JP2010011350A - Wireless communication system, cooperative sensing method, and synthetic determination central apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wireless communication system which can determine a presence/absence of wireless communication by a primary system correspondent to the signal detection performance of each terminal device and the reliability of signal detection result of difference from a cooperative sensing method; a cooperative sensing method; and a synthetic determination central apparatus. <P>SOLUTION: In a secondary system 200, the synthetic determination central apparatus 30 transmits a test signal in a common frequency band in common with a primary system 100 to a terminal 20-terminal 29, an erroneous detection probability and erroneous alarm probability are calculated based on the detection result of the test signal of each terminal device, the erroneous detection probability and erroneous alarm probability calculated in the cooperative sensing result of the terminal 20-29 in cooperative sensing processing are weighed, and thereby, the deterioration of detection accuracy of wireless signal because of the primary system is controlled. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a wireless communication system, a cooperative sensing method, and a comprehensive determination station apparatus in cooperative sensing processing when a plurality of wireless communication systems share the same frequency band and perform wireless communication.

In recent years, a technique has been proposed in which a plurality of wireless communication systems share the same frequency band and perform wireless communication.
For example, when two systems, a primary system that preferentially uses a band and a secondary system, share the same frequency band, the secondary system can only use this frequency when the primary system does not use the frequency band. There are cognitive radio technologies that can use the bandwidth. In such a cognitive radio, it is important on the secondary system side to accurately determine whether or not the primary system is using the shared frequency band.

  As a method of detecting the use or non-use of the frequency band by the primary system, energy detection method (Energy detection) that detects the primary system based on the energy of the frequency band, cyclostationary detection that utilizes the characteristics of periodic steadiness of the frequency band, etc. There is a detection method. Non-Patent Document 1 shows an example of a performance analysis result by an energy detection method.

  In addition, for example, when a terminal device included in the secondary system detects use of a frequency band by the primary system, the secondary system notifies the base station on the secondary system side, and this base station notifies all terminal devices in the secondary system. Therefore, cooperative sensing technology has been studied by instructing frequency sensing and making a comprehensive judgment using the result.

Hereinafter, a cooperative sensing technique in which a base station or a comprehensive determination station determines whether or not a frequency band of a primary system is used by using detection results of a plurality of terminal devices will be described with reference to the drawings. In addition, the comprehensive judgment station may be installed alone, or the base station may also serve as the comprehensive judgment station. FIG. 11 is a diagram showing the configuration of such a cooperative sensing system.
In FIG. 11, the primary system 100a and the secondary system 200a share a predetermined frequency band. Moreover, the secondary system 200a has the comprehensive determination station apparatus 30a as a base station and a comprehensive determination station, and the terminals 20a-29a.

In the secondary system 200a, the process flow of the cooperative sensing system when the terminal 22a detects a radio signal in a predetermined frequency band by the primary system 100a will be described with reference to FIG. 12, FIG. 13, and FIG.
FIG. 13 is a processing flow at the time of signal detection of the primary system 100a in the terminal 22a. When the terminal 22a detects a radio signal from the primary system 100a (step S2201), the terminal 22a transmits a primary system 100a detection notification for notifying that the radio signal from the primary system 100a has been detected to the comprehensive determination station device 30a (step S2202). ).

Next, the flow of processing in the comprehensive determination station device 30a will be described. FIG. 12 is a diagram illustrating a process flow when the comprehensive determination station device 30a receives the primary system 100a detection notification from any of the terminals 20a to 29a.
When the comprehensive determination station device 30a receives the primary system 100a detection notification from the terminal 22a (step S3001), the integrated determination station device 30a transmits a cooperative sensing start request instructing the start of cooperative sensing to the terminals 20a to 29a in the secondary system 200a (step S3002). ). FIG. 15 is a conceptual diagram showing the entire cooperative sensing system when all the terminals 20a to 29a of the secondary system 200a execute cooperative sensing.

  Returning to FIG. 12, the comprehensive determination station device 30a receives the cooperative sensing results from the terminals 20a to 29a (step S3003), and determines whether the cooperative sensing results have been received from all the terminal devices (step S3004). The comprehensive determination station device 30a waits for the reception of the cooperative sensing result until receiving the cooperative sensing result from all the terminal devices, and when receiving the cooperative sensing result of all the terminal devices, based on the received cooperative sensing result, the primary system The presence / absence of wireless communication using a predetermined frequency band by 100a is comprehensively determined (step S3005).

  Next, the flow of processing in the terminals 20a to 29a when receiving the cooperative sensing start request transmitted by the comprehensive determination station device 30a in step S3002 of FIG. 12 will be described. FIG. 14 is a diagram illustrating a flow of cooperative sensing processing in the terminals 20a to 29a. In FIG. 14, when receiving the cooperative sensing start request (step S2211), the terminals 20a to 29a execute a detection process for the presence / absence of a radio signal from the primary system 100a as the cooperative sensing process (step S2212). The terminals 20a to 29a transmit the detection result as the cooperative sensing result to the comprehensive determination station device 30a (step S2213).

In the secondary system 200a, the comprehensive determination station device 30a and the terminals 20a to 29a operate as described above, and the terminals 20a to 29a are not performing wireless communication in a predetermined frequency band with the primary system 100a, and perform cooperative sensing processing. Wireless communication using a predetermined frequency band is performed in a time zone in which execution is not performed. The cooperative sensing system determines the presence / absence of the primary system using the cooperative sensing results of a plurality of terminal devices according to the above-described procedure.
Qingchun Ren, Qilian Liang, “Performance Analysis of Energy Detection for Cognitive Radio Wireless Network”, WASA 2007, IEEE, pp. 139-146, Aug. 2007

However, the cooperative sensing method and detection capability are not necessarily the same between the terminal devices, so the reliability of the detection results is not the same. Further, for example, as shown in a radio signal reachable range da from the primary system 100a in FIG. 15, the primary system 100a does not always transmit a radio signal with transmission power including the entire area of the secondary system 200a. Due to the positional relationship between the systems, there are many cases where only some of the terminal devices receive radio waves of the primary system 100a, and terminal devices that are not included in the wireless signal reachable range da from the primary system 100a, for example, the terminals 24a to 24a. The cooperative sensing result by 29a is not necessarily required for determining whether or not the frequency band of the primary system 100a is used in the comprehensive determination station device 30a.
Furthermore, there is a problem in that by instructing sensing to all terminal devices, a response is received from a terminal device that has not received radio waves of the primary system, and reliability is further reduced by making a determination using this response. .

  Further, the terminals 20a to 29a may be erroneously detected or falsely alarmed at the time of signal detection of the primary system 100a due to the influence of interference or attenuation by other radio signals. When such a detection result is comprehensively determined with detection accuracy from all terminal devices as equivalent accuracy during cooperative sensing, there is a problem that the possibility of erroneous determination in the presence / absence of use of the frequency band in the primary system 100a increases. is there.

  The present invention has been made in consideration of such circumstances, and has been made to solve the above-described problems. The purpose of the present invention depends on the signal detection performance for each terminal device and the reliability of the signal detection result due to the difference in sensing method. An object of the present invention is to provide a wireless communication system, a cooperative sensing method, and a comprehensive determination station apparatus that can determine the presence or absence of wireless communication by a primary system.

