JP3674181B2 - Wireless communication device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a wireless communication device that performs bidirectional communication while switching carrier frequencies according to a predetermined hopping pattern by a frequency hopping method.
[0002]
[Prior art]
In recent years, a spread spectrum wireless communication system that obtains communication data by spreading and transmitting communication data after modulation and despreading and demodulating the received signal has been used for effective use of frequency and low power density communication. It has attracted attention from making it possible. In particular, when performing transmission / reception using a spread spectrum method, spreading and despreading by frequency hopping that sequentially switches the carrier frequency improves signal secrecy and reduces communication failures due to interference, so this frequency hopping was applied. Spread spectrum wireless communication systems are being widely adopted in various fields such as telephones and facsimile machines.
[0003]
Conventionally, a wireless communication device employed in a wireless communication system of the above-mentioned type has a hop table having a predetermined number of hop frequency data indicating carrier frequencies for spreading and despreading, and the frequency is determined according to the hopping pattern by the hop table. Communication is performed at the carrier frequency hopped. At this time, if interference occurs in the carrier frequency that has been frequency hopped, during the period in which communication is performed at this carrier frequency, a communication failure occurs due to the interference, and the reliability of communication decreases.
[0004]
Therefore, in Japanese Patent Laid-Open No. 6-334630, the interference wave level is measured for all usable carrier frequencies, and a hopping pattern having a predetermined number of hops is determined by selecting in order from the carrier frequency having the lowest interference wave level. And the method of improving the reliability of communication data is proposed by making all the wireless communication devices have a hop table as a hopping pattern so that communication is performed only at a carrier frequency having a low interference wave level.
[0005]
[Problems to be solved by the invention]
However, in the conventional method for determining the reliability of communication at each carrier frequency based on the interference wave level, the interference wave level and the reception level of the carrier frequency are obtained from different analog waves. Therefore, there is a problem that it is difficult to accurately determine whether the reliability is good or not because the interference wave level fluctuates relative to the reception level of the carrier frequency.
[0006]
That is, if the reception level of the carrier frequency is low due to, for example, the output or location of a wireless communication device, the interference wave level is relatively high with respect to the reception level of the carrier frequency even if the interference wave level is low. Therefore, the reliability greatly decreases due to a large communication failure. On the other hand, when the reception level of the carrier frequency is high, the interference wave level tends to be relatively small with respect to the reception level of the carrier frequency, and thus communication can often be performed with high reliability.
[0007]
As a result, in the conventional method in which the determination result based on the interference wave level is influenced by the reception level of the carrier frequency, if an accurate determination result is to be obtained, the interference wave level and the reception level of the carrier frequency are kept constant. Therefore, it is necessary to provide a circuit that realizes such a relationship, complicating the circuit configuration, and limiting the use conditions so that the reception level of the carrier frequency becomes a predetermined value. There will be some difficult problems.
[0008]
Accordingly, the present invention is to provide a wireless communication device capable of accurately obtaining a carrier frequency capable of communication with high reliability under a simple circuit configuration and free use conditions and performing communication using a hopping pattern of this carrier frequency. It is what.
[0009]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the invention of claim 1 selects a carrier frequency with less interference and sets a hopping pattern in advance, and switches the carrier frequency according to the hopping pattern. Between multiple other wireless communication devices In a wireless communication device that performs two-way communication, while sequentially hopping the digital test data at the pattern candidate frequency Between the other wireless communication devices Send and receive, Based on the error rate calculation means for calculating the total error rate for each pattern candidate frequency of the received test data, and the total error rate for each pattern candidate frequency obtained by the calculation of the error rate calculation means, Frequency selection means for selecting a pattern candidate frequency with good recognition of test data as the carrier frequency of the hopping pattern, and pattern setting means for setting a hopping pattern based on the selected pattern candidate frequency It is characterized by that.
As a result, the degree of recognition of test data indicating the degree of communication reliability can be obtained based on the correctness of digital values that are not affected by the output level, radio wave interference, wireless communication device placement, etc. Become. Therefore, it is possible to accurately obtain a carrier frequency that enables highly reliable communication even under a simple circuit configuration and free use conditions, and perform frequency hopping with a hopping pattern including such a carrier frequency, thereby achieving good communication. Can be done.
