JP2001016290A - Radio communication method and radio communication equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To coexist continuous communication and packet communication, to decrease a load on a collision avoidance protocol and to enhance a transmission efficiency and a wait time at radio transmission of a large capacity of data. SOLUTION: A control section 6 in a transmitter side terminal in this radio communication system controls a base band section 1, an IF-BB modulator 3, an IF-RF modulator 3 and a power amplifier 4. In the case of conducting usual packet communication with an unspecified terminal, a specific channel (channel CH 1) assigned in advance is used, and in the case of continuous communication with a specific terminal, an idle channel other than the specific channel is used. Furthermore, a control section 14 of a receiver side terminal controls a power amplifier 10, an IF-RF demodulator 11, an IF-BB demodulator 12 and a base band section 13, in the case of conducting normal packet communication with an unspecific terminal, the specific channel (channel CH 1) assigned in advance is used, and in the case of continuous communication with a specific terminal, an idle channel other than the specific channel is used.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a radio communication method and a radio communication system using spread spectrum communication.

[0002]

2. Description of the Related Art Spread spectrum communication is a technique mainly used in portable telephones, and thus, an unspecified number of people have conventionally shared a radio frequency band. For example, next generation W
In the CDMA scheme, an efficient scheme has been proposed as a multimedia service in which uplink and downlink exhibit asymmetric traffic characteristics (Japanese Patent Laid-Open No. 10-308).
722).

[0003]

However, in the conventional spread spectrum communication such as the WCDMA system described above, since it is assumed that it is used for a mobile phone, some terminals cannot occupy radio waves. It has become. Therefore, techniques for effective band utilization by devising within the same frequency band are being discussed.

On the other hand, when focusing on applications for home use (such as a wireless LAN between PCs), the transmission output of radio waves may be weak and the number of terminals is small. However, when conventional spread spectrum communication is applied for home use, radio waves cannot be occupied among some terminals.
If you try to perform image transmission (large-capacity transmission) in which continuous communication is effective, the transmission efficiency will deteriorate, and the waiting time for large-capacity wireless transmission will increase, making it impossible to take advantage of spread-spectrum communication. there were.

[0005] Accordingly, the present invention provides a wireless communication system capable of coexisting continuous communication and packet communication, reducing the load of a collision avoidance protocol, improving transmission efficiency, and improving the waiting time during large-capacity wireless transmission. It is an object to provide a method and a wireless communication system.

[0006]

To achieve the above object, a wireless communication method according to the first aspect of the present invention is a wireless communication method for dividing a predetermined wireless frequency band into a plurality of channels and performing data communication by spread spectrum. And using at least one channel among the plurality of channels as a shared channel and occupying one of the available channels between the terminals according to the amount of information transmitted and received between the terminals to perform continuous data communication. Features.

In a preferred embodiment, the continuous communication performed on the idle channel is, for example, as described in claim 2.
The same communication method as the communication method using the shared channel may be used.

In a preferred embodiment, the continuous communication performed on the idle channel is, for example, as described in claim 3.
The communication method may be different from the communication method using the shared channel.

According to another aspect of the present invention, there is provided a radio communication apparatus for dividing a predetermined radio frequency band into a plurality of channels and performing data communication by spread spectrum. When the shared channel is selected as a channel and continuous communication is performed with a partner terminal, channel switching means for switching a communication channel from the shared channel to an empty channel, and in the case of normal data communication, the shared channel When performing continuous communication while performing data communication, there is provided communication means for performing continuous communication using the empty channel switched by the channel switching means.

In a preferred aspect, the communication means includes first communication means for performing data communication using the shared channel and second communication means for performing continuous communication using the free channel. And switching means for switching a signal path so as to use the first communication means for normal data communication and the second communication means for continuous communication. You may make it.

In a preferred embodiment, the channel switching means may return the communication channel to the shared channel when the continuous communication by the second communication means is completed. .

According to the present invention, at least one of a plurality of channels is used as a shared channel, and one of the vacant channels is occupied by the terminals according to the amount of information transmitted and received between the terminals. Since communication is performed, continuous communication and packet communication can coexist. Therefore, by separating packet communication and continuous communication into different channels, a collision avoidance protocol (CSMA / CA: Carrier Sense Collision Multiple) is used.
Access with Collision Avoidance) can be reduced. Furthermore, by performing resource reservation for radio wave occupation, it becomes possible to improve transmission efficiency,
It is possible to reduce the waiting time during large-capacity wireless transmission.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. A-1. Configuration of Embodiment FIG. 1 is a block diagram showing a configuration of a wireless communication device of a basic spectrum communication system according to an embodiment of the present invention. Specifically, FIG. 1A is a block diagram illustrating a configuration of a spread spectrum transmitting unit, and FIG. 1B is a block diagram illustrating a configuration of a spread spectrum receiving unit. FIG.
In (a), the baseband (spreading processing) unit 1 packetizes transmission data into a predetermined packet, spreads the spectrum, and supplies the packet to the IF-BB modulator 2. IF-
The BB modulator 2 modulates the packetized and spread spectrum data into a baseband signal, and supplies the baseband signal to the IF-RF modulator 3.

