JP3265877B2 - Wireless communication method and device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wireless communication system for performing high-speed wireless data transmission, which is easy to connect and has a problem of multipath fading caused by reflected waves from walls and furniture. The present invention also relates to a wireless communication method and apparatus capable of obtaining high transmission quality.

[0002]

2. Description of the Related Art FIG. 13 shows a first example of a conventional radio communication method. Here, FIG. 13A shows a state at the time of connection in the communication sequence, FIG. 13B shows a state at the time of data transmission in the communication sequence, and FIG. 13C shows a state at the time of disconnection in the communication sequence. In these figures, 1a is a wireless communication device A, 1b is a wireless communication device B, 2a is an antenna A, 2b is an antenna B, 3a is a non-directional directional pattern A, 3b is a non-directional directional pattern B Reference numeral 4 denotes a connection signal, reference numeral 5 denotes data, and reference numeral 6 denotes a disconnection signal. The omnidirectional directivity pattern 3a shown in FIG.
3b means the area inside the sphere in the figure. In this example, communication is always performed using the same omnidirectional directivity regardless of the communication sequence. In this case, there is an advantage that the connection can be performed irrespective of the positions and directions of the two wireless communication devices 1a and 1b.

FIG. 14 shows a second example of a conventional wireless communication method. Here, FIG. 14A shows a state at the time of connection in the communication sequence, FIG. 14B shows a state at the time of data transmission in the communication sequence, and FIG. 14C shows a state at the time of disconnection in the communication sequence. 13, the same devices, signals, data, and the like as those in FIG. 13 are denoted by the same reference numerals, and description thereof will be omitted. In these figures, 7a and 7b both indicate directivity patterns having a small half-value angle.

In this example, communication is always performed using the same directivity having the same half-value angle regardless of the communication sequence. In this case, since an antenna having a directivity characteristic of a pencil beam having a small half-value angle is used, multipath fading does not occur because a reflected wave from a wall or a fixture is not received. Thus, there is an advantage that even if the code rate is high, the code error is small and the transmission quality is high. That is, data transmission can be performed in a shorter time than in the first example.

[0005]

According to the first example, when communication is performed in a premises or the like, in addition to a direct wave directly propagating between the two wireless communication devices 1a and 1b, a wall or a fixture is used. The multipath fading occurs due to the reception of the reflected wave due to the above. As a result, as the code rate increases, the code error increases and the transmission quality deteriorates.

In order to suppress such multipath fading, as in the second example described above, a pencil beam or an antenna having a directional characteristic with a small half-value angle is used to prevent the reflected wave from being received. There is a need to. Further, in the communication sequence, since the transmission capacity during data transmission is large, it is desirable that the code rate be high. However, the first example has a drawback that the directivity is constant and the code rate cannot be increased.

Further, according to the second example, a pencil beam or an antenna having a directional characteristic with a small half-value angle is used in order to solve the disadvantage described in the description of the "first example". Therefore, as long as the directivity directions of the two wireless communication devices 1a and 1b are not opposed to each other in advance, the connection signal 4 is not received, and there is a disadvantage that the connection cannot be made.
As described above, in the conventional wireless communication method, communication is always performed using the same directivity regardless of the communication sequence. For this reason, there is a drawback that the code rate cannot be increased or the connection becomes difficult if the code rate is increased.

[0008] The present invention has been made in view of the above points, and by solving the above-mentioned disadvantages of the "prior art", the problem of multipath fading caused by reflected waves from walls and furniture has been raised. It is an object of the present invention to provide a wireless communication method and apparatus that can increase the code rate while maintaining high transmission quality, and that can be easily connected.

[0009]

According to the first aspect of the present invention,
In a wireless communication method for performing data transmission between a plurality of wireless communication devices according to a communication sequence including connection, data transmission, and disconnection, the antenna directivity of at least one wireless communication device changes in synchronization with the communication sequence. It is characterized by: According to a second aspect of the present invention, in the first aspect of the present invention, in synchronization with the communication sequence, the antenna directivity of at least one wireless communication device changes and the multilevel number of the modulation / demodulation method changes. It is characterized by:

According to a third aspect of the present invention, in the first or second aspect of the present invention, the antenna directivity of at least one wireless communication device changes and the code rate changes in synchronization with the communication sequence. It is characterized by doing. According to a fourth aspect of the present invention, in the communication method according to any one of the first to third aspects, in the communication sequence, at the time of connection, the antenna becomes omnidirectional or has a directional characteristic having a large half-value angle, and data transmission is performed. At the time, the antenna is characterized in that it has a directivity characteristic of a pencil beam or a small half-value angle, and the direction of the antenna is directed to the direction of the opposite wireless communication device that performs data transmission.

According to a fifth aspect of the present invention, in the first aspect of the present invention, in the communication sequence, the antenna is omnidirectional or has a directional characteristic having a large half-value angle when connected. At the same time, the multilevel number of the modulation / demodulation method becomes smaller, and the antenna has a directivity characteristic of a pencil beam or a small half-value angle at the time of data transmission, and the direction of the antenna is directed to the direction of the opposite wireless communication device that performs data transmission. In addition, the multi-level number of the modulation / demodulation method is characterized in that it is large.

According to a sixth aspect of the present invention, in the first aspect of the present invention, in the communication sequence, when the antenna is connected, the antenna is omni-directional or has a directional characteristic having a large half-value angle. At the same time, the code rate becomes low, and during data transmission, the antenna becomes a directional characteristic with a pencil beam or a small half-value angle, and the pointing direction of the antenna is directed to the direction of the opposite wireless communication device that performs data transmission, and the code is transmitted. It is characterized by a high speed.

