JP2011114768A - Composite radio device - Google Patents

Abstract

In a composite wireless device equipped with a plurality of communication systems, stable and efficient communication is realized without interfering with each other when the plurality of wireless communication systems operate simultaneously.
A composite wireless apparatus including two different communication methods in the same frequency band, a first wireless communication unit 102 using a first communication method, a second wireless communication unit 104 using a second communication method, A management unit 105 that manages communication states of the first and second wireless communication units, a hopping frequency control unit 107 of the second wireless communication unit, and a cooperative control unit 106 that controls the first and second wireless communication units. And the hopping frequency control unit reduces the quality of the second wireless communication unit when hopping the frequency of the second wireless communication unit by removing the frequency band used by the first wireless communication unit detected by the management unit. If detected, the cooperative control unit controls the first and second radio communication units in a time-sharing manner, and causes the second radio communication unit means to perform frequency hopping in the frequency band used by the first radio communication unit.
[Selection] Figure 2

Description

  The present invention relates to a wireless communication apparatus and a wireless communication method for performing wireless communication using a plurality of different wireless communication systems, and more particularly, wireless communication such as WLAN (Wireless Local Area Network) and Bluetooth (registered trademark) using a 2.4 GHz band. It is related with the control of interference avoidance between.

In recent years, with the development of wireless communication technology, devices equipped with a plurality of wireless communication systems have been developed. For example, there is a device equipped with both an IEEE802.11b / g WLAN and a short-range wireless device such as Bluetooth (registered trademark) using the same 2.4 GHz band ISM (Industrial Scientific Medical) band.
When there is a possibility that the same frequency band is simultaneously used in one device as described above, interference becomes a problem. In order to avoid this, in IEEE802.11b, a direct spread (DS) spectrum is used. By using a spreading technique or using a frequency hopping type spread spectrum system in Bluetooth, it is possible to avoid a decrease in communication speed and a decrease in transmission rate due to interference.
In the Bluetooth frequency hopping type spread spectrum system, the communication frequency to be used is randomly changed (hopped) every 625 μsec in 79 channels arranged at 1 MHz intervals on the frequency axis.
In addition, when the communication frequency is randomly changed, a frequency hopping pattern that defines a time change of frequency hopping is shared in order to achieve synchronization on the frequency axis between terminals performing communication.

In this case, in the applied frequency hopping method used in Bluetooth (registered trademark), mutual interference can be avoided by using a frequency band not used by the WLAN. As a result, when transmitting data, it is possible to prevent a decrease in WLAN throughput due to a decrease in WLAN communication opportunities caused by a difference in carrier sense function for confirming whether a channel is being used. However, when there are a plurality of WLAN-equipped devices in the vicinity area of the Bluetooth-equipped device and the frequency band used by the WLAN occupies most of the 2.4 GHz band, the number of channels capable of frequency hopping of the short-range wireless device And the interference tolerance of the short-range wireless device is reduced.
This is because, for example, when an interference source such as a WLAN other than the channel used by the WLAN device of the local station exists around the composite wireless device, a hopping frequency map showing a channel capable of Bluetooth frequency hopping is shown in FIG. The reason is as shown in FIG.
(The figure number has not been changed for tentative purposes.)
As a method for solving this problem, for example, in Patent Document 1, in the case of using OFDM (Orthogonal Frequency Division Multiplexing) modulation scheme of IEEE802.11g standard in WLAN, the number of carriers is variable depending on the frequency environment of the signal. Thus, a method is described in which the frequency band is changed, while the short-range wireless device adaptively hops the frequency to a frequency band not used by the WLAN device.

Japanese Patent No. 4122789

  However, the method described above cannot be used in the IEEE802.11b standard that uses a spread spectrum method, not an OFDM modulation method, because the number of carriers in the OFDM modulation method is changed. For this reason, since it cannot be applied to the IEEE802.11b standard, which is generally considered to have a wider communication area than IEEE802.11g, there is a problem in that the WLAN communication area is reduced. In IEEE802.11g, the number of subcarriers in the OFDM modulation scheme is defined as 52, so making the number of subcarriers variable does not comply with the IEEE802.11g standard. That is, even when a general-purpose access point (AP) as a connection destination is found, there is a problem that connection with the AP cannot be made.

