JP2002300089A - Radio communication unit of frequency hopping type - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a radio communication unit of frequency hopping type that can quickly set up communication with a slave unit in existence in a communication available range of a master unit. SOLUTION: The radio communication unit is provided with a clock generating means that outputs at least two different clock values while continuously changing them in the same timing, an address generating means that generates a specific address value, a 1st hopping frequency calculation means that calculates a 1st hopping frequency depending on one of the two clock values and the address value, a 2nd hopping frequency calculation means that calculates a 2nd hopping frequency depending on the other of the two clock values and the address value, a 1st transmission means that transmits packets with the transmission frequency corresponding to the 1st hopping frequency and a 2nd transmission means that transmits packets with the transmission frequency corresponding to the 2nd hopping frequency.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a frequency hopping type radio communication device.

[0002]

2. Description of the Related Art In wireless communication using the Bluetooth technology, a frequency hopping type spread spectrum modulation system is adopted. When actually performing communication, a network called a piconet is used between communication devices within a communicable range. Is formed. Each communication device that has joined one piconet is in a state of communicating with the same hopping frequency pattern. Also, there is a relationship between the communication devices in the piconet such that one communication device becomes the master device and the other communication devices become slave devices. Communication within the piconet is performed between the master device and up to seven slave devices, and no direct communication is performed between slave devices. The wireless communication device for Bluetooth has a function that can be both a master device and a slave device.

In wireless communication using Bluetooth technology, a 2.4 GHz ISM (Industry Scient
ific and Medical) frequency band is used, 79 or 23
Is used by being divided into wireless channels. A unit obtained by dividing each wireless channel every 1/1600 second = 625 μsec is a time slot, and each wireless communication apparatus transmits a packet in the assigned time slot. At the time of wireless communication, time slots are assigned not by the same wireless channel but by switching wireless channels according to a hopping frequency pattern. The master device provides the hopping frequency of the piconet. FIG. 1 shows a change of a time slot at the time of communication between a master device and a slave device.

When starting a piconet communication between wireless communication devices for Bluetooth, an operation called an inquiry is first performed. The wireless communication device that performs the inquiry becomes a master device and transmits an IQ packet. IQ packets are sent to GIAC (General Inquiry Acces
s Code). The master device calculates a hopping frequency from the GIAC and its own clock value, and transmits an IQ packet on a wireless channel determined by the hopping frequency. The clock value is a value of a clock counter owned by each wireless communication device. There are a row A and a row B as a hopping pattern, and the row A and the row B are repeated plural times. The wireless communication device that is in a range that can communicate with the master device and that can respond to the inquiry operates as a slave device. The slave device calculates the hopping frequency from the GIAC and its own clock value, and monitors the reception of the IQ packet. Upon receiving the IQ packet, the slave device transmits a response packet including information of the slave device itself. That is, when the response packet is received, the FHS packet including its own clock value and address value is transmitted to the responding master device. The address value is a value unique to each wireless communication device called BD_ADDR. By receiving the FHS packet from the slave device, the master device obtains information on a BT (Bluetooth) device existing around the master device. Thus, the inquiry operation is completed, and the actual piconet communication can be started by performing paging (calling). In order to perform actual piconet communication, the hopping frequency is calculated from the address value of the master device and its own clock value, the data packet is transmitted to the slave device, and the sleeve device also receives the address value of the master device obtained from the data packet. Paging in which the hopping frequency is calculated based on the clock value of the master device and its own clock value, the transmission frequency is set, and the data packet is transmitted to the master device.

[0005] That is, if the master device knows the existence of a specific wireless communication device (slave device) within the communicable range, paging is performed. The master device that performs paging transmits an ID packet. The ID packet is a DAC (Device) generated from the address value of the slave device.
Access Code). The master device calculates a hopping frequency from the DAC and the estimated value of the slave clock, and transmits the ID packet on a wireless channel determined by the hopping frequency. There are a row A and a row B as a hopping pattern, and the row A and the row B are repeated a plurality of times. A slave device that can respond to paging calculates a hopping frequency from its own address value and its own clock value, and monitors reception of an ID packet. Upon receiving the ID packet, the slave device transmits a response packet including information such as the address value of the slave device itself. Upon receiving the response packet, the master device receives an FH including its own clock value and address value.
The S packet is transmitted to the responding slave device.
Upon receiving the FHS packet from the master device, the slave device transmits a response packet to the master device again. When the master device receives the response packet again, the paging operation ends, and the actual piconet communication starts as in the case of the inquiry described above.

