional coordinates, directivity, etc. of the base station antenna are input to the base station arrangement information input (step 302) and stored in the storage device. Wireless communication system information input (step 303)
Is input to the communication system of the wireless communication system, the wireless frequency, the transmission rate, etc. and stored in the storage device.

In step 304, the input information (layout information, base station arrangement information,
Radio wave propagation characteristic analysis is performed based on (wireless communication system information). In the radio wave propagation characteristic analysis, for example, “K.
R. Schoubach, N .; J. Davis and
T. S. Rappaport, "A Ray Tra
cing Method for Predictin
g Path Loss Delay Delay Spre
ad in Microcellular Envir
owners, “IEEE Vehicular T
echchnol. Conf. , Pp. 932-93
5, May 1992. The calculation of the electric field strength distribution and the delay characteristic distribution is performed using the method described in ".

In parallel with this, in step 305, it is judged whether or not there is a communication characteristic database for the stored input information. If no database exists, communication characteristic analysis (step 306), communication characteristic database creation ( Step 307) is performed.

Examples of communication characteristics against noise and error rate characteristics against delay spread of the wireless communication system to be analyzed are shown in FIGS. Normally, the characteristics in a fading-free environment are used for a wireless communication system that is often used when stationary, and the characteristics in a fading environment are used for a wireless communication system that is often used when moving. .

A method for converting the characteristics with respect to Eb / N0 (ratio of noise power density to energy per bit) to reception strength characteristics will be described. Receiver input power Pr (dBm)
Is expressed by the following equation using Eb / N0.

Pr = Eb / N0 + KBT + NF + Mj + Gp (1) Here, KBT (K: Boltzmann constant, B: radio frequency bandwidth, T: absolute temperature) is receiver noise power (dBm),
NF is the noise figure (dB) of the receiver, Mj (dB) is the demodulation method, hardware deterioration margin (d) due to band limitation, etc.
B) and Gp represent processing gains.

Further, the reception electric field strength Er (dB) of 50Ω system
μV) is expressed by the following equation.

Er = 107 + Pr (2) Therefore, the error rate with respect to the electric field strength is calculated based on the result of FIG. Further, as shown in FIG. 6, even when the received electric field strength is large with respect to noise, errors due to intersymbol interference increase as the delay spread increases. Therefore, the base station layout design of the present invention also considers communication characteristics with respect to delay spread. The relationship between delay spread and error rate is, for example,
"Justin C-I Chang, 'Simul
ation of Digital Modulati
on on Portable Radio Commu
animations Channels with F
requirement-selective Fadin
The analysis method is shown in g '"IEEE, 1986" and the like.

After the radio wave propagation characteristic analysis (step 304) and the communication characteristic database creation (step 307) are completed,
The parameters to be evaluated are selected (step 308).
As the parameters to be evaluated, a field strength distribution, a delay spread distribution, an error rate distribution, an effective transmission rate distribution, etc. are selected, and a base station having characteristics or all base stations are selected. When selecting all base stations, it is possible to select the minimum value, the maximum value, the average value, the median value or the like for each evaluation parameter within the analysis range. Finally, the selected evaluation parameter is displayed (step 309).

Here, an analysis example of the electric field strength distribution at a height of 1 m standardized with the minimum value of the base station 4-A1 of FIG. 4 as 0 dB is shown in FIG. 7, and an analysis example of the delay spread at a height of 1 m is shown in FIG. Shown in. Using the results of FIGS. 7 and 8, since the electric field strength distribution and the delay spread distribution of the wireless communication system are visualized, the area where the electric field strength is insufficient and the area where the delay spread is large can be easily extracted. it can.

Next, the bit error rate (P
The sum (Pb) of e) and the bit error rate (Pd) with respect to the delay spread is the bit error rate when there is no influence of noise and interference waves in the wireless communication system.

Pb = Pe + Pd (3) Therefore, similarly, the bit error rate distribution with a height of 1 m for the base station 4-A1 can be analyzed as shown in FIG. As shown in FIG. 9, since the distribution of the bit error rate in consideration of the electric field strength and the delay characteristic can be visualized, the area which does not satisfy the required bit error rate can be easily obtained.

Here, the transmission frame length is N bytes (8 ×
(N bits), the relationship between the frame error rate Pf and the bit error rate Pb is Pf = 1− (1−Pb) ^8N (4). For example, the effective transmission rate S (bit / sec) in Go-back-N is Is represented by S = {K · v · (1-Pf) · 8 · N / v} / {1−Pf) · 8 · N / v + Pf · M · 8 (N / v + C) + C} (5) It Here, K is the coding rate, Pf is the frame error rate, v is the transmission rate, M is the maximum number of frames to be retransmitted in response to a request from the receiving side, and C is other than the transmission time. The processing time.

Here, the effective transmission rate distribution of the height of 1 m standardized by the maximum value for the base station 4-A1 of FIG. 4 is shown in FIG.
Shown in. As shown in the figure, since the distribution of the effective transmission rate is also visualized, it is possible to easily extract the area where the original transmission rate of the wireless communication system cannot be realized.

As described above, when the evaluation parameters are displayed and the evaluation parameters are selected again (step 310), the selection is performed again in step 308 and the display is performed again (step 309). Furthermore, initial input information (communication environment layout information, base station placement information,
When resetting (wireless communication system information) (step 311), re-evaluation is performed again from step 301.

In the first embodiment of the present invention, the electric field strength, the delay characteristic, the error rate, the transmission rate, etc. are analyzed for an arbitrary observation point to realize the optimization of the base station design and the communication environment design. There is.