  The present invention has been made in view of the above points, and in a composite wireless device equipped with a plurality of communication methods, when a plurality of wireless communication methods operate simultaneously, they are stable and efficient without interfering with each other. An object of the present invention is to provide a wireless communication apparatus and a wireless communication method capable of realizing communication.

  In order to solve the above-described problem, the composite wireless device of the present invention is a composite wireless device including two different communication methods for performing wireless communication in the same frequency band, and wireless communication is performed using the first communication method. A first wireless communication unit that performs wireless communication, a second wireless communication unit that performs wireless communication using a second communication method different from the first communication method, and the first and second wireless communication units A management unit that manages a wireless state; a hopping frequency control unit that controls a frequency hopping pattern for the second wireless communication unit; and a cooperative control unit that controls the first and second wireless communication units; In the control for removing the frequency band used by the first wireless communication unit detected by the management unit and hopping the frequency of the second wireless communication unit, when quality degradation of the second wireless communication unit is detected , The control unit 1 and controls the time-division of the second radio communication unit, even in a frequency band used by the first radio communication unit, includes a control for frequency hopping of the second wireless communication section means.

  With this configuration, when the communication quality degradation of the second wireless communication unit is detected, the first wireless communication unit and the second wireless communication unit are operated in a time-sharing manner, and the second wireless communication unit However, by using the frequency band used by the first wireless communication unit by frequency hopping, the interference tolerance of the second wireless communication unit can be improved.

  In the composite radio apparatus of the present invention, when the cooperative control unit controls the first radio communication unit and the second radio communication unit in a time division manner, the communication quality of the second radio communication unit is determined. When the value exceeds a predetermined threshold, the time division control of the first wireless communication unit and the second wireless communication unit is stopped, and the second wireless communication unit is the first wireless communication unit. It includes control to remove the frequency band to be used and frequency hopping.

With this configuration, when the communication state of the second wireless communication unit is good, the time of the first wireless communication unit by time-sharing control of the first wireless communication unit and the second wireless communication unit It is possible to prevent a decrease in the band and suppress interference on the time axis between the first wireless communication unit and the second wireless communication unit.
Further, the composite radio apparatus of the present invention uses the first radio communication based on the communication quality of the second radio communication unit based on the value of the BER of the second radio communication unit and the number of channels capable of frequency hopping. And the second wireless communication unit determine a cooperative control method.
With this configuration, not only the hopping frequency of the second wireless communication unit, but also the quality is determined by BER and the control method of the first wireless communication unit and the second wireless communication unit is switched, Even in the case where the AFH function is not used in the second wireless communication unit, it is possible to improve the interference tolerance of the second wireless communication unit.
Further, the composite radio apparatus of the present invention can set the predetermined threshold value of the communication quality managed by the management unit according to the type of packet transmitted / received by the second radio communication unit. Features.
With this configuration, the SCO (Synchronous Connection-) used in Bluetooth (registered trademark) assumed as the second wireless communication unit for cooperative control of the first wireless communication unit and the second wireless communication unit. The connection type of the Oriented link and the ACL (Asynchronous Connection-Less) link and the type of packet used in each link and having different required bandwidth and quality may be used.
In Bluetooth (registered trademark), links and packets differ depending on each application.

  According to the above procedure, in the composite radio apparatus having a plurality of radio communication schemes operating in the same frequency band, the control means for the plurality of radio communication schemes is provided according to the communication quality of the second radio communication scheme having the frequency hopping function. By switching, it is possible to prevent a decrease in communication quality of the second wireless communication unit.

  According to the present invention, in a composite radio apparatus having a plurality of radio communication schemes operating in the same frequency band, when the communication quality of the second radio communication scheme having a frequency hopping function deteriorates, a plurality of radio communication By controlling the system by time division and performing frequency hopping even in the frequency band used by the first wireless communication system, it is possible to prevent deterioration in communication quality.

