JP2003309503A - Wireless terminal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To always secure a high quality of wireless communication in spite of any positional relationship between a handy wireless terminal held by a crew and a vehicle-mounted terminal. <P>SOLUTION: A reception level Q in each antenna is measured in a step S101. If a differential value (Qmax-Qmin) between the maximum value Qmax and the minimum value Qmin in each reception condition is greater than a reference value Qref1 in a step S102, then the antenna indicating the maximum value Qmax is selected in a step S103. If the differential value (Qmax-Qmin) is not greater than the reference value Qref1, then it is decided whether or not any other network which uses the same frequency band now in use exists in the neighborhood in a step S104. If another network exists, then control proceeds to a step S105 wherein the antenna indicating the minimum value of the reception level Q' of the signal transmitted to each antenna from the other terminal belonging to the other network is selected. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless terminal, and more particularly to a wireless terminal suitable for a vehicle intercom that performs short-range communication using an ISM (Industry Science Medical) band.

[0002]

2. Description of the Related Art In order to enable conversation between passengers on a two-wheeled vehicle, an in-vehicle wireless terminal is mounted on the vehicle side, and a helmet of the passenger is composed of a speaker, a microphone and a portable wireless terminal. A communication system (intercom) that is equipped with a headset that allows passengers in the same vehicle or passengers in different vehicles to talk via the in-vehicle wireless terminal is disclosed in, for example, Japanese Utility Model Publication Sho 62-1555.
No. 35 microfilm. In addition, a technology that adopts Bluetooth as a wireless communication standard for intercom is disclosed in Japanese Patent Laid-Open No. 2001-14865.
No. 7 publication.

[0003]

It is widely known that the communication quality is strongly influenced by the relative relationship between the size of the shield existing between the wireless terminals and the wavelength because the propagation of the radio wave is straight. ing. In particular, ISM (Indus) that uses the 2.5 GHz band (wavelength about 12 cm) in the region where the frequency is near the upper limit of the UHF band
In the communication of the try, science, medical) band, not only the car body but also the body of the occupant strongly acts as a shield, and its influence cannot be ignored.

On the other hand, Bluetooth, which is becoming widespread as a short-range wireless communication system, uses the 2.5 GHz ISM band. Therefore, if this is used for intercom or vehicle-to-vehicle communication, the communication quality will be the same as that of the passengers. It strongly depends on the relative positional relationship with the wireless terminal. Therefore, when communicating between the Bluetooth antenna provided on the vehicle body and the Bluetooth terminal worn by the passenger, the position of the antenna provided on the vehicle body, the riding position of the occupant who is talking, and the occupant The storage location of the Bluetooth terminal attached to the terminal strongly affects the communication quality.

In order to solve such technical problems,
However, it is desirable to provide a plurality of antennas on a wireless terminal carried by a vehicle occupant or an in-vehicle wireless terminal so as to cover a wide communication area with few blind spots.
When multiple antennas are provided, the signals received by each antenna cancel each other out due to the effect of the phase difference depending on the relative positional relationship between each antenna and the communication partner, and high reception sensitivity cannot be obtained. was there. Further, since the communication area where a plurality of antennas are provided is expanded, there is a technical problem that a collision with a signal transmitted / received on another network is likely to occur.

An object of the present invention is to solve the above-mentioned problems of the prior art, and to provide a wireless terminal capable of always ensuring high quality wireless communication regardless of the relative positional relationship with the communication partner. Especially.

[0007]

In order to achieve the above object, the present invention provides a wireless terminal mounted on a vehicle or carried by an occupant of the vehicle to mutually establish a wireless network to perform wireless communication. , The feature is that the following measures are taken. (1) The wireless terminal is characterized in that it includes a plurality of antennas and a communication means for diversity receiving signals detected by the plurality of antennas. (2) It is characterized in that the antenna has a longitudinal shape and is arranged on the helmet surface so that its long sides are substantially parallel to each other along the lower edge of the helmet outer shell.

According to the above feature (1), even if the relative position between the antenna of the in-vehicle wireless terminal and the antenna of the portable wireless terminal changes, a high reception intensity can be obtained.

According to the above feature (2), since the antennas are arranged along the lower edge of the helmet, it is possible to install a plurality of antennas on the helmet without impairing the aesthetics of the helmet and the freedom of design. it can.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram showing an example of a communication mode by intercom to which the present invention is applied, in which a vehicle A is equipped with an in-vehicle wireless terminal N,
The helmets worn by the occupants of the vehicles A and B include a microphone 11, a speaker 12, and a portable wireless terminal Nx (NC0, NC).
The intercom including 1 and NC2) is installed. The mobile telephone NTEL is owned by either the driver of the vehicle A or a passenger. The in-vehicle wireless terminal N and each portable wireless terminal Nx (including the mobile phone NTEL) comply with the Bluetooth standard, and the in-vehicle wireless terminal N is in the master mode and the other wireless terminals Nx are on the piconet that accommodates these terminals. Perform wireless communication with each other while operating in slave mode.

