JP2005045388A - Communication equipment, interference channel deciding method, and method for setting frequency channel utilized for communication - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce or prevent interference during communication by communicating while avoiding a channel where the interference interference occurs even when the interference can not be detected. <P>SOLUTION: A PDA 104 performs control by: detecting communication states of frequency channels; recording the detected communication states; deciding a channel whose communication state is inferior among the recorded communication states; correlating the communication channel with a channel to be avoided; deciding the communication state of the related channel to be avoided; and determining an actual interference channel band. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a technique for detecting a channel that interferes with another communication method using a fixed channel in a communication device such as a spread spectrum wireless communication device using frequency hopping.
[0002]
[Prior art]
At present, an increasing number of wireless communication devices use a band that can be used without a license. For example, the number of wireless communication apparatuses using the 2.4 GHz band that is open as an ISM (industrial scientific medical band) band is remarkable.
[0003]
However, in this band, IEEE802.11b (hereinafter referred to as WLAN) which is a direct spread system (DS-SS system) of a spread spectrum communication system and Bluetooth (hereinafter referred to as BT) which is a frequency hopping system (FH-SS system). When communication systems using different communication systems use the same frequency, throughput of both communication systems is reduced.
[0004]
In the future, IEEE802.11g using the OFDM system as a new communication system, and a high-speed version Bluetooth that does not perform frequency hopping with weak power will appear in the ISM band.
[0005]
It is expected that radio wave interference generated when a number of different communication methods use the same frequency band will become a big problem in the future.
[0006]
In order to prevent radio wave interference from occurring in the same frequency band, it is desirable to notify the use channel and the use timing between the communication systems and not use the channel.
[0007]
In practice, however, each communication system often operates on a separate device, and thus the above information cannot be exchanged in many cases. For this reason, it is important to detect the currently used frequency channel and avoid the used channel when a certain communication system starts communication.
[0008]
Conventionally, various methods have been proposed as a method for detecting a channel that interferes with another communication method (hereinafter referred to as an interference channel).
[0009]
For example, by setting a threshold value for each frequency unit within a frequency band to be used, there is one that can detect an interference channel more accurately when a single threshold value is used (see Patent Document 1). ).
[0010]
Also, the channel to be transmitted for each packet is switched, the number of errors in the packet or the number of retransmissions is counted for each channel, and if the count value within a certain time exceeds a predetermined value, the corresponding channel There is one that detects and avoids an interference channel by prohibiting the use of (see Patent Document 2).
[0011]
[Patent Document 1]
JP-A-6-209298
[Patent Document 2]
JP-A-8-163091
[0012]
[Problems to be solved by the invention]
However, in the above conventional example, only the detected interference channel is avoided, and detection as an interference band is not performed.
[0013]
For this reason, since the interference signal is not always output, even if the interference signal is detected in a unit time, depending on the channel, there are cases where interference occurs and cases where interference does not occur. For example, a WLAN access point outputs a signal only in a beacon period during standby. Therefore, if interference detection is performed due to a packet error due to BT frequency hopping, the channel detection time differs, so the channel detected as an interference channel is detected regardless of the channel used in the WLAN. Will be generated.
[0014]
The present invention has been made in order to solve the above-described problems of the prior art. The purpose of the present invention is to enable communication while avoiding an interfering channel even if interference cannot be detected. To reduce or prevent time interference.
[0015]
[Means for Solving the Problems]
In order to achieve the above object, a communication device of the present invention specifies a frequency channel in a predetermined communication state based on a determination unit that determines a communication state of a frequency channel that can be used for communication and a determination by the determination unit. And communication means for communicating using a frequency band excluding a frequency band of a predetermined width including the frequency channel in the predetermined communication state.
[0016]
The interference channel determination method of the present invention also includes a determination step of determining a communication state of a frequency channel that can be used for communication, a frequency channel in a predetermined communication state based on the determination in the determination step, And a determination step of determining a frequency band excluding a frequency band of a predetermined width including a frequency channel in a communication state as an available frequency band.
[0017]
The frequency channel setting method used for communication according to the present invention includes a determination step of determining a communication state of a frequency channel usable for communication, and a frequency channel of a predetermined communication state based on the determination in the determination step. It has a setting step of specifying and setting a frequency channel included in a frequency band excluding a frequency band of a predetermined width including the frequency channel in the predetermined communication state as a frequency channel used for communication.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0019]
(First embodiment)
First, a first embodiment of the present invention will be described with reference to FIGS.
