JP7351787B2 - Communication devices, communication methods and programs - Google Patents

Description

The present invention relates to a communication device, a communication method, and a program.

As a technique for communicating using audio signals, a technology has been proposed in which an audio signal generated according to transmission data is output and reception data is acquired from the input audio signal (for example, Patent Document 1).

JP 2019-102853 Publication

While the technology described in Patent Document 1 is applicable to various types of communication, there is a risk that it may be difficult to secure a communication speed due to the operating state of the communication device or the surrounding environment.

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a communication device, a communication method, and a program that can perform suitable communication.

(1) In order to achieve the above object, the communication device according to the first aspect of the invention includes:
A communication device that communicates using multiple frequency channels by frequency hopping of audio signals, the communication device comprising:
A second period in which symbols are transmitted using another frequency channel included in the plurality of frequency channels at intervals shorter than a first period in which symbols are transmitted using one frequency channel included in the plurality of frequency channels. a period is started, and frequency hopping is performed so that a portion of the first period and a portion of the second period overlap;
It is characterized by

(2) Furthermore, in the communication device of (1) above,
In the plurality of frequency channels, frequency hopping is performed using a set hopping pattern such that the interval between symbols transmitted by the same frequency channel is a specific time or more.
You can do it like this.

(3) Furthermore, in the communication device of (1) or (2) above,
In the plurality of frequency channels, frequency hopping is performed using a set hopping pattern so that when frequency hopping is performed and symbols are transmitted using different frequency channels, the frequency interval is equal to or greater than a specific frequency.
You can do it like this.

(4) The communication method according to the second aspect of the invention includes:
A communication method for communicating using multiple frequency channels by frequency hopping of audio signals, the method comprising:
A second period in which symbols are transmitted using another frequency channel included in the plurality of frequency channels at intervals shorter than a first period in which symbols are transmitted using one frequency channel included in the plurality of frequency channels. a period is started, and frequency hopping is performed so that a portion of the first period and a portion of the second period overlap;
It is characterized by

(5) The program according to the third aspect of this invention is
computer,
It functions as a signal processing means for communicating using multiple frequency channels by frequency hopping the audio signal,
The signal processing means uses another frequency channel included in the plurality of frequency channels at an interval shorter than a first period in which symbols are transmitted using one frequency channel included in the plurality of frequency channels. A second period for transmitting symbols is started, and frequency hopping is performed such that a part of the first period and a part of the second period overlap.
It is characterized by

According to this invention, suitable communication becomes possible.

1 is a diagram illustrating a configuration example of a communication device. It is a figure showing an example of composition of a transmitter. FIG. 3 is a diagram illustrating a frequency hopping signal. 3 is a flowchart illustrating an example of hopping pattern creation processing. FIG. 3 is a diagram showing an example of determining a hopping pattern. 1 is a diagram illustrating a configuration example of a communication system to which a communication device is applied.

A communication device according to an embodiment of the invention will be described below. The communication device of the present invention may be configured as a mobile communication terminal that is portable and portable by a user, or may be configured as a fixed communication terminal fixed at a specific installation location. The mobile communication terminal may be, for example, a mobile phone, a smartphone, a tablet terminal, or the like. The communication device is capable of communicating with other mobile communication terminals and fixed communication terminals by transmitting and receiving audio signals. Note that the communication device is not limited to one that transmits and receives audio signals, and may be one that only transmits audio signals and does not receive audio signals, for example.

FIG. 1 shows a configuration example of a communication device 100 according to an embodiment of the invention. The communication device 100 includes an audio processing section 110, a storage section 120, a control section 130, an input/output section 140, and a communication processing section 150. Further, a microphone 111 and a speaker 112 are connected to the audio processing section 110. The microphone 111 and the speaker 112 may be built into the communication device 100 or may be externally attached to the communication device 100. Note that when the communication device 100 only transmits audio signals, a configuration may be adopted in which the speaker 112 is connected to the audio processing unit 110 but the microphone 111 is not provided. Each part of the communication device 100 is connected to each other via an internal bus so that electrical signals can be transmitted between them.