The figure which shows the basic composition of the radio | wireless communications system which concerns on embodiment of this invention. The block diagram which shows the structure of the composite radio | wireless apparatus which concerns on this Embodiment. The figure which shows an example of the hopping frequency map which concerns on this Embodiment The figure which shows an example of the hopping frequency map which concerns on this Embodiment The figure which shows an example of the hopping frequency map at the time of the time division control of the composite radio | wireless apparatus which concerns on this Embodiment. The figure which shows cooperation operation | movement of WLAN and Bluetooth which concerns on this Embodiment Process flow diagram for selecting WLAN and Bluetooth control operations at the time of WLAN activation according to the present embodiment Process flow diagram for selecting cooperative operation from simultaneous operation of WLAN and Bluetooth according to the present embodiment Process flow diagram for selecting simultaneous operation from cooperative operation of WLAN and Bluetooth according to the present embodiment

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment)
FIG. 1 is a diagram showing a basic configuration of a radio communication system according to an embodiment of the present invention. This is an example in which a composite wireless device equipped with a plurality of wireless communication systems that commonly use an ISM band (2400 to 2483.5 MHz) is applied to a wireless terminal station as a wireless communication device constituting a wireless communication system.

  In FIG. 1, a wireless communication system includes a WLAN device (first communication method) using the IEEE 802.11 standard, a composite wireless device 100 having a Bluetooth device (second communication method) that is short-range wireless communication, and a carrier network. The mobile phone base station 10 is connected to the mobile phone, the AP (Access Point) 20 is connected using a WLAN, and the wireless headphones 30 are connected via Bluetooth (registered trademark).

In FIG. 1, the composite wireless device 100 is a mobile terminal device such as a PHS (Personal Handy-Phone System) / mobile phone, PDA (Personal Digital Assistants), etc. It transmits and receives radio waves via an antenna and connects to a carrier server through a carrier network.

  The AP 20 is an access point that performs communication by WLAN connection, transmits a beacon indicating the existence of a network at a predetermined interval, and uses a channel and an SSID (Service Set Identifier) used in the BSS (Basic Service Set). ) And other channel information.

  The wireless headphone 30 is an example of a device connected to the composite wireless device 100 via Bluetooth (registered trademark). The wireless headphones are wirelessly connected to the composite wireless device 100 by Bluetooth (registered trademark), and can listen to the audio signal reproduced by executing the music playback application of the composite wireless device 100. Note that the type and number of devices connected by Bluetooth are arbitrary.

  FIG. 2 is a block diagram illustrating a configuration of the composite radio apparatus 100 in which a plurality of radio communication schemes are mounted. This embodiment is an example applied to a cellular phone equipped with a WLAN and Bluetooth (R) function. Illustration and description of the cellular communication function unit of the mobile phone body are omitted.

  In FIG. 2, the composite wireless device 100 includes a WLAN antenna 101, a WLAN device 102, a Bluetooth antenna 103, a Bluetooth device 104, a management unit 105, and a cooperative control unit 106.

  The WLAN device 102 (corresponding to a first wireless communication unit that performs wireless communication using the first communication method) is a device that performs WLAN wireless communication based on the IEEE 802.11 standard. In this embodiment, the WLAN device 102 transmits / receives data to / from the host and performs a WLAN connection with the access point 20 via the antenna 101.

  Further, the opposite side with which the WLAN device 102 communicates is not limited to the access point 20, but may be other devices such as a mobile device equipped with a WLAN function, and the ad hoc mode (direct communication between terminals without using the access point 20). The case where communication is carried out in the above manner is also included.

  The Bluetooth device 104 (corresponding to a second wireless communication unit that performs wireless communication using the second communication method) is a device that performs communication using weaker power than the WLAN device 102. In the present embodiment, the Bluetooth device 104 transmits and receives data to and from the host, and performs wireless connection with the wireless headphones 30 via the antenna 103.