[0020]
FIG. 1 is a diagram showing an overall configuration of a wireless communication system having a communication apparatus according to a first embodiment of the present invention. In FIG. 1, 101 uses IEEE802.11b (hereinafter referred to as WLAN). The access point (AP) converts the wired LAN (local area network) and the wireless LAN. A personal computer (PC) 102 with a built-in WLAN access function communicates with the AP 101. Reference numeral 103 denotes a Bluetooth (BT) built-in mobile phone (TEL) that performs a gateway function with the public network. Reference numeral 104 denotes a personal digital assistant (PDA) with a built-in BT, which is connected by the TEL 103 and the BT 103 and can access the public network.
[0021]
FIG. 2 is a block diagram showing an internal configuration of the PDA 104 in the communication apparatus according to the present embodiment. In FIG. 2, reference numeral 201 denotes a block of the PDA main body, which includes a host CPU, an input unit, and a display unit. Reference numeral 202 denotes a wireless module, which is connected to the PDA main body 201 via a UART signal line. Reference numeral 203 denotes a UART (Universal Asynchronous Receiver Transmitter) that generates and receives a UART signal connected to the PDA main body 201 and converts it into a module-side bus signal. A ROM (read only memory) 204 stores a program. Reference numeral 205 denotes a RAM (Random Access Memory) which stores all temporary data such as a synchronization error counter, an HEC error counter, a CRC error counter, etc. 206 is a CPU (Central Processing Unit) 206 which is stored in the ROM 204. 207 is a baseband (BB), 208 is an RF (Radio Frequency), 209 is an antenna, and the CPU 206 is connected to the ROM 204, RAM 205, UART 203 and BB 207 via a bus, and The BB 207 transmits the modulated data to the RF 208 and demodulates the data received from the RF 208. The RF 208 is the CPU 206. The up-converted modulation signal received from the BB 207 at the specified transmission frequency and transmission timing is sent to the 2.4 GHz band and sent to the antenna 209. The RF 208 receives the 2.4 GHz band signal received from the antenna 209. At the reception frequency and reception timing instructed by the CPU 206, the signal is down-converted to the 1 MHz band, which is the baseband, and passed to the BB 207.
[0022]
FIG. 3 is a diagram showing the entire packet format of a hopping unit used in the communication apparatus according to the present embodiment. In FIG. 3, the head field is an access code 301, and its constituent elements are a preamble 4 bits, a BT It consists of a 64-bit synchronization word that is (64, 30) block-encoded based on the LAP (Lower Address Part) 24 bits of the address. This block code ensures a large Hamming distance between each generated synchronization word. The next field is a packet header 302, which includes packet attribute information and HEC (Header Error Check), and is error-correction coded at a rate of 1/3. The last field is a payload 303, which is composed of an information body and a CRC (Cyclic Redundancy Check) code, and may be rate 2/3 error correction encoded. As described above, the resistance to noise is stronger as the field in the previous stage.
[0023]
FIG. 4 is a diagram showing an internal configuration of the packet header 302 in the communication apparatus according to the present embodiment. In FIG. 4, the first field is AM_ADDR 401, which indicates an active member address. This is a number for identifying seven slaves with respect to one master. The next field is TYPE 402, which indicates the type of the entire packet including the payload, and consists of 4 bits. The next field is FLOW 403, which is used for flow control of packets transmitted and received on the communication link. The next field is ARQN 404, which is used to notify the packet transmission side whether or not there is an error in the received packet, and consists of 1 bit. Specifically, when there is no error in the HEC and CRC of the received packet, 1 is set to notify the transmission side of normal reception. Also, if there is an error in either the HEC or CRC of the received packet, a retransmission is requested to the transmitting side by setting 0. The next field is SEQN 405, which is a 1-bit field used for managing retransmission packets so that they are not duplicated on the receiving side. The next field is HEC (Header Error Check) 406, which is an 8-bit field representing an error detection code for a total of 10 bits of AM_ADDR 401, TYPE 402, FLOW 403, ARQN 404, and SEQN 405, and is generated using a generator polynomial.