According to a seventh aspect of the present invention, in the invention of any one of the first to sixth aspects, when a burst error occurs during data transmission in the communication sequence, the antenna is omnidirectional or non-directional. The directional characteristic of the half-value angle becomes large, and the antenna becomes the directional characteristic of the pencil beam or the small half-value angle again after being in the receivable state, and the directional direction of the antenna is changed to the direction of the opposite wireless communication device that performs data transmission. It is characterized by turning.

According to an eighth aspect of the present invention, in the invention according to any one of the first to seventh aspects, when a burst error occurs during data transmission in the communication sequence, the antenna is omnidirectional or non-directional. Along with the directional characteristic with a large half-value angle, the multi-level number of the modulation and demodulation method is reduced,
After re-entering the receivable state, the antenna becomes a pencil beam or a directional characteristic with a small half-value angle, and the directional direction of the antenna is directed to the direction of the opposite wireless communication device that performs data transmission. Is characterized by being larger.

According to a ninth aspect of the present invention, in the invention according to any one of the first to eighth aspects, when a burst error occurs during data transmission in the communication sequence, the antenna is omnidirectional or omnidirectional. After the directional characteristic of the half-value angle becomes large and the code rate becomes low, and the antenna becomes a receivable state again, the antenna becomes a directional characteristic of a pencil beam or a small half-value angle, and the directional direction of the antenna performs data transmission. It is characterized in that it is directed to the opposite wireless communication device and the code speed is increased.

According to a tenth aspect of the present invention, in a wireless communication apparatus for performing data transmission according to a communication sequence including connection, data transmission, and disconnection, the directivity of the antenna is changed to non-directional or half-valued during or after connection. A directivity control unit having a directivity characteristic having a large angle and a directivity characteristic having a small half-value angle with a pencil beam during data transmission is provided.

The invention according to claim 11 is the first invention.
0, the radio communication device has error detection means for detecting a burst error of received data, and the directivity control means sets the directivity of the antenna to non-directional or half-value when a burst error is detected. It is characterized in that the directivity of the antenna is set to a large angle, and the directivity of the antenna is changed to a pencil beam or a directivity of a small half-value angle when re-reception becomes possible.

According to a twelfth aspect of the present invention, there is provided a radio communication apparatus for modulating / demodulating transmission / reception data and transmitting data in accordance with a communication sequence including connection / data transmission / disconnection. Modulation / demodulation means for reducing the multi-level number of data modulation / demodulation and increasing the multi-level number of modulation / demodulation of the transmission / reception data during data transmission, and changing the directivity of the antenna to non-directional or large half-value angle during connection or after disconnection Directivity control means for setting the directivity of the antenna to a directivity of a pencil beam or a small half-value angle during data transmission.

The invention according to claim 13 is the first invention.
2. The invention according to 2, wherein the wireless communication device has error detection means for detecting a burst error of received data, and the modulation / demodulation means reduces a multilevel number of modulation / demodulation of the transmission / reception data when a burst error is detected, It is characterized in that the multi-level number of modulation and demodulation of the transmission / reception data is increased when re-reception becomes possible.

According to a fourteenth aspect of the present invention, there is provided a radio communication apparatus for performing data transmission by encoding transmission / reception data in accordance with a communication sequence including connection / data transmission / disconnection. A coding means for setting the code rate of the transmission and reception data to be high during data transmission, and making the directivity of the antenna omnidirectional or having a large half-value angle during connection or after disconnection. Directional control means for setting the directivity of the antenna to a directivity characteristic of a pencil beam or a small half-value angle during transmission is provided.

The invention according to claim 15 is the first invention.
5. The invention according to claim 4, wherein the wireless communication device has error detecting means for detecting a burst error of the received data, and the encoding means reduces the code rate of the transmission / reception data when detecting a burst error, and It is characterized in that the code rate of the transmission / reception data is increased when it becomes possible.

[0022]

According to the present invention, when the communication sequence is connected, the directivity of the antenna becomes omnidirectional or directivity having a large half-value angle and is switched to a low code rate. During data transmission, the directivity of the antenna changes to a pencil beam or a directivity having a small half-value angle. As a result, the connection can be reliably established regardless of the position and orientation of the wireless communication device at the time of connection, and multipath fading does not occur during data transmission. Even when the speed is increased, it is possible to perform high-speed data transmission with a small error rate.

If a burst error occurs during data transmission, the directivity of the antenna becomes omnidirectional or directional with a large half-value angle, and switches to a low code rate. Further, when the antenna is in a receivable state, the directivity of the antenna changes to a pencil beam or a directional characteristic having a small half-value angle, and in addition, the code rate is switched to a high code rate. As a result, even in an environment in which the wireless communication device performs communication while moving, burst errors can be easily recovered, and communication is not interrupted halfway.

[0024]

【Example】

[Communication Method: First Embodiment] Next, a first embodiment of the wireless communication method according to the present invention will be described. FIG. 1 is a diagram showing a communication procedure of wireless communication according to the embodiment. In the figure, (a) shows a state at the time of connection in the communication sequence, (b) shows a state at the time of data transmission in the communication sequence, and (c) shows a state after disconnection in the communication sequence. In this figure, the same devices, signals, data, and the like as those in FIGS. 13 and 14 are denoted by the same reference numerals, and description thereof will be omitted. In the embodiment according to the present invention, the “magnitude of the half-value angle” of the directivity patterns 7a and 7b having a small half-value angle is set.
Is preferably several tens degrees or less, more preferably several degrees or less.