2 and 3 are block diagrams showing the configuration of the communication system of the in-vehicle wireless terminal N and the portable wireless terminals NC0, NC1, NC2 to which the present invention is applied, which are not necessary for explaining the present invention. The description of the configuration is omitted. The present invention is characterized in that at least two antennas AT1 and AT2 are arranged in each wireless terminal.

In the first embodiment shown in FIG. 2, the two antennas AT1 and AT2 are connected to the unique Bluetooth (BT) module BT0 via the antenna control circuit 37 and the bandpass filter (BPF) 38. The antenna control circuit 37 has a diversity receiving function, which will be described in detail later. The antenna control circuit 37 selectively receives a signal received by one of the BT antennas AT1 and AT2, or combines signals received by two antennas into a BT module. Provide to BT0.

In the second embodiment shown in FIG. 3, there are two wireless terminals.
One BT module BT1, BT2 is provided, and each BT module BT1, BT2 is provided with an antenna AT1, A
T2 is connected.

The CPU 33 executes various processes according to the programs stored in the ROM 34. RAM3
Reference numeral 5 provides a work area for temporarily storing data and the like when the CPU 33 executes various processes. If the terminal is the in-vehicle wireless terminal N, various operation switches and display devices are connected to the input / output interface 36. If the terminal is any one of the mobile wireless terminals NC0, NC1, NC2, a display device, a headset or the like is connected.

Each BT module BT0, BT1, BT2
Mainly includes the RF unit 31 and the BT chip 32. The BT chip 32 executes processing for establishing intra-piconet synchronization with a partner terminal, encoding / decoding processing of transmission / reception signals, and the like. That is, each BT module digitally modulates a carrier signal with transmission data at the time of transmission, and spectrum-modulates the modulated carrier signal by frequency hopping. Then, after amplifying this transmission signal to a transmission output level equal to or lower than a specified value, the signal is transmitted from the antenna AT1 to the wireless terminal of the communication partner. Further, the wireless signal coming from the wireless terminal of the communication partner is received via the antenna AT1 and is subjected to spectrum despreading and then digitally demodulated.

4, 5, 6 and 7 show the in-vehicle wireless terminal N.
Antennas AT1 and AT when mounted on a motorcycle
2 is a diagram showing an example of arrangement, and in the present embodiment, when one antenna AT1 is arranged on the right side of the vehicle body, the other antenna AT2 is arranged on the left side of the vehicle body.

For example, one antenna AT1 is arranged at the base position [1R] of the right handle grip, and the other antenna AT2 is arranged at the base position [1L] of the left handle grip. According to such an antenna arrangement, the antenna AT1
From [1R], the line of sight is between the driver's helmet, chest and right waist, and from the antenna AT2 [1L], the line of sight is between the driver's helmet, chest and left waist. Stable communication can be expected regardless of whether the antenna of the terminal NC0 is located on the helmet, chest or waist. For passengers, if the antenna of the mobile wireless terminal NC1 is attached to the helmet, the line-of-sight distance is obtained.

Further, considering communication with another vehicle B,
According to the antenna AT1 [1R], high sensitivity is obtained when the vehicle B is parked on the right side of the vehicle due to a signal waiting or the like, or when the vehicle B is about to turn right at the intersection of the road. Also,
The antenna AT2 [1L] provides high sensitivity when the vehicle B is parked on the left side of the vehicle due to a signal waiting or the like, or when the vehicle B is approaching the intersection of the road from the left.

In this embodiment, one antenna AT is also used.
1 is located at the base position [2R] of the front right turn signal, and the other antenna AT2 is at the base position of the front left turn signal.
You may arrange in [2L]. According to such an antenna arrangement, the antenna AT1 [2R] is closer to the driver's helmet than the position [1R], but the distance to the chest is the same, and the distance to the right waist is Get closer. Further, since it can be made less noticeable as compared with the case where it is arranged at the position [1R], it is expected that the degree of freedom in appearance design will be increased and the commercial property will be improved. The same effect can be expected for the antenna AT2 [2L].

In this embodiment, one antenna A is further used.
T1 may be arranged at the root position [3R] of the rear right blinker, and the other antenna AT2 may be arranged at the root position [3L] of the rear left blinker. According to such an antenna arrangement, the distance between the antenna AT1 [3R] and the driver is the above-mentioned position [2R].
However, the distance from the passenger's right lower back becomes overwhelmingly shorter than in the case of. Further, communication with another vehicle B approaching from the right rear becomes easy. Further, as in the case of being provided at the position [2R], the degree of freedom in the appearance design is increased, so that the improvement of the commercial property is expected. The same effect can be expected for the antenna AT2 [3L].