  In order to solve the above problems, the present invention provides a primary system in which a wireless communication system preferentially uses a predetermined shared frequency band, and the shared system is used when the primary system does not use the shared frequency band. A wireless communication system including a secondary system that uses a frequency band, wherein the secondary system determines whether or not the shared frequency band is used by the primary system, and a radio signal using the shared frequency band A terminal station apparatus that detects the test signal, and the comprehensive determination station apparatus detects a test signal transmission unit that transmits a radio signal using the shared frequency band as a test signal, and the test signal received from the terminal station apparatus Reliability information for each terminal station device is calculated based on the test signal detection result including whether or not A reliability calculation unit, a reliability information database that stores the position information of the terminal station device and the reliability information in association with each other, a reception unit that receives a primary system detection signal from the terminal station device, and the primary In response to reception of a system detection signal, the reliability information database includes a cooperative sensing request unit that transmits a cooperative sensing start request of the primary system to the terminal station device, and a cooperative sensing result received from the terminal station device. A comprehensive determination unit that calculates a weighted value of the reliability information to be stored and determines whether or not the shared frequency band is used by the primary system, and the terminal station device transmits the comprehensive determination station device The shared frequency band which is either a test signal or a radio signal transmitted by the primary system A detection unit for detecting the presence or absence of a radio signal by a radio communication system, comprising a transmitter for responding to detection result by the detecting unit in the overall determination station.

  Further, in the wireless communication system of the present invention, the cooperative sensing request unit of the comprehensive determination station device is a terminal station device that is a target of cooperative sensing based on position information of the terminal station device that is a transmission source of the primary system detection signal. It is characterized by selecting.

  The radio communication system of the present invention is characterized in that the test signal transmission unit of the comprehensive decision station apparatus transmits the test signal a plurality of times with different transmission powers.

  In the radio communication system of the present invention, when the detection unit of the terminal station apparatus detects a radio signal using the shared frequency band, the reception unit detects a reception level of the received radio signal, and the transmission unit responds. The detection result is a detection result including a detection result of the presence / absence of the radio signal and a detection result of the reception level by the detection unit, and the reliability calculation unit of the comprehensive determination station apparatus performs reliability information for each reception level. Is calculated.

  Further, in the wireless communication system of the present invention, the reliability calculation unit of the comprehensive determination station device calculates a wireless signal arrival area of the test signal according to transmission power of the test signal, and the terminal station device Based on whether or not the position information is a position included in the calculated radio signal reachable area, determine the estimation detection result of the terminal station device to be determined, a test signal detection result transmitted from the terminal station device, By comparing the estimated detection result, a false detection probability value and a false alarm probability value are calculated, and the reliability is calculated based on the calculation result.

  The present invention also provides a radio comprising a primary system that preferentially uses a predetermined shared frequency band, and a secondary system that uses the shared frequency band when the primary system does not use the shared frequency band. A cooperative sensing method in a communication system, wherein a comprehensive determination station device included in the secondary system transmits a radio signal using the shared frequency band as a test signal, and the terminal station device includes the comprehensive determination A test signal detection process for detecting the presence or absence of a radio signal in the shared frequency band, which is the test signal transmitted by a station apparatus, a test result response process for responding the detected detection result to the comprehensive determination station apparatus, and the comprehensive determination The test signal received by the station device from the terminal station device included in the secondary system. Based on the test signal detection result including whether or not the signal is detected, the reliability calculation process for calculating reliability information for each terminal station apparatus, the position information of the terminal station apparatus, and the reliability information are associated with each other Reliability information storage process stored in the storage area, a primary system detection process in which the terminal station apparatus detects presence / absence of a radio signal in the shared frequency band transmitted by the primary system, and a detection result detected by the primary system In response to a primary system detection notification process responding to the comprehensive determination station apparatus as a detection signal, a reception process in which the comprehensive determination station apparatus receives a primary system detection signal from the terminal station apparatus, and reception of the primary system detection signal Cooperative sensing for transmitting the primary system cooperative sensing start request to the terminal station device. And a cooperative sensing process in which the terminal station device detects presence / absence of a radio signal in the shared frequency band transmitted by the primary system, and responds to the comprehensive determination station device with the detected detection result as a cooperative sensing result. A cooperative sensing result notification process, and the comprehensive judgment station device calculates a value obtained by weighting the reliability information stored in the reliability information database with respect to the cooperative sensing result received from the terminal station device. And a comprehensive determination process for determining whether or not the shared frequency band is used.

  The present invention also provides a radio comprising a primary system that preferentially uses a predetermined shared frequency band, and a secondary system that uses the shared frequency band when the primary system does not use the shared frequency band. In the communication system, an overall determination station apparatus of the secondary system, comprising: an overall determination station apparatus that determines whether or not the shared frequency band is used by the primary system; and a terminal station apparatus that detects a radio signal in the shared frequency band A test signal transmission unit that transmits a radio signal using the shared frequency band as a test signal, and a test signal detection result that includes whether or not the test signal received from the terminal station device has been detected. A reliability calculation unit for calculating reliability information for each device, and position information of the terminal station device; , A reliability information database that stores the reliability information in association with each other, a receiving unit that receives a primary system detection signal from the terminal station device, and cooperation of the primary system in response to reception of the primary system detection signal A cooperative sensing request unit that transmits a sensing start request to the terminal station device, and a cooperative sensing result received from the terminal station device, calculates a weighted value of reliability information stored in the reliability information database, and An overall determination station apparatus comprising: an overall determination unit that determines whether or not the shared frequency band is used by a primary system.

  According to the present invention, the comprehensive judgment station device transmits in advance a radio signal in the shared frequency band of the primary system as a test signal, calculates the false detection probability and false alarm probability of each terminal station device, and based on the calculated values Get reliability information. By performing the comprehensive determination based on the cooperative sensing result and the acquired reliability information, there is an effect that it is possible to suppress deterioration in detection accuracy during the comprehensive determination.

Hereinafter, a cooperative sensing system according to an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic block diagram showing an entire cooperative sensing system including a primary system 100 and a secondary system 200 according to the present embodiment.
The secondary system 200 performs wireless communication using a frequency band assigned to the primary system 100. Hereinafter, the frequency band assigned to the primary system 100 is referred to as a shared frequency band.

  The secondary system 200 includes terminals 20 to 29 that detect radio signals in the shared frequency band and a comprehensive determination station device 30 that controls communication in the shared frequency band, and determines whether or not the shared frequency band is used by the primary system 100. It is a cooperative sensing system which performs the cooperative sensing process which controls the communication in the secondary system 200 according to it.

  Communication control according to whether or not the shared frequency band is used by the primary system 100 will be described. The secondary system 200 restricts wireless communication using the shared frequency band in the secondary system 200 when the primary system 100 is transmitting wireless signals in the shared frequency band, that is, when wireless communication is being performed by the primary system 100. . On the other hand, in the secondary system 200, when the primary system 100 is not in operation, the restriction on the wireless communication using the shared frequency band is released.

  In the secondary system 200, the comprehensive determination station device 30 includes a communication processing unit 31, a control unit 32, a reliability information acquisition unit 33, a reliability information database 34, and a cooperative sensing processing unit 35. The comprehensive determination station device 30 includes comprehensive determination processing including reliability information acquisition processing for acquiring reliability information for each terminal device of the terminals 20 to 29 and cooperative sensing processing for determining whether or not the shared frequency band is used by the primary system 100. And do.