FIG. 3 shows a state in which the directivity changes in synchronization with a communication sequence. At connection ｛Figure 1
(A) In｝, the directional characteristics 3a and 3
b, and connection is possible regardless of the positions and directions of the two wireless communication devices 1a and 1b. Next, when the connection is completed and the data transmission becomes {FIG. 1 (b)}, the antenna 2a.
The directivity of 2b changes to a directional characteristic with a small half-value angle, and the directivity of these antennas is directed to the direction of the opposite wireless communication device that will perform data transmission.
Then, since reflected waves from walls, furniture, and the like are not received, multipath fading does not occur, code errors are small, and transmission quality is high. In addition, since radio waves are not radiated in unnecessary directions from the radio wave transmitting side, energy is effectively used, and interference or interference with other communication is reduced.

Next, when the data transmission is completed and the disconnection of the wireless transmission line is completed {FIG. 1 (c)}, the antenna 2a
(2) The directivity of 2b changes to the non-directional directivity again, and the connection wait state is established. Note that the same effect as described above can be obtained even if the directivity of only one of the wireless communication devices 1a and 1b is changed.

[Communication Method: Second Embodiment] Next, a second embodiment of the wireless communication method according to the present invention will be described.
FIG. 2 is a diagram illustrating a communication procedure of wireless communication according to the embodiment. In the figure, (a) shows a state at the time of connection in the communication sequence, (b) shows a state at the time of data transmission in the communication sequence, and (c) shows a state after disconnection in the communication sequence. In the figure, the same devices, signals, data, and the like as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. In the drawing, 8a and 8b both indicate directivity patterns having a large half-value angle. In the embodiment according to the present invention, the directivity patterns 8a and 8b having a large half-value angle
Is preferably a size that covers the whole wireless zone.

FIG. 3 shows a state where the directivity changes in synchronization with the communication sequence. At connection ｛Figure 2
(A) In｝, the antenna has a directional characteristic 8a having a large half-value angle.
8b, so that connection is possible regardless of the position or orientation of both wireless communication devices 1a and 1b. Next, when the connection is completed and the data transmission becomes as shown in FIG.
The directivity of a.2b changes to a directional characteristic having a small half-value angle, and the directivity of these antennas is directed to the direction of the opposing wireless communication device that will perform data transmission. Then, since reflected waves from walls, furniture, and the like are not received, multipath fading does not occur, code errors are small, and transmission quality is high. In addition, since radio waves are not radiated from the transmission side of radio waves in unnecessary directions, energy is effectively used, and interference or interference with other communications is reduced.

Next, when the data transmission is completed and the disconnection of the wireless transmission line is completed {FIG. 2 (c)}, the antenna 2a
(2) The directivity of 2b changes to a directivity characteristic having a large half-value angle again, and a connection wait state is set. The wireless communication device 1a.
Even if the directivity of only one of the antennas 1b is changed, the same effect as described above can be obtained.

[Communication Method: Third Embodiment] Next, a third embodiment of the wireless communication method according to the present invention will be described.
FIG. 3 is a diagram showing a communication procedure of wireless communication according to the embodiment. In the figure, (a) shows a state at the time of connection in the communication sequence, (b) shows a state at the time of data transmission in the communication sequence, and (c) shows a state after disconnection in the communication sequence. In this figure, the same devices, signals, data, and the like as those in FIGS. 1 and 2 are denoted by the same reference numerals, and description thereof will be omitted. In these figures, 15 is a code string before modulation with a low transmission rate, 16 is a code string after demodulation with a low transmission rate, 17 is a code string before modulation with a high transmission rate, and 18 is a code string after demodulation with a high transmission rate. A code sequence 19 is a code sequence modulated by a small multi-level number constituting a connection signal, 20
Indicates a code string modulated by a large multilevel number constituting data.

FIG. 4 shows how the directivity and the multi-level number of the modulation / demodulation system change in synchronization with the communication sequence. At the time of connection {FIG. 3 (a)}, the antenna has omnidirectional directional characteristics, and connection is possible regardless of the positions and orientations of both wireless communication devices 1a and 1b. At this time, the multilevel number of the modulation / demodulation method is small. When the multi-level number of the modulation / demodulation method is small, the error rate characteristics with respect to multipath and noise are good, so that communication is possible even with an omnidirectional antenna.

Next, when the connection is completed and data is transmitted {FIG.
(B) When｝, the antennas 2a and 2b change to a directional characteristic having a small half-value angle, and the directional directions of these antennas are directed to the direction of the opposing wireless communication device that will perform data transmission. At this time, the multi-level number of the modulation / demodulation scheme also increases. At this point, since reflected waves from walls, furniture, and the like are not received and multipath fading does not occur, a constant transmission quality can be maintained even if the code rate is fixed and the multi-level number of the modulation / demodulation method is increased. In addition, since radio waves are not radiated in unnecessary directions from the radio wave transmitting side, energy is effectively used, and interference or interference with other communication is reduced.

Next, when the data transmission is completed and the disconnection of the wireless transmission line is completed {FIG. 3 (c)}, the antenna 2
a.2b again changes to the non-directional directional characteristic, and the multi-level number of the modulation / demodulation system decreases, and the connection waits. Note that the same effect as described above can be obtained even if the directivity of only one of the wireless communication devices 1a and 1b is changed.

[Communication Method: Fourth Embodiment] Next, a fourth embodiment of the wireless communication method according to the present invention will be described.
FIG. 4 is a diagram showing a communication procedure of wireless communication according to the embodiment. In the figure, (a) shows a state at the time of connection in the communication sequence, (b) shows a state at the time of data transmission in the communication sequence, and (c) shows a state after disconnection in the communication sequence. 3, the same devices, signals, data, and the like as those in FIGS. 1 to 3 are denoted by the same reference numerals, and description thereof will be omitted. In the drawing, reference numeral 9 denotes a modulated code sequence having a low code rate, which constitutes a connection signal, and reference numeral 10 denotes a modulated code sequence having a high code rate, which constitutes data.

