JP2010068285A - Radio communication device - Google Patents

Abstract

A wireless communication apparatus capable of improving the performance of broadband wireless communication by using narrowband wireless communication.
A carrier signal detection unit 216 outputs a processing start signal to a report request generation unit 218 when Tc3> Tmax. The report request generation unit 218 generates a report request signal for transmission status. The narrowband wireless communication unit 24 transmits a report request signal to an adjacent node by narrowband wireless communication, receives a transmission state report signal from the adjacent node, and outputs the signal to the noise determination unit 220. The noise determination unit 220 analyzes the transmission status report signal and determines whether or not the adjacent node is transmitting a carrier signal. When the adjacent node is transmitting a carrier signal, the noise determination unit 220 determines that the own node has not received a signal including noise, and when the adjacent node is not transmitting a carrier signal, the noise determination unit 220 Is receiving a signal including noise.
[Selection] Figure 2

Description

  The present invention relates to a wireless communication apparatus.

For example, in Patent Document 1, when digital information is wirelessly transmitted in a multi-carrier communication system, an optimum modulation scheme is used for communication by estimating a propagation path state for each subcarrier, so that for each subcarrier. A communication apparatus for adaptively selecting a modulation scheme is disclosed.
JP 2006-295355 A

  The present invention has been made from the above-described background, and an object of the present invention is to provide a wireless communication apparatus capable of improving the performance of broadband wireless communication by using narrowband wireless communication.

  In order to achieve the above object, a wireless communication apparatus according to the present invention includes a broadband wireless communication unit that performs processing for broadband wireless communication, a signal detection unit that detects a signal received by the broadband wireless communication unit, When the signal reception period exceeds a predetermined time, request the other wireless communication device to report whether or not the other wireless communication device is transmitting a signal using narrowband wireless communication. A narrowband wireless communication means for transmitting a report request for receiving and receiving a report transmitted from the other wireless communication apparatus in response to the report request, and received by the broadband wireless communication means based on the report Determining means for determining whether or not the received signal is a signal transmitted from the other wireless communication apparatus.

  ADVANTAGE OF THE INVENTION According to this invention, the radio | wireless communication apparatus which can implement | achieve the performance improvement of wideband radio | wireless communication by utilizing narrowband radio | wireless communication can be provided.

[Background of the invention]
In order to help understanding of the present invention, first, the background that led to the present invention will be described.

In communication of CSMA / CA (Carrier Sense Multiple Access with Collision Avoidance) method used for wireless local area network (LAN) compliant with IEEE 802.11 (Institute of Electrical and Electronic Engineers), equipment failure or the same frequency band Interference signals may occur due to the influence of other wireless communication devices that emit part of the signal.
Here, in the carrier sense function of the CSMA / CA method, the generated jamming signal is erroneously determined as a carrier signal from another node, and the wireless transmission of the own node stops during the period when the jamming signal is detected. was there.
As a method for avoiding interference, there is a frequency hopping method in which communication is performed while switching subcarriers to be used. However, this frequency hopping method cannot improve carrier utilization efficiency in a state without interference.
The wireless communication system 1 and the wireless communication apparatus 2 described below have been improved so as to solve such problems.

[Wireless communication system 1]
FIG. 1 is a diagram illustrating a configuration of the wireless communication system 1.
As shown in FIG. 1, the wireless communication system 1 includes nodes 10-A to 10-L that perform wireless communication, and these nodes 10-A to 10-L construct an ad hoc network. The nodes 10 -A to 10 -L are, for example, mobile stations, and are the main body of information processing and communication, and perform wireless communication in the wireless communication system 1.
In the following drawings, components that are not necessary for the description of the present invention are omitted as appropriate for the purpose of illustration and clarification.
Furthermore, in the following, when any one of a plurality of constituent parts such as the nodes 10-A to 10-L is indicated without being specified, the node 10 may be simply abbreviated.

