KR20130127849A - Detect system for idle frequency band and method thereof - Google Patents

Abstract

In an idle frequency band detection system according to an embodiment of the present invention, a plurality of base stations, a plurality of CR (Repetitive Radio) repeaters provided in respective areas of the base station to detect channel information of an idle frequency band, and the CR repeater from the It includes a wireless communication terminal for receiving channel information of the idle frequency band.
The idle frequency band detection system according to the present invention can easily detect and use the channel information of the idle frequency band by region and time zone from the CR repeater without the process of preventing disconnection of the wireless network and rescanning the channel. It has an effect.

Description

Idle frequency band detection system and method {DETECT SYSTEM FOR IDLE FREQUENCY BAND AND METHOD THEREOF}

The present invention relates to an idle frequency band detection system and method.

With the development of wireless communication technology, the use of wireless multimedia services using Wi-Fi communication has increased, and new devices such as smartphones, tablet PCs, smart TVs, etc., which can be applied to these devices, have become more common, resulting in increased wireless data traffic. Demand is soaring. Accordingly, the importance of unlicensed frequency bands except for licensed frequency bands has emerged.

The TV White Space (TVWS) band of the VHF / UHF band, which will remain as an idle band due to terrestrial analog TV broadcasting termination and digital broadcasting conversion, is in the spotlight.

These TVWS bands are particularly suitable for building broadband wireless networks in large areas in the countryside or suburbs due to their excellent radio wave reach.

The use of frequencies in these TVWS bands requires no interference with TV broadcast signals, wireless microphones and other equipment signals. Accordingly, by using the CR (Cognitive Radio) technology described in Korean Patent Publication No. 2011-0013941 (published February 10, 2011), a method of selecting a frequency without causing interference with other device signals is used. have.

CR technology is one of the most feasible ways to address the lack of frequency bands in wireless communications and is of great interest to those in the field. The CR technology searches for idle bands that are not being used by an authorized user and uses some (or all) of the idle bands as available frequency channels for other users.

However, since the available frequency channels of the TVWS band are flexible by region and time zone, the user cannot conveniently obtain available frequency channel information.

An aspect of the present invention is to provide an idle frequency band detection system that detects and informs the available available frequency by region and time zone in order to solve the above problems.

Another aspect of the present invention is to provide an idle frequency band detection method for detecting and informing the available available frequency by region and time zone in order to solve the above problems.

An idle frequency band detection system according to an embodiment of the present invention includes a plurality of base stations; A plurality of CR repeaters provided in respective regions of the base station to detect channel information of an idle frequency band; And a wireless communication terminal for receiving channel information of the idle frequency band from the CR repeater.

In the idle frequency band detection system according to an embodiment of the present invention, the base station sets and stores the total number of channels based on frequency, information of the channel, and reference level information for determining the idle frequency band.

In the idle frequency band detection system according to an embodiment of the present invention, the reference level information includes channel average noise power information (Pr).

In the idle frequency band detection system according to an embodiment of the present invention, the wireless communication terminal wirelessly receives channel information of the idle frequency band from the CR repeater in a short range wireless communication method.

In addition, the idle frequency band detection method according to another embodiment of the present invention comprises the steps of the base station to set the channel information and reference level information for determining the idle frequency band and wirelessly transmitting to the CR repeater; Acquiring the channels sequentially and acquiring information on the corresponding channels using the channel information and the reference level information wirelessly received by the CR repeater; Detecting, by the CR repeater, whether the corresponding channel is a channel of an idle frequency band using the reference level information; Determining whether the CR repeater has performed a search for all the channels; And the CR repeater wirelessly transmitting channel information of the idle frequency band to a wireless communication terminal. .

In the idle frequency band detection method according to another embodiment of the present invention, the determining may include: acquiring, by the CR repeater, a search for a next channel by the CR repeater according to a result of the determining step; And detecting, by the CR repeater, whether the next channel is a channel of an idle frequency band using the reference level information.