(Second Embodiment) In the second embodiment of the present invention,
Use ray tracing for radio wave propagation characteristics analysis. In the second embodiment of the present invention, similarly to the first embodiment, based on the layout information / base station arrangement information / wireless communication system information, the radio wave propagation characteristics (electric field strength distribution / delay characteristic distribution) within the analysis range are calculated. It can be analyzed automatically. The ray tracing method is effective when the wavelength is small compared to the propagation environment (room size, wall surface irregularities, etc.), and generally U
It is effective in the frequency band above the HF band.

FIG. 11 is a diagram showing the maximum values of the electric field strengths of the radio waves of all the base stations of FIG. 4 at a height of 1 m, and FIG. 12 is the delay of the radio waves of the base stations of all the base stations of FIG. 4 at a height of 1 m. It is a figure which shows the minimum value of spread. As shown in FIGS. 11 and 12, when the ray tracing method is used, the electric field strength and the delay characteristic can be calculated with high accuracy, so that the area with weak electric field strength or the area with large delay spread can be easily extracted from all base stations. It is possible and suitable for the layout design as in the present invention.

In the second embodiment of the present invention, radio wave propagation characteristic analysis is performed using the ray tracing method, and the electric field strength and delay characteristic are analyzed with high accuracy at an arbitrary observation point to determine the optimum base station arrangement. It realizes an electromagnetic environment design method for designing and communication environment design.

(Third Embodiment) In the third embodiment of the present invention,
A base station arrangement design method of a wireless communication system using a signal processing analysis system for various communication characteristic analyzes will be described.

Currently, there are many commercially available tools for performing signal processing analysis. In these signal processing analyses, an ideal signal generator such as a sine wave, an operator such as addition, multiplication, and logical operation, and a pseudo input / output system expressing a non-linear element such as a delay element and a filter are used. It is possible to model a wireless communication system with arbitrary sample intervals and transfer functions above. The third embodiment of the present invention aims to improve the accuracy and efficiency of the design method by performing the communication characteristic simulation by combining the modeled wireless communication system, transmission channel, and interference wave / noise.

The calculation procedure of the communication characteristic with respect to the received electric field strength and the analysis example of the electromagnetic interference characteristic with respect to the noise / interference source will be shown below.

FIG. 13 shows a block diagram of signal processing analysis for calculating communication characteristics with respect to received electric field strength. In FIG. 13, 13-1 is a random data generator, 13-2 is a wireless communication system transmitter, 13-3 is a transmission channel, 13-4 is a wireless communication system receiver, 1
3-5 is an error meter. Here, an additive white Gaussian noise transmission line is used as the transmission channel 13-3,
Similar to FIG. 5, the bit error rate characteristic with respect to Eb / N0 is obtained, and the communication characteristic with respect to the received electric field strength is obtained using Expressions (1) and (2). FIG. 14 shows a wireless communication system A
It is a figure which shows the result of having performed the communication characteristic analysis about five types of -E. As shown in FIG. 14, since the physical parameters peculiar to each wireless communication system and the process of modulation / demodulation can be faithfully expressed, more accurate analysis is possible. Also, because it is possible to easily create a virtual wireless communication system,
It is also possible to analyze a wireless communication system under development.

FIG. 15 is a diagram showing a block diagram of signal processing analysis for calculating the electromagnetic interference characteristic with respect to a noise / interference source. 15-1 is a random data generator, 15-2
Is a wireless communication system transmitter, 15-3 is a noise / interference source,
Reference numeral 15-4 is a coupler, 15-5 is a wireless communication system receiver, and 15-6 is an error meter. Here, an example is shown in which electromagnetic interference between spread spectrum wireless communication systems that use the same radio frequency is defined by the ratio of desired wave to interference wave.

With respect to the analysis model of FIG. 15, an analysis model of a transmitter / receiver of a direct sequence (DS) wireless communication system is created, and frequency hopping (Frequency) using the same frequency as an interference source is created.
y Hopping (FH) wireless communication system,
An analysis example is shown in which an analysis model of a transmitter of a DS wireless communication system with different spreading codes is created and analyzed.

FIG. 16 shows F of the DS radio communication system.
It is a figure which shows the electromagnetic interference characteristic by the H type | system | group wireless communication system, and the electromagnetic interference characteristic by the DS type | mold wireless communication system with which a spreading code differs. As shown in FIG. 16, the analysis of the electromagnetic interference characteristics with respect to a specific interference wave can be performed only by combining the analysis models on the GUI. Therefore, once an analysis model for each wireless communication system or noise / interference source is created, It is also possible to easily make a database of various electromagnetic interference characteristics.

As described above, the third embodiment of the present invention easily analyzes the communication characteristics of each wireless communication system by using the signal processing analysis for analyzing the communication characteristics of each wireless communication system, and Since various electromagnetic interference characteristics can be analyzed by combining analysis models, it is effective in analyzing communication characteristics required for electromagnetic environment design.

(Fourth Embodiment) In the fourth embodiment of the present invention, in the design system of the present invention, the analysis time is shortened by providing a storage means for automatically converting the already analyzed communication characteristics into a database. It realizes that.

