JP2003134001A - Device and method for radio communication - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radio communication device for reducing retransmitting processing by avoiding data transmitting/receiving in a carrier frequency, in which the occurrence of a transmitting/receiving error is estimated. SOLUTION: When the transmitting/receiving error occurs in a radio communication part 103, a central control processing part 101 stores error occurrence information in an information storage part 102 corresponding to a carrier frequency, which is utilized for that data transmission. Besides, when this error occurrence information exceeds a predetermined threshold, the central control processing part 101 sets that carrier frequency as a skip target. Then, when a carrier frequency to be utilized as a transmitting slot is determined by a communication protocol, the central control processing part 101 investigates whether that carrier frequency is set as a skip target or not and when the carrier frequency is set as a skip target, the execution of data transmission at that time is suspended.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless communication device for transmitting and receiving data while hopping between a plurality of carrier frequencies and a wireless communication method of the device, and particularly to a carrier frequency at which a transmission / reception error is expected to occur. The present invention relates to a wireless communication device and a wireless communication method for the same, which makes it possible to reduce retransmission processing by avoiding data transmission and reception.

[0002]

2. Description of the Related Art In recent years, wireless communication systems in the personal area such as Bluetooth have attracted attention. In addition, some wireless communication systems of this type have a function of dynamically changing a carrier frequency in consideration of an unspecified operating environment called a personal area.

Further, in consideration of miniaturization and power saving of the wireless communication module, there is also one having a so-called frequency hopping function of transmitting and receiving data while switching carrier frequencies according to a pre-defined selection scheme. . In the wireless communication system using the frequency hopping function, the simple method of recovering the transmission / reception error caused by the deterioration of the transmission path quality by the retransmission processing is adopted to reduce the size and power consumption of the wireless communication module described above. Has been realized.

[0004]

By the way, in the radio communication system using the frequency hopping function, it is general that the hopping frequency selection scheme is determined at the time of communication connection and is not dynamically changed thereafter. Target. Therefore, hopping to the carrier frequency is continuously performed even in a situation where a transmission / reception error always occurs at a carrier frequency. In other words, by performing data transmission / reception at the carrier frequency where a transmission / reception error is expected to occur as usual, extra retransmission processing is unnecessarily generated.

The present invention has been made in consideration of such a situation, and it is possible to reduce the retransmission processing by avoiding the data transmission / reception at the carrier frequency where a transmission / reception error is expected to occur. It is an object of the present invention to provide a wireless communication device and a wireless communication method of the device.

[0006]

In order to achieve the above object, a wireless communication device of the present invention includes a wireless communication device for transmitting / receiving data to / from another wireless communication device while switching a carrier frequency, and the wireless communication device. Error detection means for detecting a transmission error at the time of data transmission by the communication means, and control means for avoiding data transmission / reception at a carrier frequency at which a transmission error is expected to occur based on the detection status of the transmission error by the error detection means It is characterized by including.

In this radio communication device, for example, by monitoring the frequency of occurrence of transmission errors for each carrier frequency, data transmission / reception at carrier frequencies at which transmission errors are expected to occur is avoided. This makes it possible to reduce unnecessary retransmission processing that accompanies the occurrence of a transmission error.

[0008]

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

(First Embodiment) First, a first embodiment of the present invention will be described.

FIG. 1 is a diagram showing a configuration of a wireless communication system according to the first embodiment. As shown in FIG. 1, a wireless communication device 100 has an arbitrary communication protocol (wireless communication function block). Wireless communication is performed with the target device 200 for wireless communication. In the present embodiment, the wireless communication device 100 and the wireless communication target device 20.
Data communication is performed by 0 and time-division multiple access and switching of a plurality of carrier frequencies (frequency hopping).

The arrows in the figure represent transmission / reception data, and while switching carrier frequencies one after another (TX1, RX
1, TX2, RX2, TX3, RX3, ...), to perform wireless data communication. The hopping time interval of the carrier frequency and the selection rule of the hopping frequency are determined by the communication protocol, but the number of carrier frequencies (the number of channels) is set to an upper limit, and the selection among them is statistically distributed. (Spread spectrally).