In this embodiment, one antenna A is further used.
T1 may be arranged in the front of the vehicle body and the other antenna AT2 may be arranged in the rear of the vehicle body. For example, one antenna AT1
Is arranged in the central portion [4F] of the meter unit, and the other antenna AT2 is arranged behind the rear seat [4R].

With such an antenna arrangement, the distance between the antenna AT1 [4F] and the driver's helmet, chest and waist is reduced. In particular, the same stable communication becomes possible regardless of whether the antenna of the driver is located on the right or left of the body. With respect to the other vehicle B located in the traveling direction, the same stable communication is possible regardless of whether the vehicle B is located on the right or left side of the own vehicle.

The antenna AT2 [4R] and the driver may be in sight if the antenna is attached to the helmet. For passengers, the position [3L]
And [3R] are more advantageous for communication with the antenna attached to the helmet. When communicating with a wireless terminal or the like provided in the vehicle B, if the vehicle is behind in the traveling direction,
Stable communication is possible regardless of whether the vehicle is on the right or left side.

The present invention is not limited to this, and the pair of antennas AT1 and AT2 may be arranged so as to sandwich the riding position of the occupant. For example, in addition to the combination of the central portion [4F] of the meter unit and the rear [4R] of the rear seat, a combination of the root position [1L] of the left handle grip and the root position [3R] of the rear right turn signal or the right handle grip. It may be a combination of the root position [1R] and the root position [3L] of the rear left turn signal.

As described above, in this embodiment, the pair of antennas AT1 and AT2 of the in-vehicle wireless terminal N are arranged so that when one of them is arranged on the right side of the vehicle body, the other is arranged on the left side of the vehicle body. By effectively using the width, not only can multiple antennas be separated as much as possible, but also a part of the vehicle body or occupants located between the antennas can function as a radio wave shield, so that interference between the antennas can be reduced. It can be suppressed. Further, even if the occupant becomes a radio wave shield and the reception by one of the antennas is disturbed, the other antenna can compensate for this, so that the communication quality is improved.

Further, in this embodiment, the pair of antennas AT1 and AT2 of the on-vehicle wireless terminal N are arranged such that when one of them is arranged in the front of the vehicle, the other is arranged in the rear of the vehicle. Not only can multiple antennas be maximally separated by effective use, but a part of the vehicle body or occupants located between the antennas can function as a radio wave shield, so interference between the antennas can be suppressed. . Further, even if the occupant becomes a radio wave shield and the reception by one of the antennas is disturbed, the other antenna can compensate for this, so that the communication quality is improved.

8 and 9 are views showing a method of fixing the antennas AT1 and AT2 in the portable radio terminal Nx to the outer shell of the helmet. In this embodiment, a longitudinal flat plate antenna is adopted.

In the example shown in FIG. 8, one antenna AT
1 is arranged so that its long side is parallel to the lower edge of the left side of the helmet or along the trim (edge rubber) provided on the lower edge [left side in the figure], and the other antenna AT2 is placed on the right side. Similarly, they are arranged along the lower edge [right side in the figure]. The wavelength of the ISM band is about 12 cm,
If the antenna is of a half-wavelength dipole type, the total length of the antenna can be shortened to about 6 cm. Therefore, the antenna may be provided along the edge of the helmet opening (AT1 ', AT2').

Further, if the helmet has a full face shape, as shown in FIG. 9, one antenna AT1 is arranged along the lower edge of the front of the helmet [left side in the figure],
The other antenna AT2 may be arranged [on the right side] along the lower edge of the rear part of the helmet. Even in a full-face helmet, if the antenna is a half-wave dipole type, it is provided along the edge of the helmet window (AT
1 ', AT2').

In FIGS. 8 and 9, the antennas AT1 and AT are
Although 2 is provided on the outer shell of the helmet, the antenna may be laminated with a plastic film or the like and attached to the trim on the lower edge of the helmet, or the antenna may be formed of a conductor foil and integrally formed in the trim. You may.

As described above, in this embodiment, since the pair of antennas AT1 and AT2 are spaced apart from each other on the outer shell surface of the helmet, the directivity between the antennas is not adversely affected. Further, since the antennas AT1 and AT2 are arranged along the lower edge of the helmet and the edge of the opening, a plurality of antennas can be installed without impairing the aesthetics of the helmet and the degree of freedom in design.

Next, the first embodiment shown in FIG. 2, that is, one BT module and two antennas AT1 and A
A communication operation in a wireless terminal provided with T2 will be described.

