JPH1084301A - Radio communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To complete a synchronization establishment in a short time by allowing a receiver party to easily acquire synchronization for communication start processing even when a sender communication equipment changes a resident time depending on kinds of communication data such as voice data and non-voice data. SOLUTION: In the case of making bydirectional communication between communication equipments while hopping the frequency according to a prescribed hopping pattern by the frequency hopping system, number of hops (L, K, M) and a resident time (tL, tK, tM) of the hopping pattern are devised to be revised so that a circulation time T1 for the frequency hopping by the hopping pattern is made constant.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio communication system for performing bidirectional communication between communication devices while switching frequencies according to a predetermined hopping pattern by a frequency hopping method.

[0002]

2. Description of the Related Art In recent years, a spread spectrum wireless communication system that obtains communication data by despreading and demodulating a received signal while modulating and transmitting communication data after modulation has been developed. Attention has been focused on enabling low power density communications. In particular, when performing spread and despreading by frequency hopping in which the frequency is sequentially switched during transmission and reception by the spread spectrum method, the confidentiality of the signal becomes extremely high. Therefore, the spread spectrum wireless communication using the frequency hopping is applied. Systems are about to be widely adopted in various fields such as telephones and facsimile machines.

Conventionally, in a radio communication system of the above-mentioned method, the same hop table having hop frequency data indicating spreading and despreading patterns for a predetermined channel is provided in all communication devices, and the hopping pattern of this hop table is provided. Therefore, communication between the communication devices is performed while frequency hopping is performed at every fixed residence time. Here, the channel indicates a frequency.

That is, for example, when communication is performed from a master communication device to a specific slave communication device, first,
In the communication start process, a paging signal including ID data of the child device is formed by the parent device, and this paging signal is transmitted as a spread modulation signal while being frequency-hopped every fixed dwell time. At this time, the slave unit is made to stand by to receive a spread modulation signal of a predetermined frequency, and when a spread modulation signal from the master unit is captured, a frequency of a frequency according to a hopping pattern is determined for each residence time. Switching is performed so that the call signal from the base unit is despread and received. Thereafter, after establishing synchronization between the master unit and the slave unit, a communication process of continuously transmitting and receiving communication data such as voice data is performed by repeatedly performing frequency hopping in the master unit and the slave unit. It has become.

[0005]

However, in a configuration in which frequency hopping is performed at a fixed hop number (the number of channels) based on a hopping pattern and at a constant dwell time as in the above-described conventional technique, the hop number and the dwell time are fixed. Therefore, regardless of whether any data is communicated between voice data that emphasizes high confidentiality and non-voice data that emphasizes high data transfer rate, the conditions of these confidentiality and data transfer rate It is necessary to set the number of hops corresponding to the voice data and the dwell time corresponding to the non-voice data so as to satisfy the following. Therefore, the cycle time of frequency hopping, which is an integrated value of the number of hops and the dwell time, is larger than the case where the hop number and the dwell time are determined by focusing on one of the voice data and the non-voice data, There is a problem that it takes a long time to establish synchronization during communication start processing.

Therefore, it is conceivable to reduce the cycle time of frequency hopping by reducing the residence time in the case of voice data in the calling communication device. However, in this case, since the round trip time after the change is unknown in the called communication device, the called communication device waits for reception with a stay time corresponding to the non-voice data. Therefore, since the round-trip time differs between the calling side and the called side, it is difficult to acquire synchronization during the communication start processing, and as a result, it takes a long time to establish synchronization.

Accordingly, the present invention provides a method for capturing synchronization at the time of communication start processing on the called side even when the calling side communication device changes the dwell time in accordance with the type of communication data such as voice data or non-voice data. An object of the present invention is to provide a wireless communication system that can easily perform the synchronization and can complete the establishment of the synchronization in a short time.