FIG. 17 shows the first embodiment of the present invention.
FIG. 10 is a diagram showing a design flow in the case where the fourth embodiment of the present invention is applied and a function of automatically storing communication characteristics for each wireless communication system in a storage device and making a database is provided. 17, 1701 is analysis target layout information input, 1702 is base station layout information input, 1703 is wireless communication system information input, 1704 is radio wave propagation characteristic analysis, 1705 is communication characteristic database search, 1706 is evaluation parameter selection, and 1707 is Display of evaluation parameters, 1708 is resetting. As shown in FIG. 17, since the base station design system searches the database for various communication characteristics required for analysis, the type of the target wireless communication system, noise By inputting the type of the interference source and storing it in the storage device, each evaluation parameter can be evaluated immediately after the completion of the radio wave propagation characteristic analysis, so that the base station layout design and the communication environment design are made efficient.

FIG. 18 is a diagram showing an example of the header portion of the communication characteristic database file. As shown in FIG.
If the target wireless communication system, noise / interference source, communication characteristics, and evaluation parameter can be identified, the target wireless communication system information can be easily searched by comparing it with the one input at the initial input stage and stored in the storage device.

As described above, in the fourth embodiment of the present invention, the analysis time is shortened by providing the storage means for automatically converting the already analyzed communication characteristics into a database.

(Fifth Embodiment) In the fifth embodiment of the present invention, the threshold value of each or all analysis parameters such as the electric field strength, the delay characteristic, the error rate, and the transmission rate is set to an arbitrary observation point. It is a design system that analyzes the communicable area by defining it. The details of the embodiment will be described below.

19 to 23, the threshold value of the electric field strength is the carrier sense level, the threshold value of the delay dispersion is 50 ns, the threshold value of the bit error rate is 10 ^-5 , and the threshold value of the effective transmission rate is the maximum value. Base station 4-A1 in FIG.
It is a figure which shows the analysis example with respect to. 19 is a diagram showing the communicable area of the base station 4-A1 of FIG. 4 defined by the electric field strength, and FIG. 20 is a diagram showing the communicable area of the base station 4-A1 defined by delay dispersion. 21 is a diagram showing a communicable area of the base station 4-A1 defined by the bit error rate, and FIG. 22 is a base station 4-A1 defined by the effective transmission rate.
2 is a diagram showing a communicable area, and a white portion indicates a communicable area and a shaded portion indicates an area that does not satisfy the condition. FIG. 23 is a diagram showing a communicable area defined by all parameters.

As shown in FIGS. 19 to 23, since arbitrary threshold values can be set for all evaluation parameters of electric field strength, delay dispersion, bit error rate, and effective transmission rate that determine the communicable area, the target radio The design corresponding to the performance of the communication system becomes possible.

As described above, in the fifth embodiment of the present invention, it is possible to analyze the communicable area corresponding to the target wireless communication system by setting an arbitrary threshold value in the parameter for evaluating the communicable area. Has been realized.

(Sixth Embodiment) In the sixth embodiment of the present invention, the threshold values of the electric field strength, the delay characteristic, the error rate, the transmission rate, etc., or all the analysis parameters are set to arbitrary observation points. This is a design method that evaluates the communicable area by defining it. The details of the embodiment will be described below.

In FIG. 24, the threshold value of electric field strength is the carrier sense level, the threshold value of delay dispersion is 50 ns, the threshold value of bit error rate is 10 ⁻⁵ , and the threshold value of effective transmission rate is 95% of the maximum value. 5 base stations 4- in FIG.
It is a figure which shows the analysis example of the number of receivable channels with respect to A1-4-A5.

As shown in FIG. 24, since it is possible to know how many base stations can communicate with an arbitrary observation point within the analysis range, the number of receivable channels is large at the receiving position where traffic is concentrated. The sixth embodiment of the present invention is effective for the base station arrangement design of the wireless communication system and the like.

As described above, in the sixth embodiment of the present invention, the number of receivable channels at each observation point is analyzed by setting an arbitrary threshold value in the parameter for evaluating the communicable area, and the communication traffic is analyzed. We have realized an optimal base station layout design that takes into account usage patterns such as.

(Seventh Embodiment) The seventh embodiment of the present invention is provided with means for inputting and storing position information of the noise source / interference wave source and characteristic parameters of the noise source / interference wave source in the input section, and radio wave propagation characteristics. Design to evaluate the electric field strength of noise source / interference wave source, delay characteristic, error rate in the presence of noise source / interference wave source, transmission rate, etc. at any observation point using analysis / communication characteristic analysis means Is the way.

FIG. 25 is a diagram showing the design flow of the seventh embodiment of the present invention, in which electromagnetic interference characteristics due to noise and interference sources are taken into consideration in the first to sixth embodiments. Figure 25
2, steps 2501 to 2519 correspond to steps 101 to 119 of FIG. 2, respectively. FIG. 26
FIG. 16 is a diagram showing layout information and base station / interference station arrangement information for the seventh embodiment of the present invention. 26-1 is a portion displaying the three-dimensional layout information to be analyzed.
A1 to 26-A5 are base stations of the target wireless communication system of the DS system, and 26-B1 and 26-B2 are interference sources F.
1 shows a base station of an H type wireless communication system.

FIG. 27 is a diagram showing the desired wave-to-interference wave ratio for FIG. 26, and is a diagram showing the maximum values of all base stations. 28 is a diagram showing the analysis result of the communicable area of the target wireless communication system, and uses the electromagnetic interference characteristics shown in FIG. By performing the analysis of FIG.
It is easy to extract an area that does not satisfy the required desired wave-to-interference wave ratio within the analysis range, and by performing the analysis in FIG. 28, it is possible to easily extract an area in which communication is possible even when an interference wave exists. it can. As shown in FIGS. 27 and 28, the seventh embodiment of the present invention is effective for the electromagnetic environment design of the wireless communication system even when the interference wave source exists within the analysis target range.