[0010]
A second aspect of the present invention is the wireless communication apparatus according to the first aspect, further comprising pattern resetting means for rearranging hopping patterns set by the pattern setting means at random.
Thereby, since transmission / reception is performed at a random carrier frequency, confidentiality can be improved as compared with a case where transmission / reception is performed at a carrier frequency of a simple hopping pattern such as ascending order or descending order.
[0011]
According to a third aspect of the present invention, there is provided the wireless communication device according to the first or second aspect, further comprising setting management means for periodically setting the hopping pattern.
As a result, the hopping pattern is periodically reset so as to have a carrier frequency with less interference, so that good communication can be stably performed.
[0012]
A fourth aspect of the present invention is the wireless communication apparatus according to any one of the first to third aspects, wherein the frequency selection means is , The total Select a pattern candidate frequency with an error rate smaller than a predetermined reference value Ruko It is characterized by.
As a result, communication can be performed at a carrier frequency that is more reliable than a predetermined reference value, and the carrier frequency is higher than that in the case of selecting hopping patterns in order of decreasing error rate. Since the room for selecting a frequency is expanded, it is possible to form a highly confidential hopping pattern.
[0013]
A fifth aspect of the present invention is the wireless communication apparatus according to the fourth aspect of the present invention, comprising error correction means for received data, and a value that is smaller by a predetermined value than a limit error rate that can be corrected by the error correction means. It is set as the reference value.
As a result, even if a data error occurs due to communication, it is corrected by the error correction means, so that even better communication can be performed and the carrier frequency is selected using the limit error rate of the error correction means as a reference value. Therefore, a hopping pattern that can be satisfactorily communicated can be reliably formed.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of the present invention will be described below with reference to FIGS.
The wireless communication apparatus according to the present embodiment is used in a wireless communication system that performs bidirectional communication between communication apparatuses while switching carrier frequencies according to a predetermined hopping pattern by a frequency hopping method. As shown in FIG. 2, for example, this wireless communication system includes a parent device 10 that is one wireless communication device connected to an external line, and five wireless devices that can communicate with the parent device 10 and can communicate with each other. It has the subunit | mobile_unit 11-15 which is a communication apparatus. Note that a telephone, a facsimile machine, a printer, a computer, or the like can be applied to the parent machine 10 and the child machines 11 to 15. As shown in FIG. 3, communication between the master unit 10 and the slave units 11 to 15 and communication between the slave units 11 to 15 are performed by a TDD (Time Division Duplex) method, and one of them is in a transmission state. In the case of (TX), the other is set in a reception state (RX), and communication is performed by alternately replacing the transmission state (TX) and the reception state (RX). In addition, this radio | wireless communications system may communicate by a TDMA (Time Division Mutiple Access) system.
[0015]
As shown in FIG. 1, the parent device 10 and the child devices 11 to 15 have a wireless communication unit 1 that transmits and receives communication data by a spread spectrum method for frequency hopping. The wireless communication unit 1 has an interface unit 21 that processes and inputs communication data to an external circuit (not shown). The interface unit 21 includes a codec and a compressor that mutually convert audio data and digital signals when the communication data is audio data. On the other hand, when the communication data is non-audio data, the interface unit 21 performs buffer and error correction processing. And so on.
[0016]
The interface unit 21 is connected to a modulator / demodulator 22 having a modulation unit 22a that modulates communication data and a demodulation unit 22b that demodulates communication data. The modem 22 switches the operating state of the modulation unit 22a and the demodulation unit 22b between transmission and reception of communication data based on the transmission command signal p and the reception command signal q from the controller 35. The modulation unit 22a that is activated during transmission is connected to an up-converter 23 that includes a mixer.
[0017]
A PLL local oscillator 25 is connected to the up-converter 23, and a hop table 26 is connected to the PLL local oscillator 25. The data setting signal w is input to the hop table 26 from the controller 35. When the data setting signal w is input, the hop table 26 includes the hop frequency data included in the data setting signal w. Based on the data and the channel data, for example, the hop frequency data f1, f2,... FL of FIG. 4 are stored in correspondence with the respective channels C1, C2,.