[0008]

In order to solve the above-mentioned problems, a first aspect of the present invention is a radio communication system for performing bidirectional communication between communication apparatuses while switching frequencies according to a predetermined hopping pattern by a frequency hopping method. Wherein the number of hops and the dwell time of the hopping pattern can be changed so that the repetition period of the frequency hopping by the hopping pattern becomes constant. Thus, even if the calling communication device changes the dwell time according to the type of communication data such as voice data and non-voice data, the number of hops in the hopping pattern is adjusted so that the cycle time of frequency hopping is constant. In order to change the setting, the called party sets the reception standby time to one round time so that reception failure or continuation, switching of the standby frequency, etc. can be determined in the minimum time required. Become. Therefore, the synchronization can be easily acquired at the time of the communication start processing, and the establishment of the synchronization can be completed in a short time.

According to a second aspect of the present invention, in the wireless communication system according to the first aspect, at the time of communication start processing, the called communication device waits for reception at one of the frequencies of the hopping pattern. The frequency hopping is started after receiving the signal of the communication device on the calling side. Accordingly, the reception of the hopping pattern is repeated at one frequency of the hopping pattern at the time of the communication start processing, so that the signal from the communication device on the calling side can be reliably received by repeatedly calling the hopping pattern.

According to a third aspect of the present invention, in the wireless communication system according to the first aspect, at the time of communication start processing, the called communication device waits for reception at one of the frequencies of the hopping pattern, When the frequency is interfered, the process of waiting for reception at one of the remaining frequencies is repeated until a predetermined frequency is reached, and after receiving a signal from the calling communication device, frequency hopping is started. It is characterized by: Thereby, even if one or more frequencies of the hopping pattern at the time of the communication start processing are receiving interference, it is possible to receive the signal from the calling side communication device at the remaining frequencies, Communication start processing can be performed stably.

According to a fourth aspect of the present invention, in the wireless communication system according to the second or third aspect, a period during which the called-side communication device waits for reception at the one frequency is equal to the repetition period of the frequency hopping. Or an integral multiple thereof. Thereby, since the frequency is set to be equal to or an integral multiple of the frequency hopping repetition cycle, synchronization acquisition at the time of communication start processing can be performed more easily.

According to a fifth aspect of the present invention, there is provided the wireless communication system according to any one of the first to fourth aspects, wherein during communication of a voice signal, the residence time is shortened and the number of hops is increased. . As a result, even when the residence time is shortened and the data transfer amount per hop is reduced, the obstacle at the time of transmission / reception is extremely small for the voice signal, and the high confidentiality, which is a great merit for the voice signal, is obtained by increasing the number of hops. Obtainable.

According to a sixth aspect of the present invention, in the wireless communication system according to any one of the first to fourth aspects, when a non-voice signal is communicated, the dwell time is lengthened and the number of hops is reduced. I have. Thereby, the data transfer amount per hop increases due to the long residence time, so that the communication of the non-voice signal can be completed in a short time.

According to a seventh aspect of the present invention, there is provided the wireless communication system according to any one of the first to fourth aspects, wherein when communication is performed while performing frequency hopping, as the interference increases, the residence time is shortened and the number of hops is reduced. It is characterized by increasing. As a result, by increasing the number of hops,
The probability of interference during communication can be reduced.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIGS. As shown in FIG. 3, the wireless communication system according to the present embodiment has one master device 10 (communication device) connected to an external line, and can communicate with the master device 10 and can communicate with each other. Units 11-15
(Communication device). Note that a telephone, a facsimile device, a printer, a computer, and the like can be applied to the master device 10 and the slave devices 11 to 15. Communication between master device 10 and slave devices 11 to 15 and communication between slave devices 11 to 15 are, as shown in FIG.
uplex) system, and when one is in the transmission state (TX), the other is in the reception state (RX), and communication is performed by alternately replacing the transmission state (TX) and the reception state (RX). It is supposed to do.
Note that this wireless communication system uses TDMA (Time Division M
The communication may be performed by a utiple access) method.

The master unit 10 and the slave units 11 to 15 are
As shown in FIG. 5, there is a wireless communication unit 1 for transmitting and receiving communication data by a spread spectrum method while frequency hopping. The wireless communication unit 1 has an interface unit 21 that processes and inputs and outputs communication data to and from an external circuit (not shown). Interface unit 2
1 includes a codec and a compressor for mutually converting between voice data and a digital signal when the communication data is voice data, and performs buffering and error correction processing when the communication data is non-voice data. It has a data converter to perform.