As described above, in the seventh embodiment of the present invention, the electromagnetic characteristic for a specific noise / interference source is analyzed by using the communication characteristic analysis, and the noise / interference source is considered according to the analysis result. We have achieved optimal base station layout design and communication environment design.

Next, obtaining the electric field strength distribution, the delay characteristic distribution, the error rate distribution, and the effective transmission rate distribution by the radio wave propagation characteristic analysis and the communication characteristic analysis will be described.

According to the conventional technique, by using ray tracing, the electric field intensity distribution and the delay dispersion distribution at any observation point can be obtained. The present invention estimates the distribution of the transmission quality such as the error rate and the transmission rate with respect to the calculation result of the electric field strength distribution and the delay dispersion distribution obtained by using ray tracing. Further, the transmission quality required according to the service or application of the wireless communication system is defined, and an area satisfying the required transmission quality is designed as a communication area.

FIG. 29 is a diagram showing a layout design flow of the base station layout design system of the present invention. The design method based on FIG. 29 will be described below.

In steps 1 and 2, the electric field strength distribution and the delay dispersion distribution can be obtained by ray tracing. The D / U (desired wave-to-interference wave) ratio and S / N (signal-to-noise) ratio in step 3 are obtained by calculating the ratio of the received electric field strength from the target base station and the interference wave / noise electric field strength. You can

The estimation method of the present invention for estimating the communicable area based on the calculation results obtained in steps 1 to 3 will be described below.

First, the required transmission quality corresponding to the target wireless communication system and communication service is defined (step 4). The required transmission quality is often defined by the error rate of the wireless communication system, etc., and the required error rate varies depending on the error correction method and the transmission rate at which the service is provided.

Secondly, the required reception level satisfying the required transmission quality is defined from the communication characteristics against the thermal noise of the target wireless communication system (step 5). Required reception level is Eb
The error rate characteristics for / N0 (ratio of noise power density to energy per bit) can be measured using a Gaussian noise generator. It is also possible to obtain by computer simulation corresponding to the modulation / demodulation method.

FIG. 30 shows Eb / using a Gaussian noise generator.
It is a figure which shows the block configuration of the measurement system for measuring the error rate characteristic with respect to N0, 201 is a bit error rate measuring device, 202 is a transmitter of a target wireless communication system, 203 is a combiner, Reference numeral 204 is a Gaussian noise generator, and 205 is a receiver of the target wireless communication system.

The random data transmitted from the bit error rate measuring device 201 is modulated in the transmitter 202, the Gaussian noise output from the Gaussian noise generator 204 is added using the combiner 203, and the modulated signal and the Gaussian noise are added. The bit error rate is measured by demodulating the combined signal by the receiver 205 and comparing the demodulated data with the transmission data in a bit error rate measuring device.

Here, a method of simulating the error rate characteristic with respect to Eb / N0 will be described by taking a wireless communication system using DQPSK as an example. The bit error rate of this system has been obtained by various methods in the past.

“RW Lucky, J. Salz a.
nd E. J. Weldon, “Principle
of Data Communication, “Mc
Graw-Hill, 1968 ”to Eb / N0 γ
Then, Pe = exp {−γ (1-1 / √2)} (6) “CR Cahn,“ Combined digit ”
al phase and amplitude mo
duration Communication sy
stem, “IRE Trans. Commun., v
ol. CS-8, pp. 150-155, Sept. 1
960 ”, Pe = 1/2 × erfc {2√γsin (π / 8)} (7). In addition, “Pawula, RF,“ As
ymptotics and error bounds
for M-ary DPSK, "IEEE Tra"
ns. Commun. vol. COM-32, pp. 9
3-94, Jan. 1984 "and" WR Benne.
tt and J. R. Davey, (Translated by Shogo Amari), "Data Transmission," pp. 221-230, Latteis, 1966 ”and the like. The bit error rate characteristics obtained by these methods are slightly different from the S / N ratio, but the difference is within 1 dB of the S / N ratio. Therefore, here, a case where the estimation is performed based on the equation (6) will be described.

FIG. 31 shows Eb / obtained by the measurement of FIG.
It is a figure which shows the error rate characteristic with respect to N0, and the error rate characteristic with respect to Eb / N0 calculated | required by the computer simulation. In the figure, black circles are measurement results, and solid lines are calculation results. As this result shows, the measured and calculated results are in good agreement, and Eb / N
The error rate characteristic for 0 can be obtained.

Here, a method of converting the characteristics for Eb / N0 into the reception strength characteristics will be described. Receiver input power Pr (d
Bm) is expressed by the following equation using Eb / N0.

Pr = Eb / N0 + KBT + NF + Mj (8) where KBT (K: Boltzmann constant, B: radio frequency bandwidth, T: absolute temperature) is the receiver noise power (dBm),
NF is the noise figure (dB) of the receiver, Mj (dB) is the demodulation method, hardware deterioration margin (d) due to band limitation, etc.
B) is represented.

Further, the reception electric field strength Er (dB) of the 50Ω system is
μV) is expressed by the following equation.

Er = 107 + Pr (9) However, when converting the received electric field strength at the open end, + 6d
B.

Therefore, since the error rate characteristics for Pr and Er are estimated, the required reception level is defined by Pr or Er for the required error rate.