[0018]
Further, the hop signal r is input to the hop table 26 and the PLL local oscillator 25 from the controller 35 every predetermined residence time, and the hop table 26 is input every time the hop signal r is input. The hop frequency data f corresponding to the channel c of the channel setting value S indicated by the hop signal r is output to the PLL local oscillator 25, and the hop frequency signal (local oscillation) of the frequency corresponding to the hop frequency data f is output from the PLL local oscillator 25. Signal) s is output to the up-converter 23. Hereinafter, when a carrier frequency corresponding to specific hop frequency data (for example, f1) is indicated, it is indicated, for example, as a carrier frequency (f1). The up-converter 23 adds the hop frequency signal s from the PLL local oscillator 25 and the modulation signal t of the communication data from the modulation unit 22a to form a spread modulation signal u having a spread carrier frequency. It is like that.
[0019]
The up-converter 23 is connected to a transmission / reception switch 27 via a power amplifier 24 that amplifies the spread modulation signal u. A transmission command signal p and a reception command signal q are input to the transmission / reception switch 27 from the controller 35. When the transmission designation signal p is input, the operation state is set to the transmittable state from the power amplifier 24. The spread modulation signal u is transmitted from the antenna 28. On the other hand, when the reception command signal q is input, the operating state is set to the reception enabled state, and the spread modulation signal u received via the antenna 28 is output to the low noise amplifier 31.
[0020]
The low noise amplifier 31 is connected to the down converter 32, and amplifies and outputs the spread modulation signal u to the down converter 32. The hop frequency signal s input to the above-described up converter 23 is input to the down converter 32 from the PLL local oscillator 25. The down converter 32 uses the spread modulation signal based on the hop frequency signal s. u is despread to form a modulated signal t, and this modulated signal t is output to the demodulator 22b. The demodulator 22b demodulates the input modulation signal t and then outputs it to the interface unit 21.
[0021]
The wireless communication unit 1 having the above-described configuration is configured to operate when power is supplied from the power supply unit 36. The power supply unit 36 may include a part or all of the controller 35 excluding the controller 35 before the communication start process. A power supply destination is set by the controller 35 so as to limit power supply to the wireless communication unit 1. That is, the controller 35 controls to supply power only to the controller 35 in the sleep mode, and controls to supply power except for the transmission unit including the up-converter 23 and the power amplifier 24 in the reception standby mode. Control is performed so that power is supplied to the entire wireless communication unit 1 in the mode.
[0022]
The controller 35 that controls each unit as described above includes a hop frequency data table 35a, an error rate table 35b, and a random number table 35c. The hop frequency data table 35a stores L test hop frequency data f1, f2, ..fL as shown in FIG. 4, and these hop frequency data f1, f2,. Pattern candidate frequencies (f1, f2,... FL) that are used when obtaining a carrier frequency that can be communicated with high reliability are formed. The error rate table 35b stores error rates eA (1 to L) to eB (1 to L) corresponding to each test data and a total error rate eT (1 to L) obtained by adding them. It is like that. The random number table 35c stores random data, and the random data is used when the pattern candidate frequencies are rearranged randomly.
[0023]
As shown in FIG. 1, the controller 35 includes an error rate calculation unit 35d. The error rate calculation unit 35d receives an error corresponding to the test data when digital value test data is input. The ratios eA (1 to L) to eB (1 to L) are calculated and output. The above error rates eA (1 to L) to eB (1 to L) are calculated as follows at the time of error correction by the checksum method. Note that error correction by the checksum method is substantially the same in principle as error correction by the spread RS code or CRC code, and therefore the error rate in these error corrections can be obtained by substantially the same calculation method.
[0024]
That is, as shown in FIG. 5, the test data value at address CA00 (h) is C3 (h) = 11000011 (b), and the test data value at address CA01 (h) is 35 (h) = 001110101 (b). Thus, it is assumed that there is test data at addresses CA00 (h) to CA7F (h). If there is no error during data transfer, it is sufficient to send only these test data serially, but in order to find the error during transfer, the horizontal checksum column and the vertical checksum column are respectively shown at the right end and bottom end of the diagram. Append. Note that these checksum fields only need to be arranged at arbitrary positions in the table.