FIG. 2 is a diagram showing the configuration of the wireless communication device 100. As shown in FIG. 2, the central control processing unit 101,
Information storage unit 102, wireless communication unit 103, and input unit 10
Have four.

The central control processing unit 101 comprehensively controls the operation of the wireless communication device 100, and drives and controls the information storage unit 102 and the wireless communication unit 103. The information storage unit 102 includes a control program and error occurrence information,
Holds the carrier frequency for which usage has been suspended. Specifically, it is a memory or a hard disk device. The wireless communication unit 103 controls wireless communication with the wireless communication target device 200, and switches the carrier frequency or modulates / demodulates transmission / reception data according to an instruction from the central control processing unit 1010. Then, the input unit 104 inputs a command for the user to reuse the suspended carrier frequency or initialize the error occurrence information. Specifically, it is a button, a keyboard, or the like.

FIG. 3 shows an example of the error occurrence information held in the information storage unit 102 and the carrier frequency for which the use is stopped.

In the example of FIG. 3, "a", "b", "c",
“0” for each frequency of “d”, “e”, ...
The error occurrence rates of "0", "5", "0", "65", ... Are respectively retained. Here, for example, it is assumed that a frequency with an error occurrence rate of more than 50% is determined to be a frequency with a high probability of causing a transmission / reception error, and as a result, the frequency e is set as a skip target. In addition, these pieces of information are initialized when a new wireless communication is started.

The method of knowing whether or not the data transmission executed by the wireless communication unit 103 has caused a transmission / reception error depends on the communication protocol, but here, by the acknowledge bit which is one of the general methods. It will be known by the notification from the receiving side. According to this method, when an unrecoverable error is detected as a result of error check on the receiving side, a value indicating "unsuccessful reception" is put in the Acknowledge bit and the data is sent back together with the next data. That is, the transmitting side can know whether or not a transmission / reception error has occurred by looking at the Acknowledge bit of this sent back data, and if there is a transmission / reception error, retransmit the data. On the other hand, the method of knowing whether or not the data reception executed by the wireless communication unit 103 has caused a transmission / reception error also depends on the communication protocol, but a commonly used method is, for example, cyclic redundancy code check (CRC). and so on.

The central control processing unit 101 synchronizes with the wireless communication target device 200, and transmits / receives data while instructing the wireless communication unit 103 about a carrier frequency that is determined at any time by the wireless communication protocol. That is, the central control processing unit 101 instructs the wireless communication unit 103 to modulate the transmission data to the carrier frequency at time t and transmit the modulated data, and then waits for arrival of the modulated wave at the carrier frequency at time t + 1. Instruct the wireless communication unit 103. In this way, the central control processing unit 101 realizes so-called full-duplex communication by switching transmission / reception in a time division manner and changing the carrier frequency during each transmission / reception.

The unit for switching the carrier frequency is called a slot and is divided into two, a transmission slot and a reception slot. Then, when the central control processing unit 101 knows the occurrence of the transmission / reception error by the method described above, it records the error in each of the carrier frequencies used in the transmission slot / reception slot at that time, and calculates the error occurrence rate. If the error occurrence rate exceeds the threshold value (50%), the carrier frequency is set as a skip target.

The information storage unit 1 thus accumulated.
Using the information No. 02, the central control processing unit 101 controls the execution of data transmission / reception as shown in FIG.

That is, when the carrier frequency to be used as the transmission slot is determined by the communication protocol, the central control processing unit 101 checks whether or not the carrier frequency is set as the skip target and sets it as the skip target. If so, the execution of data transmission at that time will be postponed. When the information shown in FIG. 3 is held in the information storage unit 102, the central control processing unit 101 avoids execution of the data transmission each time the frequency e is selected for the transmission slot.