FIG. 3 shows how the directivity and the code rate change in synchronization with the communication sequence. Also,
As the code rate changes, the transmission rates before modulation and after demodulation also change. At the time of connection {FIG. 4 (a)}, the antenna 2
a and 2b have non-directional directional characteristics, and connection is possible regardless of the positions and directions of the two wireless communication devices 1a and 1b. Note that the code speed at this time is low. If the code rate is low, the error rate characteristics with respect to multipath and noise are good, so that communication is possible even with an omnidirectional antenna.

Next, at the time of data transmission after connection is completed {FIG.
(B) At the time of｝, the antennas 2a and 2b are changed to directional characteristics having a small half-value angle, and the directional directions of these antennas are directed to the direction of the opposite wireless communication device that will perform data transmission. In addition, the code speed increases. At this time, since reflected waves from walls, furniture, and the like are not received and multipath fading does not occur, a constant transmission quality can be maintained even when the code rate is increased. Further, since the radio wave is not radiated from the transmission side of the radio wave in an unnecessary direction, the energy can be effectively used, and at the same time, interference or interference with other communication is reduced.

Next, when the data transmission is completed and the disconnection of the wireless transmission line is completed, {FIG. 4 (c)} antenna 2a
2b changes to the non-directional directional characteristic again, and the code rate is lowered to wait for connection. Note that the same effect as described above can be obtained even if the directivity of only one of the wireless communication devices 1a and 1b is changed.

[Communication Apparatus: First Embodiment] Next, a first embodiment of the radio communication apparatus according to the present invention will be described.
FIG. 5 is a diagram showing an example of an electric system diagram of the wireless communication device according to the embodiment. In the figure, reference numeral 2 denotes an antenna, which corresponds to the above-described antenna 2a or 2b. The modulation circuit 11 modulates the transmission radio wave,
The demodulation circuit 12 demodulates the received radio wave.

Further, during data transmission, the directivity control circuit 13 tracks the directivity according to the movement of the wireless communication device with which communication has been established. 2 is controlled. Reference numeral 14 denotes a CPU (Central Processing Unit), the function of which will be described later. 21
Is a multiplexing / demultiplexing circuit, 22 is a transmitting circuit, and 23 is a receiving circuit. The error rate detection circuit 24 monitors the error rate of the demodulated code string during data transmission, and sends a signal to the CPU 14 when detecting the occurrence of a burst error. The band control circuit 25 sets the transmission circuit 22 or the reception circuit 23 to a desired frequency band. Multi-value number control circuit 2
Numeral 6 controls the multi-level of the signal during modulation and demodulation.

Next, the operation of the wireless communication apparatus having the above configuration will be described. First, when a connection request is issued, a calling / calling operation is performed. When the connection between the wireless communication devices is completed, the CPU 14 sends a command signal to the directivity control circuit 13 to change the directivity of the antenna 2 to a pencil beam or a directivity having a small half-value angle. At the same time, the pointing direction of the antenna 2 is directed to the direction of the opposing wireless communication device that will perform data transmission. When the adjustment of the directivity is completed, the CPU 14 sends a command signal to the multi-level control circuit 26 to increase the multi-level number of the modulation / demodulation method. At the same time, a command signal is sent to the band control circuit 25 to set the transmission circuit 22 and the reception circuit 23 to a desired frequency band for data transmission, and start data transmission.

When the data transmission is completed, the CPU 14 disconnects the wireless transmission line. When recognizing that the cutting has been completed, the CPU 14 again sends a command signal to the directivity control circuit 13 to change the directivity to a non-directivity or a directivity having a large half-value angle. When the adjustment of the directivity is completed, the CPU 14 sends a command signal again to the multi-level control circuit 26 to reduce the multi-level number of the modulation / demodulation method. At this time, a command signal is sent to the band control circuit 25 at the same time, the transmission circuit 22 and the reception circuit 23 are set to a desired frequency band for connection, and the next connection is awaited.

Next, the operation when a burst error is detected during data transmission will be described. When the error rate detection circuit 24 detects a burst error, the CPU 14 sends a command signal to the directivity control circuit 13 to change the directivity to a non-directivity or a directivity having a large half-value angle. When the directivity adjustment is completed, the CPU 14 sends a command signal to the multi-level control circuit 26 to reduce the multi-level number of the modulation / demodulation method. At this time, a command signal is sent to the band control circuit 25 at the same time, the transmission circuit 22 and the reception circuit 23 are set to a desired frequency band for connection, and reconnection is performed.

When the reconnection succeeds and the reception becomes possible, the CPU 14 sends a command signal to the directivity control circuit 13 to change the directivity of the antenna 2 to a pencil beam or a directivity having a small half-value angle. In addition, the pointing direction of the antenna 2 is directed to the direction of the opposing wireless communication device that has been performing data transmission. Thereafter, when the adjustment of the directivity is completed, the CPU 14 sends a command signal to the multi-level control circuit 26 to increase the multi-level number of the modulation / demodulation method. At this time, a command signal is sent to the band control circuit 25 at the same time, the transmission circuit 22 and the reception circuit 23 are set to a desired frequency band for data transmission, and data transmission is resumed.

[Communication Apparatus: Second Embodiment] Next, a second embodiment of the radio communication apparatus according to the present invention will be described.
FIG. 6 is a diagram illustrating an example of an electric system diagram of the wireless communication device according to the embodiment. Here, the same devices, signals, data, and the like as those in FIG. 5 are denoted by the same reference numerals, and description thereof will be omitted. In the figure, a code rate control circuit 27 controls the rate of coding performed by the modulation circuit 11 or the demodulation circuit 12.