[0025]
In the horizontal checksum field, the last two digits of the test data added in the horizontal direction are stored. In the vertical checksum column, the last two digits of the test data added in the vertical direction are stored. In the total checksum column at the lower right end where the horizontal checksum column and the vertical checksum column overlap, the total value of the horizontal checksum column or the last two digits of the vertical checksum column is stored. It is like that.
[0026]
When the test data and the checksum data in each checksum column are formed as described above, these data are transmitted. Then, on the data receiving side, the values in the respective checksum fields are calculated based on the received test data, and these calculated values are compared with the received values in the received checksum field. As a result, if all values match, it is confirmed that an error has not occurred due to data communication. On the other hand, if there is a mismatch value, it is confirmed that an error has occurred in the test data or checksum data.
[0027]
Here, as a first case, when an error occurs in one place of the test data, there are different values in the calculated value and the received value in the vertical checksum column and the horizontal checksum column. It can be corrected by back calculation. As a second case, when there is an error in the received value in the checksum field, only the checksum field is determined from the relationship between the total checksum field value “1A”, the horizontal and vertical checksum fields, and the test data. Therefore, the error can be corrected.
[0028]
Further, as a third case, an error has occurred in two places (for example, CA22 (h), CA24 (h)) of the received test data, and the value in the horizontal checksum column is the same between the received value and the calculated value. When the value of “C7” is reached, it can be seen that an error has occurred in the vertical checksum column, but it cannot be corrected because it cannot be specified in which part the error has occurred. Furthermore, as a fourth case, when there are errors in four locations of the received test data (for example, CA22 (h), CA24 (h), CA58 (h), CA5A (h)), a horizontal check is performed. Since an error cannot be found by comparing the calculated value in the sum column and the vertical checksum column with the received value, the received test data cannot be corrected.
[0029]
Thus, among the various cases, the error rate is obtained by dividing the number of found error data by the total number of data regardless of whether correction is possible, as in the first, second, and third cases. It will be determined by As an error rate calculation method using an error correction code, a method using a Hamming code, a BCH code, a Reed-Solomon code, a Fire code, or the like can be considered in addition to the checksum method described above. Even these methods have the first, second, third, and fourth cases described above, but the method using Reed-Solomon code is particularly efficient and has a large degree of freedom in correction capability and code length. It is suitable as an error rate calculation method.
[0030]
The controller 35 having the error rate calculation unit 35d for calculating the error rates eA (1 to L) to eB (1 to L) as described above further executes the pattern setting processing routine of FIG. ing. The pattern setting processing routine is executed periodically or by operating a pattern setting switch (not shown). The above test data and check data are transmitted and received while sequentially hopping at the pattern candidate frequency. After the error rate eA (1 to L) to eB (1 to L) is obtained by the rate calculating unit 35d, these are added together to obtain the total error rate eT (1 to L) as the recognition degree of the test data. A pattern candidate frequency having a good total error rate eT (1 to L) is selected as the carrier frequency of the hopping pattern, and the hopping pattern is set based on the selected pattern candidate frequency.
[0031]
In the above configuration, a case where base unit 10 sets a hopping pattern based on error rates eA (1 to L) to eB (1 to L) of test data will be described based on the flowchart of FIG.
[0032]
When the controller 35 recognizes that the set time has elapsed due to an internal timer (not shown), or when the controller 35 recognizes that a pattern setting switch (not shown) has been operated by the operator, as shown in FIG. 6 pattern setting processing routine is executed. That is, “1” is set to the channel setting value S, “1” is set to the channel count value C, and “L” corresponding to the total number of channels in the hop frequency data table 35a is set to the hop number Hn (S1). Thereafter, after setting “hop number Hn = L” as the maximum channel count value Cmax (S2), the channel data indicating the channels C1, C2,... CL stored in the hop frequency data table 35a and the hop frequency data f1 , f2, .. fL hop frequency data Taka Is transferred to the hop table 26, and the test hop frequency data f1, f2,... FL are set in the hop table 26 in association with the channels C1, C2,. S3).