Each node 10 includes a wireless communication device 2. As will be described later with reference to FIG. 2, the wireless communication device 2 can perform broadband wireless communication and narrowband wireless communication.
Here, the narrowband wireless communication is wireless communication using a frequency band of the order of kHz or less, for example, SSB (Single Sideband), AM (Amplitude Modulation), FM ( This includes amateur radio communication using frequency modulation, commercial digital radio communication, or taxi radio communication.
Broadband wireless communication is wireless communication that uses a frequency band of the order of MHz or more, and includes, for example, W-CDMA (Wideband Code Division Multiple Access) mobile phone communication, terrestrial digital broadcasting, wireless LAN communication, or WiMAX (Worldwide Interoperability). for Microwave Access) communication.
The possible range of broadband wireless communication in the node 10-A is illustrated as A1, and the possible range of narrowband wireless communication is illustrated as A2. A1 includes nodes 10-A to 10-D, and A2 includes nodes 10-A to 10-L. That is, the communication range tends to be larger in narrowband wireless communication than in broadband wireless communication.
In the wireless communication system 1, for example, the node 10-A performs mobile station-mobile station communication with neighboring nodes (nodes 10-B, 10-C, 10-D). Hereinafter, the node 10-A may be referred to as a self node.

[Wireless communication device 2]
FIG. 2 is a diagram illustrating a configuration of the wireless communication device 2 included in the node 10 illustrated in FIG.
As shown in FIG. 2, the wireless communication device 2 includes a broadband wireless communication unit 20 and a narrowband wireless communication unit 24.
The broadband wireless communication unit 20 includes a control unit 200, an external interface unit 202, an application unit 204, a baseband processing unit 206, a high frequency wireless unit 208, an antenna 210, a network processing unit 212, a carrier signal detection unit 216, a narrowband wireless. The communication control unit 214, the report request generation unit 218, the noise determination unit 220, the subcarrier change control unit 222, and the transmission state analysis unit 224 are connected via a bus realized by hardware or software. .

The broadband wireless communication unit 20 performs processing for broadband wireless communication, and the narrowband wireless communication unit 24 performs processing for narrowband wireless communication.
The control unit 200 controls each component of the broadband wireless communication unit 20.
The external interface unit 202 accepts data to be transferred to other nodes using wireless communication by operating the user's keyboard or the like, and outputs data transferred from other nodes using wireless communication to a monitor or the like To do.
The application unit 204 performs conversion (media conversion, etc.) necessary for transmitting the data received by the external interface unit 202 to other nodes via the network, and receives from other nodes. Reverse conversion is performed on the received data.
The baseband processing unit 206 modulates the data converted by the application unit 204 to generate a baseband signal, and demodulates baseband signals from other nodes into data.

The high frequency radio unit 208 converts the baseband signal into a radio signal and transmits it to the network via the antenna 210. The high frequency radio unit 208 receives a radio signal from the network via the antenna 210 and converts it into a baseband signal.
The network processing unit 212 performs processing related to a protocol necessary for establishing communication between another node and a mobile station-mobile station (for example, ad hoc network communication). The network processing unit 212 also manages a routing table for communicating with other nodes 10 of the wireless communication system 1.
The narrowband wireless communication control unit 214 transmits / receives data to / from the narrowband wireless communication unit 24, performs necessary conversion on the data, and performs narrowband wireless communication to perform processing described later with reference to FIG. The unit 24 is controlled.
The carrier signal detection unit 216 detects a carrier signal for each subcarrier from the radio signal received by the high-frequency radio unit 208, and further detects the duration of the subcarrier.