In FIG. 10, the antenna control circuit 37 is made to function as an antenna switch, and a pair of antennas AT
1 is a flowchart showing an operation of diversity reception that selectively uses only one of the signals received by AT1 and AT2, which is mainly executed by the CPU 33.

At step S101, each antenna AT
1, reception state level Q of signals received at AT2
Is quantitatively measured. The reception state level Q can be obtained based on the reception intensity or a function having the reception intensity and the interference amount as parameters.

In step S102, the difference between the maximum value Qmax and the minimum value Qmin of each reception state level Q is the reference value Qref1.
Compared to. Here, the description will be continued assuming that the reception state level Q [1] of the antenna AT1 is Qmax and the reception state level Q [2] of the antenna AT2 is Qmin. If the difference (Qmax−Qmin) is larger than the reference value Qref1, the antenna control circuit 37 selects the antenna AT1 having the highest reception state level Q as the current communication antenna in step S103.

On the other hand, when it is determined in step S102 that the difference (Qmax-Qmin) is not larger than the reference value Qref1, in step S104, the same frequency band as the one currently used is used. It is determined whether there is another network in the vicinity. If it is determined that there is not, the above step S103
Proceed to and the antenna AT1 is selected. If it is determined that they exist, the process proceeds to step S105.

In step S105, the reception state level Q'at each of the antennas AT1 and AT2 of the signal transmitted from the wireless terminal belonging to the other network is measured. In step S106, the antenna control circuit 37 selects the antenna whose reception state level Q'has the lowest value Qmin.

According to the present embodiment, a plurality of antennas are spaced apart from each other, and the antenna with the best reception state is selected from them, so that high-quality wireless communication can always be performed.
Further, since the antenna position can be selected corresponding to each communication partner, it is not necessary to consider the interference due to the phase difference, unlike the case where the reception signals from a plurality of antennas are combined.

FIG. 11 shows that the signals received by the two antennas AT1 and AT2 are combined in the in-vehicle wireless terminal N or the portable wireless terminal Nx equipped with one BT module and two antennas AT1 and AT2 as described above. 6 is a flowchart showing an operation of diversity reception.

At step S201, each antenna AT
While changing the phase difference between 1 and AT2, the reception state level Q of the combined wave is measured. In step S202,
A phase difference in which the reception level Q shows the maximum value Qmax is detected. In step S203, the maximum value Qmax of the reception level Q is compared with a predetermined reference value Qref2. If the maximum value Qmax of the reception state level Q is lower than the reference value Qref2, the phase difference at this time is selected as the optimum phase difference in step S204.

On the other hand, if the maximum value Qmax exceeds the reference value Qref2, then in step S205, it is determined whether or not another network using the same frequency band as the one currently used is in the vicinity. Is determined.
If it is determined that they do not exist, the process proceeds to step S204, and the phase difference corresponding to the reception state level Qmax is selected as the optimum phase difference. If it is determined that they exist, the process proceeds to step S206, and the reception state level Q ′ of the signal transmitted from the terminal belonging to another network is measured for each phase difference. In step S207, the phase difference at which the reception state level Q is equal to or higher than the reference value Qref2 and the reception state level Q ′ of the signal transmitted from the wireless terminal belonging to the other network is the lowest is the optimum phase difference. Is selected as.

According to the present embodiment, the reception state level Q of the composite wave is measured while the phase difference between the signals received by the two antennas is made different, and the reception is performed at the phase difference of the high reception state level Q. High quality wireless communication can be secured. Further, in the present embodiment, interference with other networks existing in the vicinity is also taken into consideration, so that it becomes possible to secure higher quality wireless communication.

Further, in this embodiment, each antenna AT
Since 1 and AT 2 can be operated as a so-called phased array antenna, it is possible to select the phase difference with the strongest reception level Q for each communication partner, while the transmission source other than the communication partner can be selected. The signal state level Q'of Therefore, even if there is a piconet of another vehicle unrelated to the subject vehicle within a close range, it is possible to suppress the possibility of packet collision between piconets.

Next, the operation of the vehicle-mounted wireless terminal having the configuration shown in FIG. 3, that is, the two BT modules and the two antennas AT1 and AT2 will be described.

As shown in FIG. 3, even if a plurality of sets of antennas and BT modules are provided, if each terminal concentrates on one of the BT modules, the utilization efficiency will decrease. In addition, the call between the wireless terminals is performed mainly at the driver terminal NC0, and the driver as the operator switches the communication partner while operating the in-vehicle wireless terminal N. Therefore, the driver terminal NC0 is always in the connected state. The links of other portable wireless terminals Nx are dynamically connected and disconnected. In this way, in the intercom, the driver terminal NC0
Call frequency of the other mobile radio terminal Nz is higher than the call frequency of the other mobile wireless terminal Nz, the intra-piconet synchronization of the driver terminal NC0 is preferentially established over the other terminals NC1, NC2 and NTEL, and the driver terminal NC0 It is desirable to provide higher quality communication. Therefore, in the embodiment described below,
Both the preferential connection of the driver terminal NC0 and the improvement of wireless utilization efficiency are achieved.