[0033]
Thereafter, the controller 35 outputs the transmission command signal p to the modulator / demodulator 22 and the transmission / reception switch 27, thereby setting the modulator 22a of the modulator / demodulator 22 to the operating state and setting the transmission / reception switch 27 to the transmission state. . Further, by outputting the hop signal r having the channel setting value S “1” to the hop table 26 and the PLL local oscillator 25, the hop frequency data f1 of the first channel C1 is output to the PLL local oscillator with respect to the hop table 26. The hop frequency signal s of the pattern candidate frequency (f1) corresponding to the hop frequency data f1 is output from the PLL local oscillator 25 to the up converter 23 and the down converter 32.
[0034]
Next, after the test data and checksum data of FIG. 5 are formed, a test signal including these data is taken into the modem 22 via the interface unit 21. Then, after modulation by the modulation unit 22a, the modulation signal t is output to the up converter 23, and the modulation signal t and the hop frequency signal s from the PLL local oscillator 25 are added to form a spread modulation signal u. Thereafter, the spread modulation signal u is amplified by the power amplifier 24 and then transmitted from the antenna 28 to all the slave units 11 to 15 via the transmission / reception switch 27 (S4).
[0035]
When the transmission of the test data is completed by the above S4, the controller 35 outputs the reception command signal q to the modem 22 and the transmission / reception switch 27, thereby setting the demodulator 22b of the modem 22 to the operating state and the transmission / reception. The switch 27 is set to the reception state. When the test data and the like returned from all the slave units 11 to 15 are received (S5), these data are output to the error rate calculation unit 35d so that the error rate calculation unit 35d receives each of the slave units 11 to 15. The error rates eA (1) to eB (1) corresponding to are respectively calculated. Then, as shown in FIG. 4, the error rates eA (1) to eB (1) output from the error rate calculator 35d are stored in the error rate table 35b, and these error rates eA (1) to eB (1 ) Are added together to obtain the total error rate eT (1) at the pattern candidate frequency (f1) (S6).
[0036]
Next, it is determined whether or not the channel count value C is smaller than the maximum channel count value Cmax (“hop count Hn = L”) (S7). The set value S and the channel count value C are incremented by “1” (S8). Thereafter, when a predetermined dwell time has elapsed by an internal timer (not shown) or the like, the hop signal r indicating the channel setting value S is output to the hop table 26 and the PLL local oscillator 25 to perform frequency hopping (S9). Re-execution from S4, error rates eA (2) to eB (2) and total error rate eT (2) at the next pattern candidate frequency (f2) are obtained.
[0037]
When the total error rate eT (1 to L) of all the pattern candidate frequencies (f1, f2,... FL) is obtained in this way, the channel count value C becomes the maximum channel count value Cmax (“hop count”). Hn = L ″) (S7, YES), and as shown in FIG. 7A, these total error rates eT (1 to L) are used as test hop frequency data f1, f2 , .. fL and rearranged in ascending order (S10).
[0038]
By rearranging the total error rates eT (1 to L) in ascending order, the hop frequency data f5, f8,.. F243 rearranged in order from the one having the highest communication reliability is obtained. ), K hop frequency data f5, f8,... F125 are selected from those having a small total error rate eT (1 to L) (S11). Then, as shown in FIG. 7C, by further rearranging the K hop frequency data f5, f8,... F125 based on the random number data in the random number table 35c, a communication hopping pattern is obtained. Hop frequency data f125, f10,... FL11 are formed (S12).
[0039]
After that, by assigning the channels C1, C2, ..CK to the hop frequency data f125, f10, ..fL11, respectively, the hop frequency data f125, f10, ..fL11 and the channels C1, C2, ..CK Is formed (S13), and the hopping pattern data is transferred to the hop table 26 as a data setting signal w and set (S14). Further, the hopping pattern data is transmitted to the slave units 11 to 15 to be set in the hop table 26 of the slave units 11 to 15 (S15). As a result, the parent device 10 and the child devices 11 to 15 perform subsequent communication while performing frequency hopping with the hopping pattern based on the hop frequency data f125, f10,... FL11 that can be communicated with high reliability.