The interface unit 21 is connected to a modulator / demodulator 22 having a modulator 22a for modulating communication data and a demodulator 22b for demodulating communication data. The modulator / demodulator 22 switches the operating state of the modulator 22a and the demodulator 22b between transmission and reception of communication data by a transmission command signal p and a reception command signal q from the controller 35. Then, the modulation section 22a operated at the time of transmission is connected to an up-converter 23 having a mixer.

The up converter 23 includes a PLL.
A local oscillator 25 is connected to the PLL local oscillator 2
5, hop frequency data f1 and f for a plurality of channels (frequency) C1, C2, ..CL, ..CM, ..CN as shown in FIG.
A hop table 26 storing 2, .. fL, .. fM, .. fN is connected. These hop tables 26 and PLL
A hop signal r is input to the local oscillator 25 every predetermined dwell time from the controller 35,
The hop table 26 outputs hop frequency data f corresponding to the channel of the channel setting value S indicated by the hop signal r to the PLL local oscillator 25 every time the hop signal r is input. The up-converter 23 outputs a hop frequency signal (local oscillation signal) s having a frequency corresponding to f. Hereinafter, when a frequency corresponding to specific hop frequency data (for example, f1) is indicated, for example, the frequency (f1)
It will be shown as follows. And the up-converter 23
By adding the hop frequency signal s from the PLL local oscillator 25 and the modulation signal t of the communication data from the modulator 22a, a spread modulation signal u having a spread frequency is obtained.
Is formed.

The up converter 23 is connected to a transmission / reception switch 27 via a power amplifier 24 for amplifying the spread modulation signal u. The transmission command signal p and the reception command signal q are input from the controller 35 to the transmission / reception switch 27. When the transmission designation signal p is input, the operation state is set to the transmission enabled state and the power amplifier 24 Is transmitted from the antenna 28. On the other hand, when the reception command signal q is input, the operation state is set to the receivable state, and the spread modulation signal u received via the antenna 28 is output to the low noise amplifier 31.

The low-noise amplifier 31 is connected to a down-converter 32.
Is amplified and output. The down-converter 32 receives the hop frequency signal s input to the up-converter 23 from the PLL local oscillator 25. The down-converter 32 generates a spread modulation signal based on the hop frequency signal s. The modulated signal t is formed by despreading u, and the modulated signal t is output to the demodulation unit 22b. The demodulation unit 22b demodulates the input modulated signal t and outputs the demodulated signal t to the interface unit 21.

The wireless communication section 1 having the above-described configuration operates by being supplied with power from a power supply section 36. The power supply section 36 controls a part or the controller 35 before a communication start process. The power supply destination is set by the controller 35 so as to limit the power supply to all the wireless communication units 1 except for the power supply destination. That is, the controller 35 controls so as to supply power only to the controller 35 in the sleep mode, and controls so as to supply power except for the transmission unit including the up-converter 23 and the power amplifier 24 in the reception standby mode. In the mode, control is performed to supply power to the entire wireless communication unit 1. Further, even in the communication mode, the power may be supplied except for the up-converter and the power amplifier at the time of reception and excluding the low-noise amplifier and the down-converter at the time of transmission.

The controller 35 for controlling each section as described above executes the communication control routine shown in FIG. The communication control routine includes a paging process for transmitting a paging signal and a receiving process for receiving a paging signal so as to establish synchronization of the spread modulated signal u with the specific base unit 10 or the subunits 11 to 15 in the communication start process. After performing standby processing and establishing synchronization of the spread modulation signal u, the processing shifts to communication processing for transmitting and receiving audio data and the like.

In this communication control routine, the number of hops and the dwell time of the hopping pattern can be changed so that the cycle time (repetition period) of the frequency hopping by the hopping pattern becomes constant. Specifically, at the time of communication of audio data (audio signal), FIG.
As shown in (a), in order to improve confidentiality, the dwell time tL (ms) is reduced to about several milliseconds at which no interruption of voice is recognized by the operator, and the number of hops is increased corresponding to the reduced time. With L (pieces), a hopping pattern that forms frequency hopping for one cycle time T1 is formed.