The IF-RF modulator 3 modulates a signal modulated into a baseband signal to a predetermined transmission frequency and supplies the signal to a power amplifier 4. The power amplifier 4 power-amplifies the modulated signal and outputs the amplified signal from the antenna 5. The control unit 6
The baseband (spreading processing) unit 1, IF-BB modulator 2, IF-RF modulator 3, and power amplifier 4 are controlled.
In particular, in the present invention, when performing normal packet communication with an unspecified terminal, the control unit 6 uses a specific channel (channel CH1 in the present embodiment) allocated in advance.
When performing continuous communication with a specific terminal, each unit is controlled to use an empty channel other than the specific channel.

Next, in FIG. 1B, the power amplifier 10 amplifies the signal received from the antenna 9 and
The signal is supplied to the F demodulator 11. The IF-RF demodulator 11 demodulates the received signal into a predetermined intermediate frequency signal and supplies the signal to the IF-BB demodulator 12. The IF-BB demodulator 12 demodulates the intermediate frequency signal into a baseband signal and supplies the baseband signal to a baseband (spreading processing) unit 13. The baseband (spreading processing) unit 13 performs despreading of the spectrum code and outputs it as received data. The control unit 14 includes the power amplifier 10, the IF-RF demodulator 11, the IF-BB demodulator 1
2. Control the baseband (spreading processing) unit 13; In particular, in the present invention, when performing normal packet communication with an unspecified terminal, the control unit 14 uses a specific channel (channel CH1 in the present embodiment) allocated in advance,
When performing continuous communication with a specific terminal, each unit is controlled to use an empty channel other than the specific channel.

Next, FIG. 2 is a conceptual diagram showing a transition from packet communication to continuous communication in the present embodiment. Terminals A, B, C, and D normally transmit and receive data to and from any other terminal by packet communication using spread spectrum. Here, it is assumed that a large amount of information is continuously communicated between specific terminals, in the illustrated example, between the terminal A and the terminal B as in image transmission. When the communication is shifted to the continuous communication, the communication becomes a closed communication between the terminals A and B. Note that all terminals are equal, and there is no relationship between master and slave.

Here, FIG. 3 is a conceptual diagram showing channel control when shifting from packet communication to continuous communication in the present embodiment. As shown in the figure, channels CH1 to CH5 are allocated as a channel plan, and any one of the channels, in the illustrated example, channel CH1 is used for main packet communication. Here, when continuous communication is required between terminals A and B, first,
It is checked whether the channels CH2 to CH5 are vacant. Then, for example, the channel CH5 is reserved. Next, continuous communication is performed between the terminals A and B using the reserved channel CH5. Then, the channel CH1 is continuously used for main packet communication.

A-2. Operation of Embodiment Next, the operation of the wireless communication system according to the above-described embodiment will be described with reference to FIG. FIG. 4 is a conceptual diagram for explaining a communication protocol according to the present embodiment.
When terminal A issues a continuous communication request to terminal B using channel CH1, terminal B accepts the continuous communication request. Next, upon confirming the reception at the terminal B, the terminal A searches for an empty channel. Here, for example, if the channel CH2 is vacant, the terminal A notifies the terminal B of the movement to the channel CH2 using the channel CH1. Terminal B understands movement to channel CH2. And
When terminal A confirms that the channel has been moved, both sides release channel CH1 and move to channel CH2.

The terminal A that has moved to the channel CH2 first issues a HELLO (connection request) to the terminal B in order to connect the line with the terminal B. Terminal B responds to HELLO. Terminal A checks the connection with terminal B.
Then, the terminal B acknowledges the connection confirmation. As a result, the line connection between the terminals A and B on the channel CH2 is started.

When the line is connected, terminal A first issues a continuous communication request to terminal B using channel CH2. Upon receiving the continuous communication request from terminal A, terminal B starts transmitting continuous data (image, sound, etc.) to terminal A using channel CH2. Terminal A receives the continuous data transmitted continuously from terminal B. Then, when the transmission data ends, the terminal B transmits an end of data to the terminal A. On the other hand, the terminal A notifies the terminal B that the data end is confirmed, and the terminal B understands this.
After that, the terminal A notifies the terminal B that it returns to the channel CH1. Terminal B acknowledges the movement to channel CH1, and terminal A confirms this. Then, both release the channel CH2 and move to the channel CH1.

