JPH0865223A - Radio communication controller - Google Patents

Abstract

PURPOSE: To prevent deterioration in a data transmission efficiency due to a sporadical obstacle. CONSTITUTION: Data are received by plural directional antennas 1-6 installed in each direction and receivers 11-16 connected to them and the data are given to a statistic control section 17. The statistic control section 17 generates a table in which the antennas 1-6 are numbered in the order of higher reception radio wave strength. Then a frequency of occurrence of errors in a communication route through each antenna is managed. When the frequency of occurrence of errors exceeds a prescribed value, the route is not used for data reception. That is, the data are received with a route whose reception radio wave strength is highest among the routes in which the frequency of occurrence of errors is a prescribed value or below. The statistic control section 17 instructs a changeover logic section 18 to select the route as above. As a result, the number of occurrence of errors is reduced and retrial processing is decreased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless communication control device in data communication such as wireless LAN.

[0002]

2. Description of the Related Art Generally, in a wireless LAN system, each of the transmitting station and the receiving station is equipped with a plurality of antennas for communicating with the other station. These antennas are installed so as to have directivity in directions different from each other. Upon recognizing the operation start request from the terminal, the wireless transmission unit of the transmission station transmits data in all directions using all the antennas of the station. The receiving station receives the data from the transmitting station by each receiving antenna when starting the data communication, and selects the antenna with the largest received radio wave intensity,
After that, data reception is performed using only that antenna.

[0003]

However, the above-mentioned conventional techniques have the following problems. That is, in the above-described conventional technique, only the antenna in the direction having the highest received radio field strength is enabled during data communication, so that, for example, when a person crosses between the transmitting station and the receiving station, the data communication Data is interrupted on the way. In this case, the data sent halfway is invalidated, and data communication is restarted from the beginning. That is, a retry of data communication occurs. In other words, if a sporadic obstacle occurs between the transmitting station and the receiving station, the data is interrupted, which causes a retry. When such retries occur frequently, the data transmission efficiency is significantly reduced.

[0004]

The wireless communication control device of the present invention is characterized by the following points in order to solve the above-mentioned problems. (1) A plurality of antennas are provided. A receiver is provided for receiving data via the respective antennas. A statistical control unit is provided for monitoring the error occurrence frequency of each data received by the receiver. The statistical control unit includes a switching logic unit that selects an antenna for which the received radio field intensity is determined to be the maximum from among those for which the error occurrence frequency is determined to be a predetermined value or less.

(2) In (1), when the frequency of occurrence of the error of the antenna selected by the switching logic unit exceeds a predetermined value, the statistical control unit instructs the switching logic unit of the error at that time. Is instructed to switch to an antenna whose occurrence frequency is less than or equal to a predetermined value and whose received field strength is maximum. (3) In (1), the statistical control unit causes the switching logic unit to receive the reception when the error occurrence frequency of the antenna whose reception radio field intensity is larger than that of the antenna selected by the switching logic unit falls below a predetermined value. Instruct to switch to the antenna with the stronger signal.

[0006]

[Action]

(1) Data is received by a plurality of directional antennas installed in each direction and a receiver connected to them, and is input to the statistical control unit. The statistical control unit assigns a number to each antenna in descending order of received signal strength.
Then, the error occurrence frequency through each antenna is managed. If this error frequency exceeds a predetermined value, the antenna is not used for data reception. That is, the data reception is performed by the antenna having the highest received radio wave intensity among the antennas having the error occurrence frequency of the predetermined value or less. The statistical control unit instructs the switching logic unit to select such an antenna. As a result, occurrence of errors is reduced, retry processing is reduced, and it is possible to prevent a decrease in data transmission efficiency.

(2) In (1), when the statistical control unit detects that the antenna whose error occurrence frequency is less than a predetermined value is changed due to the fluctuation of the error occurrence frequency during data communication, the receiving antenna may be used in some cases. To change. In other words, since the error occurrence frequency was initially below the specified value and the received signal strength was the maximum, if the error occurrence frequency of the antenna used for reception exceeds the specified value, that antenna receives data. Do not use for. In this case, if the error occurrence frequency of the antenna having the next highest received radio wave intensity is less than or equal to the predetermined value, that antenna is optimal for data reception. Therefore, the switching logic is instructed to change the antenna. As a result, it is possible to reduce the occurrence of errors, reduce the retry processing, and prevent the deterioration of data transmission efficiency without restarting the operation after the occurrence of radio wave obstacles during the operation of data communication. .

(3) In (1), when the statistical control unit detects that the antenna whose error occurrence frequency is less than a predetermined value is changed due to the fluctuation of the error occurrence frequency during the data communication, the receiving antenna may be used in some cases. To change. That is, when the error occurrence frequency of the antenna not used because the error occurrence frequency initially exceeded the predetermined value becomes equal to or lower than the predetermined value, the antenna is also made available for data reception. In this case, if an antenna having a larger received radio wave intensity is usable, the antenna is optimal for data reception. Therefore, the switching logic is instructed to change the antenna. As a result, after the obstruction of the radio wave is eliminated, the data is received by the antenna in the best reception condition.