The audio processing unit 110 uses, for example, a digital signal processor (DSP), a digital-to-analog converter (DAC), and an analog-to-digital converter (ADC). The control unit 130 cooperates with the control unit 130 to execute signal processing for transmitting and receiving audio signals. The signal processing by the audio processing unit 110 includes processing for outputting an audio signal from the speaker 111 based on the transmitted data, and processing for acquiring received data based on the audio signal input to the microphone 112. . Audio signals are used as carrier waves for transmitting various data. The audio processing unit 110 converts a digital signal corresponding to the transmission data into analog and supplies it to the speaker 111, thereby outputting an audio signal. The audio processing unit 110 also digitally converts an analog signal corresponding to the audio signal input to the microphone 112 to obtain received data.

The storage unit 120 includes, for example, RAM (Random Access Memory), ROM (Read Only Memory), flash memory, etc., and stores various information, fixed data, applications, screen data, terminal ID, and the control unit 130 for various processing. Stores programs, etc. for executing. The programs executed by the control unit 130 include a sending program 121 and a receiving program 122. When the control unit 130 executes the transmission program 121, the communication device 100 functions as a transmitter. When the control unit 130 executes the reception program 122, the communication device 100 functions as a receiver. The transmission program 121 and the reception program 122 may be prepared as separate programs or may be prepared as a single program.

The control unit 130 includes, for example, a microprocessor such as a CPU (Central Processing Unit), and executes a program stored in the storage unit 120 to control communication using audio signals. The control unit 130 may control the communication device 100 to switch to either a transmitter or a receiver by executing either the transmission program 121 or the reception program 122. Alternatively, the control unit 130 may control the communication device 100 to function as both a transmitter and a receiver by executing the transmission program 121 and the reception program 122 in parallel.

The input/output unit 140 includes a keypad, a liquid crystal display, a light emitting diode, etc., and provides an interface for inputting or outputting various information. Note that the communication device 100 may have a configuration in which part or all of the input/output unit 140 is not provided. The microphone 111 and the speaker 112 may constitute part of the input/output section 140.

The communication processing unit 150 includes, for example, an antenna, an RF (Radio Frequency) signal processing circuit, a baseband signal processing circuit, etc., and is connected to a mobile communication network, a short-range wireless communication network, a wired communication network, the Internet, or any other electrical Executes processing for communicating with external devices via part or all of a communication network.

The communication device 100 communicates using a plurality of frequency channels in an audio signal by switching between a plurality of frequency channels and transmitting symbols using a frequency hopping method (Frequency Hopping: FH). The communication device 100 uses, for example, an audio signal in an inaudible band as a carrier wave. In this way, if a voice signal in the inaudible band is used for communication, it will be impossible or difficult for humans to hear, so the user of the communication device 100 will not feel any noise and will not feel uncomfortable. It can be prevented.

In the communication device 100, the control unit 130 executes the transmission program 121 and cooperates with the audio processing unit 110, thereby functioning as the transmitter 500. In this way, the transmitter 500 is realized by the execution of the transmission program 121 by the control unit 130, and has various functional configurations.

FIG. 2 shows a configuration example of the transmitter 500. The transmitter 500 includes a primary modulation section 501, a serial-to-parallel conversion section 502, a hopping pattern generation section 503, a hopping frequency generation section 504, a frequency conversion section 505, a window processing section 506, and a parallel-to-serial conversion section 507. , is provided. These functional configurations may be constructed by cooperation of software and hardware resources, and information processing by software may be realized using hardware resources.

The primary modulation section 501 performs modulation according to the bit value of transmission data, for example, by narrowband modulation such as frequency shift keying (FSK). At this time, the transmission data may be divided into a predetermined size, such as one bit, and the frequency of the modulated signal may be shifted for each symbol period to which each divided data is allocated. Note that the present invention is not limited to dividing transmission data into bits, and may be MFSK (M-ary FSK) in which multiple bits of transmission data are collectively converted into symbols and multiple frequencies are used. However, in communication using audio signals, it is difficult to use MFKS because the usable band is limited. The transmission data may be data read from the storage unit 120 or may be data created through processing by the control unit 130.