Note that the modulation method may be different from that of packet communication as long as the frequency used for communication between terminals performing continuous communication is the same. FIG. 5 is a block diagram showing a configuration of a wireless communication device for realizing continuous communication by means different from packet communication. Specifically, FIG.
Is a block diagram showing a configuration of a spread spectrum transmission unit,
FIG. 5B is a block diagram illustrating a configuration of the spread spectrum receiving unit. Note that the same reference numerals are given to portions corresponding to FIG.

In FIG. 5A, a switch 20 selectively transmits data to be transmitted to a baseband (spreading processing) unit 1 or a baseband (analog / digital modulation) unit 21 under the control of a control unit 23. Switch to supply. More specifically, when packet communication is performed, the signal is supplied to a baseband (spreading processing) unit 1. When continuous communication is performed, the baseband (analog / digital modulation) unit 2 is used.
Supply to 1. A baseband (analog / digital modulation) unit 21 performs analog / digital modulation on data to be transmitted by a predetermined method, and outputs the IF-BB signal via a switch 22.
The signal is supplied to the modulator 2. The switch 22 selectively switches one of the signal from the baseband (spreading processing) unit 1 and the signal from the baseband (analog / digital modulation) unit 21 according to the control from the control unit 23 to perform IF- The signal is supplied to the BB modulator 2. Specifically, when performing packet communication, a signal from the baseband (spreading processing) unit 1 is supplied to the IF-BB modulator 2, and when performing continuous communication, the baseband (analog / digital modulation) is used. )
The signal from the section 21 is supplied to the IF-BB modulator 2.

Next, referring to FIG.
Transmits the demodulated signal from the IF-BB demodulator 12 to the baseband (spreading processing) unit 1 under the control of the control unit 23.
3 or baseband (analog / digital demodulation) section 3
1 is selectively switched and supplied. Specifically, when performing packet communication, the baseband (spreading processing) unit 1
3 for continuous communication, and to a baseband (analog / digital demodulation) unit 31. The baseband (analog / digital demodulation) unit 31 performs analog / digital demodulation on the received signal by a predetermined method, and outputs the data as data received via the switch 32. The switch 32 selectively switches and outputs one of the signal from the baseband (spreading processing) section 13 and the signal from the baseband (analog / digital demodulation) section 31 according to the control from the control section 23. . In particular,
When performing packet communication, a signal from the baseband (spreading processing) unit 13 is output, and when performing continuous communication, a signal from the baseband (analog / digital demodulation) unit 31 is output.

FIG. 6 shows a 2.4 GHz DSSS (Direct Sequence) currently used for spectrum communication.
3 shows a frequency channel plan of the nce spread spectrum. In the FCC (Federal Communications Commission), channel CH1 (2412 MHz)
Up to CH11 (2462 MHz) are reserved.
In Japan, channel CH12 (2484 MHz)
Is reserved. In addition, ETSI (European Telec
ommunication Standards Institute (European Telecommunications Standards Institute), channel CH3 (2422 MHz)
Up to CH13 (2472 MHz) are reserved.

As described above, according to this embodiment, at home, by changing the frequency according to the amount of information,
Packet communication and continuous communication can coexist. In addition, by separating packet communication and continuous communication into different channels, a collision avoidance protocol (CSMA / CA: Carrier) is used.
Sense Collision Multiple Access with Collision Avo
idance) load can be reduced. Furthermore, by performing resource reservation for radio wave occupation, transmission efficiency can be improved, and waiting time during large-capacity wireless transmission can be reduced.

[0026]

According to the first aspect of the present invention, at least one of a plurality of channels is used as a shared channel, and one of the vacant channels is set according to the amount of information transmitted and received between the terminals. Since the continuous communication of data is performed by occupying the space, the advantage that continuous communication and packet communication can coexist is obtained. Also, since the packet communication and the continuous communication are different channels, the collision avoidance protocol (CSMA / CA: Carr
ier Sense Collision Multiple Access with Collision
The advantage is that the load of Avoidance can be reduced. Further, by performing resource reservation for radio wave occupation, there is an advantage that transmission efficiency can be improved. In addition, there is an advantage that the waiting time during large-capacity wireless transmission can be reduced.