[0024]
FIG. 5 is a diagram showing the internal structure of the payload in the communication apparatus according to the present embodiment. In FIG. 5, reference numeral 501 denotes a payload header, which is a parameter for managing data in the baseband layer and higher, and includes packet length and the like. It is included and consists of 1 to 2 bytes. Reference numeral 502 denotes a payload body, which contains data having a length specified by the length of the payload header 501. Reference numeral 503 denotes a CRC, which is a 16-bit field representing an error detection code. The CRC 503 is used to detect whether or not there is an error in the payload header 501 and the payload body 502, and is generated using a generator polynomial.
[0025]
FIG. 6 is a diagram showing the relationship between the BT channel, its center frequency [MHz], and occupied band [MHz] used in the BT in the communication apparatus according to the present embodiment. Frequency hopping using all 79 channels from 2402 MHz to 2480 MHz. Here, for the sake of distinction, channels having a low frequency are called B1ch and B2ch, and B79ch is set. The occupied band is 1 MHz for each channel.
[0026]
FIG. 7 is a diagram showing a relationship between a WLAN channel used in WLAN, a center frequency [MHz], and an occupied band [MHz] in the communication apparatus according to the present embodiment. One channel is selected from all 14 channels from 2412 MHz to 2484 MHz, and the frequency is fixedly used. The occupied band is 22 MHz for each channel.
[0027]
FIG. 8 is a diagram showing transmission / reception timing of BT in the communication apparatus according to the present embodiment. With the frequency hopping period 625 us as one time slot, even slots (2k, 2k + 2) are transmitted by the master and received by the slave. The odd slots (2k + 1, 2k + 3) are transmitted by the slave and received by the master. For example, when a CRC error occurs in the packet received by the master in the 2k + 1 slot, the ARQN field of the packet transmitted by the master in the 2k + 2 slot is set to 0 and transmitted. When the slave normally receives the master packet in the 2k + 2 slot, it recognizes that the data transmitted in the 2k + 1 slot was not normally received because the header is ARQN = 0, and again the 2k + 1 slot in the 2k + 3 slot. The same packet as the data sent in is sent.
[0028]
FIG. 9 is a diagram showing the relationship between transmission power and frequency when WLAN is transmitted on the L6 channel in the communication apparatus according to the present embodiment. In FIG. 9, the vertical axis indicates transmission power [dBm]. Each axis indicates a frequency [MHz].
[0029]
As shown in FIG. 9, the transmission power value decreases around the center frequency 2437 MHz, and the transmission power becomes −30 dBm or less at 2426 MHz and 2448 MHz which are plus or minus 11 MHz.
[0030]
FIG. 10 is a diagram showing bands used by BT and WLAN on the frequency over time in the communication apparatus according to the present embodiment, in which the vertical axis represents time [msec] and the horizontal axis represents frequency. [MHz] is shown respectively.
[0031]
In FIG. 10, a portion intermittently transmitted with a width from 2426 MHz to 2448 MHz centering on 2437 MHz indicates a WLAN transmission signal using the L6 channel. The other black squares indicate BT transmission signals that are frequency-hopped. Moreover, the part which overlaps partially is an interference area | region.
[0032]
FIG. 11 is a diagram illustrating a result of measuring 20 packets of a BT master reception signal for each BTch corresponding to each center frequency for WLAN 14ch in the BT master in the communication apparatus according to the present embodiment. Shows the number of errors.
[0033]
In FIG. 11, the number of errors in the L6 channel is a measurement of the number of errors in the B36ch. While receiving 20 packets in the B36ch, the synchronization error occurred 3 times, the HEC error occurred 6 times, and the CRC error occurred 2 times. This indicates that the number of normally received packets was nine.
[0034]
FIG. 12 is a diagram showing a result of weighting the measurement results shown in FIG. 11 for each error and counting them as error values. The weighting is converted into an error value 3 per synchronization error, an error value 2 per HEC error, and an error value 1 per CRC error.
[0035]
In FIG. 12, it is shown that L6ch exceeds the threshold 20 for determining the avoidance channel. The determination is not based solely on the number of errors, but also takes into account the frequency of synchronization errors or HEC errors that occur when the interference signal is stronger.
[0036]
FIG. 13 is a diagram showing channels (ch) used after the avoidance by the actual BT master in response to the counting result shown in FIG. Here, since the L6 channel is determined as the avoidance channel, the BT avoids the B25 channel to the B47 channel, and indicates that the channels used by the BT master are the B1 to B24 channel and the B48 to B79 channel.