[0006]

In the inquiry and paging operations, the radio channel of the IQ packet transmitted by the master device is set based on the clock value of the master device, while the slave device monitors the IQ packet. Is set based on its own clock value different from the clock value of the master device, so that the slave device receives an IQ packet even if the master device and the slave device are within a communicable range. In some cases, it takes a long time, and in that case, there is a problem that the actual piconet communication cannot be started immediately.

[0007]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a frequency hopping type radio communication device which can quickly establish communication with a slave device existing within a communication range of a master device. It is. A frequency hopping type wireless communication apparatus according to the present invention includes: a clock generation unit that outputs while changing at least two different clock values at the same timing continuously; an address generation unit that generates a unique address value; First hopping frequency calculating means for calculating a first hopping frequency according to one of the two clock values and the address value, and the other of the two clock values and the address value. Second hopping frequency calculating means for calculating a second hopping frequency in accordance with
It is characterized by comprising a first transmitting means for transmitting a packet at a transmission frequency corresponding to a hopping frequency, and a second transmitting means for transmitting a packet at a transmission frequency corresponding to a second hopping frequency.

[0008]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 2 shows a transmitting portion of a wireless communication device having three Bluetooth transmitting / receiving functions. This wireless communication device includes a clock generation circuit 11, a selection control circuit 12, an address generation circuit 13, three hopping frequency calculation circuits 14 to 16, a selection control circuit 17, and transmission circuits 18 to 20.

As shown in FIG. 3, the clock generation circuit 11 has three master clock generation units 21 to 23, three slave clock generation units 24 to 26, and a memory 27. The first master clock generator 21 includes a clock signal generator 31, a clock counter 32, an offset circuit 33, and an adder 34. The clock signal generation circuit 31 includes a crystal oscillator and generates a clock signal having a predetermined frequency. The clock counter 32 counts pulses of the clock signal. The offset circuit 33 outputs the offset value to the memory 27 and the adding circuit 34. Addition circuit 3
4 is the count value of the clock counter 32 and the offset circuit 3
3 is added to the output offset value and output to the memory 27.

The second master clock generator 22 comprises an offset circuit 35 and an adder 36, and the third master clock generator 23 comprises an offset circuit 37 and an adder 38. The offset circuits 35 and 37 output an offset value. Offset circuits 33, 35 and 3
7 are different from each other. The addition circuit 36 adds the count value of the clock counter 32 and the output offset value of the offset circuit 35 and outputs the result to the selection control circuit 12. The addition circuit 38 is a clock counter 3
The count value of 2 and the output offset value of the offset circuit 37 are added and output to the memory 27.

The first slave clock generator 24 includes a clock counter 42, an offset circuit 43, and an adder circuit 44. The clock signal is supplied from the clock signal generator 31 to the clock counter 42. The configuration is the same as that of the first master clock generation unit except that the clock signal generation circuit 31 is not provided. The clock counter 42 has a function of presetting received data.

Second slave clock generators 25 and 26
Each of them has the same configuration as the first slave clock generator 24. The memory 27 includes a count value of the clock counter 32 of the first master clock generation unit 21 and an output value of the addition circuit 34, an output value of the addition circuit 36 of the second master clock generation unit 22, a third master clock generation unit. 23
Output value of the addition circuit 38, the count value of the clock counter 42 of the first slave clock generation unit 24, and the addition value of the addition circuit 4.
4, the count value of the clock counter (not shown) of the second slave clock generator 25, the output value of the adder circuit (not shown), and the clock counter of the third slave clock generator 26 (see FIG. (Not shown) and the output value of an adding circuit (not shown) are individually held and output, and updated and held when a new value is supplied.