[0009]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a block diagram of an embodiment of a wireless communication control device of the present invention. The illustrated device includes antennas 1 to
6, receivers 11 to 16, a statistical control unit 17, a switching logic unit 18, a reception control unit 19, and a reception upper interface unit 20. Multiple (for example, 6) antennas 1 to 6
Are directional antennas, respectively, and are evenly provided in all directions. For example, when six antennas are provided, the orientations of the respective antennas form an angle of 90 degrees with each other. These antennas are connected to the receivers 11 to 16, respectively, and the receivers 11 to 16 are connected to the statistical control unit 17 and the switching logic unit 18.

Each of the receivers 11 to 16 always operates simultaneously during operation and receives radio waves of the same frequency in each direction. As a result, the received data from each direction is simultaneously sent to the statistical control unit 17 and the switching logic unit 18. Statistics control unit 1
Reference numeral 7 examines the received signal strength of the received data sent from each of the receivers 11 to 16 and also measures the frequency of occurrence of reception errors. This procedure will be described in detail in the description of the flowcharts in FIGS. 4 and 5 described later. Switching logic unit 18
Is composed of a selection circuit and the like, and selects one of the reception data sent from each of the receivers 11 to 16 and sends it to the reception control unit 19 according to the switching instruction of the statistical control unit 17. This received data has a large received signal strength by the statistical control unit 17,
And the one with a low error occurrence frequency is selected. The reception control unit 19 sends the reception data sent from the switching logic unit 18 to the terminal via the reception upper interface unit 20.

FIG. 2 shows an example of the configuration of a transmitting station and a receiving station of a wireless LAN. The transmitting station 21 includes a terminal 22 and a wireless transmitting unit 23, and the wireless transmitting unit 23 includes the transmitting antenna 2
4, a transmitter 25, a transmission control unit 26, and a transmission upper interface unit 27. Similar to the antenna shown in FIG. 1, the transmitting antenna 24 is provided so that the orientation of each antenna is uniform with respect to all the directions of the space, and radio waves are simultaneously transmitted from each antenna. The receiving station 31 includes a terminal 32 and a wireless receiving unit 33, and as illustrated in FIG. 1, includes a receiving antenna 34, a receiver / switching logic unit 35, a receiving control unit 36, and a receiving upper interface unit 37. However, in FIG. 2, the plurality of receivers 11 to 16 and the switching logic unit 18 illustrated in FIG. 1 are collectively shown in one block.

FIG. 3 shows a process in which radio waves of a wireless LAN avoid obstacles by the device of the present invention. In FIG. 3, the radio waves transmitted from the transmitting station 21 are the routes 41 and 42 shown in the figure.
Is sent to the receiving station 31. In one route 41, radio waves are directly sent from the transmitting station 21 to the receiving station 31. In this route 41, the received radio wave intensity at the receiving station 31 is maximum. However, as shown in the figure, when a person appears during data communication, the person becomes an obstacle to radio waves and a data reception error occurs. Then, it is necessary to retry the data communication, and the transmission efficiency decreases. At this time, as shown in the figure, in the route 42 reflected on the wall, although the received radio wave intensity is slightly reduced, data communication can be performed without being affected by a human obstacle. In consideration of such a situation, the present invention automatically selects a route with few obstacles and performs data communication, so that the receiving antenna at the receiving station is appropriately switched.

Next, the operation of the above-mentioned device will be described. At the start of operation of the wireless system, the transmitting station transmits training data. In this case, the transmitting station performs transmission using all transmitting antennas. 4 and 5 show the control procedure of the device of the present invention on the receiving station side. The receiving station receives the training data transmitted from the transmitting station, the statistical control unit 17 measures the received radio wave intensity of each antenna in step S1, and stores this in the received radio wave intensity table shown in FIG. 6 in step S2. To do. Then, in step S3, the received field strength table shown in FIG. 6 is sorted in descending order of received field strength. That is, the routes through the plurality of antennas are set to the first to sixth routes in descending order of received signal strength. Then, by setting n to 1 in step S4, the statistical control unit 17 instructs the switching logic unit 18 to select the first route as the reception route in step S5, and starts data reception in step S6.

However, after the data reception is started, the first route is not always used as the receiving route as in the conventional case, and if a sporadic obstacle is frequently generated on the first route, another case is taken. Try to switch to the root. Therefore, the data is not received by only one selected reception route, but the reception from all the antennas is simultaneously performed by the receivers 11 to 16 which are respectively connected to the antennas as shown in FIG. . Then, the statistical control unit 17 selects the route having the highest received radio wave intensity among all the received data and instructs the switching logic unit 18 to send only the received data of one reception route to the reception control unit 19. Then, the reception control unit 19 transfers the data to the terminal via the reception upper interface unit 20.

During data reception, the statistical control unit 17 monitors whether or not an error has occurred in the received data of all routes in step S7, and holds the number of times of error occurrence in step S8. In step S9, if the number of error occurrences of the current receiving route exceeds a certain number within a certain time, that is, if the error occurrence frequency exceeds a predetermined value,
The statistical control unit 17 considers that many obstacles occur. Then, in steps S10 and S11, the second route is selected as the route having the next highest intensity of the received radio wave intensities from all the routes at that time, and the process returns to step S5 to set the second route as the reception route. Switch to root. Therefore,
After this switching operation is performed, the reception data is connected to the reception control unit 19 by the second route.