Also, a computer or facsimile machine,
During communication of non-speech data (non-speech signal) from a printer or the like, as shown in FIG. 1B, in order to improve the data transfer rate, the dwell time tK (ms) increased to about several tens to 100 ms. A hopping pattern that is frequency hopping for one cycle T1 is formed by the number of hops K (pieces) reduced corresponding to the increase.

When interference occurs during the communication of the voice data shown in FIG. 1A, as shown in FIG. 1C, the residence time is further improved in order to further improve the confidentiality and make the interference less likely to occur. Residence time tM (ms) shorter than tL (ms)
And the number of hops M (number) increased corresponding to the shortened amount
Thus, a hopping pattern which is a frequency hopping of the cycle time T1 is formed.

The operation of the wireless communication system in the above configuration will be described with reference to the flowcharts of FIGS.

First, as shown in FIGS. 5 and 6, when the controller 35 executes the sleep mode, the power supply from the power supply section 36 is limited to only the controller 35, and the power consumption is suppressed to a necessary minimum. (S
1). The controller 35 receiving the power supply continues to execute the communication control routine, and determines whether or not an instruction to make a call is made by checking the operation state of a call switch (not shown) or the like (S2). If it is determined that a call is to be made (S2, YES), the stay time t and the number of hops Hn are determined according to the type of communication data and the state of interference. That is, if voice data is to be communicated, for example, as shown in FIGS. 1A to 1C, it is determined that the dwell time t is “tL” ms and the hop number Hn is “L”. If voice data is to be communicated, it is determined that the residence time t is “tK” ms and the number of hops Hn is “K”. If voice data is to be communicated in an environment where interference due to frequency interference occurs, it is determined that the dwell time t is “tM” ms and the number of hops Hn is “M”. (S15). The degree of frequency interference can be determined based on the error rate calculated from the data redundancy. The presence or absence of interference is determined based on whether the error rate exceeds a predetermined reference value. Is determined.

After the residence time t and the number of hops Hn are determined in this manner, the called communication device (master device 1)
0, a calling process for performing communication with the slave units 11 to 15) is executed (S50). When the calling process is executed, first, as shown in FIG. 7, the communication mode is set to start the power supply from the power supply unit 36 in FIG. 5 to each unit of the wireless communication unit 1, and the maximum channel count value Cmax is set to " Hop count H
n "," 1 "for the channel set value S, and" 1 "for the channel count value C (S51).

Thereafter, the controller 35 outputs the transmission command signal p to the modulator / demodulator 22 and the transmission / reception switch 27, thereby setting the modulation section 22a of the modem 22 to the operation state and setting the transmission / reception switch 27 to the transmission state. Set to.
Further, by outputting the hop signal r having the channel setting value “1” to the hop table 26 and the PLL local oscillator 25, the hop frequency data f1 of the first channel C1 is transmitted to the hop table 26 by the PLL local oscillator. The PLL local oscillator 25 outputs the hop frequency signal s having a frequency (f1) corresponding to the hop frequency data f1 to the up converter 23 and the down converter 32.

Next, the parent device 10 and the child devices 11 to 1 on the called side are called.
5 is taken into the modem 22 via the interface unit 21 and modulated by the modulation unit 22a, and then converted into a modulated signal t.
Output to 3. Then, in the up-converter 23, 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 transmitted to the power amplifier 24.
After amplification by the antenna 28 via the transmission / reception switch 27
(S52).

When the call transmission is completed in S52, the controller 35 transmits the reception command signal q to the modem 22.
By setting the output to the transmission / reception switch 27, the demodulation unit 22b of the modem 22 is set to the operation state, the transmission / reception switch 27 is set to the reception state (S53), and the response signal from the called side is received. Is determined (S5).
4). If there is no response (S54, NO), the channel count value C becomes the maximum channel count value Cmax.
It is determined whether the value is smaller than (“hop number Hn”) (S55), and if it is smaller (S55, YE).
S) While the channel set value S and the channel count value C are counted up by "1" (S56), if not small (S55, NO), the channel set value S and the channel count value C are reset to "1". (S57). Then, when the residence time t determined in S15 by the internal timer or the like (not shown) elapses,
The hop signal r indicating the channel set value S is output to the hop table 26 and the PLL local oscillator 25 to perform frequency hopping (S58), and then re-executed from S52 to continue the calling process.