[0037]
FIGS. 11 to 13 show that a synchronization error occurs in the frequency region where the interference is the most intense, a HEC error occurs in the frequency region where the interference is the most, and a CRC error occurs in a region where the interference slightly occurs. As described in the explanation of FIG. 3, this is derived from the difference in error resistance for each field.
[0038]
Hereinafter, the interference channel detection operation by the PDA 104 will be described with reference to the flowchart of FIG.
[0039]
As a premise for the description here, it is assumed that WLAN communication using the L6 channel is performed between the AP 101 and the PC 102 as the interference source during the BT communication between the TEL 103 and the PDA 104.
[0040]
According to the program stored in the ROM 204 in FIG. 2, the PDA 104 sets that the CPU 206 can use all 79 channels as a frequency hopping area for the RF 208. In addition, the number of transmission packets and error values of BTch (B11, B16, B21, B26, B31, B36, B41, B46, B51, B56, B61, B66, B71, B79) corresponding to the center frequencies from L1 to L14ch are cleared. (Step S1401).
[0041]
The PDA 104 performs a calling operation on the TEL 103 as a master. This calling operation is to exchange both address and clock information between the master and the slave. As a result, a synchronization word to be used by both is determined. After the exchange of information, the connection procedure ends and the connection state is established (step S1402).
[0042]
Here, the connection state is a state in which a synchronization maintaining operation is performed between the master and the slave. In such a connection state, the number of BTch transmission packets corresponding to the center frequency from L1ch to L14ch and an error value can be counted.
[0043]
After the connection, the master transmits a data packet including information in the payload in one time slot time (step S1403). If this time slot is k = 0 in FIG. 8, the master has transmitted at slot number 0. The master waits to receive the data packet transmitted by the slave at slot number 1 which is the next time slot. If the received channel is a channel equivalent to the L1-L14 center, the master increments the number of packets of the channel (step 1). S1404).
[0044]
The master receives a data packet at slot number 1, and determines packet synchronization based on whether or not the access code, which is the first field, the synchronization word determined between the master and the slave and the correlation level exceed a threshold ( Step S1405). If packet synchronization cannot be established, the error counter value of the channel stored in the RAM 205 as a synchronization error is incremented by 3 (step S1408), and then the process proceeds to the packet number completion detection routine (step S1411).
[0045]
If packet synchronization is established, the packet header is rate 1/3 error correction decoded, and it is determined whether or not the HEC is normal after decoding (step S1406).
[0046]
If an error occurs in the HEC, the error counter value of the channel stored in the RAM 205 is incremented by 2 (step S1409), and then the process proceeds to the packet number completion detection routine (step S1411).
[0047]
If the HEC is normal, the payload is inspected. If the payload is a rate 2/3 error correction code, it is decoded and it is determined whether or not the CRC is normal (step S1407). If the CRC error occurs, the error counter value of the channel stored in the RAM 205 is incremented by 1 (step S1410), and then the process proceeds to the packet number completion detection routine (step S1411).
[0048]
If the CRC is normal, the process proceeds to the packet number completion detection routine (step S1411).
[0049]
In the packet number completion detection routine, it is determined whether or not the reception of the designated number of packets has been performed (step S1411). This is to make the number of count packets the same in each count channel. If the number of packets does not reach the designated number of packets, the data packet is transmitted again (step S1403), the reception is waited again (step S1404), and then error count is performed.
[0050]
If the number of packets reaches the specified number of packets, it is determined whether or not the number of errors of the channel exceeds a threshold (step S1412). If the number of errors in the channel does not exceed the threshold, it is determined that there is little interference and the channel is not an avoidance channel (step S1415), and then the interference band detection routine is terminated.
[0051]
If the error count of the channel exceeds the threshold, it is determined that the BT channel exceeding the threshold is an interference channel (step S1413).
[0052]
In the example shown in FIG. 12, the threshold value of the number of errors is 20, and it is determined that channel B36 exceeding the threshold value interferes with L6ch.
[0053]
Next, an interference avoidance channel is calculated from the L6 channel usage band (step S1414). B25ch to B47ch corresponding to 11 MHz before and after 2437 MHz which is the center frequency of L6ch are determined as avoidance channels. Thereafter, the interference band detection routine is terminated.