Similarly, in step S9, when the statistical control unit 17 detects that the number of error occurrences in the second receiving route has exceeded a certain number within a certain time, it instructs the switching logic unit 18 by Next, switch to an antenna and receiver that have a high received signal strength. In this way, when the statistical control unit 17 detects that the error occurrence frequency of the current reception route exceeds the predetermined value, the switching logic unit 18
By instructing to, the antennas are switched one after another in order from the antenna with the strongest received radio field. When the sporadic obstacles frequently occur on the first route by the above method, the result is shown in FIG.
By using the radio waves reflected on the wall as shown in, it becomes possible to use a route that is not affected by obstacles.

After switching to the second route or later,
Once again, there is a high possibility that sporadic obstacles will not occur on routes with higher received signal strength. For example, in FIG. 3, there may be a case where there are many people coming and going between the transmitting station and the receiving station temporarily, but thereafter there are no people. For this reason, when the error occurrence frequency of the route with the higher received radio wave intensity becomes low again, the route is used again as the reception route.

For example, assume that the second route is used as a receiving route. In this case, the statistical control unit 17 monitors whether or not the error occurrence frequency of the second route has exceeded a predetermined value in step S9, and steps S12 to S12.
In step 15, the variable m monitors whether or not the error occurrence frequency is less than or equal to a predetermined value for all the first to sixth routes.
Then, in step S14, when the statistical control unit 17 detects that the error occurrence frequency of the received data of the first route is equal to or less than the predetermined value, the variable n = 2 is replaced with the variable m = 1 in step S16, and step S5 Switching logic part 18
The first route is again selected as the reception route by instructing the. In this way, it becomes possible to receive again with the antenna having the high received radio wave intensity after the sporadic obstacle is not generated.

As described above, in the case where a sporadic failure occurs in the route for transmission and reception, the receiving station switches to a route with a lower error frequency to prevent the transmission efficiency of the wireless communication system from decreasing. It becomes possible to do. Also, after switching to another route,
When it is detected that the error occurrence frequency of the route with the higher received radio wave intensity is low, the route is changed to the route with the higher received radio wave intensity again, so that it is possible to always perform reception on the optimum route.

The present invention is not limited to the above-mentioned embodiments, and it goes without saying that various modifications can be made. For example, in the above-described embodiment, the error occurrence frequency is calculated for each entry of the table of FIG. 6 in the flowcharts of FIGS. 4 and 5, but the present invention is not limited to this, and it corresponds to each entry of the table of FIG. The error occurrence frequency is stored, and in the route switching control, these error occurrence frequencies are constantly referred to, and the route with the highest received radio field intensity is selected from the entries whose error occurrence frequency is below a predetermined value. May be. Further, the number of routes corresponds to the number of antennas, and the number of antennas is 6 in the above-mentioned embodiment, but the number is not limited, of course.

[0021]

As described above, according to the wireless communication control device of the present invention, the communication route is switched in consideration of not only the received signal strength but also the error occurrence frequency at the time of reception. For example, if a person temporarily crosses between the transmitting station and the receiving station, causing an obstacle and frequent data communication retries, switch to another route that avoids the obstacle. can do. Therefore, it is possible to prevent a decrease in data transmission efficiency.

[Brief description of drawings]

FIG. 1 is a block diagram of an embodiment of a wireless communication control device of the present invention.

FIG. 2 is an explanatory diagram of a configuration example of a wireless LAN.

FIG. 3 is an explanatory diagram of an obstacle avoidance process.

FIG. 4 is a flowchart illustrating a control procedure (No. 1) of the device of the present invention.

FIG. 5 is a flowchart illustrating a control procedure (No. 2) of the device of the present invention.

FIG. 6 is an explanatory diagram of an example of a received signal strength table.

[Explanation of symbols]

 1 to 6 antennas 11 to 16 receivers 17 statistical control unit 18 switching logic unit 19 reception control unit

Claims (3)

[Claims] 1. A plurality of antennas, a receiver that receives data via each of the antennas, a statistical control unit that monitors an error occurrence frequency of each data received by the receiver, and a statistical control unit. 2. A wireless communication control device, comprising: a switching logic unit that selects an antenna whose received radio field intensity is determined to be the maximum from among those whose error occurrence frequency is determined to be a predetermined value or less. 2. The statistical control unit, when the error occurrence frequency of the antenna selected by the switching logic unit exceeds a predetermined value, causes the switching logic unit to generate the error frequency at that time. The wireless communication control device according to claim 1, wherein the wireless communication control device instructs to switch to an antenna having a maximum received electric field strength of less than a predetermined value. 3. The statistical control unit, when the occurrence frequency of an error of an antenna whose reception radio field intensity is larger than that of the antenna selected by the switching logic unit is equal to or less than a predetermined value, receives the reception signal from the switching logic unit. The wireless communication control device according to claim 1, wherein an instruction is made to switch to an antenna having a higher radio field intensity.