FIG. 12 shows the second embodiment shown in FIG. 3, that is, the operation of distributing a plurality of wireless terminals to the vehicle-mounted wireless terminal N equipped with two antennas AT1 and AT2 and two BT modules BT1 and BT2. It is the flowchart shown.

In step S301, the BT assigned in advance to each wireless terminal Nx operating in the slave mode.
The (Bluetooth) address is registered in the in-vehicle wireless terminal N in association with the identifier. FIG. 17 is a plan view of the in-vehicle wireless terminal N, which is a toggle-type rebound switch 51, 5
2, an address display section 53 and a rotary encoder rotary knob 54.

Here, if the identifier "C1" is to be assigned to the BT address of the wireless terminal NC1 of the passenger of the vehicle A, the rotary knob 54 is turned in the piconet connection device registration mode of the portable wireless terminal NC1. As shown in (a), "C1" is displayed on the display unit 53, and then the rebound switch 51 is tilted to the "COM1" side.

Similarly, if the identifier "C2" is assigned to the BT address of the wireless terminal NC2 of the vehicle B, the portable wireless terminal NC2 is caused to display "C2" on the display unit 53 in the piconet connection device registration mode state [ 18 (b)], and then the rebound switch 51 is tilted to the "COM2" side. Similarly, the identifier "TE" is added to the BT address of the mobile telephone NTEL.
If “L” is assigned, “P” is displayed on the display unit 53 with the mobile telephone NTEL accommodated within the coverage of Piconet.
"-" Is displayed [Fig. 18 (c)], and then the rebound switch 52 is tilted to the "TEL" side.

When the registration of the BT address to each portable wireless terminal Nx is completed as described above, in step S302 of FIG. 12, an IQ packet is sent from one BT module BT1 to each wireless terminal Nx via the antenna AT1. By broadcasting, an inquiry (Inquiry) defined in the Bluetooth standard is executed. In this embodiment, one BT module BT1 and the other BT module BT1
Internal communication is possible with the module BT2, and the BT module BT2 has previously acquired the frequency skip pattern performed by the BT module BT1.

In step S303, a response signal (FHS) returned from each wireless terminal Nx in response to this inquiry.
Packet) is received by the BT module BT1 via the antenna AT1. Here, in this embodiment, since the BT module BT2 recognizes the frequency skip pattern, the BT module BT2 also receives the response signal via the antenna AT2.

In step S304, the BT modules BT1 and BT of the response signal returned from the driver terminal NC0.
The reception status levels QC0 [1] and QC0 [2] in 2 are compared. In step S305, the reception status level QC0
When it is determined that [1] is higher than the reception state level QC0 [2], in step S306, the BT module BT1 calls the driver terminal NC0 (Page) to establish intra-piconet synchronization. In step S307, the BT module BT2 calls (Page) another terminal Nx (NC1, NC2, NTEL) to establish intra-piconet synchronization.

On the other hand, in step S305, B
The reception status level QC0 [1] in the T module BT1 is the reception status level QC0 [2] in the BT module BT2.
If it is determined that it is not higher than the above, in step S308, the BT module BT2 calls (Page) the driver terminal NC0 to establish intra-piconet synchronization. Here, the frequency skip patterns of the BT modules BT1 and BT2 can be different from each other. In step S309, the BT module BT1 calls another wireless terminal Nx (Page) to establish intra-piconet synchronization.

FIG. 19 is a diagram schematically showing the method of allocating each wireless terminal according to the present embodiment, and the reception state level Q of the driver terminal NC0 in the BT module BT1.
Since C0 [1] is higher than the reception state level QC0 [2] in the BT module BT2, the BT module BT1 establishes intra-piconet synchronization with the driver terminal NC0, and the BT module BT2 uses another wireless terminal NC1, Establishes intra-piconet synchronization with NC2 and NTEL.

According to this embodiment, the driver terminal NC0 establishes intra-piconet synchronization with one BT module having a strong reception state level Q of the antenna, and the other wireless terminals communicate with the other BT module. Since the intra-piconet synchronization is established at the same time, not only the preferential connection of the driver terminal NC0 and the improvement of wireless utilization efficiency are compatible, but also high communication quality can be secured for the driver terminal NC0 having a high priority. become.