[0054]
As shown in FIG. 13, the channels used as a result are B1ch to B24ch and B48ch to B79ch.
[0055]
In the present embodiment, the radio wave interference state is detected by using the reception state of the data packet transmitted by the BT slave in the BT master.
[0056]
In FIG. 14, the counting of the number of packets waiting for reception for each channel detected in step S1402 is started, and the number of errors is measured until reception of a predetermined number of packets is completed in step S1412. When the predetermined number of packets is reached, the routine is terminated after determining whether or not there is an avoidance channel. However, it is more desirable to receive a predetermined number of packets for all L14 channels and determine the avoidance channel. Further, by periodically clearing the number of packets waiting to be received and the error value, measurement may be repeatedly performed during communication, and the interference state may be sequentially determined. Further, instead of the predetermined number of packets, the number of errors may be measured until a predetermined reception time is reached for each channel.
[0057]
In FIG. 14, the packet received in step S1404 needs to include a payload in order to use the CRC check. When counting without including the payload signal, it is possible to detect the interference band by changing the threshold value of the number of errors in step S1412.
[0058]
As described above, according to the interference channel detection apparatus according to the present embodiment, the BTch for detecting interference is prepared in advance only for the central band used in the wireless LAN, and each communication after commencing communication by hopping is prepared. By detecting the interference channel according to the communication state of the channel, the band used in the WLAN is accurately specified. As a result, communication is possible without reducing the throughput of the WLAN system and the throughput of the BT system.
[0059]
(Second Embodiment)
Next, a second embodiment of the present invention will be described with reference to FIGS.
[0060]
The basic configuration of the communication apparatus according to the present embodiment is the same as that of the first embodiment described above, but the method for detecting the interference band is different.
[0061]
In the present embodiment, the power value of each BT channel detected by the inquiry scan and the page scan performed by the BT master at a timing other than the transmission / reception with the BT slave is used.
[0062]
When performing a normal scan, the master assumes that a channel with a large received power is interfering, and determines an interference band using association with a WLAN channel. Each scan is performed every 1.28 seconds for both 11 and 25 milliseconds, and the scan channel is changed in units of 1.28 seconds. Therefore, when all 64 channels are scanned, 1.28 * 32 = 40.96 seconds It will take.
[0063]
Since this embodiment is common to FIGS. 1 to 10 and 13 in the first embodiment described above, these drawings will be used as necessary.
[0064]
FIG. 15 is a diagram showing an arrangement of WLAN channels in the communication apparatus according to the present embodiment. The use bands from L1ch to L14ch are overlapped as shown in FIG. Therefore, FIG. 16 shows the result of mapping on BTch with reference to the center frequency of the LWAN channel. For example, since 34ch is closest to the center frequency of L6ch, the interference source in the case of interference is classified as L6ch.
[0065]
FIG. 17 corresponds to FIG. 16 and is a table in which which channel of WLAN receives the most interference in each BTch, and is stored in the ROM 204 in advance. This table is used for avoidance channel determination at the time of BT channel interference. The BT scan uses 32 ch at the time of inquiry scan and 32 ch at the time of page scan. The ch is determined from the address and the like, and not all 79 ch of the BT are used.
[0066]
Hereinafter, the interference channel detection operation by the PDA 104 will be described using the flowchart of FIG. As a premise for explanation here, it is assumed that WLAN communication using the L6 channel is performed between the AP 101 and the PC 102 which are interference sources between the TEL 103 and the PDA 104 during the BT communication.
[0067]
First, according to the program stored in the ROM 204 in FIG. 2, the CPU 206 describes the channel for the inquiry (i) scan BT32 ch and the page (p) scan BT32 ch from the address of the PDA 104 to the RF 208. , P scan list is set in the RAM 205, and the RSSI value prepared for each scan channel set in the RAM 205 is cleared (step S1801).
[0068]
Next, the PDA 104 selects the first scan channel from the i and p2 scan lists secured in the RAM 205 (step S1802). Next, the PDA 104 starts scanning at the head ch of the i-scan list selected in step S1802 (step S1803). Next, the PDA 104 measures the RSSI value during the scan (step S1804). Next, the PDA 104 ends the scan of the i-scan channel selected in step S1802 (step S1805). Next, the PDA 104 stores the average RSSI of the i-scan list head ch in the RAM 205 (step S1806). Next, the PDA 104 starts scanning at the head ch of the p-scan list selected in step S1802 (step S1807).