FIG. 3 is a diagram illustrating a signal detection state of the carrier signal detection unit 216. (A) illustrates a case where the own node does not receive noise, and (B) illustrates that the own node receives noise. An example is given.
Here, the noise includes a signal that hinders communication other than a carrier signal used in broadband wireless communication.
In the example shown in FIG. 3A, when an adjacent node (for example, node 10-B in FIG. 1) is transmitting a carrier signal, the carrier signal detection unit of its own node (for example, node 10-A in FIG. 1). 216 detects the carrier signal.
On the other hand, when the transmission of the carrier signal of the adjacent node is completed, the carrier signal detection unit 216 of the own node does not detect the carrier signal, and therefore, it is determined by the CSMA / CA method that the signal transmission path is free. A signal can be transmitted from a node to an adjacent node.
At this time, the carrier signal detection times Tc1 and Tc2 often do not exceed the maximum transmission time Tmax (including a delay margin due to radio wave propagation) in the broadband wireless communication system. That is, Tc1 <Tmax and Tc2 <Tmax.

On the other hand, in the example shown in FIG. 3B, when a disturbing node (for example, the node 10-C in FIG. 1) transmits noise such as a disturbing signal, the carrier signal detection unit 216 of the own node Noise from the interfering node is erroneously detected as a carrier signal, and transmission and transmission completion of the carrier signal of the adjacent node cannot be detected correctly.
At this time, the carrier signal detection time Tc3 may exceed the maximum transmission time Tmax. When Tc3> Tmax, the carrier signal detection unit 216 outputs, to the report request generation unit 218, a signal (processing start signal) for selecting a subcarrier without noise and starting processing for avoiding noise. To do.

The report request generation unit 218 (FIG. 2) generates a report request signal for reporting the signal transmission state of the adjacent node, and outputs this report request signal to the narrowband wireless communication control unit 214.
The narrowband wireless communication control unit 214 controls to transmit a report request signal to the narrowband wireless communication unit 24, and the narrowband wireless communication unit 24 transmits the report request signal to the adjacent node by narrowband wireless communication. To send.
Here, if narrowband wireless communication is used, even if the local node is receiving noise, it can reliably communicate with an adjacent node.

When the narrowband wireless communication unit 24 of the adjacent node (for example, the node 10-B) receives the report request signal from the own node (for example, the node 10-A), the transmission state analysis unit 224 of the adjacent node (the node 10-B) The transmission state of the broadband wireless communication is analyzed, and a transmission state report signal including information on the analysis result is created.
The narrowband wireless communication unit 24 of the adjacent node (node 10-B) transmits a transmission status report signal to the own node (node 10-A) by narrowband wireless communication.

The narrowband wireless communication unit 24 of its own node (node 10-A) receives the transmission status report signal from the adjacent node (node 10-B) and outputs it to the noise determination unit 220.
The noise determination unit 220 analyzes the transmission status report signal and determines whether or not the adjacent node (node 10-B) is transmitting a carrier signal.
Here, when the adjacent node (node 10-B) transmits the carrier signal, the noise determination unit 220 receives the carrier signal from the own node (node 10-A), and outputs a signal including noise. If it is determined that the adjacent node (node 10-B) is not transmitting a carrier signal, it is determined that the own node (node 10-A) is receiving a signal including noise.
When it is determined that the own node (node 10-A) is receiving noise, the carrier signal detection unit 216 determines an available subcarrier, in other words, a subcarrier without noise, and if there is no noise. Information regarding one or more determined subcarriers (no-carrier subcarrier information) is output to subcarrier change control section 222.

The subcarrier change control unit 222 generates a signal (subcarrier change request signal) for requesting a change of subcarrier based on the received noise-free subcarrier information, and the narrowband wireless communication control unit 214 Output.
The narrowband wireless communication control unit 214 controls to transmit a subcarrier change request signal to the narrowband wireless communication unit 24, and the narrowband wireless communication unit 24 sends the subcarrier change request signal by narrowband wireless communication. Send to neighboring nodes.