The selection control circuit 12 selectively supplies each value output from the memory 27, that is, a clock value, to the hopping frequency calculation circuits 14 to 16. The address generation circuit 13 generates three address values and supplies each of the address values to the hopping frequency calculation circuits 14 to 16.
The address generation circuit 13 includes a hopping frequency calculation circuit 1
Different address values are supplied to the hopping frequency calculation circuits 14 to 1 at the time of inquiry.
6 to the same address value.

The hopping frequency calculation circuits 14 to 16 have the same configuration, and calculate the hopping frequencies f1 to f3 based on the clock value supplied from the selection control circuit 12 and the address value supplied from the address generation circuit 13. . The hopping frequencies f1 to f3 calculated by the hopping frequency calculation circuits 14 to 16 are supplied to the selection control circuit 17.

The selection control circuit 17 selectively supplies the hopping frequencies f1 to f3 from the hopping frequency calculation circuits 14 to 16 to the transmission circuits 18 to 20. Further, the selection control circuit 17 has a detection circuit 17a for detecting the hopping frequencies f1 to f3. When any two of the hopping frequencies f1 to f3 detected by the detection circuit 17a are the same, the selection control circuit 17 forcibly stops the supply of one hopping frequency.

Each of the transmission circuits 18 to 20 includes a modulator and a transmitter, performs frequency hopping type spread spectrum modulation on data using the hopping frequency supplied from the modulator, and then transmits power to the transmitter. In this configuration, the signal is amplified and transmitted from an antenna. In such a wireless communication device, at the time of an inquiry operation for establishing wireless communication by detecting the wireless communication (slave device) of a communication partner with this device as a master device, as shown in FIG. It is determined whether or not there is an empty Bluetooth transmission / reception system (step S1). If there is a Bluetooth transmission / reception system that is not currently in a communication state among the three Bluetooth transmission / reception systems, that is, an empty Bluetooth transmission / reception system, the number is determined (step S2).

The first master clock generator 21,
The hopping frequency calculation circuit 14 and the transmission circuit 18
The second master clock generation unit 22, the hopping frequency calculation circuit 15, and the transmission circuit 19 belong to the second Bluetooth transmission / reception system, and the third
, The hopping frequency calculation circuit 16 and the transmission circuit 20 belong to the second Bluetooth transmission / reception system.

If there is one empty Bluetooth transmitting / receiving system, an inquiry operation by the one empty Bluetooth transmitting / receiving system is started (step S3). 2
If there are two empty Bluetooth transmission / reception systems, an inquiry operation by the two empty Bluetooth transmission / reception systems is started (step S4). If there are three empty Bluetooth transmission / reception systems, the inquiry operation by the three empty Bluetooth transmission / reception systems is started (step S5). When the slave device as the communication partner device responds by the inquiry operation (step S6), communication by the Bluetooth transmission / reception system that has received the response packet from the slave device is executed (step S7).

On the other hand, if there is no free Bluetooth transmission / reception system, that is, if any Bluetooth transmission / reception system is communicating, it is determined whether or not there is a free time slot (step S8). If there is an empty time slot, an inquiry operation by any of the Bluetooth transmission / reception systems is started using the empty time slot (step S9). If there is no vacant time slot, the communication of one of the three vacant Bluetooth transmitting / receiving systems is stopped (step S10), and the inquiry operation by the Bluetooth transmitting / receiving system whose communication has been stopped is started (step S10). Step S11). In the method of selecting the Bluetooth communication system for stopping transmission and reception in step S10, for example, importance of information and real-time property are considered. In other words, information to be communicated from now on may be selected by comparison with information of the current communication system.