[0069]
Next, the PDA 104 measures the RSSI value during the scan (step S1808). Next, the PDA 104 ends the scan of the i-scan channel selected in step S1802 (step S1809). Next, the PDA 104 stores the average RSSI of the i-scan list head ch in the RAM 205 (step S1810). Next, since the ip scan list is the head, the process returns to step S1802 (step S1811).
[0070]
Similarly, the steps S1802 to S1810 are repeated until the 32nd in the ip scan list. When the scan for all 32 channels is completed, the scan list number 32 is obtained, and the process proceeds to step S1812 (step S1811). Next, the value of each scan ch average RSSI stored in the RAM 205 is compared with a threshold (step S1812). Then, it is assumed that the RSSI average value of B35ch which is the fifth p scan list exceeds −30 dBm at −25 dBm. In this case, B35ch is moved to the avoidance channel calculation step S1813 as an interference channel. The RSSI average value for 63 ch in the other scan lists falls below the threshold of −30 dBm, and the process proceeds to step S1814.
[0071]
In step S1813, avoidance channels are calculated, and from the table shown in FIG. 17 stored in the ROM 204, the BT avoidance channel is determined from B25 to B47 (step S1813), and other channels are determined to have no avoidance channel (step S1814). Thereafter, the avoidance channel detection routine is terminated.
[0072]
As described above, according to the interference channel detection apparatus according to the present embodiment, the BT master detects reception intensity during scanning, and the wireless LAN whose reception intensity exceeds the threshold is closest to the center frequency of the wireless LAN. It is determined that the channel interferes with the channel, and the avoidance band is determined. This makes it possible to detect the interference band regardless of whether the BT master of communication communicates with the BT slave, and it is possible to restore the channel once avoided by the BT.
[0073]
A storage medium storing software program codes for realizing the functions of the above-described embodiments is supplied to the system or apparatus, and the computer (or CPU, MPU, etc.) of the system or apparatus is stored in the storage medium. It goes without saying that the present invention can also be achieved by reading and executing the program code.
[0074]
In this case, the program code itself read from the storage medium realizes the functions of the above-described embodiment, and the storage medium storing the program code constitutes the present invention.
[0075]
The storage medium for supplying the program code includes, for example, RAM, NV-RAM, floppy (registered trademark) disk, hard disk, optical disk, magneto-optical disk, MO, CD-ROM, CD-R, CD-RW. , DVD-ROM, DVD-RAM, DVD-RW, DVD + RW, magnetic tape, non-volatile memory card, or the like that can store the program code, or can be downloaded via a network.
[0076]
Further, by executing the program code read by the computer, not only the functions of the above-described embodiments are realized, but also an OS (operating system) running on the computer based on an instruction of the program code, etc. However, it is needless to say that a case where the functions of the above-described embodiment are realized by performing part or all of the actual processing.
[0077]
Further, after the program code read from the storage medium is written in a memory provided in a function expansion board inserted into the computer or a function expansion unit connected to the computer, the function expansion is performed based on the instruction of the program code. It goes without saying that the CPU or the like provided in the board or the function expansion unit performs part or all of the actual processing, and the functions of the above-described embodiments are realized by the processing.
[0078]
Although various examples and embodiments of the present invention have been described above, those skilled in the art will recognize that the spirit and scope of the present invention are not limited to the specific descriptions and drawings in this specification, It goes without saying that various modifications and changes, which are all described in the claims, can be covered.
[0079]
【The invention's effect】
As described above, according to the present invention, even if interference cannot be detected, a channel that causes interference can be avoided, and interference during communication can be reduced or prevented.
[Brief description of the drawings]
FIG. 1 is a diagram showing an overall configuration of a wireless communication system having a communication apparatus according to a first embodiment of the present invention.
FIG. 2 is a block diagram showing an internal configuration of the PDA in the wireless communication system having the communication apparatus according to the first embodiment of the present invention.
FIG. 3 is a diagram showing a configuration of a packet used in the communication apparatus according to the first embodiment of the present invention.
FIG. 4 is a diagram showing a configuration of a packet header in a packet used in the communication apparatus according to the first embodiment of the present invention.
FIG. 5 is a diagram showing a structure of a payload in a packet used in the communication apparatus according to the first embodiment of the present invention.