FIG. 13 is a flow chart showing another example of the operation of distributing a plurality of wireless terminals to the vehicle-mounted wireless terminal N having the configuration of the second embodiment shown in FIG. 3, and in steps S401 to S403, Step S of FIG.
Processing equivalent to that of steps 301 to S303 is executed.

In this embodiment, the BT module accommodating the driver terminal NC0 having a high priority is reserved based on the arrangement state thereof (BT module BT1 in this embodiment), and in step S404, the BT module is set. Module B
T1 calls (Page) the driver terminal NC0 to establish intra-piconet synchronization. In step S405,
The BT module BT2 calls (Page) another wireless terminal Nx to establish intra-piconet synchronization.

According to the present embodiment, the antenna arranged at the optimum position for communication with the driver terminal NC0 is reserved for the driver terminal, and the driver terminal NC0 is connected to the reserved antenna. Since the synchronization within the piconet is established,
It is possible to secure high communication quality for the mobile wireless terminal NC0 of the driver having a high priority.

FIG. 14 is a flowchart showing still another example of the operation of distributing a plurality of wireless terminals to the vehicle-mounted wireless terminal N having the configuration of the second embodiment shown in FIG.
In steps S501 to S503, the step S30 is performed.
The same processing as 1 to S303 is executed.

In step S504, either one of B
It is determined whether the intra-piconet synchronization has been established between the T module and the driver terminal NC0. Where one B
When the piconet synchronization is established between the T module and the driver terminal NC0, the piconet synchronization is established between the other BT module and the other portable wireless terminal Nx in step S505.

According to this embodiment, the piconet synchronization can be preferentially established for the driver terminal NC0 having a high priority.

FIG. 15 is a flowchart showing still another example of the operation of distributing a plurality of wireless terminals to the vehicle-mounted wireless terminal N having the configuration of the second embodiment shown in FIG.
In steps S601 to S604, the step S30 is performed.
The same processing as 1 to S304 is executed.

In step S605, the lowest value Qmin among the reception state levels Q of all wireless terminals is the predetermined reference value Qr.
Compared with ef3, if the minimum value Qmin is not below the reference value Qref3, the process proceeds to step S606. Step S606
Then, the reception state level QC0 [1] at the antenna AT1 of the driver terminal NC0 is compared with the reception state level QC0 [2] at the antenna AT2. If QC0 [1]> QC0 [2], the process proceeds to step S607. The BT module BT1 calls (Page) the driver terminal NC0 to establish synchronization within the piconet. In step S608, the BT module BT2 calls (Page) another wireless terminal Nx (NC1, NC2, NTEL) to establish intra-piconet synchronization.

On the other hand, in step S606, QC0
If it is determined that [1]> QC0 [2] is not satisfied, step S60.
In 9, the BT module BT2 calls (Page) the driver terminal NC0 to establish synchronization within the piconet. In step S610, the BT module BT1 calls (Page) another terminal Nx to establish intra-piconet synchronization.

Further, in step S605,
If it is determined that the minimum value Qmin is below the reference value Qref3, in step S611, if the combination recording the minimum value Qmin is the combination of the BT module [1] and the wireless terminal Nx, the other BT module BT The intra-piconet synchronization is established between [2] and the wireless terminal Nx (for example, if the combination recording the minimum value Qmin is the combination of the BT module BT1 and the wireless terminal Nx, the BT
Intra-piconet synchronization is established between the module BT2 and the wireless terminal Nx).

In step S612, the minimum value Qmin
It is determined whether or not the wireless terminal that has recorded is the driver terminal NC0. If it is the driver terminal NC0, step S614.
In, the intra-piconet synchronization is established between the other BT module BT [1] and the remaining wireless terminals Nx.

On the other hand, if the wireless terminal recording the minimum value Qmin is other than the driver terminal NC0, step S61.
At 3, the intra-piconet synchronization is established between the driver terminal NC0 and the BT module [1]. Step S615
Then, intra-piconet synchronization is established between the wireless terminal Nx and the BT module BT [2] other than the wireless terminal Nx that has already established piconet synchronization with the driver terminal NC0 and the BT module BT [2].

FIG. 20 is a diagram schematically showing the method of allocating each wireless terminal according to this embodiment. The reception state level QT of the wireless terminal NTEL in the BT module BT2.
Since EL [2] is less than the reference value Qref3, wireless terminals NC1 and NC other than the driver terminal NC0 including this wireless terminal NTEL.
2. NTEL establishes intra-piconet synchronization with BT module BT1, and driver terminal NC0 has BT module BT2.
Has established intra-piconet synchronization with.

According to this embodiment, the combination having the lowest reception state level Q is avoided from all the combinations, so that it is possible to secure excellent communication quality on average.