When the narrowband wireless communication unit 24 of the adjacent node (for example, node 10-B) receives the subcarrier change request signal from its own node (for example, node 10-A), the carrier signal detection unit 216 of the adjacent node (node 10-B). Determines a subcarrier without noise based on the received subcarrier change request signal, and outputs the determination result to the subcarrier change control unit 222 of the adjacent node (node 10-B).
The subcarrier change control unit 222 of the adjacent node (node 10-B) determines whether or not all of the subcarriers related to the subcarrier change request signal do not include noise, and when all the subcarriers do not include noise. Generates a change acknowledgment signal indicating that the change is affirmed, and generates a change negative response signal indicating that the change is denied if any one of them includes noise.
The narrowband wireless communication unit 24 of the adjacent node (node 10-B) transmits a change acknowledgment signal or a change negative response signal (response signal) to the own node (node 10-A) by narrowband wireless communication. .

The narrowband wireless communication unit 24 of the own node (node 10-A) receives the response signal from the adjacent node (node 10-B) and outputs the response signal to the subcarrier change control unit 222.
The subcarrier change control unit 222 analyzes the response signal, and generates a signal (subcarrier change start notification signal) for notifying the start of subcarrier change when the response from the adjacent node is a change acknowledgment. Then, the data is output to the narrowband wireless communication control unit 214 and processing for changing the subcarrier is performed.
The narrowband wireless communication control unit 214 controls the narrowband wireless communication unit 24 to transmit a subcarrier change start notification signal, and the narrowband wireless communication unit 24 notifies the subcarrier change start notification by narrowband wireless communication. A signal is transmitted to an adjacent node.

When the narrowband wireless communication unit 24 of the adjacent node (for example, node 10-B) receives the subcarrier change start notification signal from the own node (for example, node 10-A), the subcarrier change control of the adjacent node (node 10-B) Unit 222 performs processing for changing a subcarrier.
Thereafter, broadband wireless communication between the own node and the adjacent node is performed using the changed subcarrier.

[Overall operation]
The overall operation will be described below.
FIG. 4 is a flowchart (S10, S20, S30) showing the processing of the own node (for example, node 10-A) and the adjacent node (for example, node 10-B), where S10 shows the processing of the own node, and S20 is The process of the adjacent node when the transmission state report request is received from the own node is shown. S30 shows the process of the adjacent node when the subcarrier change request is received from the own node.

First, the flowchart S10 will be described.
In step 102 (S102), the carrier signal detection unit 216 determines that the carrier signal detection time Tc (for example, Tc3) has exceeded the maximum transmission time Tmax.
In step 104 (S104), the narrowband wireless communication unit 24 transmits a report request signal to the adjacent node by narrowband wireless communication.
In step 106 (S106), the narrowband wireless communication unit 24 receives a transmission status report signal from an adjacent node by narrowband wireless communication.
In step 108 (S108), the noise determination unit 220 determines whether or not the own node has received a signal including noise. If the node has received the signal, the process proceeds to S110. If not, the noise determination unit 220 determines a subcarrier. The process ends without changing.
In step 110 (S110), the carrier signal detection unit 216 determines a subcarrier without noise.

In step 112 (S112), the narrowband wireless communication unit 24 transmits a subcarrier change request signal to the adjacent node by narrowband wireless communication.
In step 114 (S114), the narrowband wireless communication unit 24 receives a response signal from the adjacent node by narrowband wireless communication.
In step 116 (S116), the subcarrier change control unit 222 determines whether or not the response from the adjacent node is a change acknowledgment, and if it is a change acknowledgment, the process proceeds to S118, and if it is a change negative response Returns to S102.
In step 118 (S118), the narrowband wireless communication unit 24 transmits a subcarrier change start notification signal to the adjacent node by narrowband wireless communication.
In step 120 (S120), the subcarrier change control unit 222 completes the subcarrier change process and ends the process.

Next, the flowchart S20 will be described.
In step 200 (S200), the narrowband wireless communication unit 24 of the adjacent node receives the report request signal from the own node through the narrowband wireless communication.
In step 202 (S202), the transmission state analysis unit 224 of the adjacent node analyzes the transmission state of the broadband wireless communication and creates a transmission state report signal including information related to the analysis result.
In step 204 (S204), the narrowband wireless communication unit 24 of the adjacent node transmits a transmission status report signal to the own node by narrowband wireless communication.

