JP6255565B2 - Millimeter-wave radio equipment - Google Patents

Description

  The present disclosure relates to a communication apparatus in a wireless network including a coordinator and a plurality of devices.

In the video interface HDMI standard used in video display devices such as projectors, high-definition signals of 720p and 1080i that require a data transfer rate of 1.5 Gbps with a bit error ratio (BER) of 10 ^−9. The specification to cope with it is defined. IEEE802.11ac is a standard for wireless LAN using the 2.4 GHz band ISM (Industry-Science-Medical) band, but it requires a wide band of 80 MHz, so the 100 MHz band allocated to the ISM band However, there are concerns about problems such as communication failure and performance degradation due to interference by using the same frequency band between users.

  On the other hand, since millimeter-wave band wireless transmission using the 30 GHz to 300 GHz band is easy to ensure a wide band, WirelessHD, IEEE 802.15.3c, IEEE 802.11ad, WiGig, and the like exist as HDMI transmission standards using the 60 GHz band. To do.

  FIG. 5 and FIG. 6 show a configuration example and protocol sequence diagram of a conventional millimeter wave radio.

  Reference numeral 300 denotes a device unit, and 400 denotes a coordinator unit. Reference numeral 201 denotes a first wireless transmission / reception unit using a millimeter-wave band carrier frequency, and 204 denotes a device registration DB (database). Reference numeral 101 denotes a first wireless transmission / reception unit, and 104 denotes a device registration ID. In the device unit 300, transmission data and a device registration ID are input to the first wireless transmission / reception unit 101, modulated into millimeter waves, and transmitted. The modulated radio wave is demodulated by the first wireless transmission / reception unit 201, and the unique ID of the device unit 300 is registered in the device registration DB.

  However, compared to the quasi-millimeter wave band, the millimeter wave band has a problem that it is susceptible to strong propagation directivity and shielding. As a means for solving this problem, in a network composed of a receiver called a coordinator and a transmitter called a source, searching for a communication partner is performed by a beam search in which a radiation gain is electrically controlled by an adaptive array antenna. Yes.

  However, the beam search has a problem that the power consumption increases because the search is performed using millimeter waves with high power consumption.

  As one technique for solving this problem, beam pattern information indicating the priority of the beam direction based on the evaluated channel quality by evaluating the channel quality of the radio channel using the radio wave transmitted from the second radio unit There is known a technique of generating (information on where to emit radio waves in space) and controlling the beam direction based on the beam pattern information (Patent Document 1).

JP 2010-147620 A

  The present disclosure provides a millimeter-wave radio apparatus capable of establishing a link of a millimeter-wave radio network with low power consumption.

  The millimeter wave wireless device according to the present disclosure is a second wireless device that communicates with a first wireless device that exists in a wireless network, and the second wireless device transmits and receives radio waves having a frequency in the millimeter wave band. A first wireless transmission / reception unit to perform, a second wireless transmission / reception unit to perform transmission / reception of radio waves having a frequency equal to or lower than the quasi-millimeter wave band, and a control unit to control the first wireless transmission / reception unit and the second wireless transmission / reception unit. The control means establishes a link with the first wireless device by the second wireless transmission / reception unit, acquires control information obtained from the first wireless device, and performs first wireless communication based on the acquired control information. Control the transceiver.

  The millimeter wave radio apparatus according to the present disclosure can establish a link of a millimeter wave radio network with low power consumption.

1 is a schematic configuration diagram illustrating an embodiment of the present disclosure. FIG. 3 is a schematic protocol sequence diagram illustrating an embodiment of the present disclosure. It is a figure which shows the utilization form of the radio | wireless communications system concerning embodiment of this indication. It is a figure which shows the frame structure of the network used by embodiment of this indication. It is a schematic block diagram which shows the conventional common radio | wireless machine. It is a conventional general protocol sequence diagram.

Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.
(Embodiment)
1 to 3 are diagrams illustrating the configuration of the embodiment of the present disclosure.

  FIG. 3 is a diagram illustrating a network configuration diagram according to the present embodiment, and a network is configured from one coordinator unit 200 and a plurality of device units 100 in a wireless network.

  The coordinator unit 200 is, for example, a projection display apparatus, and the device unit 100 is an image source supply apparatus such as a PC (personal computer) or a DVD apparatus.