The communication processing unit 31 of the comprehensive determination station device 30 includes a communication unit 311 and a communication control unit 312 and transmits and receives radio signals.
The communication unit 311 transmits a radio signal based on the set transmission power, and receives radio signals from the terminals 20 to 29 and the primary system 100. The communication control unit 312 controls transmission power by changing the setting of the transmission power of the radio signal transmitted by the communication unit 311.
The control unit 32 controls each unit in the comprehensive determination station device 30.

The reliability information acquisition unit 33 includes a reliability information acquisition control unit 331, a false detection false alarm probability calculation unit 332, and a reliability calculation unit 333, and acquires the reliability information of the terminals 20 to 29.
The reliability information acquisition control unit 331 controls the respective units of the reliability information acquisition unit 33, the signal transmission / reception request by the communication processing unit 31, and the request for writing reliability information to the reliability information database 34. And the reliability information acquisition process is controlled.
The false detection false alarm probability calculation unit 332 calculates false detection probabilities and false alarm probabilities in the terminals 20 to 29 related to detection of whether or not the shared frequency band is used by the primary system 100.
The reliability calculation unit 333 calculates the reliability of the terminals 20 to 29 based on the false detection probability calculated by the false detection false alarm probability calculation unit 332 and the false alarm probability.

The reliability information database 34 stores reliability information in which terminal identification information for each terminal device, position information, and reliability information are associated with each other.
The cooperative sensing processing unit 35 includes a cooperative sensing control unit 351, a cooperative sensing area determination unit 352, and an overall determination unit 353, and receives a primary system 100 detection notification that notifies the use of the shared frequency band by the primary system 100. In response, cooperative sensing processing is performed.

The cooperative sensing control unit 351 controls the cooperative sensing area determination unit 352 and the comprehensive determination unit 353 to perform overall control of the cooperative sensing process.
The cooperative sensing area determination unit 352 determines the target range of the cooperative sensing process according to the location information of the transmission source terminal of the primary system 100 detection notification.
The comprehensive determination unit 353 includes the cooperative sensing results from the terminals 20 to 29 within the target range of the cooperative sensing process determined by the cooperative sensing area determination unit 352 and the reliability for each of the terminals 20 to 29 stored in the reliability information database 34. Based on the information, the presence / absence of use of the shared frequency band by the primary system 100 is determined.

Since the terminals 20 to 29 have the same configuration, the internal configuration will be described using the terminal 20 as a representative example. The terminal 20 includes a communication unit 201, a terminal control unit 202, a signal detection unit 203, and a storage unit 204, and is, for example, a computer terminal or a mobile phone terminal.
The communication unit 201 detects a radio signal from the primary system 100 and transmits / receives a radio signal.

The terminal control unit 202 controls each unit of the terminal 20. Moreover, the terminal control part 202 transmits the detection result by the signal detection part 203 to the comprehensive determination station apparatus 30 as a cooperative sensing result according to a cooperative sensing start request | requirement. Also, the terminal control unit 202 transmits the detection result by the signal detection unit 203 of the test signal in the shared frequency band transmitted by the comprehensive determination station device 30 to the comprehensive determination station device 30 as a test result notification in response to the test start signal. .
The signal detection unit 203 detects whether the frequency band of the radio signal received by the communication unit 201 is a shared frequency band and the reception level of the radio signal, and outputs the detection result to the terminal control unit 202.
The storage unit 204 stores terminal identification information of the terminal 20 and position information.

Next, the process flow of the terminals 20 to 29 in the cooperative sensing system according to the embodiment of the present invention will be described using the terminal 20 as a representative example. FIG. 2 is a diagram illustrating a procedure for detecting a test signal transmitted from the comprehensive determination station device 30 by the terminal 20.
In the figure, in the terminal 20, the terminal control unit 202 receives a test start signal via the communication unit 201 (step S201). As the test start signal is received, the terminal control unit 202 determines the presence / absence of a radio signal in the shared frequency band every predetermined time, the measurement result of the signal level of the test signal, and the position information stored in the storage unit 204 Then, a test result notification including the terminal identification information of the own device is transmitted to the comprehensive determination station device 30 (step S202).

  In addition, the flow of operations related to detection of the primary system 100 in the terminal 20 will be described with reference to the drawings. FIG. 3 shows a procedure for detecting a radio signal from the primary system 100 when the terminal 20 does not transmit a test signal by the comprehensive determination station device 30 and does not execute cooperative sensing processing in the own device.

  In the terminal 20, the signal detection unit 203 determines whether or not the wireless signal received by the communication unit 201 is a wireless signal in the shared frequency band by determining whether or not there is a wireless signal in the shared frequency band by the primary system 100. Determine. When the signal detection unit 203 detects the radio signal of the primary system 100, the signal detection unit 203 outputs a transmission request for the primary system 100 detection signal including information on the reception level of the received radio signal to the terminal control unit 202 (step S211).

  The terminal control unit 202 sends a notification indicating that the primary system 100 has detected a radio signal, a reception level information, location information of the own device read from the storage unit 204, and terminal identification information. The communication unit 201 transmits the information to the comprehensive determination station device 30 (step S212).

In addition, the flow of the cooperative sensing process in the terminal 20 will be described with reference to the drawings. FIG. 4 is a diagram illustrating the flow of the cooperative sensing process in the terminal 20.
In the terminal 20, the communication unit 201 receives the cooperative sensing start request from the comprehensive determination station device 30, and outputs the cooperative sensing start request to the terminal control unit 202 (step S221).

The terminal control unit 202 outputs a signal detection request to the signal detection unit 203 in response to the cooperative sensing start request. Based on the signal detection request, the signal detection unit 203 detects the presence / absence of a radio signal from the primary system 100 in the shared frequency band from the radio signal received by the communication unit 201 and the reception level when the radio signal is detected, The detection result is output to the terminal control unit 202 (step S222).
The terminal control unit 202 outputs from the communication unit 201 a cooperative sensing result including information on presence / absence of signal detection output from the signal detection unit 203, a reception level, position information of the own device read from the storage unit 204, and terminal identification information. It is made to transmit to the comprehensive determination station apparatus 30 (step S223).

<Reliability information acquisition process>
Next, regarding the operation of the comprehensive determination station device 30 in the cooperative sensing system according to the embodiment of the present invention, the flow of processing including the reliability information acquisition process of the terminals 20 to 29 and the cooperative sensing process will be described.
First, an outline of the reliability information acquisition process by the comprehensive determination station device 30 will be described.
During this reliability information acquisition process, the shared frequency band is not used by the primary system 100. For example, the comprehensive determination station device 30 notifies the primary system 100 of the start of the reliability information acquisition process in advance, and the primary system 100 does not perform wireless communication using the shared frequency band in response to this notification. .

The comprehensive judgment station device 30 transmits a test start signal for notifying the transmission of the test signal to the terminals 20 to 29, and then sets the transmission of the test signal N times (where N> 1) as one set for each set. M sets of test signals are transmitted with different transmission powers (where M> 1).
Based on the test result notification received from the terminals 20 to 29, the position information of the terminals 20 to 29, and the value of the transmission power of the test signal corresponding to the received test result notification, the comprehensive determination station device 30 The reliability of is calculated.