Next, the flowchart S30 will be described.
In step 300 (S300), the narrowband wireless communication unit 24 of the adjacent node receives the subcarrier change request signal from the own node through the narrowband wireless communication.
In step 302 (S302), the carrier signal detector 216 of the adjacent node determines a subcarrier without noise.
In Step 304 (S304), the subcarrier change control unit 222 of the adjacent node determines whether or not all of the subcarriers related to the subcarrier change request signal do not include noise, and when all the subcarriers do not include noise. Advances to S308, and if even one noise is included, advances to S306.
In step 306 (S306), the narrowband wireless communication unit 24 of the adjacent node transmits a change negative acknowledgment signal to the own node by narrowband wireless communication, and ends the process.

In step 308 (S308), the narrowband wireless communication unit 24 of the adjacent node transmits a change acknowledgment signal to the own node by narrowband wireless communication.
In step 310 (S310), the narrowband wireless communication unit 24 of the adjacent node receives the subcarrier change start notification signal from its own node by narrowband wireless communication.
In step 312 (S312), the subcarrier change control unit 222 of the adjacent node completes the subcarrier change process and ends the process.

In the above-described embodiment, the case where there is one adjacent node is illustrated. However, even when there are a plurality of adjacent nodes, the processing procedure described with reference to FIG. 4 is repeated for the number of adjacent nodes. do it.
Each component may be included in another component, and a plurality of functions of each component may be used as a function of a plurality of components.
For example, the functions of the report request generation unit 218, the noise determination unit 220, the subcarrier change control unit 222, and the transmission state analysis unit 224 may be realized by the narrowband wireless communication control unit 214, or the carrier signal detection unit It may be realized by H.216, or may be realized by the narrowband wireless communication unit 24.

As described above, the wireless communication apparatus according to the present invention selects a subcarrier that does not include noise even when receiving noise such as an interference signal, and communicates with an adjacent node by narrowband wireless communication. Since subcarriers can be changed, broadband wireless communication using an optimal set of subchannels is possible.
The wireless communication apparatus according to the present invention can automatically avoid noise according to various noises, and can improve noise resistance performance in broadband wireless communication.

  The present invention is applicable to a wireless communication device.

It is a figure which shows the structure of a radio | wireless communications system. It is a figure which shows the structure of the radio | wireless communication apparatus which the node shown in FIG. 1 has. It is a figure which illustrates the signal detection state of a carrier signal detection part. It is a flowchart which shows the process of each own node and an adjacent node.

Explanation of symbols

1 ... wireless communication system,
10-A to 10-L node,
2 ... wireless communication device,
20: Broadband wireless communication unit,
200 ... control unit,
202 ... External interface section,
204 ... application section,
206 ... Baseband processing unit,
208... High frequency radio section,
210 ... antenna,
212 ... Network processing unit,
214 ... Narrowband wireless communication control unit,
216 ... Carrier signal detector,
218: Report request generation unit,
220: Noise determination unit,
222... Subcarrier change control unit,
224: Transmission state analysis unit,
24: Narrowband wireless communication unit,

Claims (1)

A wireless communication device,
Broadband wireless communication means for performing processing for broadband wireless communication;
Signal detection means for detecting a signal received by the broadband wireless communication means;
When the reception period of the signal exceeds a predetermined time, report whether the other wireless communication device is transmitting a signal to the other wireless communication device using narrowband wireless communication. Narrowband wireless communication means for transmitting a report request for requesting and receiving a report transmitted from the other wireless communication device in response to the report request;
A wireless communication apparatus comprising: determination means for determining whether the signal received by the broadband wireless communication means is a signal transmitted from the other wireless communication apparatus based on the report.

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