The idle frequency band detecting method according to another embodiment of the present invention includes channel average noise power information (Pr) as the reference level information in detecting whether the idle frequency band is a channel, and the CR repeater includes the channel. Each of the power information Pi is compared with the channel average noise power information Pr to detect whether the channel is in an idle frequency band.

In the idle frequency band detection method according to another embodiment of the present invention, the reference level information includes channel average noise power information (Pr), and the CR repeater outputs power information Pi of the next channel to the channel average noise power. It compares with information Pr and detects whether it is a channel of an idle frequency band.

In the method for detecting an idle frequency band according to another embodiment of the present invention, detecting whether the channel is the idle frequency band is detected as a channel of the frequency band being used, and thus adjacent channel information of the corresponding channel is determined. It is deleted or avoided.

In the idle frequency band detecting method according to another embodiment of the present invention, the adjacent channel information includes lower neighbor channel information and upper neighbor channel information of the corresponding channel, the lower neighbor channel information is deleted, and the upper neighbor channel information. Is avoided by the unavailable channel.

The features and advantages of the present invention will become more apparent from the following detailed description based on the accompanying drawings.

Prior to this, terms and words used in the present specification and claims should not be construed in a conventional, dictionary sense, and should not be construed as defining the concept of a term appropriately in order to describe the inventor in his or her best way. It should be construed in accordance with the meaning and concept consistent with the technical idea of the present invention.

The idle frequency band detection system according to the present invention can easily detect and use the channel information of the idle frequency band by region and time zone from the CR repeater without the process of preventing disconnection of the wireless network and rescanning the channel. It has an effect.

The idle frequency band detecting method according to the present invention can easily detect a TV White Space (TVWS) frequency channel band that is flexible for each region and for each time zone to use a wireless communication service.

1 is an exemplary view for explaining an idle frequency band detection system according to an embodiment of the present invention.
2 is a flowchart illustrating an idle frequency band detection method according to another embodiment of the present invention.
3 is an exemplary view for explaining an idle frequency band detection method according to another embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The objects, particular advantages and novel features of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: FIG. It should be noted that, in the present specification, the reference numerals are added to the constituent elements of the drawings, and the same constituent elements are assigned the same number as much as possible even if they are displayed on different drawings. Also, the terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. 1 is an exemplary view for explaining an idle frequency band detection system according to an embodiment of the present invention.

The idle frequency band detection system according to an embodiment of the present invention includes a plurality of base station (100, 200, 300), each of the base station (100, 200, 300) in each of the plurality of CR (Cognitive Radio) repeater 401 for detecting channel information of the idle frequency band 411), and a wireless communication terminal 500 for receiving channel information of an idle frequency band from the CR (Cognitive Radio) repeaters 401 to 411.

The base station 100, 200, 300 sets and stores the total number of channels based on frequency, information of each channel, and reference level information for determining an idle frequency band. Here, the reference level information is a level information that is used as a reference to determine whether each channel is in an idle state or used for other purposes, and may be set according to a real-time propagation environment of a corresponding region, for example, channel average noise. It may be set including the power information (Pr).

The CR repeaters 401 to 411 are provided in a number of areas, for example, roads, railways, canals, and the like, corresponding to the wireless communication ranges of the base stations 100, 200, and 300. The CR repeaters 401 to 411 receive reference level information including the total number of channels, information of each channel, and channel average noise power information Pr for determining an idle frequency band from the base stations 100, 200, and 300, respectively. The idle state of each channel may be determined using the reference level information.

At this time, the CR repeaters 401 to 411 transmit the channel information of the idle frequency band detected in the idle state to the wireless communication terminal 500 in a short range.

The wireless communication terminal 500 is a wireless communication terminal provided with an idle frequency band detection service using an idle frequency band detection system, for example, a short range wireless communication method from the CR repeaters 401 to 411 using a short range wireless communication method such as Zigbee or Wi-Fi. Receive channel information wirelessly.