Next, details of the operation flow of the reliability information acquisition process in the comprehensive determination station device 30 will be described with reference to the drawings.
In addition, the comprehensive determination station device 30 holds in advance an internal storage area of terminal device information in which terminal identification information of a terminal device provided in the secondary system 200 is associated with position information.
For example, the comprehensive determination station device 30 may hold the terminal identification information and the position information of all terminal devices included in the secondary system 200 in the reliability information database 34 in advance, or according to the test start signal The terminal device of the secondary system 200 may transmit the response signal including the terminal identification information and the position information of the device itself to the integrated determination station device 30 so that the integrated determination station device 30 acquires the information of the terminal device.

FIG. 5 is a flowchart showing a processing flow of the comprehensive determination station device 30 in the process of obtaining reliability information.
In the comprehensive determination station apparatus 30, the reliability information acquisition control unit 331 causes the communication unit 311 to transmit a signal notifying the primary system 100 of the start of the reliability information acquisition process as the start of the reliability information acquisition process (step S301). .

Next, the reliability information acquisition control unit 331 causes the communication unit 311 to transmit a test start signal with the transmission power that reaches the entire communication area of the secondary system 200 (step S302). The reliability information acquisition control unit 331 outputs a transmission power change request when transmitting a test signal to the communication control unit 312, and the communication control unit 312 sets the transmission power of the communication unit 311 (step S <b> 303).
Here, the transmission power at the time of transmitting the test signal is, for example, a value “W / M” obtained by dividing the value of the maximum transmission power W by M of the number of test signal transmission sets as the reference transmission power Ws. The transmission power of the reference transmission power Ws × the number of sets m (where m = 1, 2,..., (M−1), M).

Next, the reliability information acquisition control unit 331 causes the communication unit 311 to transmit a test signal (step S304). This test signal is a radio signal using a shared frequency band according to the communication method of the primary system 100.
FIG. 6 shows that when m = 1, the test signal reachable range (range in which the radio signal is equal to or higher than the predetermined signal strength) based on the transmission power “reference transmission power Ws × number of sets 1” from the comprehensive determination station apparatus 30 is wireless. The conceptual diagram of a cooperative sensing system at the time of setting it as the signal reachable range a is shown. In the figure, the range of the radio signal reachable range a includes a terminal 23 and a terminal 25.

Of the terminal devices included in the wireless signal reachable range a, the terminal device that has successfully detected the test signal, for example, the terminal 25 transmits a detection notification indicating the presence of signal detection to the comprehensive determination station device 30 as a test result notification. To do. Here, the test result notification includes information indicating presence / absence of signal detection, information on the reception level of the test signal, position information of the own apparatus, and terminal identification information of the own apparatus.
In addition, among the terminal devices included in the wireless signal reachable range a, the terminal device in which the test signal cannot be detected, for example, the terminal 23 sends a non-detection notification indicating no signal detection as the test result notification to the comprehensive determination station device 30. Send to. As described above, a terminal device that is included in the wireless signal reachable range a and originally should transmit a detection notification but transmits a non-detection notification as a test result notification is defined as a terminal device that is erroneously detected.

Similarly, among terminal devices included in the secondary system 200 and existing in a region other than the radio signal reachable range a, a terminal device that has not been able to detect a test signal, for example, the terminal 23 has no signal detection as a test result notification. Is transmitted to the comprehensive determination station device 30.
In addition, among the terminal devices included in the secondary system 200 and existing in a region other than the wireless signal reachable range a, a terminal device that notifies that a test signal has been detected, for example, the terminal 22 may detect a signal as a test result notification. A detection notification indicating the presence is transmitted to the comprehensive determination station device 30.
In this way, a terminal device that is not included in the wireless signal reachable range a and should originally transmit a non-detection notification but transmits a detection notification as a test result notification is defined as a terminal device that has falsely alarmed.

Returning to FIG. 5, the comprehensive determination station device 30 receives a test result notification from the terminals 20 to 29 (step S306).
As described above, when the terminals 20 to 29 receive the test start signal from the comprehensive determination station device 30, the test results notification is sent to the comprehensive determination station device 30 at predetermined intervals regardless of whether or not the test signal is detected. Since it transmits, the comprehensive determination station | game apparatus 30 can acquire the detection notification which notifies that the test signal was detected, and the non-detection notification which notifies that a test signal was not able to be detected.

The reliability information acquisition control unit 331 temporarily sets test result notification information in which the value of the transmission power of the test signal is associated with N test result notifications for each terminal device received by the communication unit 311 in the internal state. It is stored in the storage area, and it is determined whether or not the number of test signal transmissions has reached N (step S307).
The reliability information acquisition control unit 331 transmits the test signal N times, and repeats the processes of steps S304 to S306 until receiving N times of test result notifications of the terminals 20 to 29. When the transmission of N test signals with the set transmission power has been completed, the reliability information acquisition control unit 331 causes the false detection / false alarm probability calculation unit 332 to perform erroneous detection and error including N times of test result notification information. The alarm probability calculation request is output to the false detection false alarm probability calculation unit 332.

  The false detection false alarm probability calculation unit 332 responds to the false detection and false alarm probability calculation request, the transmission power information, the position information stored in the reliability information database 34, and the N test results for each terminal device. Based on the notification information, a false detection probability and a false alarm probability are calculated for each terminal device. Specifically, the false detection false alarm probability calculation unit 332 reads the position information from the reliability information database 34 using the terminal identification information of the terminal device included in the test result notification information as a search key, and based on the read position information. The terminals 20 to 29 determine whether the terminal device is included in the wireless signal reachable range a corresponding to the input transmission power information or the terminal device not included in the wireless signal reachable range a.

Next, the false detection false alarm probability calculation unit 332 uses the following calculation formula based on the N test result notifications for each terminal device, and the false detection probability P _ed (i) and false alarm probability P _ea (j ) Is calculated.
False detection probability P _ed (i) = {number of false detections N _ed (i) ÷ number of test transmissions N} × 100 [percent,%]
However, i shows one of the identification numbers of the terminal devices included in the wireless signal reachable range a. The number of erroneous detections N _ed (i) indicates the number of erroneous detections in the terminal device with the identification number i (where N _ed (i) = 0, 1,..., (N−1), N).

False alarm probability P _ea (j) = {number of false alarms N _ea (j) ÷ number of tests N} × 100 [%]
However, j represents one of the identification numbers of the terminal devices included in the secondary system 200 and not included in the wireless signal reachable range a. The number of false alarms N _ea (j) indicates the number of false detections in the terminal device with the identification number j (where N _ad (j) = 0, 1,..., (N−1), N).

For example, in FIG. 6, when N = 10 and the comprehensive determination station device 30 transmits a test signal 10 times, the terminal 23 included in the wireless signal reachable range a detects the test signal 7 times out of 10 times ( It is assumed that the test signal was not detected three times (false detection).
In this case, since the terminal 23 is included in the wireless signal reachable range a, the false alarm probability P _ea (23) = 0%.

On the other hand, the false detection probability P _ed (23) is
False detection probability P _ed (23) = {number of false detections N _ed (23) ÷ number of test transmissions N} × 100 = (3 ÷ 10) × 100 = 30 [%]
As a result, the false detection false alarm probability calculation unit 332 calculates.