Also, a method of defining the propagation loss with respect to the transmission power can be considered. FIG. 32 is a diagram showing a configuration of a measurement system for measuring a required reception level, 401 is an error rate measuring device, 402 is a base station of a target wireless communication system, 403 is an attenuator, and 404. Is a terminal of the target wireless communication system. The error rate measuring device 401 is a device that measures the error rate by transmitting random data or a data frame and comparing the received data and the received frame received on the terminal side. The base station 402 transmits a communication signal with fixed transmission power used for service. The terminal 404 demodulates the received signal in which the communication signal is attenuated by the attenuator 403, and the error rate measuring device 401 measures the error rate of the demodulated random data and data frame. Using this measurement system, the maximum attenuation that satisfies the required transmission quality is defined as the allowable propagation loss, and the value obtained by subtracting the allowable propagation loss (dB) from the transmission power (dBm) is defined as the required reception level.

Thirdly, the delay characteristic satisfying the required transmission quality is defined from the delay characteristic of the target wireless communication system (step 6). With the practical use of digital mobile communication systems, frequency selective fading caused by the propagation of multiple waves with different delay times has become a problem, so a frequency selective fading simulator that can simulate multipath propagation characteristics has been used for evaluation. There is. The frequency-selective fading simulator can artificially create a transmission line of a delay profile having an arbitrary delay dispersion and evaluate the transmission quality on the transmission line. By using this fading simulator, the maximum delay dispersion that satisfies the required transmission quality is defined.

The maximum delay dispersion can also be specified by computer simulation. In a frequency selective fading environment, since the transfer function is not uniform within the band of the transmission signal, the transmission waveform is distorted, and intersymbol interference causes an error. Further, since the wireless communication system uses a frequency band defined for each system, a bandpass filter is used. When the bandpass filter is a Nyquist filter, its impulse response h
(T) is represented by h (t) = [sin (πt / T) / (πt / T)] × cos (απt / T) / (1-2αt / T) ² (10). Here, T is the symbol period, and α is the roll-off rate.

The impulse response h (t) when the bandpass filter is a Gaussian filter is represented by h (t) = f ₀ × √π × exp {-(πf ₀ t)} (11). However, f ₀ is given as follows: f ₀ = B / √ (2ln2) (12) where B is 3 dB bandwidth.

In a frequency selective fading environment, the S / N ratio is inversely proportional to the square of the standardized delay dispersion standardized by the code rate, regardless of the shape of the delay profile. Therefore, since the S / N ratio due to intersymbol interference is inversely proportional to the square of the effective delay dispersion τ,

[Equation 1]

It is represented by Since the bit error rate Pe under the Rayleigh fading environment is calculated by Pe = 1/2 × [1-γ / √ (γ ² + 4γ + 2)] (14), the S / N ratio of the equation (13) is calculated by the equation ( 14)
, The bit error rate under the frequency selective fading environment is calculated, and the delay dispersion satisfying the required transmission quality can be defined.

FIG. 33 is a diagram showing the calculation result of the bit error rate with respect to the delay dispersion of the radio communication system having the transmission rate of 32 Kbps and the roll-off rate of 0.2 and the measurement result using the fading simulator. As shown in FIG. 33, the calculation result and the measurement result are in good agreement, and it is possible to define the delay dispersion for the required transmission quality by using either method.

Fourth, the required signal-to-noise power ratio (S / N ratio) and the required desired-to-interference wave power ratio (D / D) that satisfy the required transmission quality based on the noise characteristics and interference characteristics of the target wireless communication system.
U ratio) is defined (step 7). FIG. 34 is a diagram showing a noise / interference characteristic measurement system for noise and interference waves, 601 is a bit error rate measuring device, 602 is a transmitter of the target wireless communication system, and 603 is an adder. , 604 are sources of noise and interference, and 605 is a receiver.

The measuring method is the same as that in FIG. 30, but unlike electromagnetic waves radiated intentionally, it is difficult to apply noise using a general-purpose connector or cable. Therefore, the present invention proposes a method of measuring the amplitude and phase of noise in an anechoic room and reproducing the noise with an arbitrary waveform generator.

FIG. 35 shows a noise waveform measuring system according to the present invention. 701 is an anechoic chamber, 702 is a noise generating source, 703 is a table, and 704 is for receiving noise. Is an antenna, 705 is a cable, and 706 is a device for measuring and storing amplitude and phase information of a signal received by the antenna.

In FIG. 35, the noise generation source 702 and the antenna 704 are installed at a sufficiently long interval with respect to the wavelength of the radio signal of the target radio communication system, and the noise is set to be received by the antenna 704 as a plane wave. Using the measurement system of FIG. 35, the amplitude and phase information of noise is stored and input to the arbitrary waveform generator. By using the noise reproduced using the arbitrary generator in 604 of FIG. 34, it becomes possible to measure the noise characteristic of the radio signal of the target radio communication system.

Further, the characteristics with respect to noise and interference waves can be specified by computer simulation. Currently, there are many commercial tools for performing signal processing analysis. In these signal processing analysis, an ideal signal generator such as a sine wave, an operator such as addition, multiplication and logical operation,
Also, it is possible to model a wireless communication system having an arbitrary sample interval and transfer function on the GUI by using a pseudo input / output system expressing a nonlinear element such as a delay element and a filter. The present invention proposes a modeled wireless communication system and a method of performing communication characteristic simulation using interference waves and noise.