The serial-to-parallel converter 502 receives the modulated signal from the primary modulator 501 and converts this input signal from a serial signal system to a parallel signal system. At this time, an input signal of a serial signaling system corresponding to a symbol sequence in which a plurality of symbols are consecutive is outputted as a signal in a symbol interval divided into unit intervals in a parallel signaling system. This output signal may be a signal having a frequency corresponding to a symbol value transmitted in each symbol period for each of a plurality of frequency channels. Therefore, serial-parallel conversion section 502 outputs a signal obtained by dividing the symbol sequence into unit intervals. The signal converted into a parallel signal system by the serial-parallel converter 502 is supplied to the frequency converter 505.

Hopping pattern generation section 503 generates a preset hopping pattern. A hopping control signal corresponding to the generated hopping pattern is supplied to hopping frequency generation section 504. The hopping control signal may be any signal that controls switching of the output frequency of the hopping frequency generation section 504 in accordance with a preset hopping pattern. Hopping frequency generation section 504 switches the frequency of the tone signal, for example, according to a hopping control signal from hopping pattern generation section 503 and supplies it to frequency conversion section 505 .

The frequency converter 505 converts the signal supplied from the serial-parallel converter 502 into a signal in an audio frequency band corresponding to a plurality of frequency channels. For example, the signal supplied from the serial-parallel converter 502 may be multiplied by the signal supplied from the hopping frequency generator 504. As a result, a plurality of channel signals are generated in which symbols are assigned to a plurality of frequency channels in correspondence with a plurality of symbol periods for respectively transmitting a plurality of symbols. Each channel signal may be any signal that forms a localized wave in a symbol period. Therefore, frequency conversion section 505 generates a plurality of channel signals in which the signal obtained by dividing the symbol sequence into unit intervals by serial-parallel conversion section 502 is assigned to a plurality of frequency channels used for frequency hopping. The channel signal output from frequency conversion section 505 is input to window processing section 506. The window processing unit 506 functions as a bandpass filter to remove unnecessary frequency components. This prevents intersymbol interference from occurring. Thereafter, each channel signal is input to a parallel-to-serial converter 507.

The parallel-to-serial conversion unit 507 receives the output signal from the window processing unit 506, and converts the parallel signal system into the serial signal system by supplying this input signal to an adder. At this time, in a plurality of frequency channels, a symbol period in which symbols are transmitted in another frequency channel is started at a shorter interval than a symbol period in which symbols are transmitted in one frequency channel. In this way, when performing serialization to convert from a parallel signaling system to a serial signaling system, the intervals between symbols assigned to a plurality of frequency channels are shortened to be shorter than the symbol period required for symbol transmission in each frequency channel. Then, part of the symbol period in which transmission is started first becomes the same period as a part of the symbol period in which transmission is started later, so that frequency hopping is performed while overlapping symbols.

For example, in the case of FSK, which converts 1-bit data into a symbol, in conventional frequency hopping, if the symbol length is Ts, the maximum communication speed is 1/Ts [bps]. On the other hand, by reducing the interval between symbols assigned to multiple frequency channels to be shorter than the symbol period required for symbol transmission in each frequency channel, the communication speed can be made faster than 1/Ts [bps]. can.

The signal converted into a serial signal format by the parallel-serial conversion section 507 may be supplied to the DAC of the audio processing section 110 as an audio output signal and converted into an analog signal. The audio output signal thus converted into an analog signal is supplied to the speaker 112 and output as an audio signal.

FIG. 3 illustrates a frequency hopping signal depending on the presence or absence of channel multiplexing, which is a process of overlapping symbols assigned to multiple frequency channels. Here, a case is shown in which the hopping rate is the same as the symbol rate among FFH (Fast-FH) where the hopping rate is equal to or higher than the symbol rate. Further, eight frequency channels Ch0 to Ch7 are used as the plurality of frequency channels. Note that SFH (Slow-FH) in which the hopping rate is less than the symbol rate may be used. FFH may be used in which the hopping rate is higher than the symbol rate. Channel multiplexing in this embodiment does not mean that all of the periods during which symbols are transmitted in multiple frequency channels overlap, but rather a portion ( The second half) may overlap with a portion (the first half) of the period in which symbol transmission is later started on the second channel included in the plurality of frequency channels.