Similarly, when the terminal 22 not included in the wireless signal reachable range a detects the test signal once out of 10 times (false alarm) and fails to detect the test signal 9 times (normal detection), Since the terminal 22 is not included in the wireless signal reachable range a, the false detection probability P _ea (22) = 0%.
On the other hand, the false alarm probability P _ea (22) is
False alarm probability P _ea (22) = {number of false alarms N _ea (22) ÷ number of tests N} × 100 = (1 ÷ 10) × 100 = 10 [%]
As a result, the false detection false alarm probability calculation unit 332 calculates.

Returning to FIG. 5, the false detection false alarm probability calculation unit 332 outputs the calculation result associated with the terminal identification information of the terminals 20 to 29 to the reliability information acquisition control unit 331. The reliability information acquisition control unit 331 updates the reliability information by writing the calculation result in the reliability information database 34 in the reliability item corresponding to the terminal identification information of the calculation result (step S308).
The reliability information acquisition control unit 331 determines whether or not the current transmission power setting of the test signal is the maximum transmission power W (step S309). If the reliability information acquisition control unit 331 determines that the transmission power of the current test signal is not the maximum transmission power W, the reliability information acquisition control unit 331 adds the reference transmission power Ws to the transmission power of the current test signal and resets the number of times of transmission of the test signal. Then, the process returns to step S303.

FIG. 7 shows the concept of the cooperative sensing system when the arrival range of the test signal based on the transmission power “reference transmission power Ws × number of sets 2” from the comprehensive determination station device 30 is the wireless signal arrival range b when m = 2. The figure is shown. In the figure, the range of the wireless signal reachable range b includes terminals 22 to 27, and the detection results of the terminals 20 to 29 do not include false detections or false alarms.
Thus, by transmitting a test signal having different transmission power for each set number, each terminal apparatus receives a test signal at a different reception level. Accordingly, there is an effect that the comprehensive determination station device 30 can calculate the probability of false detection and false alarm for each reception level for each terminal device.

Returning to FIG. 5, after the reliability information acquisition control unit 331 performs M sets of transmission of one set of N test signals, and determines in step S309 that the current transmission power is the maximum transmission power W, the maximum transmission power is transmitted. The power W notifies the terminals 20 to 29 of the end of the test and notifies the primary system 100 of the end of the reliability information acquisition process, thereby ending the reliability information acquisition process.
The above is the operation flow in the reliability information acquisition process by the comprehensive determination station device 30.

  The comprehensive determination station device 30 changes the radio signal arrival area to be transmitted by controlling the transmission power of the radio signal. Thereby, it becomes possible for the comprehensive determination station apparatus 30 to acquire the test result notification for each reception level of the reception signal in the terminals 20 to 29. That is, it is possible to calculate the false detection probability and false alarm probability for each reception level, and in the comprehensive determination process, the primary system with high accuracy according to the reception level included in the cooperative sensing result from the terminal device as the cooperative sensing target. There is an effect that it is possible to determine whether or not 100 shared frequency bands are used.

<Comprehensive judgment process>
Next, the process flow of the comprehensive determination process will be described for the operation of the comprehensive determination station device 30 in the cooperative sensing system according to the embodiment of the present invention.
First, an overview of comprehensive determination processing by the comprehensive determination station device 30 will be described.
Based on the cooperative sensing result of the cooperative sensing process executed by the terminals 20 to 29 and the reliability information for each terminal device, the comprehensive determination station device 30 determines whether the primary system 100 performs wireless communication using the shared frequency band. The overall judgment process is performed. In this comprehensive determination process, the comprehensive determination station apparatus 30 determines a part of the terminals 20 to 29 as a cooperative sensing target, and performs a cooperative sensing process in which the cooperative sensing target terminal apparatus performs cooperative sensing. Do.

FIG. 8 is a diagram illustrating an arrangement example of the terminals 20 to 29 when the wireless signal reachable range of the secondary system 200 is divided into three areas of area A, area B, and area C. In the figure, in order from the primary system 100 side, area A includes terminals 20 to 23, area B includes terminals 24 and 25, and area C includes terminals 26 to 29.
These areas are pre-divided according to the distance from the primary system 100, and the radio signal of the shared frequency band from the primary system 100 in a time zone that is not the reliability information acquisition process and the comprehensive determination process process. You may divide | segment into the predetermined range centering on the position of the detected terminal device, and the outside of this predetermined range.

Here, the area is divided into area A, area B, and area C in advance, and the cooperative sensing area determination unit 352 of the comprehensive determination station device 30 stores area information in an internal storage area in advance. .
Next, details of the process flow of the comprehensive determination station apparatus 30 in the comprehensive determination process will be described with reference to the drawings. FIG. 9 is a flowchart showing a flow of comprehensive determination processing by the comprehensive determination station device 30.

In the comprehensive determination station device 30, the control unit 32 via the communication unit 311 detects the detection of the radio signal using the shared frequency band of the primary system 100 from any terminal device, for example, the terminal 22. Receive notifications.
Upon receipt of the primary system 100 detection notification, the control unit 32 outputs a determination request as to whether or not it is a false alarm including the primary system 100 detection notification including the terminal identification information of the terminal 22 to the cooperative sensing processing unit 35. (Step S321).

  In the cooperative sensing processing unit 35, the cooperative sensing control unit 351 reads the position information of the terminal 22 from the reliability information database 34 using the input terminal identification information of the terminal 22 as a search key, and includes the position information of the terminal 22. The sensing target area determination request is output to the cooperative sensing area determination unit 352. The cooperative sensing area determination unit 352 determines in which region the terminal 22 is present based on the position information of the terminal 22 and the information on the region stored in the internal storage region, and the determination result is the cooperative sensing control unit. It outputs to 351 (step S322). Here, the cooperative sensing control unit 351 determines that the terminal 22 exists in the area A.

  Next, the cooperative sensing control unit 351 selects a terminal device included in the area A that is the cooperative sensing target area based on the determination result. For example, the cooperative sensing control unit 351 reads the position information of all terminal devices stored in the reliability information database 34 and the corresponding terminal identification information, and the terminal of the position information included in the area A among the read position information. Extract the device. The cooperative sensing control unit 351 causes the communication unit 311 to transmit a cooperative sensing start request signal to the extracted terminal device as a destination (step S323).

  FIG. 10 illustrates a situation where the terminals 20 to 23 included in the area A are performing the cooperative sensing process in response to the cooperative sensing start request signal transmitted from the comprehensive determination station device 30 to the terminal device in the area A. It is a conceptual diagram.

Returning to FIG. 9, when the cooperative sensing control unit 351 receives the cooperative sensing result via the communication unit 311 (step S324), based on the terminal identification information included in the cooperative sensing result, all the terminal devices in the area A, that is, It is determined whether or not cooperative sensing results have been received from the terminals 20 to 23 (step S325).
The cooperative sensing control unit 351 waits for reception until the cooperative sensing result is received from all the terminal devices of the terminals 20 to 23. When the cooperative sensing result of the terminals 20 to 23 is received, the cooperative sensing control unit 351 corresponds to the terminal identification information of the terminals 20 to 23. The reliability information to be read is read from the reliability information database 34 (step S326).

The cooperative sensing control unit 351 outputs a comprehensive determination processing request including the read reliability information and the received cooperative sensing result to the comprehensive determination unit 353. The comprehensive determination unit 353 performs weighting processing of reliability information on the cooperative sensing result for each terminal device in response to the input comprehensive determination processing request (step S327).
The weighting process by the comprehensive determination unit 353 will be described for the terminal i (where i = 20, 21, 22, 23) having the false detection probability P _ed (i) and the false alarm rate P _ea (i).