For example, as shown in FIG. 1, a channel being used by a user of the wireless communication terminal 500 in the process of using the TVWS band through the wireless communication terminal 500 while using a vehicle, a train, or a ship is a second base station. When affected by a signal of the same channel being used for other purposes in the entry area of 200, the wireless communication terminal 500 passes through the fourth CR repeater 404 or the ninth CR repeater 409 prior to network disconnection. Channel information of an idle frequency band can be acquired.

Accordingly, the wireless communication terminal 500 facilitates the channel information of the idle frequency band, which is flexible by region and time zone, from the CR repeaters 401 to 411 without the process of preventing the disconnection of the wireless network and rescanning the channel. Can be received and used.

Hereinafter, an idle frequency band detection method according to another embodiment of the present invention will be described with reference to FIGS. 2 and 3. 2 is a flowchart illustrating a method for detecting an idle frequency band according to another embodiment of the present invention, and FIG. 3 is an exemplary view for explaining an method for detecting an idle frequency band according to another embodiment of the present invention.

In the idle frequency band detecting method according to another embodiment of the present invention, the user of the wireless communication terminal 500, for example, using a vehicle or the like of the third base station 300 in the wireless communication area of the first base station 100; A method of easily detecting and using channel information of idle frequency bands that are flexible for each region and time zone while moving to a wireless communication region through the CR repeaters 401 to 411 will be described.

First, in the idle frequency band detection method according to another embodiment of the present invention, the base station 100, 200, 300 sets the total number of channels, information on each channel, and reference level information for determining the idle frequency band. Wireless transmission to step 411 (S210).

For example, as shown in FIG. 3, the total number of channels used as a TV band in an arbitrary region is 18, and information on the usage status of each frequency channel when the CR repeaters 401 to 411 search for a channel is shown. The reference level information is set and wirelessly transmitted to the CR repeaters 401-411. Here, the channel reference level information is level information used as a reference for determining whether a channel being searched for is empty or used for other purposes, and may vary according to a real-time propagation environment of a corresponding region, for example, channel average noise power. It can be set including (Pr).

After setting the reference level information and wirelessly transmitting it to the CR repeaters 401 to 411, the CR repeaters 401 to 411 use the total number of received channels, each channel information, and the reference level information of the newly entered region. Search for channels to obtain information on each corresponding channel (S220).

Specifically, the CR repeaters 401 to 411 use the total number of channels received from the base stations 100, 200, and 300, the respective channel information, and the reference level information, as shown in FIG. 3, from 1 to 18 in the corresponding region. Channels 3, 12, 13, and 17 are used for TV broadcasting, channels 6 and 8 are already used for TVWS service, and channel 7 is being used for wireless microphone service, which is another license service. The rest of the channel can be obtained as an empty idle frequency channel.

At this time, in order to detect an idle frequency channel among all channels 1 to 18, the CR repeaters 401 to 411 search for channel power sequentially from channel 1 according to the channel frequency, and power of the i-th corresponding channel. The information Pi is compared with the channel average noise power information Pr (S230).

In the step of comparing the power information Pi of the i-th corresponding channel with the channel average noise power information Pr, if the power information Pi of the i-th corresponding channel is smaller than or equal to the channel average noise power information Pr, i The corresponding channel is determined as an empty idle frequency channel and stores corresponding channel information (S240).

On the other hand, when the power information Pi of the i-th corresponding channel is larger than the channel average noise power information Pr, it is determined that the i-th corresponding channel is a non-empty channel and the adjacent channel information of the i-th corresponding channel is avoided erased. (S235).

That is, if the power information Pi of the i-th corresponding channel is larger than the channel average noise power information Pr, the i-th corresponding channel may be in use by another service, and thus interference due to the adjacent channel signal of the i-th corresponding channel In order to protect from the effect, in principle, the lower adjacent channel of "i-1" and the upper adjacent channel of "i + 1" are not used, in principle.

At this time, if the lower neighboring channel of "i-1" is stored as a usable channel in the comparison determination step S230, the lower neighboring channel information of i-1 is deleted and the upper neighboring channel information of "i + 1" is also used. Avoidance is set to an unknown channel.

Thereafter, the CR repeaters 401 to 411 compare the number of the i-th corresponding channel with the number of all channels to determine whether the entire channel has been searched (S250).