FIG. 3(a) shows a case without channel multiplexing, in which symbols are transmitted by one frequency channel included in multiple frequency channels at the same interval as the symbol period, and other frequencies included in multiple frequency channels are transmitted. Initiate a symbol period for transmitting symbols over the channel. For example, in the case shown in FIG. 3A, during the symbol transmission period from timing T0 to timing T1, symbols are transmitted by frequency channel Ch0, and symbols are not transmitted by other frequency channels. At timing T1, frequency hopping is performed to switch the frequency used for symbol transmission. As a result, during the symbol transmission period from timing T1 to timing T2, symbols are transmitted by frequency channel Ch2, and symbols are not transmitted by other frequency channels.

FIG. 3B shows a case with channel multiplexing, in which the intervals between symbols assigned to a plurality of frequency channels are shortened to time Ts/3, which is 1/3 of the symbol length Ts. In other words, a symbol period in which a symbol is transmitted by another frequency channel included in a plurality of frequency channels at a time Ts/3 that is a shorter interval than a symbol period in which a symbol is transmitted by one frequency channel included in the plurality of frequency channels. start. Note that until the symbol period set corresponding to one frequency channel ends, even if a symbol period for transmitting symbols using another frequency channel has started, the symbol transmission using the first frequency channel that started earlier will not be possible. will continue to be carried out. Therefore, a part of the symbol period in one frequency channel is the same as a part of the symbol period in another frequency channel, so that frequency hopping is performed while overlapping symbols.

In the case shown in FIG. 3(b), from timing T0 to timing T1 is a symbol period in which symbols are transmitted by frequency channel Ch0, as in the case shown in FIG. 3(a). On the other hand, in the case shown in FIG. 3(b), unlike the case shown in FIG. 3(a), symbol transmission using another frequency channel is started from timing T0 to timing T1. For example, at timing T01 when time Ts/3 has elapsed from timing T0, symbol transmission via frequency channel Ch2 is started. Furthermore, at timing T02 when time Ts/3 has elapsed from timing T01, symbol transmission via frequency channel Ch6 is started. Symbol transmission by frequency channel Ch2, which started at timing T01, continues until timing T11. Symbol transmission by frequency channel Ch6, which started at timing T02, continues until timing T12.

When the period from timing T0 to timing T1 shown in FIG. 3(b) is defined as a first period, and the period from timing T01 to timing T11 is defined as a second period, one frequency channel Ch0 included in the plurality of frequency channels A second period in which symbols are transmitted using another frequency channel Ch2 included in the plurality of frequency channels is started at an interval shorter than the first period in which symbols are transmitted using Ch2. Also, the period from timing T01 to timing T1, which is included in a part of the first period from timing T0 to timing T1, is from timing T01 to timing T1, which is included in a part of the second period from timing T01 to timing T11. It is the same period that overlaps with the period of .

If the period from timing T01 to timing T11 shown in FIG. 3(b) is the first period, and the period from timing T02 to timing T12 is the second period, one frequency channel Ch2 included in the plurality of frequency channels A second period in which symbols are transmitted using another frequency channel Ch6 included in the plurality of frequency channels is started at an interval shorter than the first period in which symbols are transmitted using Ch6. Also, the period from timing T02 to timing T11, which is included in a part of the first period from timing T01 to timing T11, is from timing T02 to timing T11, which is included in a part of the second period from timing T02 to timing T12. It is the same period that overlaps with the period of .

In the period from timing T02 to timing T1 shown in FIG. 3(b), three symbols based on frequency channels Ch0, Ch2, and Ch6 are multiplexed and transmitted. In each subsequent period as well, three symbols are similarly multiplexed and transmitted. In this way, when the symbol interval is shortened to the time Ts/3, which is 1/3 of the symbol length Ts, and the transmission speed is reduced to 3/3, which is 3 times the communication speed compared to the case without channel multiplexing. The speed can be increased to Ts. Note that the amount of reduction to shorten the symbol interval may be determined in advance as a communication specification, and may be smaller than 1/3, such as 1/2, or 1/4, for example. The amount of shortening may be greater than /3. In any case, the communication speed can be increased by transmitting the symbols at shorter intervals. In the example shown in FIG. 3, the hopping rate is the same as the symbol rate, so one symbol is multiplexed with other symbols and transmitted. On the other hand, in the case of FFH where the hopping rate is higher than the symbol rate, channel multiplexing may be performed so that localized waves corresponding to multiple chips transmitting one symbol overlap. For example, in the case shown in FIG. 3A, one symbol may be transmitted using a symbol transmission period from timing T0 to timing T1 and a symbol transmission period from timing T1 to timing T2. In this case, in the first period from timing T0 to timing T1 shown in FIG. 3(b), one symbol common to the second period from timing T01 to timing T11 is transmitted. The period from timing T01 to timing T1, which is included in part in the first period from timing T0 to timing T1, is from timing T01 to timing T1, which is included in part in the second period from timing T01 to timing T11. It is the same period that overlaps with the period of . In this case as well, it is possible to transmit symbols with shortened intervals, and furthermore, by shortening the interval between chips for transmitting one symbol and transmitting them, the communication speed can be increased.