Next, when a response signal from the called side is received (S54, YES), the channel count value C
Is the maximum channel count value Cmax (“Hop number H
n ”) is determined (S5).
9) If the value is small (S59, YES), the channel set value S and the channel count value C are counted up by "1" (S60). If not (S59, NO), the channel set value S is incremented. And the channel count value C is reset to "1" (S61). Then, when the residence time t has elapsed by an internal timer or the like (not shown), a hop signal r indicating the channel set value S
Is output to the hop table 26 and the PLL local oscillator 25 for frequency hopping (S62), and then the communication data is transmitted (S63) and received with the spread modulated signal u having a frequency corresponding to the hop frequency data fS of the channel set value S. (S64). Then, it is determined whether or not the communication has been completed (S65), and if not completed (S65, N
O), by re-executing from S59, the residence time t
The transmission and reception of the communication data are continued while repeating the frequency hopping every time, and when the communication is completed (S65, YES),
The process returns to the communication control routine of FIG. 6 and shifts to the sleep state of S1.

Next, if it is determined in S2 that the call is not to be made (S2, NO), it is determined whether or not the time has elapsed after a predetermined time has elapsed using an internal timer or the like (S3). If not up (S3, N
O) The sleep mode of S1 is continued. On the other hand, when the time is up (S3, YES), the mode is set to the reception standby mode, and power supply is started from the power supply unit 36 except for the transmission unit (the up-converter 23 and the power amplifier 24) of the wireless communication unit 1 (S4).

Then, the controller 35 outputs the reception command signal q to the modem 22 and the transmission / reception switch 27, thereby setting the demodulation unit 22b of the modem 22 to the operation state and setting the transmission / reception switch 27 to the reception state. Set. If the channel setting value S is, for example, “start =
The 3 ″ hop signal r is transferred to the hop table 26 and the PLL.
The hop frequency data f3 of the third channel C3 is output to the local oscillator 25 and stored in the hop table 26 of FIG.
Is output to the PLL local oscillator 25, and a hop frequency signal s having a frequency (fstart = f3) corresponding to the hop frequency data f3 is output from the PLL local oscillator 25 to the down converter 3.
2 (S5). And down converter 3
2 is set to be despread at the frequency (f3), and the spread modulation signal u at this frequency (f3) is set in a receivable state (S6).

Next, it is determined whether or not the spread modulation signal u of the frequency (f3) has been received (S7).
7, NO), it is determined whether or not the cycle time T1 has elapsed (S8). If the cycle time T1 has not elapsed (S8,
YES), S6 is re-executed, the reception of the frequency (f3) is continued, and when the cycle time T1 has elapsed (S8, NO),
Shift to the sleep mode of S1.

On the other hand, when the spread modulation signal u of the frequency (f3) is received in S7 (S7, YES), the ID data of the called side included in the received spread modulation signal u is used. Then, it is determined whether or not it has called itself (S9). If it is a signal calling itself (S
9, YES), it recognizes whether the communication data of the calling side is voice data or non-voice data based on the ID data of the calling side, and determines the residence time according to the type of the recognized communication data and the situation of the interference. t and the number of hops Hn are determined (S10). Thereafter, a response process for performing communication with the calling communication device (master device 10 and slave devices 11 to 15) is executed (S7).
0).