FIG. 36 is a diagram showing a block diagram of signal processing analysis for calculating communication characteristics with respect to noise and interference wave sources, and 801 is a random data generator.
Reference numeral 02 is a signal processing analysis model of a transmitter of the target wireless communication system, 803 is a signal processing analysis model of a noise and interference wave source generator to which the noise characteristics obtained by the measurement of FIG. 35 are input, and 804 is an adder. 805 is a signal processing analysis model of the receiver of the target wireless communication system, and 806 is an error meter for calculating an error rate.

FIG. 37 shows the noise characteristic calculation results using the signal processing analysis of FIG. 36 for a certain noise source, and FIG.
It is a figure which shows the measurement result of the noise characteristic using the measuring system of FIG. As shown in FIG. 37, the calculation result and the measurement result are in good agreement, and whichever method is used, the required S / N ratio and the required D / U ratio for the required transmission quality can be defined.

Finally, in steps 8 to 11, in the target area, the required reception level, maximum delay dispersion, and required S
An area that satisfies all of the / N (signal to noise) ratio and D / U (desired wave to interference wave) ratio is extracted and used as the communication area.

FIG. 38 shows a layout example of a radio communication system for designing the present invention. Reference numeral 1001 is a building layout, 1002 is a base station of the target radio communication system, and 1003 is an interference wave source.

Here, an example will be shown in which the required transmission quality in step 4 of FIG. 29 is set to a bit error rate of 10 ⁻⁴ and the design is performed. FIG. 39 is a diagram showing a result of estimating the range in which the radio wave of the base station 1002 of FIG. 38 reaches at an electric field strength that satisfies the bit error rate of 10 ⁻⁴ or more. In this figure, the electric field strength distribution is calculated using ray tracing, and the area that satisfies the required transmission quality based on the characteristics of FIG. 31 is shown in white and the other areas are shown in diagonal lines.

FIG. 40 is a diagram showing the result of estimation of the range in which the radio wave of the base station 1002 of FIG. 38 reaches within the delay dispersion that satisfies the bit error rate of 10 ⁻⁴ . In this figure, the delay dispersion distribution is calculated by using ray tracing, and the area that satisfies the required transmission quality is shown in white and the other areas are shown in diagonal lines based on the characteristics of FIG.

FIG. 41 shows the result of estimation of the range satisfying the required transmission quality with a bit error rate of 10 ⁻⁴ or less when the radio wave of the base station 1002 and the electromagnetic wave of the interference wave source 1003 of FIG. 38 cause electromagnetic interference. It is a figure. The figure shows the radio wave of the base station 1002 and the interference wave source 1 using ray tracing.
The electric field intensity distribution of the electromagnetic wave 003 is calculated, and based on the characteristics of FIG. 37, the area that satisfies the required transmission quality is shown in white, and the other areas are shown in diagonal lines.

FIG. 42 is a diagram showing a result of estimating an area satisfying all the conditions of FIGS. 39, 40, and 41. As shown in the figure, it can be seen that the communicable area can be estimated based on the electric field strength distribution, the delay dispersion distribution, and the noise / interference characteristics.

As described above, the communicable area estimation method of the present invention for the base station layout design system allows communication based on the evaluation parameters of the electric field strength distribution, the delay dispersion distribution, and the S / N / D / U ratio distribution. Since the feasible area can be estimated, it is possible to perform sufficient base station layout design in consideration of transmission quality such as transmission rate required for the wireless communication system, traffic, and obstacles due to noise and interference.

The electromagnetic environment design method is specifically executed by a computer such as a personal computer (PC) based on a design program recorded in a predetermined recording medium in advance.

That is, according to the present invention, in a recording medium recording a design program for designing the number of base stations communicable with a communicable area of a wireless communication system by using computer simulation, layout information of communication environment,
A first procedure for inputting the base station arrangement information and the target wireless communication system information and storing the information in a storage device, analyzing the radio wave propagation characteristics based on the input information stored in the storage device in the first procedure, A second procedure of obtaining an intensity distribution and a delay characteristic distribution and storing them in a storage device, analyzing communication characteristics based on information stored in the storage device, obtaining an error rate distribution and an effective transmission rate distribution, and storing them in the storage device. The third procedure, which is to perform communication with the communicable area of the base station of the wireless communication system by setting a predetermined threshold value for the electric field strength, delay characteristic, error rate, and effective transmission rate stored in the storage device The computer is caused to execute the fourth procedure for obtaining the number of appropriate base stations.

The present invention is also characterized in that, in the recording medium in which the design program is recorded, ray tracing is used for analysis of radio wave propagation characteristics.

The present invention is also characterized in that a signal processing analysis system is used for communication characteristic analysis in the recording medium in which the design program is recorded.

Further, the present invention is characterized in that the recording medium in which the design program is recorded is provided with a storage means for automatically converting the calculated communication characteristics into a database to shorten the analysis time.

The present invention also provides a noise / interference wave source (a noise source is an electronic device or the like that is an unintentional source of electromagnetic waves) in the recording medium in which the design program is recorded, and the interference wave sources intentionally generate electromagnetic waves. Other wireless communication systems using the same frequency band, etc.) position information and noise / interference wave source characteristic parameters are input, and using the radio wave propagation characteristic analysis and communication characteristic analysis, the noise / interference wave source exists. It is characterized by analyzing the electric field strength distribution, delay characteristic distribution, error rate distribution, and effective transmission rate distribution in the case of performing.