FIG. 16 is a flowchart showing still another example of the operation of distributing a plurality of wireless terminals to the vehicle-mounted wireless terminal N having the configuration of the second embodiment shown in FIG.
In steps S701 to S703, the step S30 is performed.
The same processing as 1 to S303 is executed.

In step S704, the reception status level QC0 [1] in the BT module BT1 of the driver terminal NC0.
And reception status levels QC1 [2], QC2 [2], Q in the BT module BT2 of the other wireless terminals NC1, NC2, NTEL.
The difference ΔQa between the highest value (MAX) and the lowest value (MIN) in TEL [2] is obtained. Furthermore, the BT of the wireless terminal NC0
Reception state level QC0 [2] in module BT2 and BT module BT1 of wireless terminals NC1, NC2, NTEL
ΔQ between the highest value (MAX) and the lowest value (MIN) of the reception status levels QC1 [1], QC2 [1], QTEL [1] at
b is required.

In step S705, the difference value ΔQ
a and ΔQb are compared, and if ΔQa is larger than ΔQb, the process proceeds to step S706. In step S706, the BT module BT2 calls the driver terminal NC0 (Page).
To establish intra-piconet synchronization. Step S7
At 07, the BT module BT1 calls (Page) another terminal Nx to establish intra-piconet synchronization.

On the other hand, at the step S705, ΔQ
If it is determined that a is not larger than ΔQb, step S7.
Go to 08. In step S708, the BT module B
T1 calls (Page) the driver terminal NC0 to establish intra-piconet synchronization. In step S709, B
The T module BT2 is connected to another wireless terminal Nx (NC1, NC2,
(NTEL) to establish intra-piconet synchronization.

FIG. 21 is a diagram schematically showing the method of allocating each wireless terminal according to this embodiment. Here,
The driver terminal NC0 establishes intra-piconet synchronization with the BT module BT1, and the other wireless terminals NC1, NC2 and NTEL are connected to the BT.
The opposite of the case where the intra-piconet synchronization is established with the module BT2 is the opposite of the driver terminal NC0 and the other wireless terminal NC.
Since the maximum difference between 1, NC2 and NTEL is large, the driver terminal NC0 establishes intra-piconet synchronization with the BT module BT1 and the other wireless terminals NC1, NC2 and NTEL establish intra-piconet synchronization with the BT module BT2. Has been established.

According to this embodiment, the difference between the reception state level Q of the driver terminal NC0 and the reception state level Q of the other wireless terminals is small, so that the driver can communicate in the same reception state as that of each terminal. You will be able to do it.

In each of the above embodiments, the Bluetooth module is used as the wireless module, but the present invention is not limited to this, and other wireless network standards (for example, IEEE802.
The same can be applied to the case of using a wireless module conforming to 11 or 802.11b).

[0077]

According to the present invention, the following effects are achieved. (1) No matter how the relative position of the antenna of the in-vehicle wireless terminal and the antenna of the portable wireless terminal changes, high reception intensity can be obtained. (2) Since the antennas are arranged along the lower edge of the helmet, it is possible to install a plurality of antennas on the helmet without impairing the aesthetics and design freedom of the helmet.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a communication mode by intercom to which the present invention is applied.

FIG. 2 is a block diagram showing a configuration (first form) of a communication system of an in-vehicle wireless terminal N and portable wireless terminals NC0, NC1, NC2 to which the present invention is applied.

FIG. 3 is a block diagram showing a configuration (second embodiment) of a communication system of an in-vehicle wireless terminal N and portable wireless terminals NC0, NC1, NC2 to which the present invention is applied.

FIG. 4 is a side view showing an arrangement example of two antennas on a motorcycle.

FIG. 5 is a top view showing an arrangement example of two antennas on a motorcycle.

FIG. 6 is a front view showing an arrangement example of two antennas on a motorcycle.

FIG. 7 is a rear front view showing an arrangement example of two antennas on a motorcycle.

FIG. 8 is a diagram showing an arrangement example of two antennas on a jet-type helmet.

FIG. 9 is a diagram showing an arrangement example of two antennas on a full-face type helmet.

FIG. 10 is a flowchart (part 1) showing the antenna selection method in the wireless terminal of the first embodiment.

FIG. 11 is a flowchart (part 2) showing the antenna selection method in the wireless terminal of the first embodiment.

FIG. 12 is a flowchart (No. 1) showing a method of distributing wireless terminals to each antenna in the vehicle-mounted wireless terminal of the second embodiment.

FIG. 13 is a flowchart (No. 1) showing a method of distributing wireless terminals to each antenna in the vehicle-mounted wireless terminal of the second embodiment.

FIG. 14 is a flowchart (No. 1) showing a method of allocating wireless terminals to each antenna in the vehicle-mounted wireless terminal of the second embodiment.