[0040]
As described above, the wireless communication device according to the present embodiment, as shown in FIG. 4, converts the digital test data into the pattern candidate frequencies (f1, f2 corresponding to the test hop frequency data f1, f2, .. fL). , .. fL), and sequentially transmitting and receiving frequency hopping, as shown in FIG. 7A, based on the total error rate eT (1 to L), the pattern candidate frequency (f5 , f8,.. f125) as frequency carrier means (S1 to S11) for selecting the carrier frequency of the hopping pattern, and setting the hopping pattern based on the selected pattern candidate frequency (f5, f8, .. f125) The pattern setting means (S13 to S15) is included. Note that the degree of recognition may be the number of errors instead of the error rate.
[0041]
As a result, the total error rate eT based on the correctness of the digital value in which the degree of recognition of the test data indicating the degree of communication reliability is not affected by the output level, radio wave interference, wireless communication device arrangement status, etc. (1 to L). Therefore, good communication can be performed by accurately obtaining a carrier frequency that can be communicated with high reliability even under a simple circuit configuration and free use conditions, and performing frequency hopping with a hopping pattern composed of such a carrier frequency. Can be done.
[0042]
Further, the wireless communication device of the present embodiment has a pattern resetting means (S12) for randomly rearranging the pattern candidate frequencies (f5, f8, .. f125) of the hopping pattern set by the pattern setting means (S13 to S15). It has the composition which has. As a result, as shown in FIG. 7C, since transmission / reception is performed at random carrier frequencies (f125, f10,... FL11), simple hopping pattern carrier frequencies (f5, f8,. ..f125), it is possible to improve secrecy compared to the case of transmission / reception.
[0043]
Further, in the present embodiment, a function (setting) for periodically setting the hopping pattern by executing the pattern setting processing routine of FIG. 6 when it is recognized that the set time has elapsed by an internal timer (not shown). Management means). As a result, the hopping pattern is periodically reset so as to have a carrier frequency with less interference, so that good communication can be stably performed.
[0044]
In this embodiment, as shown in FIG. 7B, the pattern candidate frequencies (f5, f8,... F125) are selected in ascending order of the total error rate eT (1 to L). However, it is not limited to this. That is, the error which calculates error rate eA (1-L) -eB (1-L) and total error rate eT (1-L) of the test data received for every pattern candidate frequency (f1, f2, .. fL) Rate calculating means (error rate calculating unit 35d, S6) and selecting means for selecting a pattern candidate frequency whose total error rate eT (1-L) calculated by the error rate calculating means is smaller than a predetermined reference value. It may be configured as follows. In this case, it is possible to perform communication at a carrier frequency that is more reliable than a predetermined reference value, and select hopping in order from the smallest total error rate eT (1 to L). Since there is more room for selection of the carrier frequency than when forming a pattern, it is possible to form a hopping pattern with higher secrecy.
[0045]
Further, the above-mentioned reference value is smaller by a predetermined value than the limit error rate that can be corrected by the error correction means by providing error correction means for the received data in the master unit 10 and the slave units 11-15. It is desirable to be a value. As a result, even if a data error occurs due to communication, it is corrected by the error correction means, so that even better communication can be performed and the carrier frequency is selected using the limit error rate of the error correction means as a reference value. Therefore, a hopping pattern that can be satisfactorily communicated can be reliably formed.
[0046]
【The invention's effect】
According to the first aspect of the present invention, a carrier frequency with less interference is selected in advance to set a hopping pattern, and the carrier frequency is switched according to the hopping pattern. Between multiple other wireless communication devices In a wireless communication device that performs two-way communication, while sequentially hopping the digital test data at the pattern candidate frequency Between the other wireless communication devices Send and receive, Based on the error rate calculation means for calculating the total error rate for each pattern candidate frequency of the received test data, and the total error rate for each pattern candidate frequency obtained by the calculation of the error rate calculation means, Frequency selection means for selecting a pattern candidate frequency with good recognition of test data as the carrier frequency of the hopping pattern, and pattern setting means for setting a hopping pattern based on the selected pattern candidate frequency It is a configuration.
As a result, the degree of recognition of test data indicating the degree of communication reliability can be obtained based on the correctness of digital values that are not affected by the output level, radio wave interference, wireless communication device placement, etc. Become. Therefore, it is possible to accurately obtain a carrier frequency that enables highly reliable communication even under a simple circuit configuration and free use conditions, and perform frequency hopping with a hopping pattern including such a carrier frequency, thereby achieving good communication. There is an effect that it can be performed.