However, since the audio signal is transmitted by air vibration, it is easily influenced by the operating state of the communication device 100 and the surrounding environment. Therefore, if the symbol intervals are made too short, a problem arises in that symbols transmitted on the same frequency channel are susceptible to interference due to a multipath environment. Also, because part of the symbol period in which transmission started first is the same as part of the symbol period in which transmission started later, the frequency interval becomes narrower when frequency hopping is performed while overlapping symbols. If it is too large, a problem arises in that it becomes susceptible to interference due to Doppler shift. In order to solve these problems, a pattern that satisfies predetermined conditions is set in advance as a hopping pattern generated by the hopping pattern generation unit 503.

FIG. 4 is a flowchart illustrating an example of a hopping pattern creation process executed to create a hopping pattern. The hopping pattern creation process may be executed according to a program read from the storage unit 120 by the control unit 130 of the communication device 100, or may be executed using a computer system different from the communication device 100. The hopping pattern created by the hopping pattern creation process is stored in the storage unit 120 of the communication device 100 and used by the hopping pattern generation unit 503. In this hopping pattern creation process, first, the initial value "0" of variable i is set (step S101).

Next, the series value Pn[i] indicated using the variable i in the hopping pattern is determined (step S102). The sequence value Pn[i] is the i+1st sequence value in the hopping pattern, and indicates the number of the frequency channel used for symbol transmission. For example, when variable i=0, the first (initial) series value Pn[0] is determined to be an arbitrary value. If the variation i≧1, the sequence value Pn[i] is determined by a random number generated using a random number generator, such as a PN sequence generator.

Next, it is determined whether or not the determined series value Pn[i] is the same as the previously determined series value Pn[i-j] (step S103). Here, the variable j is an integer in the range of 1 to m, and the constant m may be determined in advance as a specification of the hopping pattern. In step S103, if the same sequence value Pn[i] determined this time is included among the sequence values determined one to m times before the current determination, the same sequence value Pn[i] is determined. What is necessary is to determine that it is. If the series value Pn[i] is the same as the series value Pn[ij] (step S103; Yes), the process returns to step S102 and the series value Pn[i] is determined again.

If the sequence value Pn[i] is not the same as the sequence value Pn[i-j] (step S103; No), the sequence value Pn[i] determined this time and the sequence value Pn[i -1] to determine whether the difference is included in range k (step S104). The variable k indicating the range k is an integer in the range of 1 to n, and the constant n may be determined in advance as a specification of the hopping pattern. The difference between the sequence value Pn[i] and the sequence value Pn[i-1] is also called a hopping distance, and corresponds to the frequency interval in the frequency channel to be switched by frequency hopping. In step S104, the difference between the series value Pn[i] determined this time and the series value Pn[i-1] determined last time is calculated using a predetermined constant n (positive integer) to be greater than or equal to n. If the difference is within the following range, it may be determined that the difference is included in the range k. If it is included in this range k (step S104; Yes), the process returns to step S102 and the series value Pn[i] is determined again. Note that in step S104, regarding the currently determined series value Pn[i], not only the difference from the previously determined series value Pn[i-1] but also the previously determined series value Pn[i-j '] may be determined as to whether or not the difference is included in the range k. The variable j' is an integer of 2 or more, and may be determined in advance as a specification of the hopping pattern so as to prevent interference due to Doppler shift. The processing when it is included in the range k and the processing when it is not included in the range k may be the same as in the case of the difference with the series value Pn[i-1].

If the difference is not included in the range k (step S104; No), it is determined whether the variable i has reached the creation upper limit (step S105). If it is not the creation upper limit value (step S105; No), the variable i is updated to add 1 (step S106), and the process returns to step S102 to determine the next series value.