Next, the operation of the wireless communication apparatus having the above configuration will be described. First, when a connection request is issued, a calling / calling operation is performed. When the connection between the wireless communication devices is completed, the CPU 14 sends a command signal to the directivity control circuit 13 to change the directivity of the antenna 2 to a pencil beam or a directivity having a small half-value angle. At the same time, the pointing direction of the antenna 2 is directed to the direction of the opposing wireless communication device that will perform data transmission. When the adjustment of the directivity is completed, the CPU 14 sends a command signal to the code rate control circuit 27 to increase the code rate. At the same time, a command signal is sent to the band control circuit 25 to set the transmission circuit 22 and the reception circuit 23 to a desired frequency band for data transmission, and start data transmission.

When the data transmission is completed, the CPU 14 disconnects the wireless transmission line. When recognizing that the cutting has been completed, the CPU 14 again sends a command signal to the directivity control circuit 13 to change the directivity to a non-directivity or a directivity having a large half-value angle. When the adjustment of the directivity is completed, the CPU 14 sends a command signal to the code speed control circuit 27 again to lower the code speed. At this time, a command signal is sent to the band control circuit 25 at the same time, the transmission circuit 22 and the reception circuit 23 are set to a desired frequency band for connection, and the next connection is awaited.

Next, the operation when a burst error is detected during data transmission will be described. When the error rate detection circuit 24 detects a burst error, the CPU 14 sends a command signal to the directivity control circuit 13 to change the directivity to a non-directivity or a directivity having a large half-value angle. When the adjustment of the directivity is completed, the CPU 14 sends a command signal to the code rate control circuit 27 to lower the code rate. At this time, a command signal is sent to the band control circuit 25 at the same time, the transmission circuit 22 and the reception circuit 23 are set to a desired frequency band for connection, and reconnection is performed.

When the reconnection succeeds and the reception becomes possible, the CPU 14 sends a command signal to the directivity control circuit 13 to change the directivity of the antenna 2 to a pencil beam or a directivity having a small half-value angle. In addition, the pointing direction of the antenna 2 is directed to the direction of the opposing wireless communication device that has been performing data transmission. Thereafter, when the directivity adjustment is completed, the CPU 14 sends a command signal to the code rate control circuit 27 to increase the code rate. At this time, a command signal is sent to the band control circuit 25 at the same time, the transmission circuit 22 and the reception circuit 23 are set to a desired frequency band for data transmission, and data transmission is resumed.

[Communication Sequence: First Embodiment] Next, a first embodiment of a communication sequence according to the wireless communication method of the present invention will be described. FIG. 7 is a diagram showing a communication sequence according to the embodiment, and shows an example of a sequence when communication is performed between two wireless communication devices A and B. This communication sequence can be performed using the wireless communication device shown in FIGS. The two wireless communication devices A and B communicate while moving, and the directivity control circuit 13 has a function of changing the half-value angle and the directivity direction.
If the antenna 2 is, for example, a phased array antenna, the directivity can be arbitrarily varied by changing the phase and amplitude by the directivity control circuit 13.

First, in the connection waiting state, both wireless communication devices A
B has a large half-value directivity. Next, when the wireless communication device A sends a call request signal, the wireless communication device B receives the call request signal and reduces the half-value angle while directing the directional direction toward the wireless communication device A, and performs beam forming. I do. Then, when the directivity is determined, the wireless communication device B sends out a call acceptance signal. The wireless communication device A receives the incoming call reception signal, reduces the half-value angle while directing the pointing direction toward the wireless communication device B, and performs beam shaping. Then, when the directivity is determined, the wireless communication device A starts data transmission.

During data transmission, the directivity control circuit 13 in each of the two wireless communication devices A and B tracks the direction of the movement in accordance with the movement of the device so that the two directions always face each other. Control. When the data transmission is completed, the wireless communication device A sends a recovery request signal. Upon receiving the restoration request signal (disconnection instruction), the wireless communication device B transmits a disconnection confirmation signal, and thereafter increases the half-value angle. Upon receiving the disconnection confirmation signal, the wireless communication device A increases the half-value angle,
The cutting is completed. Note that the same effect as above can be obtained even if the directivity of only one of the two wireless communication devices is changed.

[Communication Sequence: Second Embodiment] Next, a second embodiment of the communication sequence according to the wireless communication method of the present invention will be described. FIG. 8 is a diagram showing a communication sequence according to the embodiment, and shows an example of a sequence when communication is performed between two wireless communication devices A and B. FIG. 11 shows an example of a sequence in the case where a burst error occurs during data transmission in the communication sequence shown in the first embodiment (see FIG. 7). This communication sequence is shown in FIG.
And the wireless communication device shown in FIG.

When a burst error is detected, both wireless communication devices A and B increase the half angle. Next, one of the wireless communication devices transmits a reception impossible signal. In the figure, it is assumed that the wireless communication device A that has transmitted the call request transmits the reception impossible signal first. The wireless communication device B receives the reception impossible signal, reduces the half-value angle while directing the directional direction toward the wireless communication device A, and performs beam shaping. When the directivity is determined, the wireless communication device B sends out a reception enable signal. The wireless communication device A receives the reception enable signal, reduces the half-value angle while directing the directional direction toward the wireless communication device B,
Perform beam forming. When the directivity is determined, the wireless communication device A restarts data transmission.

The other sequences are the same as those described in the description of FIG. 7, and the description is omitted. Further, even if the directivity of only one of the two wireless communication devices is changed, the same effect as above can be obtained.

[Communication Sequence: Third Embodiment] Next, a third embodiment of the communication sequence according to the wireless communication method of the present invention will be described. FIG. 9 is a diagram showing a communication sequence according to the embodiment, and shows an example of a sequence in a case where communication is performed between two wireless communication devices A and B. This communication sequence can be performed using the wireless communication device shown in FIG. The two wireless communication devices A and B communicate while moving, and the directivity control circuit 13 has a function of changing the half-value angle and the directivity direction. If the antenna 2 is, for example, a phased array antenna, the directivity can be arbitrarily changed by changing the phase and amplitude by the directivity control circuit 13.