[0047]
A second aspect of the present invention is the wireless communication apparatus according to the first aspect, further comprising a pattern resetting unit that rearranges the hopping patterns set by the pattern setting unit at random.
Thereby, since transmission / reception is performed at a random carrier frequency, it is possible to improve secrecy as compared to transmission / reception at a carrier frequency of a simple hopping pattern such as ascending order or descending order.
[0048]
A third aspect of the present invention is the wireless communication apparatus according to the first or second aspect, further comprising setting management means for periodically setting the hopping pattern.
Thereby, since the hopping pattern is periodically reset so as to have a carrier frequency with less interference, there is an effect that good communication can be stably performed.
[0049]
A fourth aspect of the present invention is the wireless communication apparatus according to any one of the first to third aspects, wherein the frequency selection means is , The total Select a pattern candidate frequency with an error rate smaller than a predetermined reference value That It is a configuration.
As a result, communication can be performed at a carrier frequency that is more reliable than a predetermined reference value, and the carrier frequency can be selected more than when a hopping pattern is formed by selecting the ones with the smallest error rate. Since the room for selecting the frequency is expanded, it is possible to form a highly confidential hopping pattern.
[0050]
A fifth aspect of the present invention is the wireless communication apparatus according to the fourth aspect of the present invention, comprising error correction means for received data, and a value that is smaller by a predetermined value than a limit error rate that can be corrected by the error correction means. This is a configuration set as the reference value.
As a result, even if a data error occurs due to communication, the error correction unit corrects the error, so that even better communication can be performed and the carrier frequency is selected using the limit error rate of the error correction unit as a reference value. Therefore, there is an effect that a hopping pattern that can be satisfactorily communicated can be reliably formed.
[Brief description of the drawings]
FIG. 1 is a block diagram of a wireless communication unit.
FIG. 2 is an explanatory diagram showing a relationship between a parent device and a child device.
FIG. 3 is an explanatory diagram showing a communication form according to a TDD scheme.
FIG. 4 is an explanatory diagram showing the contents of a hop frequency data table and an error rate table.
FIG. 5 is an explanatory diagram showing the contents of test data and checksum data.
FIG. 6 is a flowchart of a pattern setting processing routine.
FIGS. 7A and 7B are explanatory diagrams showing a process of selecting hop frequency data. FIG. 7A shows a case where the error rates are rearranged in ascending order, FIG. 7B shows a case where K pieces are selected, and FIG. It shows when it is placed.
[Explanation of symbols]
1 wireless communication unit
10 Master unit
11-15 handset
21 Interface section
22 modem
23 Upconverter
24 Power amplifier
25 PLL local oscillator
26 Hop table
27 duplexer
28 Antenna
31 Low noise amplifier
32 Downconverter
35 controller
35a Hop frequency data table
35b Error rate table
35c random number table
35d Error rate calculator
36 Power supply

Claims (5)

In a wireless communication device that selects a carrier frequency with less interference and sets a hopping pattern, and performs bidirectional communication with a plurality of other wireless communication devices while switching the carrier frequency according to the hopping pattern,
An error rate for calculating the total error rate for each pattern candidate frequency of the received test data by transmitting / receiving digital test data to / from the other wireless communication devices while sequentially performing frequency hopping at the pattern candidate frequency Computing means;
Frequency selection means for selecting, as a carrier frequency of the hopping pattern, a pattern candidate frequency with good test data recognition based on the total error rate for each pattern candidate frequency obtained by the calculation of the error rate calculation means When,
A wireless communication device comprising pattern setting means for setting a hopping pattern based on a selected pattern candidate frequency.   2. The wireless communication device according to claim 1, further comprising pattern resetting means for rearranging hopping patterns set by the pattern setting means at random.   The wireless communication device according to claim 1 or 2, further comprising setting management means for periodically setting the hopping pattern. It said frequency selection means, the radio communication apparatus according to any one of claims 1 to 3 wherein the total error rate and wherein the benzalkonium select a smaller pattern candidate frequency than a predetermined reference value.   5. The radio according to claim 4, further comprising an error correction unit for received data, wherein a value that is smaller by a predetermined value than a limit error rate correctable by the error correction unit is set as the reference value. Communication machine.

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