FIG. 5 is a flowchart showing an operation procedure relating to data transmission / reception control of the wireless communication device 100.

The central control processing unit 101 first determines a carrier frequency (step A1), and determines whether or not the determined carrier frequency is set as a skip target (step A2). If it is set as a skip target (YES in step A2), the central control processing unit 101
The execution of data transmission / reception in that slot is forgotten (step A3).

On the other hand, if it is not set as the skip target (NO in step A2), the central control processing unit 101
The wireless communication unit 103 is instructed to execute data transmission / reception (step A4). Then, the central control processing unit 101 checks whether or not a transmission / reception error has occurred (step A
5) If a transmission / reception error has occurred (YES in step A5), the error occurrence information held in the information storage unit 102 is updated (step A6).

When the threshold value is exceeded by this update (YES in step A7), the central control processing unit 101 sets the carrier frequency as a skip target (step A).
8). Then, the central control processing unit 101 repeats the processing from step A1 if the data transmission / reception is to be continued (NO in step 9).

Thus, the wireless communication device 100 is
By avoiding data transmission / reception at a carrier frequency where transmission / reception errors are expected to occur, it is possible to reduce unnecessary retransmission processing.

Although the error occurrence rate per unit time is used as the error occurrence information here, the present invention is not limited to this, and it is also possible to use the cumulative occurrence number, for example.

(Second Embodiment) Next, a second embodiment of the present invention will be described.

FIG. 6 shows a wireless communication device 10 of the second embodiment.
FIG. 6 is a diagram for explaining data transmission / reception control executed by 0. In the above-described first embodiment, when the carrier frequency to be used as the transmission slot is determined by the communication protocol, if the carrier frequency is set as the skip target, the data transmission at that time is forgotten (see FIG. 4). .
On the other hand, in the second embodiment, in addition to the transmission slot, the carrier frequency to be used as the receiving slot is also considered, and any carrier frequency used in the transmitting slot and the receiving slot is set as the skip target. If not, send and receive data. In other words,
If either one (of course both) is set as the skip target, execution of data transmission / reception is avoided.

In other words, the radio communication device 100 can further reduce unnecessary retransmission processing by more strictly avoiding data transmission / reception at the carrier frequency where transmission / reception errors are expected to occur.

(Third Embodiment) Next, a third embodiment of the present invention will be described.

FIG. 7 is a diagram showing an example of the error occurrence information held in the information storage unit 102 and the carrier frequency which is the object of use suspension in the wireless communication device 100 of the third embodiment.

As shown in FIG. 7, in the third embodiment, when any carrier frequency is set as a skip target, the time is recorded. Then, after a lapse of a certain time from the recorded time, the error occurrence information is reset and data transmission / reception at the carrier frequency is restarted.

In the above-described first and second embodiments, when a certain carrier frequency is a skip target, data transmission / reception in a slot in which the frequency should be used will be postponed while the communication is continued. . However, there are cases where the deterioration of the transmission path quality at a certain carrier frequency is temporary. In view of this, in the third embodiment, the skip duration is defined in advance, so that the error occurrence information of the carrier frequency is reset and the transmission at the carrier frequency is restarted after a certain time has elapsed. .

By performing such processing, it becomes possible to automatically reuse the carrier frequency whose transmission path quality has been recovered. It is also conceivable that the deterioration of the transmission path quality is caused by an external device and can be easily recognized by the user of the wireless communication device 100A. Considering such a case, it is also effective to have a mechanism for canceling the skip by a user operation.

On the other hand, in actual use, the quality of the transmission line at a certain carrier frequency may be always poor. In such a case, if the error occurrence information is reset by a certain period of time from the skip setting time or by user operation, the reused carrier frequency becomes a skip target again, that is, the error occurrence information is thresholded again. Until the value is exceeded, a considerable number of data transmissions and receptions will be repeated. Therefore, here, for carrier frequencies that were once skipped, lower the threshold that is the condition for being skipped again (for example, normally, the error rate of 50% is set to 30%. The time until the skip is restarted is shortened. In that case, it is also effective to lengthen the time until the use is resumed (until the error occurrence information is reset). That is, by lengthening the time until the restart, it is possible to always reliably skip a frequency with poor quality.