  The management unit 105 performs frequency management used by the WLAN device 102 and the Bluetooth device 104. Also, communication quality such as BER between the WLAN device 102 and the short-range wireless device 104 is managed.

The cooperative control unit 106 controls transmission timings of the WLAN device 102 and the Bluetooth device 104. Specifically, a WLAN_Active signal and a BT_Active signal are transmitted to each of the WLAN device 102 and the Bluetooth device 104, respectively, so that the operation is performed in a time division manner. For example, when the cooperative control unit 106 performs a cooperative operation, when the WLAN device 102 performs communication, the WLAN_Active signal is set to “H”, and the BT_Active signal is set to “L” in order to stop transmission of the Bluetooth device 104. ". Conversely, when the Bluetooth device 104 performs communication, the BT_Active signal is set to “H” and the WLAN_Active signal is set to “L”.
The hopping frequency control unit 107 designates a frequency band for the Bluetooth device 104 to hop by AFH (Adaptive Frequency Hopping: hopping avoiding a frequency channel in which interference is adaptively generated). In general, Bluetooth (registered trademark) uses frequency hopping that divides 79 channels per 1 MHz, which are evenly spaced within the 79 MHz frequency band, into 1600 transmissions per second to reduce interference with other devices. ing.
Further, in the hopping frequency control unit 107, the Bluetooth device 104 performs a hopping operation by the AFH method, and other devices using the 2.4 GHz band in order to reduce interference between radio technologies sharing the 2.4 GHz band frequency. Is detected, the frequency used by the device is removed from the hopping pattern. At this time, the hopping frequency control unit 107 generates a hopping frequency map indicating channels to be used in 79 channel lists used in Bluetooth, and passes the generated hopping frequency map to the Bluetooth device 104.

  In this embodiment, in the composite wireless device 100 configured as described above, when the WLAN device 102 and the Bluetooth device 104 are combined and operated, when the communication quality of the Bluetooth device 104 is deteriorated, the cooperative control unit 106 performs the WLAN operation. This is solved by performing frequency hopping in the frequency band used by the WLAN device 102 by performing time-sharing control of the device 102 and the Bluetooth device 104.

Next, a cooperative control method when WLAN communication and Bluetooth communication operate simultaneously in the composite wireless apparatus 100 configured as described above will be described.
This embodiment is an application example in which Bluetooth (registered trademark) performs frequency hopping except for a frequency band used by WLAN included in the same device, and WLAN and Bluetooth transmit at the same timing. is there.
In the composite wireless terminal 100, when the WLAN device 102 establishes a WLAN connection with the AP 20, the WLAN device 102 performs Scan (search for a network) and searches for the AP 20. When there is a Scan response from the AP 20, the BSS information of the AP 20 is acquired by the Scan response. Since the BSS information includes information on the used frequency of the AP 20, the WLAN used frequency is input to the management unit 105 when connecting to the AP 20.
When the WLAN usage frequency is input from the WLAN device 102, the management unit 105 inputs the WLAN usage frequency of the WLAN device 102 to the hopping frequency control unit 107.
The hopping frequency control unit 107 deletes and updates the WLAN use frequency from the hopping frequency map, and inputs the updated hopping frequency map to the Bluetooth device 104.

  FIG. 3 shows an example of the hopping frequency map. When six channels are used in the WLAN device 102, a band of 22 MHz from the center frequency 2437 MHz to ± 11 MHz of the six channels is excluded from the hopping frequency map as a frequency band used by the own station. The Bluetooth device 104 notifies the input hopping frequency map to the opposite device, and performs hopping based on the updated hopping frequency map.