If the variable i is the creation upper limit value (step S105; Yes), a predetermined cyclic check is performed to determine whether it satisfies a predetermined criterion (step S107). For example, if the beginning and end of the hopping pattern determined in steps S101 to S106 are connected, it may be determined whether the same conditions as in steps S103 and S104 are satisfied.

If the cyclic check result does not satisfy the conditions (step S107; No), part or all of the hopping pattern is re-determined as cyclic re-determination (step S108). For example, for the tail part of the hopping pattern, the series values may be determined again so as to satisfy the same conditions as in steps S103 and S104.

When the patrol check result satisfies the conditions (step S107; Yes), or after the patrol re-determination is performed, a predetermined quality evaluation is performed to determine whether or not predetermined criteria are met (step S109). For example, when the autocorrelation function is calculated using the series values of the determined hopping pattern, it is determined whether the S/N ratio (Signal-to-Noise Ratio) is greater than or equal to a predetermined reference value. good. Furthermore, when the correlation function between the whole series value of the determined hopping pattern and a part thereof is calculated, it may be determined whether the S/N ratio is equal to or higher than a predetermined reference value.

If the quality evaluation result does not satisfy the conditions (step S109; No), the hopping pattern is re-determined for quality (step S110). For example, the hopping pattern may be determined again by executing steps S101 to S108 again. Note that, among a plurality of hopping patterns determined by performing steps S101 to S108 a plurality of times, a hopping pattern with the highest S/N ratio when the autocorrelation function is calculated may be selected. Also, among a plurality of hopping patterns determined by executing steps S101 to S108 multiple times, the hopping with the highest S/N ratio when calculating the correlation function between all and some of the series values is selected. You may choose a pattern.

In such a hopping pattern creation process, if the interval between symbols transmitted by the same frequency channel is less than a specific time in a plurality of frequency channels, it is assumed that the conformity condition determined in step S103 is not satisfied, and the sequence value is will be redetermined. Furthermore, if the frequency interval of a frequency channel selected by frequency hopping once or multiple times is less than a specific frequency in a plurality of frequency channels, it is assumed that the conformity condition determined in step S104 is not satisfied, and the series value is Redetermination takes place. The hopping pattern created in this way is stored in the storage unit 120 and set in advance as a hopping pattern to be generated by the hopping pattern generation unit 503. Therefore, in a plurality of frequency channels, frequency hopping is performed using a hopping pattern that is set so that the interval between symbols transmitted through the same frequency channel is equal to or longer than a specific time. In addition, when frequency hopping is performed a predetermined number of times in multiple frequency channels and symbols are transmitted using different frequency channels, the frequency interval in one or more frequency hoppings is equal to or greater than a specific frequency. Frequency hopping is performed using the set hopping pattern so that the interval is equal to or greater than a specific frequency. In this way, the hopping pattern is set so that the frequency channel changed by frequency hopping satisfies the predetermined time compatibility condition of the usage interval of the same frequency channel. In addition, a hopping pattern is set such that the frequency channel after frequency hopping satisfies a predetermined frequency compatibility condition, which is a frequency interval with respect to one or more frequency channels used before the change. . This makes it less susceptible to the operating environment and surrounding environment of the communication device 100, such as the influence of interference due to a multipath environment and the influence of interference due to Doppler shift, and it is possible to improve the quality of communication using audio signals. .

Hopping frequency generation section 504 switches the output frequency according to the hopping control signal corresponding to the hopping pattern generated by hopping pattern generation section 503 and supplies the output frequency to frequency conversion section 505 . Frequency converter 505 multiplies the signal supplied from serial-parallel converter 502 by the signal supplied from hopping frequency generator 504, thereby generating a channel signal that forms a localized wave in a symbol period. In a channel signal corresponding to a plurality of frequency channels, adjacent localized waves in the time domain have an interval of a specific time or more, and adjacent localized waves in the frequency domain have an interval of a specific frequency or more. In this way, by generating a hopping pattern in which localized waves are arranged so that they do not overlap, mutual interference can be avoided and the quality of communication using voice signals can be improved.