(Fourth Embodiment) Next, a fourth embodiment of the present invention will be described.

In the above-mentioned first to third embodiments,
The error occurrence information was used while a certain wireless communication continued. However, when wireless communication is actually repeated, a communication environment in which the transmission path quality of a specific carrier frequency is deteriorated at a specific time can be considered. In such a case, for example, it is effective to store past error occurrence information for each time zone without performing a reset at the start of new communication, and determine the frequency skip based on that information. is there. Specifically, the error occurrence information to be used is dynamically switched according to the change of the time zone even while the wireless communication is continuing. As a result, it becomes possible to execute the frequency skip while reflecting the tendency for each time zone.

The invention of the present application is not limited to the above-described embodiment, and can be variously modified at the stage of implementation without departing from the spirit of the invention. Furthermore, the embodiments include inventions at various stages, and various inventions can be extracted by appropriately combining a plurality of disclosed constituent elements. For example, even if some constituent elements are deleted from all the constituent elements shown in the embodiment, the problem described in the section of the problem to be solved by the invention can be solved,
When the effects described in the section of the effects of the invention can be obtained, a structure in which this constituent element is deleted can be extracted as the invention.

[0039]

As described above, according to the present invention, for example, the frequency of occurrence of transmission / reception errors is monitored for each carrier frequency to avoid data transmission / reception at carrier frequencies at which transmission / reception errors are expected to occur. By doing so, it is possible to reduce unnecessary retransmission processing associated with the occurrence of a transmission / reception error.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a wireless communication system according to a first embodiment of the present invention.

FIG. 2 is a diagram showing a configuration of a wireless communication device according to the first embodiment.

FIG. 3 is a diagram showing an example of error occurrence information held in an information storage unit of the wireless communication device according to the first embodiment and a carrier frequency which is a target of use suspension.

FIG. 4 is a view for explaining data transmission / reception control executed by the wireless communication device of the first embodiment.

FIG. 5 is a flowchart showing an operation procedure relating to data transmission / reception control of the wireless communication device of the first embodiment.

FIG. 6 is a view for explaining data transmission / reception control executed by the wireless communication device of the second embodiment.

FIG. 7 is a diagram showing an example of error occurrence information held in an information storage unit and a carrier frequency for which use is stopped in the wireless communication device of the third embodiment.

[Explanation of symbols]

100 ... Wireless communication device 101 ... Central control processing unit 102 ... Information storage unit 103 ... Wireless communication unit 104 ... Input section

Claims (22)