First, in the connection waiting state, both wireless communication devices A
B has a large directivity with a half-value angle, and the multilevel number of the modulation / demodulation method is small. Next, when the wireless communication device A sends a call request signal, the wireless communication device B receives the call request signal, reduces the half-value angle while directing the pointing direction toward the wireless communication device A, Perform molding.

When the directivity is determined, the radio communication device B
Sends a call acceptance signal. The wireless communication device A receives the incoming call reception signal, reduces the half-value angle while directing the pointing direction toward the wireless communication device B, and performs beam shaping. Then, the radio communication device A whose directivity is determined transmits the receivable A signal, and thereafter increases the multilevel number of the modulation / demodulation method. Upon receiving the reception enable A signal, the wireless communication device B transmits the reception enable B signal, and thereafter increases the multi-level number of the modulation / demodulation method. The wireless communication device A starts data transmission when receiving the reception enable B signal.

During the data transmission, the directivity control circuit 13 in each of the two radio communication devices A and B tracks the directivity according to the movement of the devices, so that the two directivity directions always face each other. Control. When the data transmission is completed, the wireless communication device A sends a recovery request signal. Upon receiving the restoration request signal (disconnection instruction), the wireless communication device B sends a disconnection confirmation signal. Thereafter, the half-value angle is increased and the multi-level number of the modulation / demodulation method is reduced. Also, the wireless communication device A
Upon receiving this disconnection confirmation signal, the disconnection is completed by increasing the half-value angle and decreasing the multi-level number of the modulation / demodulation method. Note that the same effect as above can be obtained even if the directivity of only one of the two wireless communication devices is changed.

[Communication Sequence: Fourth Embodiment] Next, a fourth embodiment of the communication sequence according to the wireless communication method of the present invention will be described. FIG. 10 is a diagram illustrating a communication sequence according to the embodiment, and illustrates an example of a sequence in a case where communication is performed between two wireless communication devices A and B. This figure shows an example of a sequence when a burst error occurs during data transmission in the communication sequence shown in the third embodiment (see FIG. 9). This communication sequence can be performed using the wireless communication device shown in FIG.

When a burst error is detected, both radio communication devices A and B increase the half-value angle and further decrease the multi-level number of the modulation / demodulation system. Next, one of the wireless communication devices transmits a reception impossible signal. In the figure, it is assumed that the wireless communication device A that has transmitted the call request transmits the reception impossible signal first. The wireless communication device B receives the reception impossible signal, reduces the half-value angle while directing the directional direction toward the wireless communication device A, and performs beam shaping. Then, when the directivity is determined, the wireless communication device B transmits a receivable B signal, and thereafter increases the multilevel number of the modulation / demodulation method. The wireless communication device A receives the receivable B signal, reduces the half-value angle while directing the directional direction toward the wireless communication device B, and performs beam shaping.
Then, when the directivity is determined, the wireless communication device A increases the multilevel number of the modulation / demodulation method. Thereafter, the reception enable A signal is transmitted to the wireless communication device B side to restart the data transmission.

The other sequence is as described in the description of FIG. 9, and the description is omitted. The same effect can be obtained even if the directivity of only one of the two wireless communication devices A and B is changed.

[Communication Sequence: Fifth Embodiment] Next, a fifth embodiment of the communication sequence according to the wireless communication method of the present invention will be described. FIG. 11 is a diagram illustrating a communication sequence according to the embodiment, and illustrates an example of a sequence in a case where communication is performed between two wireless communication devices A and B. This communication sequence can be performed using the wireless communication device shown in FIG. Here, both wireless communication devices A and B
Communicates while moving, and the directivity control circuit 1
Reference numeral 3 has a function of changing the half value angle and the directivity direction. If the antenna 2 is, for example, a phased array antenna, the directivity can be arbitrarily varied by changing the phase and amplitude by the directivity control circuit 13.

First, in the connection waiting state, the two radio communication apparatuses A and B have directivity with a large half-value angle, and the code rate is low. Next, when the wireless communication device A sends a call request signal, the wireless communication device B receives the call request signal, reduces the half-value angle while directing the pointing direction toward the wireless communication device A, Perform molding. Then, when the directivity is determined, the wireless communication device B sends out a call acceptance signal. Then, the wireless communication device A receives this incoming call reception signal,
The beam forming is performed by reducing the half-value angle while directing the pointing direction toward the wireless communication device B. Then, when the directivity is determined, the wireless communication device A transmits a reception enable A signal, and thereafter switches the code rate to “high”. Upon receiving the reception enable A signal, the wireless communication device B transmits the reception enable B signal. After that, the code speed is switched to “high speed”. When the wireless communication device A receives the receivable B signal,
Start data transmission.

During data transmission, the directivity control circuit 13 in each of the two radio communication devices A and B tracks the directivity according to the movement of the two devices, so that the two directivity directions always face each other. Control. When the data transmission is completed, the wireless communication device A sends a recovery request signal. Upon receiving the restoration request signal (disconnection instruction), the wireless communication device B sends a disconnection confirmation signal. After that, the half value angle is increased and the code speed is switched to “low speed”. On the other hand, the wireless communication device A
Upon receiving this disconnection confirmation signal, the half value angle is increased and the code rate is switched to "low speed", whereby the disconnection is completed. Note that the same effect as described above can be obtained even if the directivity of only one of the two wireless communication devices A and B is changed.

[Communication Sequence: Sixth Embodiment] Next, a sixth embodiment of the communication sequence according to the wireless communication method of the present invention will be described. FIG. 12 is a diagram showing a communication sequence according to the embodiment, and shows an example of a sequence in a case where communication is performed between two wireless communication devices A and B. This figure shows an example of a sequence when a burst error occurs during data transmission in the communication sequence of the fifth embodiment (see FIG. 11). This communication sequence is shown in FIG.
This can be implemented using the wireless communication device indicated by.