FIG. 5 shows an example of determining a hopping pattern. Here, in order to execute the hopping pattern creation process of FIG. 4, the predetermined constants m=6 and constants n=1 are used. That is, if the same sequence value is included among the sequence values determined six times before, the process returns to step S102 and the sequence value is determined again based on the determination result in step S103. If the difference from the previously determined series value is ±1, the process returns to step S102 and the series value is determined again based on the determination result in step S104.

FIG. 5A shows an example of determining the hopping pattern HP01, which includes sequence values that do not satisfy the conditions of step S103 and sequence values that do not satisfy the conditions of step S104. For example, when variable i=6 and when variable i=8, the series value Pn[i]=6, but in step S103, when variable i=8 and variable j=2, Pn[8]=Pn [6], and it is determined that they are the same. Further, when the variable i=11, the series value Pn[i]=0, and when the variable i=12, the series value Pn[i]=1, but in step S104, when the variable i=12, the series value Pn[i]=0. Pn[12]=Pn[11]+1, and it is determined that the difference is included in range k.

FIG. 5B is an example of determining the hopping pattern HP02, and does not include sequence values that do not satisfy the conditions of step S103 or sequence values that do not satisfy the conditions of step S104. In the hopping pattern HP02, the sequence value Pn[3]=2 when the variable i=3, the sequence value Pn[4]=0 when the variable i=4, and the sequence value Pn when the variable i=5. [5]=4, series value when variable i=8 Pn[8]=3, series value when variable i=9 Pn[9]=5, series value when variable i=12 Pn[12]=2, sequence value when variable i=13 Pn[13]=6, sequence value when variable i=14 Pn[14]=4, sequence when variable i=15 The value Pn[15]=1 has been changed from the hopping pattern HP01.

In the communication device 100, the control unit 130 executes the reception program 122 and cooperates with the audio processing unit 110, thereby functioning as a receiver. The receiver obtains received data from the received audio signal using a method that is opposite to the method used by transmitter 500 to create an audio signal corresponding to the transmitted data. Alternatively, some or all of the receiving method may be modified in order to obtain a more reliable received data output than simply using the reverse method of the transmitting method. The communication device 100 serving as a receiver is realized by the execution of the reception program 122 by the control unit 130, and has various functional configurations.

FIG. 6 shows a configuration example of a communication system 1 to which the communication device 100 can be applied. The communication system 1 includes a user terminal 10 owned by a user and a store terminal 20 installed in a store. The above-described communication device 100 is applied as the user terminal 10 and the store terminal 20, and they communicate with each other by transmitting and receiving audio signals.

In the communication system 1, for example, when a user visits a store, the user terminal 10 transmits information for identifying the user to the store terminal 20. In response to the information received from the user terminal 10, the store terminal 20 can send back various store information and the like. The store information may include product information, service information, schedule information, point allocation information, location information, some or all of these information, and any other information regarding the store.

Communication system 1 may be used as a payment system. In this case, the store terminal 20 executes various processes as a payment terminal. For example, when purchasing a product, the user terminal 10 transmits a user ID (Identifier) to the store terminal 20 by communication using an audio signal in response to a user's operation. The store terminal 20 performs payment processing using the user ID received from the user terminal 10 and the payment amount obtained in the procedure at the time of product purchase. In the payment process, for example, the store terminal 20 transmits a user ID and a payment amount to a payment server connected via a telecommunications network, and receives an authentication result and a payment result from the payment server. After executing the payment process, the store terminal 20 transmits the authentication result and the payment result to the user terminal 10 through communication using an audio signal. The user terminal 10 that has received the authentication result and the payment result notifies the user that the payment has been completed or that an error has occurred by displaying the screen, outputting audio, or the like.

As described above, in communication using a plurality of frequency channels by frequency hopping of an audio signal, the communication device 100 starts from the first period in which symbols are transmitted using one frequency channel included in the plurality of frequency channels. A second period in which symbols are transmitted using another frequency channel included in the plurality of frequency channels is started at short intervals, and a part of the first period and a part of the second period overlap and become the same. It will be a period. This makes it possible to increase the communication speed when using voice signals and increase the amount of communication data.

By performing frequency hopping using the hopping pattern created by the hopping pattern creation process shown in FIG. 4, the interval between symbols transmitted through the same frequency channel becomes longer than a specific time in multiple frequency channels. . This makes it possible to reduce the influence of interference caused by a multipath environment, improve the quality of communication using audio signals, and prevent a decrease in communication speed.