  FIG. 1 is a diagram showing a detailed configuration of the coordinator unit 200 and the device unit 100 in the network described in FIG.

  The device unit 100 includes a first wireless transmission / reception unit 101 that uses radio waves of a carrier frequency in the millimeter wave band, a second wireless transmission / reception unit 102 that uses a carrier frequency in the quasi-millimeter wave band, a control unit 103, and a device registration ID storage unit 104. .

  The coordinator unit 200 includes a first wireless transmission / reception unit 201 that uses radio waves with a carrier frequency in the millimeter wave band, a second wireless transmission / reception unit 202 that uses a carrier frequency in the quasi-millimeter wave band, a control unit 203, and a device registration DB 204.

  The first wireless transmission / reception unit 101 and the second wireless transmission / reception unit 102 of the device unit 100 and the first wireless transmission / reception unit 201 and the second wireless transmission / reception unit 202 of the coordinator unit 200 are respectively composed of an RF circuit, a baseband circuit, and a media access control. Become.

  The coordinator unit 200 has a function of adjusting a network timing by transmitting a reference signal called a beacon. The device unit 100 receives a beacon and transmits / receives data at a timing designated by the coordinator unit 200. The coordinator unit 200 controls the formation of the communication path of each device unit by managing time resources (such as time intervals) assigned to each device unit.

  FIG. 2 is a diagram showing a communication protocol sequence in the present embodiment, and FIG. 4 is a diagram showing a frame structure of a network generated by a beacon.

  The frame shown in FIG. 4 is called a super frame, and this super frame is composed of three parts from the top.

  The first part is a beacon, which functions as a reference signal (synchronization signal), is broadcast (broadcasted) from the coordinator unit 200 to the device unit 100, and transmits a super frame to all device units. The start timing is synchronized, and necessary information and commands are sent to each device unit at the same time.

  The second part is a contention access period (CAP). Contention is the contention (contention) of multiple device units to acquire the right to access the communication line (channel), and during this contention access period, all device units are connected to the channel. It is an accessible period. In the contention access period, a CSMA / CA (Carrier Sense Multiple Access with Collision Avoidance) method that avoids collision of transmission data is used.

  The third part is the channel time allocation period (CTAP), which allows the coordinator unit to communicate only to specific device units for the contention access period. It has become a period. In the channel time allocation period, a time division multiple access (TDMA) time slot is formed in which a certain time interval (time slot) is allocated to each device unit within one frequency and communication is performed. . MCTA is a time slot used for communication between the coordinator and the device, and CTA is a time slot used for communication between the devices.

  Next, the flow of processing operations in this embodiment will be described using the protocol sequence diagram of FIG. 2 and the network frame configuration diagram of FIG.

  First, the second radio transmission / reception unit 102 of the device unit 100 receives the beacon transmitted from the second radio transmission / reception unit 202 of the coordinator unit 200 during the beacon period of FIG. 4 and performs timing synchronization.

Next, during the CAP period, the device unit 100 obtains an access right by CSMA / CA and establishes a link. Thereafter, the coordinator unit 200 makes a device ID request to the device unit 100 and receives a device ID response from the device unit 100.
The coordinator unit 200 registers the device ID of the device unit 100 in the device registration DB (database) from the received device ID response.

  Subsequently, the coordinator unit 200 receives a reception metric value from the device unit 100. The reception metric value is a signal strength (RSSI: Received Signal Strength Indicator), signal quality (Signal Quality) of the second radio transmission / reception unit 102, and transmission power of the second radio transmission / reception unit 102.

  Next, the coordinator unit 200 transmits a radio resource to be assigned to the device unit 100 based on the registered device ID and the received metric value. A radio resource refers to an empty frequency channel or time slot. This is the communication performed between the second wireless transmission / reception unit 202 and the second wireless transmission / reception unit 102.

  Subsequently, in the coordinator unit 200, the control unit 203 activates the first radio transmission / reception unit 201, allocates the radio resource, and transmits a beacon in the beacon period of the next super frame. In the device unit 100, the first radio transmission / reception unit 101 is activated by the control unit 103, and the radio resource is set.