FIG. 6 is a diagram showing a configuration of a channel on a side for detecting interference of the communication apparatus according to the first embodiment of the present invention.
FIG. 7 is a diagram showing a configuration of a channel on the side where interference is detected in the communication apparatus according to the first embodiment of the present invention.
FIG. 8 is a diagram showing transmission / reception timing on the side of detecting interference of the communication apparatus according to the first embodiment of the present invention.
FIG. 9 is a diagram showing a transmission power spectrum on the side where interference is detected in the communication apparatus according to the first embodiment of the present invention.
FIG. 10 is a diagram illustrating an interference state of the communication device according to the first embodiment of the present invention.
FIG. 11 is a diagram illustrating an example of the number of errors in a received packet in the communication apparatus according to the first embodiment of the present invention.
FIG. 12 is a diagram illustrating an example of the number of errors in a received packet in the communication device according to the first embodiment of the present invention.
FIG. 13 is a diagram illustrating an avoidance channel example in the communication device according to the first embodiment of the present invention.
FIG. 14 is a flowchart showing an operation procedure in the communication apparatus according to the first embodiment of the present invention.
FIG. 15 is a diagram illustrating an arrangement example of a WLAN channel in a communication apparatus according to a second embodiment of the present invention.
FIG. 16 is a diagram illustrating a BT mapping example of a WLAN channel in the communication apparatus according to the second embodiment of the present invention.
FIG. 17 is a diagram illustrating a correspondence relationship between a BT channel and an avoidance channel in the communication apparatus according to the second embodiment of the present invention.
FIG. 18 is a flowchart showing an operation procedure in the communication apparatus according to the second embodiment of the present invention.
[Explanation of symbols]
101 Access point (AP)
102 Personal computer (PC) with built-in WLAN access function
103 Mobile phone with built-in Bluetooth (BT) function (TEL)
104 BT built-in personal digital assistant (PDA)
201 PDA body
202 wireless module
203 UART (Universal Asynchronous Receiver Transmitter)
204 ROM (read only memory)
205 RAM ((random access memory)
206 CPU (central processing unit)
207 Baseband (BB)
208 RF (Radio Frequency)
209 Antenna
301 Access code
302 packet header
303 payload
401 AM_ADDR
402 TYPE
403 FLOW
404 ARQN
405 SEQN
406 HEC (Header Error Check)
501 Payload header
502 Payload body
503 CRC

Claims (10)

A communication device,
A discriminating means for discriminating a communication state of a frequency channel usable for communication;
A communication unit that identifies a frequency channel in a predetermined communication state based on the determination by the determination unit, and communicates using a frequency band excluding a predetermined frequency band including the frequency channel in the predetermined communication state. A communication device. In claim 1,
The communication device performs communication by a first communication method,
Storage means for storing each frequency channel used in the first communication method and an occupied band of each frequency channel used in a second communication method different from the first communication method in association with each other ,
The communication device performs communication using a frequency band excluding an occupied band of a frequency channel of the second communication method associated with a frequency channel in a predetermined communication state. In claim 2,
The first communication method is a method of performing communication while switching frequency channels, and the second communication method is a method of performing communication using a fixed frequency channel. In claim 2,
The communication apparatus characterized in that an occupied band of each frequency channel of the first communication method is wider than an occupied band of each frequency channel of the second communication method. In claim 1,
The communication device according to claim 1, wherein the determining means determines a channel having a poor communication state. In claim 1,
The communication device is characterized in that the determining means determines a channel having a large received power. In claim 1,
A communication apparatus for determining a communication state based on an error of a received signal. In claim 7,
The communication device is characterized in that the determining means weights according to the type of error to determine the communication state of the frequency channel. In the interference channel determination method,
A discriminating step for discriminating a communication state of a frequency channel usable for communication;
A determination step of identifying a frequency channel in a predetermined communication state based on the determination in the determination step and determining a frequency band excluding a predetermined frequency band including the frequency channel in the predetermined communication state as an available frequency band And an interference channel determination method. In the setting method of the frequency channel used for communication,
A discriminating step for discriminating a communication state of a frequency channel usable for communication;
Based on the determination in the determination step, a frequency channel in a predetermined communication state is specified, and a frequency channel included in a frequency band excluding a predetermined frequency band including the frequency channel in the predetermined communication state is used for communication. A setting method comprising a setting step of setting as a channel.

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