[Claims] 1. A wireless communication unit that transmits and receives data to and from another wireless communication device while switching a carrier frequency, an error detection unit that detects a transmission error at the time of data transmission by the wireless communication unit, and the error detection. And a control unit for avoiding data transmission at a carrier frequency in which a transmission error is expected to occur, based on the detection status of the transmission error by the unit. 2. The wireless communication according to claim 1, wherein the control means suspends execution of the data transmission when the carrier frequency switching destination at the time of data transmission is a carrier frequency that should be refrained from being used. apparatus. 3. A counting means for counting the number of transmission / reception errors detected by the error detection means for each carrier frequency, wherein the carrier frequency control means has a predetermined number of cases counted by the counting means. The data transmission / reception at a carrier frequency exceeding a threshold value is avoided.
The wireless communication device described. 4. The counter means further comprises counting means for counting, for each carrier frequency, the rate of occurrence of transmission / reception errors detected by the error detecting means per unit time, and the carrier frequency control means is counted by the counting means. The wireless communication device according to claim 1, wherein data transmission / reception at a carrier frequency whose occurrence rate exceeds a predetermined threshold value is avoided. 5. The wireless communication device according to claim 3, further comprising an initialization unit that initializes the count value of the counting unit at the start of new communication. 6. An instructing unit for instructing to restart the use of a carrier frequency whose use during data transmission and reception is suppressed, and initialization for initializing the count value of the counting unit for the carrier frequency instructed by the instructing unit. 5. The wireless communication device according to claim 3, further comprising: means. 7. A time recording means for recording, for each carrier frequency, a time when use is suppressed during data transmission / reception, and the carrier when the predetermined time has elapsed from the time recorded by the time recording means. The wireless communication device according to claim 3, further comprising an initialization unit that initializes a count value of the counting unit with respect to a frequency. 8. The carrier frequency control means lowers the threshold value for the carrier frequency when the count value of the counting means is initialized by the initialization means. The wireless communication device described. 9. The wireless communication device according to claim 7, wherein the initialization unit lengthens the elapsed time for the carrier frequency when the count value of the counting unit is initialized. 10. The carrier frequency control means manages the threshold value for each time zone.
Alternatively, the wireless communication device according to item 9. 11. A wireless communication unit that transmits and receives data to and from another wireless communication device while switching a carrier frequency, an error detection unit that detects a transmission / reception error during data transmission and reception by the wireless communication unit, and the error detection. A wireless communication device comprising: a control unit that avoids data transmission / reception at a carrier frequency in which a transmission / reception error is expected to occur, based on a situation of transmission / reception error detection by the unit. 12. The control means, when at least one of a carrier frequency switching destination during data transmission and a corresponding carrier frequency switching destination during data reception is a carrier frequency that should not be used, The wireless communication device according to claim 11, wherein execution of data transmission / reception is postponed. 13. The method further comprises counting means for counting, for each carrier frequency, the number of transmission / reception errors detected by the error detecting means, wherein the carrier frequency control means has a predetermined number of cases counted by the counting means. The data transmission / reception at a carrier frequency exceeding a threshold value is avoided.
1. The wireless communication device according to 1. 14. The counter means further comprises counting means for counting, for each carrier frequency, the rate of occurrence of transmission / reception errors detected by the error detecting means for each carrier frequency, and the carrier frequency control means is counted by the counting means. The wireless communication device according to claim 11, wherein data transmission / reception at a carrier frequency whose occurrence rate exceeds a predetermined threshold value is avoided. 15. The wireless communication apparatus according to claim 13, further comprising an initialization unit that initializes the count value of the counting unit when a new communication is started. 16. Instructing means for instructing restart of use of a carrier frequency whose use during data transmission / reception is suppressed, and initialization for initializing a count value of said counting means for the carrier frequency instructed by said instructing means. 15. The wireless communication device according to claim 13, further comprising: means. 17. A time recording means for recording, for each carrier frequency, a time when use is suppressed during data transmission / reception, and the carrier when the predetermined time has elapsed from the time recorded by the time recording means. 15. The wireless communication device according to claim 13, further comprising an initialization unit that initializes a count value of the counting unit with respect to a frequency. 18. The carrier frequency control means lowers the threshold value for the carrier frequency when the count value of the counting means is initialized by the initialization means. The wireless communication device described. 19. The wireless communication device according to claim 17, wherein the initialization unit lengthens the elapsed time for the carrier frequency when the count value of the counting unit is initialized. 20. The carrier frequency control means manages the threshold value for each time zone.
8. The wireless communication device according to 8 or 19. 21. A wireless communication method of a wireless communication device for transmitting / receiving data to / from another wireless communication device while switching a carrier frequency, the method comprising: detecting a transmission error during data transmission; And a step of avoiding data transmission at a carrier frequency in which a transmission error is expected to occur, based on the detection situation. 22. A wireless communication method of a wireless communication device for transmitting / receiving data to / from another wireless communication device while switching a carrier frequency, the method comprising: detecting a transmission / reception error during data transmission / reception; And a step of avoiding data transmission / reception at a carrier frequency in which a transmission / reception error is expected to occur, based on the detection situation.