When a burst error is detected, both wireless communication devices A and B increase the half-value angle and switch the code rate to “low”. Next, one of the wireless communication devices transmits a reception impossible signal. In the figure, it is assumed that the wireless communication device A that has transmitted the call request transmits the reception impossible signal first. The wireless communication device B receives the reception impossible signal, reduces the half-value angle while directing the directional direction toward the wireless communication device A, and performs beam shaping. Then, when the directivity is determined, the wireless communication device B transmits a receivable B signal, and thereafter switches the code rate to “high”. On the other hand, the wireless communication device A receives the receivable B signal, reduces the half-value angle while directing the directional direction toward the wireless communication device B, and performs beam shaping. Then, when the directivity is determined, the wireless communication device A sends a receivable A signal to the wireless communication device B side. Then, the code rate is switched to "high speed" and data transmission is resumed.

The other sequence is the same as that described in the description of FIG. 11, and the description is omitted. Also,
The same effect can be obtained even if the directivity of only one of the two wireless communication devices A and B is changed.

The antennas described in the above embodiments include all types of antennas such as linear antennas, planar antennas, aperture antennas, multi-beam antennas, and phased array antennas. All modifications are included in the present invention. Further, the switching of the multi-level number of the modulation and demodulation method described above includes not only the switching in two stages but also the switching in at least two stages. In addition, the above-described switching of the code rate includes not only two-stage switching of high speed and low speed, but also at least two-stage switching is included in the present invention.

[0069]

As described above, according to the present invention, when a communication sequence is connected, the directivity of the antenna becomes omnidirectional or directivity having a large half-value angle, and is switched to a low code rate. During transmission, the directivity of the antenna changes to a pencil beam or a directional characteristic with a small half-value angle.

[0070] Thereby, at the time of connection, the connection can be reliably performed irrespective of the position and orientation of the wireless communication device.
Since multipath fading does not occur during data transmission, even when the multi-level number of the modulation / demodulation method is increased or the code rate is increased, the effect that the error rate is small and high-speed data transmission can be performed can be obtained. . As a result, moving image data can be transmitted in real time, and large amounts of data can be transmitted in a short time.
Since radio waves are not radiated from the wireless communication device on the transmitting side in unnecessary directions, energy can be effectively used, and the effect of interfering or obstructing other communications is reduced.

When a burst error occurs during data transmission, the directivity of the antenna is changed to a non-directivity or a directional characteristic having a large half-value angle, and is switched to a low code rate. The characteristic changes to a pencil beam or a directional characteristic with a small half-value angle, and additionally switches to a high code rate. This allows
Even in an environment where the wireless communication device performs communication while moving, burst errors can be easily recovered, and the effect that communication is not interrupted on the way can be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram showing a first embodiment of a wireless communication method according to the present invention. (A) is a state at the time of connection in the communication sequence, (b) is a state at the time of data transmission, and (c) is a state at the same time after disconnection.

FIG. 2 is a diagram showing a second embodiment of the wireless communication method. (A) is the state at the time of connection in the communication sequence,
(B) is a state at the time of data transmission, and (c) is a state after disconnection.

FIG. 3 is a diagram showing a third embodiment of the wireless communication method. (A) is the state at the time of connection in the communication sequence,
(B) is a state at the time of data transmission, and (c) is a state after disconnection.

FIG. 4 is a diagram showing a fourth embodiment of the wireless communication method. (A) is the state at the time of connection in the communication sequence,
(B) is a state at the time of data transmission, and (c) is a state after disconnection.

FIG. 5 is a block diagram showing a configuration of a first embodiment of the wireless communication apparatus according to the present invention.

FIG. 6 is a block diagram showing a configuration of a second embodiment of the wireless device.

FIG. 7 is a diagram showing a first embodiment of a communication sequence of the wireless communication method according to the present invention.

FIG. 8 is a diagram showing a second embodiment of the communication sequence.

FIG. 9 is a diagram showing a third embodiment of the communication sequence.

FIG. 10 is a diagram showing a fourth embodiment of the communication sequence.

FIG. 11 is a diagram showing a fifth embodiment of the communication sequence.

FIG. 12 is a diagram showing a sixth embodiment of the communication sequence.

FIG. 13 is a diagram showing a first example of a conventional wireless communication method. (A) is the state at the time of connection in the communication sequence,
(B) is a state at the time of data transmission, and (c) is a state after disconnection.

FIG. 14 is a diagram showing a second example of the wireless communication method.
(A) is the state at the time of connection in the communication sequence, (b)
Is the state at the time of data transmission, and (c) is the state after disconnection.

[Explanation of symbols]

 1a, 1b Wireless communication device 2, 2a, 2b Antenna 3a, 3b Non-directional directivity pattern 4 Connection signal 5 Data signal 6 Disconnection signal 7a, 7b Directivity pattern with small half-value angle 8a, 8b Directivity with large half-value angle Pattern 9 Code sequence after modulation with low code speed 10 Code sequence after modulation with high code speed 11 Modulation circuit 12 Demodulation circuit 13 Directivity control circuit 14 CPU 15 Code sequence before modulation with low transmission speed 16 Demodulation with low transmission speed Code sequence after 17 Code sequence before modulation with high transmission speed 18 Code sequence after demodulation with high transmission speed 19 Code sequence modulated with small multi-level number 20 Code sequence modulated with large multi-level number 21 Multiplex Wave circuit 22 transmission circuit 23 reception circuit 24 error rate detection circuit 25 band control circuit 26 multilevel number control circuit 27 code rate control circuit