In a hopping method called AFH (avoid frequency channels that cause interference adaptively), channels that cause interference in frequency hopping during communication are excluded from hopping targets, so there are 2.4 GHz band interference sources around In this case, the frequency band hopped by the Bluetooth device 102 is lowered, and as a result, the interference tolerance is deteriorated.
As shown in FIG. 4, when the hopping frequency channel band of the Bluetooth device 102 of the composite wireless device 100 decreases and the number of channels divides the specified threshold value,
The management unit 105 passes the frequency band used in the WLAN device 102 to the hopping frequency control unit 107.
In the present embodiment, as shown in FIG. 5, by enabling hopping of the frequency band used in the WLAN device 102, it is possible to prevent the interference tolerance of the Bluetooth device 104 from decreasing and to prevent interference due to simultaneous transmission. The WLAN device 102 and the Bluetooth device 104 are controlled in a time-sharing manner.
FIG. 6 shows control by the cooperative control unit 106 when the WLAN device 102 and the Bluetooth device 104 are operated in a time division manner. The cooperative control unit 106 causes the WLAN_Active sent to the WLAN device 102 and the BT_Active sent to the Bluetooth device 104 to be fixed to “H” and “L” as appropriate. When the Bluetooth device 104 is operated and the WLAN device 102 is stopped, BT_Active is fixed to “H” and WLAN_Active is fixed to “L”.
When operating WLAN and Bluetooth in a time-sharing manner, it is necessary to consider the applications that are running on each. However, in this embodiment, since the Bluetooth interference tolerance is reduced, the Bluetooth device 104 is given priority. Then, the WLAN device 102 is stopped. Further, the control that does not interrupt the voice when VoIP (Voice over IP) is performed in the WLAN device 102 will be described later.
Next, a description will be given of a control method when the WLAN and Bluetooth of the wireless communication apparatus 100 configured as described above operate cooperatively. Here, the cooperative operation means that (when WLAN and Bluetooth respectively communicate with the opposite device, mutual interference is suppressed).

  FIG. 7 is a flowchart showing details of processing for determining the operation content with Bluetooth when the WLAN is activated in the wireless communication apparatus 100. In the figure, S indicates each step of the flow.

First, in step S71, the WLAN device 102 is activated, performs a scan, and starts searching for an AP.
In step 72, the WLAN device 102 determines whether or not it is connected to the AP before passing information to the management unit.
In step 73, the WLAN device 102 notifies the management unit 104 of the channel connected to the AP.
In step 74, the management unit 104 checks the hopping frequency map in the Bluetooth device 104 and monitors the communication quality such as BER, and determines whether the communication quality of the Bluetooth communication has deteriorated.

If it is determined in step 74 that cooperative control is unnecessary, the management unit 104 notifies the hopping frequency control unit 105 of the frequency band used in the WLAN device 102 in step 75, and the hopping frequency control unit 105 The hopping frequency map at that time is updated to a hopping frequency map excluding the WLAN use band.

  In step 76, the management unit 105 notifies the cooperative control unit 106 of the cooperative operation OFF, and the WLAN device 102 and the Bluetooth device 104 perform a simultaneous operation without performing the cooperative operation.

  On the other hand, if it is determined in step 74 that cooperative control is necessary, in step 77, the management unit 105 notifies the cooperative control unit 106 of the cooperative operation ON, and the WLAN device 102 and the Bluetooth device 104 operate in cooperation. To start.

  FIG. 8 is a flowchart showing the details of the processing when transitioning from the simultaneous operation state of WLAN and Bluetooth to the cooperative operation.

  When both WLAN and Bluetooth are activated and are operating simultaneously, in step 81, a cooperative control start trigger is waited. When the management unit 105 detects quality degradation of the Bluetooth device 104, a cooperative control start trigger is activated.

  In step 82, the management unit 104 notifies the hopping frequency control unit 105 of the frequency band used in the WLAN device 102, and the hopping frequency control unit 105 adds the WLAN use band from the hopping frequency map at that time. Update to hopping frequency map.

  In step 83, the management unit 105 notifies the cooperative control unit 106 that the cooperative operation is ON, and the WLAN device 102 and the Bluetooth device 104 start the cooperative operation.

  FIG. 9 is a flowchart showing details of the processing when transitioning from a cooperative operation state of WLAN and Bluetooth to simultaneous operation.