[0122]

As described above, according to the present invention, the optimum base station layout design and the optimum base station layout design are performed by using the evaluation parameters suitable for the target wireless communication system such as the electric field strength, the delay characteristic, the error rate, and the effective transmission rate. Communication environment can be designed.
Further, according to the present invention, since the analysis is performed by combining the radio wave propagation characteristic analysis and the communication characteristic analysis, it is possible to easily consider various noise and interference sources. Furthermore, according to the present invention, an arbitrary threshold value for determining the communicable area can be set for each evaluation parameter, and using the set threshold value,
Since the number of receivable channels at any observation point can also be analyzed, it is possible to design a base station arrangement suitable for the usage pattern of the wireless communication system.

[Brief description of drawings]

FIG. 1 is a system configuration diagram showing an example of an electromagnetic environment design system used in the present invention.

FIG. 2 is a diagram showing a layout design flow of a base station layout design method according to the embodiment of the present invention.

FIG. 3 is a diagram showing a base station arrangement design flow according to the first embodiment of the present invention.

FIG. 4 is a diagram showing layout information and base station arrangement information on a floor according to the first embodiment of the present invention.

FIG. 5 is a diagram showing an example of communication characteristics with respect to noise in the target wireless communication system according to the first embodiment of this invention.

FIG. 6 is a diagram showing an example of error rate characteristics with respect to delay spread of the target wireless communication system according to the first embodiment of the present invention.

7 is a halftone image displayed on the display showing an example of analysis of the electric field intensity distribution of the base station 4-A1 of FIG. 4 according to the first embodiment of the present invention.

FIG. 8 is a halftone image displayed on the display showing an example of analysis of delay spread of the base station 4-A1 of FIG. 4 according to the first embodiment of the present invention.

9 is a halftone image displayed on the display showing the distribution of bit error rates for the base station 4-A1 of FIG. 4 according to the first embodiment of the present invention.

FIG. 10 is a base station 4-A1 of FIG. 4 according to the first embodiment of the present invention.
2 is a halftone image displayed on a display showing the distribution of effective transmission rates for

11 is a halftone image displayed on the display showing the maximum values of the electric field strengths of all the radio waves of the base station in FIG. 4 of the second embodiment of the present invention.

12 is a halftone image displayed on the display showing the minimum value of the delay spread of the base station radio waves of all the base stations of FIG. 4 of the second embodiment of the present invention.

FIG. 13 is a block diagram of signal processing analysis for calculating communication characteristics with respect to received electric field strength according to the third embodiment of the present invention.

FIG. 14 is a wireless communication system A- of a third embodiment of the present invention.
It is a figure which shows the result of having performed 5 types of communication characteristic analysis of E.

FIG. 15 is a diagram showing a block diagram of a signal processing analysis for calculating an electromagnetic interference characteristic with respect to a noise / interference source according to a third embodiment of the present invention.

FIG. 16 is a diagram showing the electromagnetic interference characteristics of the frequency hopping wireless communication system and the electromagnetic interference characteristics of the direct spreading wireless communication system with different spreading codes in the system of the direct spreading wireless communication according to the third embodiment of the present invention. is there.

FIG. 17 is a diagram showing a design flow of base station arrangement design of the wireless communication system according to the fourth exemplary embodiment of the present invention.

FIG. 18 is a diagram showing an example of a header portion of a communication characteristic database file according to the fourth embodiment of the present invention.

19 is a diagram showing a communicable area of the base station 4-A1 of FIG. 4 defined by the electric field strength of the fifth embodiment of the present invention.

20 is a diagram showing a communicable area of the base station 4-A1 of FIG. 4 defined by delay dispersion according to the fifth embodiment of the present invention.

FIG. 21 is a diagram showing a communicable area of the base station 4-A1 of FIG. 4 defined by the bit error rate of the fifth embodiment of the present invention.

22 is a diagram showing a communicable area of the base station 4-A1 of FIG. 4 defined by the effective transmission rate of the fifth embodiment of the present invention.

FIG. 23 is a diagram showing the communicable area of the base station 4-A1 of FIG. 4 defined by all the parameters of the fifth embodiment of the present invention.

FIG. 24 is a halftone image displayed on the display showing an analysis example of the number of receivable channels for the five base stations of FIG. 4 according to the sixth embodiment of the present invention.

FIG. 25 is a diagram showing a design flow of a base station design system according to a seventh embodiment of the present invention.

FIG. 26 is a diagram showing layout information and base station / interference station arrangement information for the seventh embodiment of the present invention.

FIG. 27 is a halftone image displayed on the display showing the desired wave-to-interference wave ratio with respect to FIG. 25 of the seventh embodiment of the present invention.

FIG. 28 is a diagram showing an analysis result of a communicable area of the target wireless communication system according to the seventh embodiment of the present invention.

FIG. 29 is a diagram showing an arrangement design flow of the base station arrangement design system of the present invention.

FIG. 30 is a graph showing Eb obtained by using the Gaussian noise generator according to the present invention.
It is a figure which shows the block configuration of the measurement system for measuring the error rate characteristic with respect to / N0.

31 is a diagram showing an error rate characteristic for Eb / N0 obtained by the measurement of FIG. 30 and an error rate characteristic for Eb / N0 obtained by a computer simulation.

FIG. 32 is a diagram showing a configuration of a measurement system for measuring a required reception level according to the present invention.

FIG. 33 is a diagram showing a calculation result of a bit error rate with respect to delay dispersion and a measurement result using a fading simulator in a wireless communication system having a transmission rate of 32 Kbps and a roll-off rate of 0.2 according to the present invention.

FIG. 34 is a diagram showing a noise / interference characteristic measurement system for noise and interference waves according to the present invention.