As a result of the cooperative sensing instruction, when the terminal i notifies “the shared frequency band is being used from the primary system 100”, the comprehensive determination unit 353 calculates the reliability R and the weighting values by the following equations.
Reliability R (with detection) = (100−false alarm rate P _ea (i)) [%]
Weight (with detection) = Reliability R (with detection) / 100%
On the other hand, when the terminal i notifies “no detection”, the comprehensive determination unit 353 calculates the reliability R and the weighting value by the following equations.
Reliability R (no detection) = (100−false detection probability P _ed (i)) [%]
Weight (no detection) = Reliability R (no detection) / 100%

A specific example of the procedure of the weighting process by the comprehensive determination unit 353 will be described.
As a determination target terminal device, for example, an overall determination process related to the terminal 21 having a false detection probability P _ed (21) = 10% and a false alarm rate P _ea (21) = 0% will be described.
As a result of the cooperative sensing instruction, when the terminal 21 notifies “the shared frequency band is being used from the primary system 100”, the comprehensive determination unit 353 calculates the reliability R and the weighting values using the above-described formulas. To do.

Reliability R (with detection) = (100−false alarm rate P _ea (21)) = (100−0) = 100 [%]
Weight (with detection) = Reliability R (with detection) / 100% = 100/100 = 1
On the other hand, when this terminal device notifies "no detection"
Reliability R (no detection) = (100−false detection probability P _ed (21)) = (100−10) = 90%
Weight (no detection) = Reliability R (no detection) ÷ 100% = 90 ÷ 100 = 0.9

Similarly, the comprehensive determination unit 353 calculates the reliability R and the weight in all the terminals 20 to 23 that have transmitted the cooperative sensing instruction.
Next, the overall determination unit 353 multiplies the following equation, that is, the weight Ri and the variable Xi for each terminal device, and adds the calculated results for all the terminal devices to be cooperatively sensed. Is calculated (step S328).
Overall judgment result T = ΣRiXi
However, Ri is a weight value at the terminal i, and the variable Xi is a value “1” when there is a detection, and a value “−1” when there is no detection.

At this time, when the comprehensive determination result T ≧ 0, the comprehensive determination unit 353 determines that the shared frequency band is used by the primary system 100. When the comprehensive determination result T <0, the shared frequency by the primary system 100 is determined. It is determined that there is no bandwidth usage.
The comprehensive determination unit 353 outputs the determination result to the cooperative sensing control unit 351. When the shared frequency band is used by the primary system 100 based on the determination result, the cooperative sensing control unit 351 instructs the communication of the secondary system 200 to stop communication or requests use of another frequency band. By transmitting from 311, communication control is performed (step S 328).

It should be noted that the terminal device that exists in the area where the terminal device that transmitted the primary system 100 detection notification in step S321 exists, here, the terminal device that exists in area A, when instructing to stop communication or request to use another frequency band It is good also as performing communication control only.
The comprehensive determination station device 30 transmits test radio waves using the same frequency band and communication method, and repeats reception of results from each terminal device an arbitrary number of times (for example, N times). The false detection probability and false alarm probability for the level are calculated as weights and written to the reliability information database 34. In this process, as the number of repetitions increases, the accuracy of the false detection probability and false alarm probability values improves. The processing procedure described above is a cooperative sensing processing process by the comprehensive determination station device 30.

  According to the above-described embodiment, the comprehensive determination station device 30 transmits in advance a test signal to which the communication method of the primary system 100 is applied using the shared frequency band used by the primary system 100, and the terminals 20 to 20 included in the secondary system 200. 29 test result notifications are acquired. Based on this, the comprehensive determination station device 30 calculates the sensing false detection probability and false alarm probability for each of the terminals 20 to 29, and calculates the reliability value based on the calculated false detection probability and false alarm probability. . The comprehensive determination station device 30 performs weighting processing on the cooperative sensing detection results transmitted from the terminals 20 to 29 based on the calculated reliability value, thereby performing wireless communication using the shared frequency band in the primary system 100. There is an effect that the presence or absence of execution can be determined more accurately.

  Further, the comprehensive determination station device 30 performs cooperative sensing processing on a part of the secondary system 200 (for example, area A) based on the location information of the transmission source of the primary system 100 detection notification that notifies that the primary system 100 has been detected. As a range to be performed, the cooperative sensing process is executed only for the terminal devices included in the range.

  As a result, as shown in FIG. 10, the cooperative sensing result that may include a false detection or a false alarm from a terminal device (for example, the terminals 24 to 29) outside the wireless signal reachable range d from the primary system 100. Therefore, it is possible to more accurately determine whether the primary system 100 performs wireless communication in the shared frequency band. Furthermore, unnecessary sensing processing can be suppressed for the terminals 24 to 29, and even if the terminals 20 to 23 are executing the cooperative sensing processing, the terminals 24 to 29 are not interrupted. There is an effect that the processing can be continued.

In addition, with respect to the cooperative sensing result in response to the cooperative sensing start request of the primary system 100, the total determination result T is calculated using the false detection probability or false alarm probability stored in advance in the reliability information database 34 as a weight. By calculating, the reliability of the cooperative sensing result for each terminal device is improved.
Further, the sensing instruction is transmitted with the area limited according to the position information of the terminal device that first notifies that the primary system has been detected. Accordingly, it is possible to improve the reliability of the determination result by causing the terminal device that is more easily influenced by the primary system 100 and that is present at a position where the radio signal from the primary system 100 is easily received to be cooperatively sensed. There is an effect.

  Moreover, the comprehensive determination station apparatus 30 estimates which area | region of the secondary system 200 the signal of the primary system 100 influences by acquiring the positional information on each terminal device. Thereby, the comprehensive determination station device 30 transmits a sensing instruction only to an area where the primary system 100 needs to be detected during cooperative sensing, and performs comprehensive determination based on the reliability of the cooperative sensing result. It is possible to suppress deterioration in detection accuracy.

In the above-described embodiment, the comprehensive determination station device 30 calculates the reliability R based on the false alarm rate P _ea (i) and the false detection probability P _ed (i). However, the present invention is not limited to this. The reliability may be calculated by the following calculation formula.
When the terminal i is within the radio signal reachable range, the comprehensive determination station device 30 detects (normally detects) the test signal and indicates a normal detection probability P _ad (i) indicating the probability of notifying the detection, When the terminal i exists outside the radio signal reachable range, the reliability R ′ is calculated based on the normal alarm rate P _aa (i) indicating the probability of notifying that the test signal has not been received.