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-5-167489 (JP, A) JP-A-7-87011 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H04B 7/10 H04B 7/26 H04L 1/00

Claims (15)

(57) [Claims] 1. A wireless communication method for performing data transmission between a plurality of wireless communication devices in accordance with a communication sequence including connection, data transmission, and disconnection, wherein an antenna of at least one wireless communication device is synchronized with the communication sequence. A wireless communication method, wherein the directivity changes. 2. The wireless communication method according to claim 1, wherein the antenna directivity of at least one wireless communication device changes and the multilevel number of the modulation / demodulation method changes in synchronization with the communication sequence. . 3. The apparatus according to claim 1, wherein the antenna directivity of at least one wireless communication apparatus changes and the code rate changes in synchronization with the communication sequence.
Or the wireless communication method according to 2. 4. In the communication sequence, at the time of connection, the antenna has omnidirectionality or a directional characteristic having a large half-value angle, at the time of data transmission, the antenna has a directional characteristic having a pencil beam or a small half-value angle, and the directional direction of the antenna. The wireless communication method according to any one of claims 1 to 3, wherein the wireless communication device is directed toward the opposite wireless communication device that performs data transmission. 5. In the communication sequence, at the time of connection, the antenna has omnidirectionality or a directional characteristic having a large half-value angle, and the multi-valued number of the modulation / demodulation method becomes small. 5. The directional characteristic of the present invention is small, and the directional direction of the antenna is directed toward an opposite wireless communication apparatus that performs data transmission, and the multilevel number of the modulation / demodulation method is increased. The wireless communication method according to the item. 6. In the communication sequence, at the time of connection, the antenna has omnidirectionality or a directional characteristic having a large half-value angle, and at the same time, has a low code rate. At the time of data transmission, the antenna has a directivity of a pencil beam or a small half-value angle. 6. The wireless communication device according to claim 1, wherein the wireless communication device has a characteristic, and the directional direction of the antenna is directed toward an opposite wireless communication device that performs data transmission, and the code rate is increased. Communication method. 7. In the communication sequence, if a burst error occurs during data transmission, the antenna becomes omnidirectional or has a directional characteristic with a large half-value angle. After the antenna is again in a receivable state, the antenna becomes a pencil beam or a half-value angle. 7. The wireless communication method according to claim 1, wherein the directional characteristic is small, and the directional direction of the antenna is directed to a direction of an opposite wireless communication apparatus that performs data transmission. 8. In the communication sequence, when a burst error occurs during data transmission, the antenna becomes omni-directional or has a directional characteristic with a large half-value angle, and the multi-level number of the modulation / demodulation system is reduced, and the antenna is ready for reception again. After that, the antenna becomes a pencil beam or a directional characteristic with a small half-value angle, and the pointing direction of the antenna is directed to the opposite wireless communication device that performs data transmission, and the multilevel number of the modulation / demodulation method becomes large. The wireless communication method according to claim 1, wherein: 9. In the communication sequence, if a burst error occurs during data transmission, the antenna becomes omnidirectional or has a directional characteristic with a large half-value angle, the code rate decreases, and the antenna returns to a receivable state. 2. The antenna according to claim 1, wherein the antenna has a directivity characteristic of a pencil beam or a small half-value angle, and the pointing direction of the antenna is directed toward an opposite wireless communication apparatus that performs data transmission, and the code rate is increased. 9. The wireless communication method according to any one of items 8 to 8. 10. A wireless communication apparatus for performing data transmission in accordance with a communication sequence consisting of connection, data transmission, and disconnection, wherein, during or after connection, the directivity of the antenna is made non-directional or directional with a large half-value angle. A wireless communication apparatus comprising directivity control means for setting the directivity of the antenna to a pencil beam or a directivity having a small half-value angle during transmission. 11. The wireless communication apparatus has error detection means for detecting a burst error of received data, and the directivity control means changes the directivity of the antenna to non-directional or half-value angle when a burst error is detected. The radio communication apparatus according to claim 10, wherein the directivity of the antenna is changed to a directivity of a pencil beam or a small half-value angle when re-reception becomes possible. 12. A wireless communication apparatus for performing data transmission by modulating / demodulating transmission / reception data in accordance with a communication sequence including connection / data transmission / disconnection, wherein a multi-level number of modulation / demodulation of the transmission / reception data is determined during connection or after disconnection. Modulation / demodulation means for decreasing the number of modulation / demodulation of the transmission / reception data during data transmission, and setting the directivity of the antenna to non-directional or a large half-value directional characteristic during or after connection, and during data transmission. A radio communication apparatus comprising: a directivity control unit that sets a directivity of the antenna to a directivity characteristic of a pencil beam or a small half-value angle. 13. The wireless communication apparatus has error detection means for detecting a burst error of received data, and the modulation / demodulation means reduces a multilevel number of modulation / demodulation of the transmission / reception data when a burst error is detected. 13. The wireless communication apparatus according to claim 12, wherein a multi-level number of modulation and demodulation of the transmission / reception data is increased at a time when reception becomes possible. 14. A wireless communication apparatus for transmitting and receiving data by encoding transmission / reception data according to a communication sequence including connection, data transmission, and disconnection, wherein a code rate of the transmission / reception data is reduced during connection or after disconnection, Encoding means for increasing the code rate of the transmitted / received data during transmission; and directivity of the antenna being omnidirectional or having a large half-value angle during connection or disconnection, and directivity of the antenna during data transmission. And a directivity control unit that sets a directivity characteristic of a pencil beam or a half-value angle to be small. 15. The wireless communication apparatus has error detecting means for detecting a burst error of received data, and the encoding means makes the code rate of the transmitted / received data low when a burst error is detected, and enables re-reception. The wireless communication apparatus according to claim 14, wherein the code rate of the transmission / reception data is increased at the point in time.