If the number of the i-th corresponding channel is less than the number of all channels compared to the number of all channels, the CR repeaters 401 to 411 start searching for the next channel (S255).

Here, the next channel where the search is started includes the next channel excluding the channel set to be avoided in the step of avoiding deleting of adjacent channel information (S235).

By repeating the above process, if the number of the i-th corresponding channel is 18th equal to the total number of channels, the CR repeater 401 to 411 transmits the channel information stored in the idle frequency channel to the wireless communication terminal 500 at short range. (S260).

For example, the CR repeaters 401 to 411 may store information on channels 1, 10, and 15 stored as a channel that can be used as an idle frequency channel among all the channels 1 to 18 shown in FIG. It transmits to the wireless communication terminal 500 which is moving by the same short range wireless communication method.

The wireless communication terminal 500 having received the 1, 10, 15 times idle frequency channel information may select the idle frequency channel according to the performance or condition of the wireless communication to perform a wireless communication service.

Therefore, the idle frequency band detection method according to another embodiment of the present invention can easily detect the TV White Space (TVWS) frequency channel band that is flexible for each region and time zone.

Accordingly, the wireless communication terminal 500 easily prevents the disconnection of the wireless network and does not need to rescan the channel, and facilitates the channel information of the idle frequency band that is flexible by region and time zone from the CR repeaters 401 to 411. It can receive and provide a wireless communication service.

Although the technical idea of the present invention has been specifically described according to the above preferred embodiments, it is to be noted that the above-described embodiments are intended to be illustrative and not restrictive.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit and scope of the invention.

100, 200, 300: base station 401 to 411: CR repeater
500: wireless communication terminal

Claims (10)

Multiple base stations;
A plurality of CR repeaters provided in respective regions of the base station to detect channel information of an idle frequency band; And
A wireless communication terminal for receiving channel information of the idle frequency band from the CR repeater
Idle frequency band detection system comprising a.
The method according to claim 1,
And the base station sets and stores a total number of channels based on frequency, information on the channel, and reference level information for determining the idle frequency band.
The method according to claim 2,
The reference level information includes channel average noise power information (Pr).
The method according to claim 1,
And the wireless communication terminal wirelessly receives channel information of the idle frequency band from the CR repeater in a short range wireless communication method.
Setting, by the base station, reference level information for determining channel information and an idle frequency band and wirelessly transmitting it to the CR repeater;
Acquiring the channels sequentially and acquiring information on the corresponding channels using the channel information and the reference level information wirelessly received by the CR repeater;
Detecting, by the CR repeater, whether the corresponding channel is a channel of an idle frequency band using the reference level information;
Determining whether the CR repeater has performed a search for all the channels; And
The CR repeater wirelessly transmitting channel information of the idle frequency band to a wireless communication terminal;
Idle frequency band detection method comprising a.
The method according to claim 5,
The determining step
Acquiring, by the CR repeater, a search for a next channel to obtain information of the next channel according to a result of the determining step; And
Detecting, by the CR repeater, whether the next channel is a channel of an idle frequency band using the reference level information;
Idle frequency band detection method further comprising.
The method according to claim 5,
Detecting whether the channel is in the idle frequency band;
The reference level information includes channel average noise power information (Pr),
And the CR repeater compares power information (Pi) of each of the channels with the channel average noise power information (Pr) to detect whether the channel is in an idle frequency band.
The method of claim 6,
The reference level information includes channel average noise power information (Pr),
And the CR repeater compares the power information Pi of the next channel with the channel average noise power information Pr to detect whether the CR repeater is a channel of an idle frequency band.
The method according to claim 5,
Detecting whether the channel is in the idle frequency band
And the adjacent channel information of the corresponding channel is deleted or avoided as the corresponding channel is detected as a channel of a frequency band in use.
The method of claim 9,
The neighbor channel information includes lower neighbor channel information and upper neighbor channel information of the corresponding channel.
And the lower neighboring channel information is deleted, and the upper neighboring channel information is avoided and set to an unavailable channel.

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