Here, the comprehensive determination station device 30 calculates the normal detection probability P _ad (i), the normal alarm rate P _aa (i), and the reliability R ′ by the following equations.
Normal detection probability P _ad (i) = (100−false detection probability P _ed (i)) = {number of normal detections N _ad (i) ÷ number of test transmissions N} × 100 [percent,%]
Normal alarm rate P _aa (i) = (100−false alarm rate P _ea (i)) = {number of normal alarms N _aa (i) ÷ number of tests N} × 100 [%]
Reliability R ′ = {(normal detection probability P _ad (i) / 100) × (normal alarm rate P _aa (i) / 100)} × 100 [%]

Here, unlike the reliability R (with detection) and R (without detection) calculated for each detection result, the reliability calculated based on the normal detection probability P _ad (i) and the normal alarm rate P _aa (i). The degree R ′ is a value indicating the overall reliability of the detection result of the terminal i that is uniformly applied to the detection result of the terminal i for each reception level.
Then, in the comprehensive determination station device 30, the comprehensive determination unit 353 calculates a weighting value and a comprehensive determination result T ′ by the following expression based on the reliability R ′.
Weight = Reliability R ′ ÷ 100%
Overall determination result T ′ = ΣRi′Xi

However, Ri ′ is a weight value at the terminal i, and the variable Xi is a value “1” when there is a detection, and a value “−1” when there is no detection.
By using the reliability R ′, the comprehensive determination unit 353 can calculate the comprehensive determination result T ′ without performing weighting with a different value for each detection result. In addition, since only the reliability R ′ is stored in the reliability information database 34, an increase in data can be suppressed.

Further, the reliability R ′ described above may be calculated by the average value of the normal detection probability P _ad (i) and the normal alarm rate P _aa (i), that is, by the following equation.
Reliability R ′ = {normal detection probability P _ad (i) + normal alarm rate P _aa (i)} ÷ 2 [%]
Similarly, the reliability R described above may be calculated based on the average value of the false alarm rate P _ea (i) and the false detection probability P _ed (i), that is, based on the following equation.
Reliability R = 100− (false alarm rate P _ea (i) + false detection probability P _ed (i)) ÷ 2 [%]

Further, the above-described reliability R (with detection) and reliability R (without detection) may be calculated based on the following equations.
Reliability R (with detection) = (100−probability of detection P _ed (i)) [%]
Reliability R (no detection) = (100−false alarm rate P _ea (i)) [%]
Further, the weight value is a combination of the reliability based on the normal detection probability P _ad (i) and the reliability based on the normal alarm rate P _aa (i), or the reliability based on the false alarm rate P _ea (i). It is also possible to multiply each reliability using a combination of the degree and the reliability based on the false detection probability P _ed (i), that is, to calculate by the following equation.
Weight = (Reliability R (no detection) ÷ 100%) × (Reliability R (detection) ÷ 100%)

  In the above-described embodiment, as shown in FIG. 5, after transmitting N test signals with a predetermined transmission power, the false detection false alarm probability calculation unit 332 calculates the false detection and false alarm probabilities in step S307. Although the reliability is calculated and the reliability calculation unit 333 calculates the reliability, the present invention is not limited to this, and may be as follows. That is, in step S309, after receiving a response to the test signal with the maximum transmission power, the false detection false alarm probability calculating unit 332 calculates the probability for each reception level included in the test signal that has received responses to all the test signals. The reliability calculation unit 333 may calculate the reliability.

  Thereby, the system monitoring device 30 calculates in advance the false detection probability and false alarm probability for each reception level of each terminal, and based on the terminal identification information and the reception level information included in the cooperative sensing result, There is an effect that it becomes possible for the system monitoring device 30 to comprehensively determine the presence or absence of the radio signal of the monopolar device 100 using the reliability information at the level. As described above, the reliability and the weight value are calculated as reliability as the accuracy of the sensing result for each terminal, and if the system monitoring apparatus 30 performs comprehensive determination based on this reliability, A reliability calculation method and a weight value calculation method can also be applied.

As an example of the method for determining the target area, for example, as shown in FIG. 8, the secondary system area is divided into a plurality of sub-areas (areas A, B, and C in FIG. 6) in advance, and primary system detection is performed. In the above description, the area where the terminal device that has notified is present as the cooperative sensing target area, but is not limited thereto, and may be another area.
For example, a range included in a circle with a radius x around the terminal device that is the transmission source of the primary system 100 detection notification may be used as the cooperative sensing area. In addition, when a plurality of terminal devices notify the detection of the primary system, a range surrounded by the plurality of terminal devices to be notified (in the case of two terminal devices, a range surrounded by the comprehensive determination station and the two terminal devices) It may be a cooperative sensing area.

  Further, the position information in the terminals 20 to 29 has been described as being stored in the storage unit 204 in advance. However, the present invention is not limited to this. For example, the terminals 20 to 29 include a GPS (Global Positioning System) device. Any configuration is applicable as long as the location information of the terminals 20 to 29 can be acquired, such as acquiring the location information by the GPS device and notifying the comprehensive determination station device 30 of the location information.

  Moreover, although the comprehensive determination station apparatus 30 transmitted the test start signal and the terminals 20 to 29 have been described as transmitting the test result notification every predetermined period, the present invention is not limited to this. Terminal identification information and position information of all terminal devices included in the secondary system 200 are acquired in advance, and a test result notification is sent to the comprehensive determination station device 30 only when the terminals 20 to 29 receive a test signal. You may make it transmit. In this case, the comprehensive determination station device 30 can be realized by determining whether the terminal device that has not transmitted the test result notification is a false detection based on the position information and the transmission power of the test signal. It is.

In addition, the above-described comprehensive determination station device 30, the terminals 20 to 29, and the primary system 100 have a computer system therein. And the communication processing part 31, the control part 32, the reliability information acquisition part 33, the reliability information database 34, the cooperative sensing process part 35 of the comprehensive determination station apparatus 30, and the communication part 201 of the terminals 20-29, the terminal control part 202, the signal detection unit 203, and the storage unit 204 are stored in a computer-readable recording medium in the form of a program, and the computer system reads and executes the program to perform the above-described processing. Is called. The “computer system” herein includes a CPU, various memories, an OS, and hardware such as peripheral devices.
Further, the “computer system” includes a homepage providing environment (or display environment) if a WWW system is used.

Also, a program for realizing each step shown in FIGS. 2, 3, 4, 5, and 9 is recorded on a computer-readable recording medium, and the comprehensive decision station device 30 shown in FIG. By recording a program for realizing the functions and the functions of the terminals 20 to 29 on a computer-readable recording medium, causing the computer system to read and execute the program recorded on the recording medium, the primary system 100 A cooperative sensing process for determining whether or not the shared frequency band is used may be performed.
The “computer-readable recording medium” means a flexible disk, a magneto-optical disk, a ROM, a writable nonvolatile memory such as a flash memory, a portable medium such as a CD-ROM, a hard disk built in a computer system, etc. This is a storage device.

Further, the “computer-readable recording medium” means a volatile memory (for example, DRAM (Dynamic DRAM) in a computer system that becomes a server or a client when a program is transmitted through a network such as the Internet or a communication line such as a telephone line. Random Access Memory)), etc., which hold programs for a certain period of time.
The program may be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium or by a transmission wave in the transmission medium. Here, the “transmission medium” for transmitting the program refers to a medium having a function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line.
The program may be for realizing a part of the functions described above. Furthermore, what can implement | achieve the function mentioned above in combination with the program already recorded on the computer system, and what is called a difference file (difference program) may be sufficient.