FIG. 15 is a flowchart (No. 1) showing a method of distributing wireless terminals to each antenna in the vehicle-mounted wireless terminal of the second embodiment.

FIG. 16 is a flowchart (No. 1) showing a method of distributing wireless terminals to each antenna in the vehicle-mounted wireless terminal of the second embodiment.

FIG. 17 is a plan view of an in-vehicle wireless terminal.

FIG. 18 is a diagram showing a method of registering an address of a mobile wireless terminal with an in-vehicle wireless terminal.

FIG. 19 is a diagram schematically showing the operation of the flowchart shown in FIG.

20 is a diagram schematically showing the operation of the flowchart shown in FIG.

FIG. 21 is a diagram schematically showing the operation of the flowchart shown in FIG.

[Explanation of symbols]

AT1, AT2 ... Antenna, BT1, BT2 ... BT module, Nx, NC0, NC1, NC2 ... Portable wireless terminal, N ...
In-vehicle wireless terminal, 11 ... Microphone, 12 ... Speaker, 51,
52 ... Toggle type rebound switch, 53 ... Address display section, 54 ... Rotating knob

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kazumitsu Kushida             1-4-1 Chuo 1-4-1 Wako City, Saitama Prefecture             Inside Honda Research Laboratory (72) Inventor Yu Hino             8-18-4 Nohidome, Niiza City, Saitama Prefecture Co., Ltd.             Inside Honda Access F-term (reference) 5K059 CC03 DD02 DD12 DD16 DD27                 5K067 AA23 BB03 CC24 DD44 EE02                       EE12 KK03

Claims (10)

[Claims] 1. A wireless terminal mounted on a vehicle or carried by an occupant of a vehicle, which wirelessly communicates with each other to form a wireless network, comprising: a plurality of antennas; and signals detected by the plurality of antennas. A wireless terminal including a communication means for receiving. 2. The communication means comprises only a Bluetooth module to which the plurality of antennas are connected, and selection means for selecting one of the plurality of antennas, the selection means being one of the plurality of antennas. A procedure for detecting a reception state level, a procedure for selecting an antenna having the highest reception state level when the difference between the lowest value and the highest value of the reception state level is larger than a predetermined value, and the lowest value. When the difference between the maximum value and the maximum value is smaller than a predetermined value, a procedure for detecting whether or not another network using the same frequency band exists in the vicinity, and if the other network exists, the other network A procedure for detecting the reception state level of the electric wave transmitted from the terminal accommodated in each antenna for each antenna, and the terminal accommodated in the other network. Wireless terminal according to claim 1, et transmitted radio wave reception level executes a procedure for selecting the lowest antenna, and performs wireless communication using the selected antenna. 3. The communication means combines a plurality of Bluetooth modules to which the plurality of antennas are respectively connected, a phase control means for controlling a phase of each of the antennas, and a signal received by the plurality of antennas. And a step of detecting the combined reception state level using the phase difference of each antenna as a parameter, a step of comparing the highest value of the reception state level with a predetermined value, and Means for selecting a phase difference showing the highest value when the maximum value of the reception level is less than a predetermined value, and using the same frequency band when the maximum value of the reception level is a predetermined value or more A procedure for detecting whether or not the network exists in the vicinity, and means for selecting the phase difference showing the highest value when the other network does not exist, Note that if another network exists, the phase for selecting the antenna with the lowest reception level of the signal transmitted from the terminal accommodated in the other network among the phase differences in which the reception level shows a predetermined value or more. 2. The wireless terminal according to claim 1, wherein the wireless terminal performs wireless communication with the selected phase difference. 4. The radio according to claim 1, wherein the antenna has a longitudinal shape, and a pair of the antennas is arranged along an edge portion of the helmet and apart from each other. Terminal. 5. The wireless terminal according to claim 1, wherein the antenna has an elongated shape, and a pair of the antennas is arranged along lower edges of a front portion and a rear portion of the helmet. . 6. The radio according to claim 1, wherein the antenna has an elongated shape, and a pair of the antennas is arranged along lower edges of a right side portion and a left side portion of the helmet. Terminal. 7. The wireless terminal according to claim 6, wherein the pair of longitudinal antennas are integrally formed with trims provided at lower edges of left and right side portions of the helmet. 8. The wireless terminal according to claim 6, wherein the pair of elongated antennas are fixed to trim surfaces provided at lower edges of left and right side portions of the helmet. 9. The wireless terminal according to claim 1, wherein the antenna has a longitudinal shape, and a pair of the antennas are arranged at positions facing each other on a helmet outer shell. 10. The wireless terminal according to the Bluetooth standard, and establishes intra-piconet synchronization with another wireless terminal located in the vicinity, according to claim 1. Wireless terminal.