When the inquiry operation is performed by a plurality of Bluetooth transmission / reception systems as in step S4 or S5, the change timing of the clock value for calculating each hopping frequency of the plurality of Bluetooth transmission / reception systems is substantially one. Therefore, the hopping frequency of each of the plurality of Bluetooth transmission / reception systems is changed at substantially the same timing. For example, in the case of step S5,
The selection control circuit 12 uses the count value of the clock counter 32 of the first master clock generation unit 21 held in the memory 27 as a clock value to generate the first hopping frequency calculation circuit 14.
And supplies the output value of the adder circuit 36 of the second master clock generation unit 22 as a clock value to the second hopping frequency calculation circuit 15, and the third master clock generation unit 2
The output value of the third adder circuit 38 is supplied to the third hopping frequency calculation circuit 16 as a clock value. The address generation circuit 13 supplies the same address value to the hopping frequency calculation circuits 14 to 16. Since the clock values supplied to the first to third hopping frequency calculation circuits 14 to 16 change at substantially the same timing, the hopping frequencies f1 to f3 calculated by the first to third hopping frequency calculation circuits 14 to 16 respectively. Changes occur at substantially the same timing.
Therefore, the time slots of the transmission signals of the transmission circuits 18 to 20 have substantially the same timing, and the hopping patterns are different from each other due to the difference of each clock value itself. Sex is extremely low. In other words, since the IQ packet is transmitted from the master device on three different wireless channels at the same timing, the probability that the slave device monitoring the wireless channel with different hopping patterns will immediately receive the IQ packet from the master device increases. .

In the above embodiment, the inquiry operation has been described, but the same applies to the case of the paging operation. FIG. 5 shows a clock generation circuit of a wireless communication apparatus as another embodiment of the present invention. In this clock generation circuit, a preset counter 51 is provided at the output of the clock counter 32 of the first master clock generation unit 21 shown in FIG. A clock data receiver 52 that receives standard time data is connected to the preset counter 51. Standard time data output from the clock data receiver 52 at a predetermined time is set in the preset counter 51. That is, the preset counter 51 calibrates the count value of the clock counter 32 based on the standard time data and outputs it. Other configurations are the same as those in FIG. If the wireless communication device provided with the clock generation circuit shown in FIG. 5 is used as a master device and a slave device, the hopping pattern is the same clock value, so that the communication operation is quicker in the case of an inquiry operation or a paging operation. It can be established. Also, in consideration of the case where such a wireless communication device operates as a slave device, the first to third slave clock generators 24 to 26 are also provided with a preset counter similarly to the first master clock generator 21. However, FIG. 5 shows only a configuration in which a preset counter 53 is provided in the first slave clock generator 24.

In each of the embodiments described above, the case of the wireless communication device using the Bluetooth technology has been described. However, the present invention can be applied to other frequency hopping type wireless communication devices. Further, the wireless communication device of each of the above-described embodiments has three transmission systems, but the present invention can be applied to any wireless communication device having a plurality of transmission systems.

[0023]

As described above, according to the present invention, the master device can quickly establish communication with the slave devices existing within the communicable range.

[Brief description of the drawings]

FIG. 1 is a diagram showing a change in a time slot at the time of communication between a master device and a slave device.

FIG. 2 is a block diagram showing a wireless communication device according to the present invention.

FIG. 3 is a block diagram showing a specific configuration of a clock generation circuit in the device of FIG.

FIG. 4 is a flowchart showing an inquiry operation.

FIG. 5 is a block diagram showing a specific configuration of a clock generation circuit as another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Clock generation circuit 12, 17 Selection control circuit 13 Address generation circuit 14-16 Hopping frequency calculation circuit 18-20 Transmission circuit

Claims (3)

[Claims] 1. A clock generating means for continuously changing at least two different clock values at the same timing and outputting the same, an address generating means for generating a unique address value, and First hopping frequency calculating means for calculating a first hopping frequency according to one of the clock values and the address value; and second hopping frequency according to the other of the two clock values and the address value. Second hopping frequency calculating means for calculating a frequency, first transmitting means for transmitting a packet at a transmitting frequency corresponding to the first hopping frequency, and second transmitting means for transmitting a packet at a transmitting frequency corresponding to the second hopping frequency And a frequency hopping-type wireless communication device. 2. The clock generating means includes: a clock signal generating means for generating a clock signal; a clock counter for counting pulses of the clock signal to generate the one clock value; and an offset value for the one clock value. 2. The frequency hopping type wireless communication apparatus according to claim 1, further comprising an adding means for adding and outputting the other clock value. 3. The clock generating means includes a standard time receiving means for receiving a standard time signal, and means for calibrating a count value of the clock counter based on the standard time to generate the one clock value. Claim 2
A frequency hopping-type wireless communication device according to claim 1.