When the response process is executed, as shown in FIG. 8, a response signal including the ID data of the calling side is transmitted (S71). Thereafter, the "hop number Hn" determined in S10 is set to the maximum channel count value Cmax so that frequency hopping is performed with the same hopping pattern as the residence time t and the hop number Hn of the calling side (S72).
Thereafter, it is determined whether or not the channel count value C is smaller than the maximum channel count value Cmax ("Hn") (S73). If the value is small (S73, Y
ES), while the channel set value S and the channel count value C are incremented by "1" (S74), if not small (S73, NO), the channel set value S
And the channel count value C is reset to "1" (S75). When the residence time t determined in S10 by an internal timer or the like (not shown) has elapsed, the hop signal r indicating the channel set value S is transmitted to the hop table 26.
And output to the PLL local oscillator 25 for frequency hopping (S76), and receive (S77) and transmit (S78) communication data with a spread modulated signal u of a frequency (fs) corresponding to the hop frequency data fs of the channel set value S. I do.
Then, it is determined whether or not the communication is completed (S79). If the communication is not completed (S79, NO), transmission and reception of communication data are continued while repeating frequency hopping for each residence time t, and when the communication is completed ( (S79, YES), the process returns to the communication control routine of FIG. 6, and shifts to the sleep state of S1.

Next, if it is determined in S10 that the signal is not a signal calling itself (S10, NO), it is then determined whether or not the standby frequency (f3) is obstructing communication by interference. A determination is made (S11), and if there is no interference (S11, NO), the process shifts to the sleep mode of S1.

In S11, as shown in FIG. 9, when it is determined that the standby frequency (f3) is obstructed (S11, YES), it is determined whether or not the cycle time T1 has elapsed. Then, if the cycle time T1 has not elapsed (S13, YES), the process is re-executed from S6, and reception is waited at the current frequency (f3). On the other hand, if the cycle time T1 has elapsed (S13, NO), the current standby frequency (f3) is the last of the frequencies (f1, f2,... FL) used for the reception standby. It is determined whether or not the frequency is (f = fend) (S13). If it is the final frequency (f = fend) (S13, YES), the process shifts to the sleep mode of S1, while if it is not the final frequency (f = fend) (S13, N).
O), the frequency (f7) which is the next frequency (f = fnext) is set for standby (S14), and S6 is executed again to wait for reception at the frequency (f7).

As described above, the radio communication system according to the present embodiment, as shown in FIGS. 1 (a) to 1 (c), switches between the communication devices while switching the frequency in accordance with the predetermined hopping pattern by the frequency hopping method. When performing bidirectional communication, the number of hops (L, K, M) and the dwell time (tL, tK, tM) can be changed.

Thus, even when the calling communication device changes the dwell time (tL, tK, tM) according to the type of communication data such as voice data or non-voice data, the cycle time T1 of frequency hopping is constant. In order to change the number of hops (L, K, M) of the hopping pattern so that
By setting to 1, it becomes possible to determine the failure or continuation of the reception, the switching of the standby frequency, and the like in a minimum necessary time. Therefore, the synchronization can be easily acquired at the time of the communication start processing, and the establishment of the synchronization can be completed in a short time.

More specifically, as shown in FIG. 1A, when voice data is communicated, the residence time is set to "tL" ms.
And the number of hops is increased to “L”. Even if the dwell time is shortened and the amount of data transferred per hop is reduced, the transmission / reception obstacle for voice data is extremely small. However, high confidentiality, which is a great merit for voice data, can be obtained by increasing the number of hops. On the other hand, as shown in FIG. 1B, during communication of non-voice data, the residence time is set to “t”.
The length of K is set to ms and the number of hops is reduced to "K". The non-voice data communication can be completed in a short time by increasing the data transfer amount per hop due to the long residence time. Also, as shown in Fig. 1 (c), the more the interference during communication while performing frequency hopping, the longer the residence time becomes "t".
The length of the hop is increased to M and the number of hops is increased to "M", so that the probability of interference during communication can be reduced by increasing the number of hops.

The radio communication system according to the present embodiment
At the time of communication start processing, the called-side communication device is configured to wait for reception at one of the frequencies of the hopping pattern (f3) and start frequency hopping after receiving the signal of the calling-side communication device. ing. Thus, the reception of the hopping pattern is repeated at one frequency (f3) of the hopping pattern at the time of the communication start processing, so that the signal from the communication device on the calling side can be reliably received by repeatedly calling the hopping pattern. It has become.