  The beacon transmitted from the coordinator unit 200 is received, the timing is synchronized, and the link is established. Since the access right acquisition of the CAP section has already been performed between the second wireless transmission / reception unit 202 and the second wireless transmission / reception unit 102, it is not performed between the first wireless transmission / reception unit 201 and the first wireless transmission / reception unit 101. In the CTAP section, data communication is performed using predetermined radio resources.

  Thus, according to the present embodiment, the coordinator obtains the reception metric data of the device unit 100 using the second radio transmission / reception unit that is a quasi-millimeter wave transceiver, and the coordinator unit 200 looks at the reception metric information. The beacon transmission conditions are determined from the first wireless transceiver that is a millimeter wave transceiver.

  That is, if the transmission power of the device unit is large and the reception electric field strength is strong, the coordinator unit can determine that the device unit is in the vicinity, and can perform a beam search for a device unit near the beacon as a beam search (search) request. To send out.

  Conversely, if the transmission power of the device unit is large and the reception field strength is weak, the coordinator determines that the device unit is far away and sends a beacon so that it can search for a far device unit (beam search). To do.

  When a new device unit is added to the wireless network, the device unit transmits the device registration ID 104 to the second wireless transmission / reception unit 202 of the coordinator unit 200 via the second wireless transmission / reception unit 102. The second wireless transmission / reception unit 202 demodulates the received signal and notifies the control unit 203 of it.

  The control unit 203 searches the existing device registration DB 204 for the demodulated device registration ID. If there is no matching ID, the first wireless transmission / reception is performed based on the reception metric value received this time via the control unit 203. The beam search by the first radio transmission / reception unit 201 and the first radio transmission / reception unit 101 is started.

  If there is a matching ID, the current reception metric value is compared with the previous reception metric value stored in the device registration DB 204. If the respective reception metric values match, the control unit 203 is used to compare the previous reception metric value. Based on the received metric value, the transmission power is set in the first wireless transmission / reception unit 201, and beam search by the first wireless transmission / reception unit 201 and the first wireless transmission / reception unit 101 is started. If the received metric values do not match, the process is restarted from the beginning according to the protocol shown in FIG.

  As described above, according to this embodiment, since the start of the beam search between the first radio transmission / reception units is controlled using the reception metric value obtained between the second radio transmission / reception units, unnecessary beam search can be suppressed. It is possible to reduce power consumption by optimizing transmission power.

  In addition, by registering the device unit radio parameters in advance using a low carrier frequency band that does not require directivity control, the standby power can be reduced by limiting the start of beam search by the millimeter wave radio unit when necessary. Is possible.

  In addition, the communication system between the 2nd radio | wireless transmission / reception parts used for this indication is not limited. For example, if the wireless LAN unit provided in the personal computer is used as the second wireless transmission / reception unit and the millimeter-wave wireless unit that is the first wireless transmission / reception unit is controlled, the cost of the entire system can be reduced. .

  The present disclosure is applicable to a wireless network including a coordinator and a device.

100 device unit 101 first wireless transmission / reception unit 102 second wireless transmission / reception unit 103 control unit 104 device registration ID storage unit 200 coordinator unit 201 first wireless transmission / reception unit 202 second wireless transmission / reception unit 203 control unit 204 device registration DB
300 device units

Claims (3)

A second wireless device for communicating with a first wireless device present in a wireless network,
The second wireless device is
A first wireless transmission / reception unit for transmitting / receiving radio waves of a millimeter-wave frequency;
A second wireless transmission / reception unit that transmits / receives radio waves having a frequency equal to or lower than the quasi-millimeter wave band;
A device registration database storing reception signal strength, transmission power of the first wireless device, and signal quality, which are reception metric values;
Control means for controlling the first wireless transceiver and the second wireless transceiver;
The control means establishes a link with the first wireless device by the second wireless transmission / reception unit,
A millimeter-wave radio apparatus that controls the first radio transmission / reception unit based on a comparison between a current reception metric value and a previous reception metric value stored in the device registration database .   The millimeter wave radio apparatus according to claim 1, wherein the control unit makes a beam search request to the first radio transmission / reception unit after the first establishment of the link by the second radio transmission / reception unit.   The millimeter-wave radio apparatus according to claim 1, wherein the first radio transceiver unit and the second radio transceiver unit include an RF circuit, a baseband circuit, and media access control.

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