  In step 91, the management unit 104 determines whether the WLAN device 102 or the Bluetooth device 104 has released the connection with the counterpart device, and whether the communication quality of the Bluetooth device 104 has exceeded the threshold value of the cooperative control trigger. .

  In step 92, it is determined whether or not the AP connection of the WLAN device 102 continues for updating the hopping frequency map.

  In step 93, when the WLAN AP connection is disconnected, the hopping frequency control unit 107 deletes and updates the WLAN use frequency band from the hopping frequency map.

  In step 94, the management unit 105 notifies the cooperative control unit 106 of the cooperative operation OFF, and the WLAN device 102 and the Bluetooth device 104 perform a simultaneous operation without causing the cooperative operation.

  If the WLAN AP disconnection is detected in step 92, the Bluetooth device 104 can continue to use the frequency band used by the WLAN device 102, so the hopping frequency map is not updated. Further, the management unit 105 notifies the cooperative control unit 106 that the cooperative operation is OFF.

  As described above, according to the present embodiment, when a Bluetooth and WLAN perform communication operation with an opposite device at the same time in a composite wireless device equipped with a plurality of Bluetooth and WLAN communication methods, a Bluetooth hopping frequency map, Monitor the communication quality such as BER, and if the Bluetooth communication quality deteriorates, switch to the time-sharing control method of WLAN and Bluetooth, and add the frequency used by the local WLAN to the Bluetooth hopping frequency map By doing so, it is possible to prevent Bluetooth communication quality deterioration.

  The above description is an illustration of a preferred embodiment of the present invention, and the scope of the present invention is not limited to this. For example, the system configuration and the configuration of each device are not limited.

  The composite wireless apparatus according to the present invention can be widely applied to communication terminal apparatuses equipped with a plurality of wireless communication systems such as WLAN based on the IEEE802.11x standard and Bluetooth based on the IEEE802.15.1 standard. In addition, the present invention can be widely applied to portable electronic devices having a wireless communication function such as notebook personal computers and PDAs.

10 Mobile phone base station 20 AP
DESCRIPTION OF SYMBOLS 30 Headphones 100 Composite radio | wireless apparatus 101, 103 Antenna 102 WLAN apparatus 104 Bluetooth apparatus 105 Management part 106 Cooperation control part 107 Hopping frequency control part

Claims (4)

A composite wireless device including two different communication methods for performing wireless communication in the same frequency band,
A first wireless communication unit that performs wireless communication using the first communication method;
A second wireless communication unit that performs wireless communication using a second communication method different from the first communication method;
A management unit for managing a communication state such as the number of communicable channels of the first wireless communication unit and the second wireless communication unit;
A hopping frequency control unit for controlling a frequency hopping pattern for the second wireless communication unit;
A cooperative control unit that controls the first wireless communication unit and the second wireless communication unit;
The hopping frequency control unit removes the frequency band used by the first wireless communication unit detected by the management unit and hops the frequency of the second wireless communication unit when the second wireless communication unit is hopped. When the quality deterioration of the communication unit is detected, the cooperative control unit controls the first wireless communication unit and the second wireless communication unit in a time-sharing manner, and is used by the first wireless communication unit And a second wireless communication unit that performs frequency hopping control in a frequency band to be transmitted. The composite wireless device according to claim 1,
When the communication quality of the second wireless communication unit exceeds a predetermined threshold when controlling the time division in the first wireless communication unit and the second wireless communication unit, the first wireless communication unit and the second wireless communication unit Stop the time-sharing control between the second wireless communication unit and the second wireless communication unit, and the second wireless communication unit performs frequency hopping by removing the frequency band used by the first wireless communication unit. A combined wireless device. The composite wireless device according to claim 2, wherein
Furthermore, the predetermined threshold value of the communication quality is a value of the BER of the second wireless communication unit and the number of channels capable of frequency hopping. The composite wireless device according to claim 3, wherein
Furthermore, the predetermined threshold value of the communication quality managed by the management unit can be set according to the type of packet transmitted / received by the second wireless communication unit.

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