The radio communication system according to the present embodiment
As shown in FIG. 9, at the time of communication start processing, the called communication device waits for reception at one of the frequencies of the hopping pattern (f3), and when the frequency (f3) is interfered, The processing of waiting for reception at one frequency (f7) of the remaining frequencies is repeated until a predetermined frequency is reached, and frequency hopping is started after receiving a signal from the communication device on the calling side. As a result, even if one or more frequencies (f3) of the hopping pattern at the time of the communication start processing are subject to interference, a signal from the calling communication device is received at the remaining frequency (f7). Therefore, the communication start process can be performed stably.

In the wireless communication system according to the present embodiment, the period during which the called-side communication device waits for reception at the one frequency is equal to the repetition period of the frequency hopping or an integral multiple thereof. It is desirable to be. According to this configuration, since the frequency is set to be equal to or an integral multiple of the frequency hopping repetition cycle, it is possible to more easily perform synchronization acquisition during communication start processing without wasting time. Become.

Further, in the present embodiment, when there is interference during voice data communication, the staying time is shortened to increase the number of hops. However, it is desirable that the dwell time is shortened and the number of hops is increased in order to minimize the time of interference. The dwell time and the number of hops set for such a disturbance during communication may be changed according to the number of disturbances.

As shown in FIG. 2, the hopping pattern in this embodiment is a system of hop frequency data corresponding to channels C1, C2,... CL,. All hop frequency data f1, f
2, ..fL, ..fM, ..fN are set, and are formed from this hop frequency data sequence f in accordance with the number of hops of each condition, but are not limited to this. There is no. That is, as shown in FIG. 10, the channels C1, C2,.
3 systems of hop frequency data series f corresponding to M, .. CN
The hop frequency data f1 to fK, f for each condition are stored in A, fB, and fC.
A hopping pattern may be formed by setting 1 to fL and f1 to fM in advance and selecting these hop frequency data series fA, fB, fC according to each condition. Further, as shown in FIG. 11, for example, the hopping pattern is formed by selecting a hop frequency data sequence fC and then randomly rearranging the hop frequency data f1 to fM of the hop frequency data sequence fC. May be.

Further, the frequency at the time of standby for reception in the present embodiment does not need to be always the same, and may be set to standby at a random frequency every time the mode exits from the sleep mode. In addition, the probability of constant interference can be reduced.

[0049]

According to the first aspect of the present invention, there is provided a wireless communication system for performing bidirectional communication between communication apparatuses while switching frequencies according to a predetermined hopping pattern by a frequency hopping method, wherein frequency hopping is repeated by the hopping pattern. In this configuration, the hop number and the dwell time of the hopping pattern can be changed so that the period is constant. Thus, even if the calling communication device changes the dwell time according to the type of communication data such as voice data and non-voice data, the number of hops in the hopping pattern is adjusted so that the cycle time of frequency hopping is constant. In order to change the setting, the called party sets the reception standby time to one round time so that reception failure or continuation, switching of the standby frequency, etc. can be determined in the minimum time required. Become. Therefore, there is an effect that the synchronization can be easily acquired at the time of the communication start processing, and the establishment of the synchronization can be completed in a short time.

According to a second aspect of the present invention, in the wireless communication system according to the first aspect, at the time of communication start processing, the called communication device waits for reception at one of the frequencies of the hopping pattern. In this configuration, frequency hopping is started after receiving a signal from a communication device on the calling side. Accordingly, the reception of the hopping pattern is repeated at one frequency of the hopping pattern at the time of the communication start process, so that the signal of the calling side communication device can be reliably received by repeating the hopping pattern. .

According to a third aspect of the present invention, in the wireless communication system according to the first aspect, at the time of communication start processing, the called communication device waits for reception at one of the frequencies of the hopping pattern, When the frequency is interfered, the process of waiting for reception at one of the remaining frequencies is repeated until a predetermined frequency is reached, and after receiving a signal from the calling communication device, frequency hopping is started. Configuration. Thereby, even if one or more frequencies of the hopping pattern at the time of the communication start processing are receiving interference, it is possible to receive the signal from the calling side communication device at the remaining frequencies, There is an effect that the communication start process can be performed stably.