By performing frequency hopping using the hopping pattern created by the hopping pattern creation process shown in FIG. 4, the interval between frequencies in one frequency hopping becomes equal to or more than a specific frequency. Thereby, it is possible to reduce the influence of interference due to Doppler shift, improve the quality of communication using voice signals, and prevent a decrease in communication speed.

This invention is not limited to the embodiments described above, and various modifications and applications are possible. For example, the communication device 100 does not need to have all the technical features shown in the above embodiments, but may have the configuration shown in the above embodiments so as to solve at least one problem in the prior art. It may also be something that enables a part of a function or operation.

Signals and information may be represented using any number of technologies, such as data, instructions, instructions, information, signals, bits, symbols, channels, voltages, currents, electromagnetic waves, magnetic fields or particles, photoelectric fields or particles, etc. , may be represented by a combination of some or all of these. The communication device 100 described in the above embodiment and the communication method thereof may be applied when performing wireless communication using electromagnetic wave signals without being limited to communication using audio signals.

The logical blocks, modules, circuits, processing steps, and algorithms that realize the configuration, functions, and operations of the communication device 100 may be implemented as hardware such as electronic circuits, software such as computer programs, or a combination thereof. Bye. For example, application software for realizing the functions of the communication device 100 described in the above embodiment is provided, and by installing it on an information communication device such as a smartphone, voice communication can be performed without adding new dedicated hardware. It is sufficient if communication using signals becomes possible.

The logic blocks, modules, and circuits that realize the configuration, functions, and operations of the communication device 100 include a general-purpose microprocessor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), It may be implemented as a programmable logic device including an FPGA (Field Programmable Gate Array), another semiconductor integrated circuit, or a combination thereof.

Software that implements the configuration, functionality, and operation of communication device 100 may be stored or transmitted as one or more instructions or codes on various computer-readable media. Various computer readable media may be storage media or communication media. The storage medium can be configured using any storage device such as RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage, semiconductor storage. The communication medium can be configured using any signal transmission medium, such as wired, infrared, wireless, microwave, or ultrasound.

1 Communication system 10 User terminal 20 Store terminal 100 Communication device 110 Audio processing section 111 Microphone 112 Speaker 120 Storage section 121 Transmission program 122 Reception program 130 Control section 140 Input/output section 150 Communication processing section 500 Transmitter 501 Primary modulation section 502 Serial parallel Conversion unit 503 Hopping pattern generation unit 504 Hopping frequency generation unit 505 Frequency conversion unit 506 Window processing unit 507 Parallel-serial conversion unit

Claims (5)

A communication device that communicates using multiple frequency channels by frequency hopping of audio signals, the communication device comprising:
A second period in which symbols are transmitted using another frequency channel included in the plurality of frequency channels at intervals shorter than a first period in which symbols are transmitted using one frequency channel included in the plurality of frequency channels. a period is started, and frequency hopping is performed so that a portion of the first period and a portion of the second period overlap;
A communication device characterized by: In the plurality of frequency channels, frequency hopping is performed using a set hopping pattern such that the interval between symbols transmitted by the same frequency channel is a specific time or more.
The communication device according to claim 1, characterized in that: In the plurality of frequency channels, frequency hopping is performed using a set hopping pattern so that when frequency hopping is performed and symbols are transmitted using different frequency channels, the frequency interval is equal to or greater than a specific frequency.
The communication device according to claim 1 or 2, characterized in that: A communication method for communicating using multiple frequency channels by frequency hopping of audio signals, the method comprising:
A second period in which symbols are transmitted using another frequency channel included in the plurality of frequency channels at intervals shorter than a first period in which symbols are transmitted using one frequency channel included in the plurality of frequency channels. a period is started, and frequency hopping is performed so that a portion of the first period and a portion of the second period overlap;
A communication method characterized by: computer,
It functions as a signal processing means for communicating using multiple frequency channels by frequency hopping the audio signal,
The signal processing means uses another frequency channel included in the plurality of frequency channels at an interval shorter than a first period in which symbols are transmitted using one frequency channel included in the plurality of frequency channels. A second period for transmitting symbols is started, and frequency hopping is performed such that a part of the first period and a part of the second period overlap.
A program characterized by:

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