It is a figure which shows the structure of the radio | wireless communications system in one Embodiment of this invention. It is a figure which shows the operation | movement flow of the test signal detection process of the terminal 20 in the embodiment. It is a figure which shows the operation | movement flow at the time of the primary system 100 detection of the terminal 20 in the embodiment. It is a figure which shows the operation | movement flow of the cooperative sensing process of the terminal 20 in the embodiment. It is a figure which shows the operation | movement flow of the reliability information acquisition process of the comprehensive determination station apparatus 30 in the embodiment. It is a figure which shows an example of the reach | attainment range of the test signal which the comprehensive determination station apparatus 30 in the embodiment transmits. It is a figure which shows an example of the reach | attainment range of the test signal which the comprehensive determination station apparatus 30 in the embodiment transmits. It is a figure which shows the example of an area | region division in the secondary system 200 in the embodiment. It is a figure which shows the operation | movement flow of the comprehensive determination process process of the comprehensive determination station apparatus 30 in the same embodiment. In the secondary system 200 in the embodiment, it is a conceptual diagram when only the terminal device in area A performs the cooperative sensing process. It is a figure which shows the structural example of the conventional cooperative sensing system. It is a figure which shows the operation | movement flow of the comprehensive determination station apparatus 30a. It is a figure which shows the operation | movement flow of the terminal 22a. It is a figure which shows the operation | movement flow of the terminal 20a-the terminal 29a. It is a conceptual diagram of the cooperative sensing process in the conventional cooperative sensing system.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100, 100a Primary system 200, 200a Secondary system 20-29, 20a-29a Terminal 201 Communication part 202 Terminal control part 203 Signal detection part 204 Storage part 30, 30a Comprehensive judgment station apparatus 31 Communication processing part 311 Communication part 312 Communication control part 32 control unit 33 reliability information acquisition unit 331 reliability information acquisition control unit 332 false detection false alarm probability calculation unit 333 reliability calculation unit 34 reliability information database 35 cooperative sensing processing unit 351 cooperative sensing control unit 352 cooperative sensing area determination unit 353 Comprehensive determination unit a, b Radio signal reach range d Radio signal reach range from primary system 100 da Radio signal reach range from primary system 100a A, B, C area

Claims (7)

In a wireless communication system comprising: a primary system that preferentially uses a predetermined shared frequency band; and a secondary system that uses the shared frequency band when the primary system does not use the shared frequency band;
The secondary system is
A comprehensive determination station apparatus that determines whether or not the shared frequency band is used by the primary system;
A terminal station device for detecting a radio signal by the shared frequency band,
The comprehensive judgment station device is:
A test signal transmitter for transmitting a radio signal using the shared frequency band as a test signal;
A reliability calculation unit for calculating reliability information for each terminal station device based on a test signal detection result including whether or not the test signal received from the terminal station device is detected;
A reliability information database that stores the positional information of the terminal station device and the reliability information in association with each other;
A receiver for receiving a primary system detection signal from the terminal station device;
In response to receiving the primary system detection signal, a cooperative sensing request unit that transmits a cooperative sensing start request of the primary system to the terminal station device,
Comprehensive determination unit that calculates a value obtained by weighting reliability information stored in the reliability information database with respect to the cooperative sensing result received from the terminal station apparatus, and determines whether or not the shared frequency band is used by the primary system And
The terminal station device
A detection unit for detecting presence or absence of a radio signal in the shared frequency band, which is either the test signal transmitted by the comprehensive determination station device or the radio signal transmitted by the primary system;
A wireless communication system comprising: a transmission unit that responds to the comprehensive determination station device with a detection result by the detection unit. The cooperative sensing request unit of the comprehensive judgment station device,
The radio communication system according to claim 1, wherein a terminal station apparatus that is a target of cooperative sensing is selected based on position information of a terminal station apparatus that is a transmission source of the primary system detection signal. The test signal transmission unit of the comprehensive judgment station device,
The wireless communication system according to claim 1, wherein the test signal is transmitted a plurality of times with different transmission powers. The detection unit of the terminal station apparatus is
When detecting a radio signal by the shared frequency band, detect the reception level of the received radio signal,
The detection result to which the transmitter responds is:
The detection result includes the detection result of the presence or absence of the wireless signal and the detection result of the reception level by the detection unit,
The wireless communication system according to any one of claims 1 to 3, wherein the reliability calculation unit of the comprehensive determination station apparatus calculates reliability information for each reception level. The reliability calculation unit of the comprehensive determination station device,
Calculate a radio signal arrival area of the test signal according to the transmission power of the test signal, and determine whether or not the position information of the terminal station apparatus is a position included in the calculated radio signal arrival area Determine the estimated detection result of the target terminal station device,
By comparing the test signal detection result transmitted from the terminal station device with the estimated detection result, the value of the false detection probability and the value of the false alarm probability are calculated, and the reliability is calculated based on the calculation result. The wireless communication system according to claim 1, wherein the wireless communication system is calculated. A cooperative sensing method in a wireless communication system comprising: a primary system that preferentially uses a predetermined shared frequency band; and a secondary system that uses the shared frequency band when the primary system does not use the shared frequency band Because
Comprehensive determination station device provided in the secondary system,
A test signal transmission process of transmitting a radio signal using the shared frequency band as a test signal;
The terminal station device is
A test signal detection process for detecting presence / absence of a radio signal in the shared frequency band which is the test signal transmitted by the comprehensive judgment station device;
A test result response process for responding the detected detection result to the comprehensive judgment station device;
The comprehensive judgment station device is
Based on a test signal detection result including whether or not the test signal received from the terminal station device included in the secondary system is detected, a reliability calculation process for calculating reliability information for each terminal station device;
A reliability information storage process for storing the position information of the terminal station device and the reliability information in a storage area in association with each other;
The terminal station device is
A primary system detection process for detecting presence or absence of a radio signal by the shared frequency band transmitted by the primary system;
A primary system detection notification process for responding to the comprehensive determination station device as a detected result of detection as a primary system detection signal;
The comprehensive judgment station device is
A receiving process of receiving a primary system detection signal from the terminal station device;
In response to receiving the primary system detection signal, a cooperative sensing request process for transmitting a cooperative sensing start request of the primary system to the terminal station device;
The terminal station device is
A cooperative sensing process for detecting the presence or absence of a radio signal by the shared frequency band transmitted by the primary system;
A cooperative sensing result notification process of responding to the comprehensive determination station device as a detected result of the detection as a cooperative sensing result;
The comprehensive judgment station device is
Comprehensive determination process for calculating a value obtained by weighting reliability information stored in the reliability information database with respect to a cooperative sensing result received from the terminal station apparatus, and determining whether or not the shared frequency band is used by the primary system A cooperative sensing method characterized by comprising: In a wireless communication system comprising: a primary system that preferentially uses a predetermined shared frequency band; and a secondary system that uses the shared frequency band when the primary system does not use the shared frequency band. A comprehensive determination station apparatus of the secondary system comprising a comprehensive determination station apparatus that determines whether or not the shared frequency band is used by a system, and a terminal station apparatus that detects a radio signal using the shared frequency band,
A test signal transmitter for transmitting a radio signal using the shared frequency band as a test signal;
A reliability calculation unit for calculating reliability information for each terminal station device based on a test signal detection result including whether or not the test signal received from the terminal station device is detected;
A reliability information database that stores the positional information of the terminal station device and the reliability information in association with each other;
A receiver for receiving a primary system detection signal from the terminal station device;
In response to receiving the primary system detection signal, a cooperative sensing request unit that transmits a cooperative sensing start request of the primary system to the terminal station device,
Comprehensive determination unit that calculates a value obtained by weighting reliability information stored in the reliability information database with respect to the cooperative sensing result received from the terminal station apparatus, and determines whether or not the shared frequency band is used by the primary system Comprehensive judgment station apparatus characterized by including these.

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