According to a fourth aspect of the present invention, in the wireless communication system according to the second or third aspect, a period during which the called-side communication device waits for reception at the one frequency is equal to the frequency hopping repetition period. Or a configuration set to an integral multiple of that. As a result, it is set equal to or an integral multiple of the repetition period of frequency hopping,
There is an effect that synchronization acquisition at the time of communication start processing can be performed more easily without wasting time.

According to a fifth aspect of the present invention, there is provided the wireless communication system according to any one of the first to fourth aspects, wherein a residence time is shortened and a hop number is increased at the time of voice signal communication. As a result, even when the residence time is shortened and the data transfer amount per hop is reduced, the obstacle at the time of transmission / reception is extremely small for the voice signal, and the high confidentiality, which is a great merit for the voice signal, is obtained by increasing the number of hops. This has the effect that it can be obtained.

According to a sixth aspect of the present invention, in the wireless communication system according to any one of the first to fourth aspects, when a non-voice signal is communicated, the residence time is lengthened and the number of hops is reduced. As a result, the data transfer amount per hop increases due to the long residence time, so that there is an effect that the communication of the non-voice signal can be completed in a short time.

According to a seventh aspect of the present invention, there is provided the wireless communication system according to any one of the first to fourth aspects, wherein when performing communication while performing frequency hopping, the more the interference, the shorter the residence time and the number of hops. The configuration is to increase. Thus, there is an effect that the probability of interference during communication can be reduced by increasing the number of hops.

[Brief description of the drawings]

1A and 1B are explanatory diagrams of a hopping pattern having a fixed round time, wherein FIG. 1A is a hopping pattern for audio data, FIG. 1B is a hopping pattern for non-audio data,
(C) is a hopping pattern for audio data at the time of interference.

FIG. 2 is an explanatory diagram showing data contents of a hop table.

FIG. 3 is an explanatory diagram showing a relationship between a parent device and a child device.

FIG. 4 is an explanatory diagram showing a communication mode according to the TDD scheme.

FIG. 5 is a block diagram of a wireless communication unit.

FIG. 6 is a flowchart of a communication control routine.

FIG. 7 is a flowchart of a call processing routine.

FIG. 8 is a flowchart of a response processing routine.

FIG. 9 is an explanatory diagram of a hopping pattern during communication start processing and communication processing.

FIG. 10 is an explanatory diagram showing data contents of a hop table.

FIG. 11 is an explanatory diagram showing data contents of a hop table.

[Explanation of symbols]

 Reference Signs List 1 wireless communication unit 10 master unit 11-15 slave unit 21 interface unit 22 modem 23 up converter 24 power amplifier 25 PLL local oscillator 26 hop table 27 transmission / reception switch 28 antenna 31 low noise amplifier 32 down converter 35 controller 36 power supply unit

Claims (7)

[Claims] 1. A wireless communication system for performing bidirectional communication between communication devices while switching frequencies according to a predetermined hopping pattern by a frequency hopping method, wherein a repetition period of frequency hopping according to the hopping pattern is constant. A hop number and a dwell time of the hopping pattern can be changed. 2. In a communication start process, a called communication device waits for reception at one of the frequencies of the hopping pattern, and starts frequency hopping after receiving a signal from the calling communication device. The wireless communication system according to claim 1, wherein: 3. The communication device on the called side waits for reception at one of the frequencies of the hopping pattern during communication start processing, and when the frequency is interfered, one of the remaining frequencies is received. 2. The wireless communication system according to claim 1, wherein a process of waiting for reception at a frequency is repeated until a predetermined frequency is reached, and frequency hopping is started after receiving a signal from a communication device on the calling side. 4. The period during which the called-side communication device waits for reception at the one frequency is set to be equal to or an integral multiple of the repetition period of the frequency hopping. 3. The wireless communication system according to 3. 5. The wireless communication system according to claim 1, wherein a residence time is shortened and a number of hops is increased at the time of voice signal communication. 6. The communication system according to claim 1, wherein, during communication of a non-voice signal, the residence time is lengthened and the number of hops is reduced.
5. The wireless communication system according to any one of claims 4 to 4. 7. The wireless communication system according to claim 1, wherein, when performing communication while performing frequency hopping, as the interference increases, the residence time is shortened and the number of hops is increased.