FIG. 35 is a diagram showing a noise waveform measurement system according to the present invention.

FIG. 36 is a diagram showing a block diagram of signal processing analysis for calculating communication characteristics for noise and interference wave sources according to the present invention.

FIG. 37 is a noise characteristic calculation result using the signal processing analysis of FIG. 36 for a certain noise source according to the present invention;
It is a figure which shows the measurement result of the noise characteristic using the measuring system of FIG.

FIG. 38 is a diagram showing a layout example of a wireless communication system for designing according to the present invention.

39] FIG. 39 shows that the radio wave from the base station in FIG.
It is a figure which shows the result of estimating the range which reaches | attains more than the electric field strength which satisfies ^-4 .

FIG. 40 shows a bit error rate of 10 when the radio wave from the base station in FIG.
It is a figure which shows the result of estimating the range which arrives below delay dispersion which satisfies ^-4 .

41 shows a bit error rate of 10 ⁻⁴ when the radio wave of the base station and the electromagnetic wave of the interference wave source in FIG. 38 cause electromagnetic interference.
It is a figure which shows the result of having estimated the range which satisfy | fills the following required transmission quality.

FIG. 42 is a diagram showing a result of estimating an area satisfying all the conditions of FIGS. 39, 40, and 41.

[Explanation of symbols]

1-1 Input device 1-2 Display device 1-3 Central processing unit 1-4 Storage devices 4-1 and 26-1 Three-dimensional display of analysis target layout information 4-A1 to 3-A5, 26-A1 to 26- A5 Base stations 13-1 and 15-1 of the target wireless communication system Signal processing analysis model 13-2 of random data generator, 15-2 Signal processing analysis model 13-3 of wireless communication system transmitter Signal processing analysis of transmission channel Models 13-4, 15-5 Signal processing analysis model of wireless communication system receiver 13-5, 15-6 Signal processing analysis model of error meter 15-3 Signal processing analysis model of noise / interference source model 15-4 Adder Signal processing analysis model 26-B1, 26-B2 base station of interfering wireless communication system

─────────────────────────────────────────────────── ─── Continuation of the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) H04B ^7/ 24-7/26 H04Q ⁷ /00-7/38

Claims (10)

(57) [Claims] 1. An electromagnetic environment design method for designing the number of base stations communicable with a communicable area of a wireless communication system by using a computer simulation, wherein layout information of communication environment, base station arrangement information, and a target wireless communication system are provided. A first step of inputting information and storing it in a storage device; and analyzing a radio wave propagation characteristic based on the input information stored in the storage device in the first step to obtain an electric field strength distribution and a delay characteristic distribution. A second step of storing in a storage device; a third step of analyzing communication characteristics based on the information stored in the storage device to obtain an error rate distribution and an effective transmission rate distribution and storing in the storage device; By setting predetermined threshold values for the electric field strength, delay characteristic, error rate, and effective transmission rate stored in the storage device, the communication enable area of the base station of the wireless communication system is set. Electromagnetic design method characterized by comprising a fourth step of obtaining the number of available communication base station. 2. The electromagnetic environment design method according to claim 1, wherein ray tracing is used for analysis of radio wave propagation characteristics. 3. The electromagnetic environment design method according to claim 1, wherein a signal processing analysis system is used for communication characteristic analysis. 4. The electromagnetic environment design method according to claim 1, further comprising a storage unit for automatically converting the calculated communication characteristics into a database to shorten an analysis time. 5. The electromagnetic environment design method according to claim 1, wherein position information of the noise / interference wave source and characteristic parameters for the noise / interference wave source are input, and the noise / interference is analyzed by using radio wave propagation characteristic analysis and communication characteristic analysis. An electromagnetic environment design method characterized by analyzing electric field strength distribution, delay characteristic distribution, error rate distribution, and effective transmission rate distribution in the presence of a wave source. 6. A recording medium in which a design program for designing the number of base stations communicable with a communicable area of a wireless communication system by computer simulation is recorded, and layout information of communication environment, base station arrangement information, and target information. A first procedure of inputting the wireless communication system information and storing it in a storage device; analyzing a radio wave propagation characteristic based on the input information stored in the storage device in the first procedure to obtain an electric field strength distribution and a delay characteristic distribution. A second procedure for obtaining and storing in a storage device, a third procedure for analyzing communication characteristics based on information stored in the storage device, obtaining an error rate distribution and an effective transmission rate distribution, and storing in a storage device, A predetermined threshold value is set for the electric field strength, delay characteristic, error rate, and effective transmission rate stored in the storage device to communicate with the communicable area of the base station of the wireless communication system. A recording medium recording a design program for executing the fourth step of obtaining a number of possible base stations in the computer. 7. A recording medium on which the design program according to claim 6 is recorded, wherein ray tracing is used for radio wave propagation characteristic analysis. 8. A recording medium on which the design program according to claim 6 is recorded, wherein the signal processing analysis system is used for communication characteristic analysis. 9. A recording medium on which the design program according to claim 6 is recorded, comprising a storage means for automatically converting calculated communication characteristics into a database, and recording the design program characterized by shortening analysis time. Recording medium. 10. A recording medium on which the design program according to claim 6 is recorded, wherein position information of a noise / interference wave source and characteristic parameters for the noise / interference wave source are input, and using radio wave propagation characteristic analysis and communication characteristic analysis, A recording medium recording a design program characterized by analyzing electric field strength distribution, delay characteristic distribution, error rate distribution, and effective transmission rate distribution in the presence of a noise / interference wave source.