According to the second aspect of the present invention, since the continuous communication performed on the empty channel is the same communication method as the communication method using the shared channel, the continuous communication and the packet communication can be performed with a simple circuit configuration. Can be coexisted.

According to the third aspect of the present invention, since the continuous communication performed on the empty channel is performed by a communication method different from the communication method using the shared channel, there is an advantage that the transmission efficiency can be further improved. can get.

According to the fourth aspect of the present invention, when the channel switching means normally selects the shared channel as a communication channel and performs continuous communication with a partner terminal, the communication channel is set to the shared channel. And switch to a free channel, and by means of communication,
In the case of normal data communication, data communication is performed on the shared channel, while in the case of continuous communication, continuous communication is performed using an empty channel switched by the channel switching means. The advantage is that communication and packet communication can coexist.
In addition, since packet communication and continuous communication are separate channels, a collision avoidance protocol (CSMA / CA: Carrier) is used.
Sense Collision Multiple Access with Collision Avo
The advantage is that the load of the idance can be reduced. Further, by performing resource reservation for radio wave occupation, there is an advantage that transmission efficiency can be improved. In addition, there is an advantage that the waiting time during large-capacity wireless transmission can be reduced.

According to the fifth aspect of the present invention, in the case of normal data communication, a signal path is switched to the first communication means to perform data communication using the shared channel, while continuous data communication is performed. In the case of communication, since the signal path is switched to the second communication means side and continuous communication is performed using an empty channel, continuous communication and packet communication can coexist with a simple configuration. The advantage is obtained.

According to the sixth aspect of the present invention, when the continuous communication by the second communication means is completed by the channel switching means, the communication channel is returned to the shared channel. Is improved,
The advantage is that the load of the collision avoidance protocol can be reduced and the transmission efficiency can be improved. In addition, there is an advantage that the waiting time during large-capacity wireless transmission can be reduced.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a wireless communication device of a basic spectrum communication system according to an embodiment of the present invention.

FIG. 2 is a conceptual diagram showing a state of shifting from packet communication to continuous communication in the present embodiment.

FIG. 3 is a conceptual diagram illustrating channel control when shifting from packet communication to continuous communication in the present embodiment.

FIG. 4 is a conceptual diagram illustrating a communication protocol according to the present embodiment.

FIG. 5 is a block diagram showing a configuration of a wireless communication device for realizing continuous communication by means different from packet communication.

FIG. 6 is currently used for spectrum communication
It is a key map showing a frequency channel plan of 4GHz.

[Explanation of symbols]

1... Baseband section (communication means, first communication means),
2 IF-BB modulator (communication means) 3 IF-R
F modulator (communication means), 4 ... power amplifier, 5 ... antenna, 6 ... control section (channel switching means), 9 ... antenna, 10 ... power amplifier, 11 ... IF-RF demodulator ( Communication means), 12 IF-BB demodulator (communication means), 13 baseband section, 14 control section (channel switching means, switching means), 20 switches (channel switching means, switching means) , 21... Baseband analog / digital modulator, 22... Switch (channel switching means, switching means), 30... Switch (channel switching means, switching means), 31. Means, second communication means), 32... Switches (channel switching means, switching means)

Claims (6)

[Claims] 1. A radio communication method for dividing a predetermined radio frequency band into a plurality of channels and performing data communication by spread spectrum, wherein at least one of said plurality of channels is used as a shared channel and between terminals. A wireless communication method characterized in that continuous communication of data is performed by occupying any available channel between terminals according to the amount of information to be transmitted and received. 2. The wireless communication method according to claim 1, wherein the continuous communication performed on the empty channel is the same communication method as the communication method using the shared channel. 3. The wireless communication method according to claim 1, wherein the continuous communication performed on the empty channel is a communication method different from the communication method using the shared channel. 4. A radio communication apparatus which divides a predetermined radio frequency band into a plurality of channels and performs data communication by spread spectrum, usually selects the shared channel as a communication channel,
Channel switching means for switching a communication channel from the shared channel to a free channel when performing continuous communication with a partner terminal; and performing normal data communication while performing continuous communication while performing data communication on the shared channel. A wireless communication device for performing continuous communication using the vacant channel switched by the channel switching device when performing the wireless communication. 5. The communication means comprises: a first communication means for performing data communication using the shared channel; a second communication means for performing continuous communication on the free channel; 5. The wireless communication system according to claim 4, further comprising: switching means for switching a signal path so as to use the first communication means and to use the second communication means in the case of continuous communication. Communication device. 6. The wireless communication device according to claim 4, wherein the channel switching unit returns the communication channel to the shared channel when the continuous communication by the second communication unit ends.