KR20140118506A - System and method for allocating frequency in wireless terminal - Google Patents

Abstract

A frequency allocation system for a wireless terminal of the present invention comprises a storage unit in which user information of the wireless terminal and information on a TV white space database usable by the wireless terminal; a spectrum sensing information receiving unit which receives spectrum sensing information transferred from the wireless terminal; an interference reference setting unit which sets an interference reference by comparing an interference reference value of the TV white space database with an interference reference value on the basis of the spectrum sensing information; and a frequency allocating unit which sets an emission mask reference of the wireless terminal on the basis of the set interference reference, and allocates a frequency to a TV white space usable by the wireless terminal on the basis of the emission mask reference, wherein the interference reference setting unit sets the interference reference value of the TV white space database as the interference reference when the interference reference value on the basis of the spectrum sensing information is smaller than the interference reference value of the TV white space database.

Description

[0001] SYSTEM AND METHOD FOR ALLOCATING FREQUENCY IN WIRELESS TERMINAL [0002]

The present invention relates to a system and method for frequency assignment of wireless terminals.

In the wireless communication environment, the objects are connected through the network, so that it is possible to easily acquire and transmit necessary information anytime and anywhere, and M2M (Machine to Machine) service, which can realize various services based on this, It is becoming a major issue for the telecom market.

In particular, a variety of connected M2M-type converged wireless devices will be popularized to realize a high-efficiency wireless communication network for public and industrial services by utilizing a number of low-cost heterogeneous wireless devices and measurement sensors in accordance with the changing environment of ubiquitous convergence It is expected.

Meanwhile, diversification of ecosystem in the mobile industry and increase of converged wireless devices are expected to rapidly increase wireless traffic demand, which is expected to result in network overload due to limitations of existing wireless network infrastructure have.

In order to cope with such a surge in wireless data demand, interest in new frequency utilization schemes such as TV white space is increasing. For this purpose, the database interworking method of TV whitespace is considered as an interference protection scheme for the existing primary broadcasting service of this band. However, in order to secure the reliability of the in-house radio wave detection and coexistence of frequencies with various existing wireless devices, It is essential to use the white space database and spectrum sensing technology in parallel.

1 is a diagram for explaining a menstrual interference phenomenon.

In case of UHF (Ultra High Frequency) broadcasting band, it is necessary to prepare measures to solve the menstrual interference phenomenon in order to coexist with the existing primary broadcasting service and TV whitelist based service which require interference protection. In this case, the term 'menstrual interference' refers to a phenomenon of interference propagation that can occur in the domestic frequency policy environment where the use frequency is allocated at the center of the administrative area. For example, a broadcast channel radio wave designated to be used only in Gyeongsang area is transited to a neighboring Chungcheong province and mutual interference occurs. Due to such a menstrual interference phenomenon, it is difficult to set the interference protection standard of the existing broadcasting service required for using the domestic TV white space service.

In this regard, the existing US Federal Communications Commission (FCC) and the UK Communications Commission (Offcom) officially adopted the TV white space database management method alone, but the spectrum sensing technology and the TV white space database method are merged There is no way to operate TV white space service. In Korea, there are no measures against menstrual interference or officially announced technical specifications.

FIG. 2 is a diagram comparing interference measurable ranges for DTV protection.

As described above, in Korea, there are no solution, interference protection and operation standard for menstrual interference. In addition, when using the existing database method of TV whitespace, interference limit setting criteria for broadcasting service protection is limited.

In such a situation, if the database of TV whitespace is used alone, it is possible to extend the protection service area of broadcasting service, but the efficiency of locally usable frequency usage is reduced. In addition, there is a problem that it is difficult to cope with the domestic menses interference phenomenon due to the single operation of the database of the TV whitespace, and it is difficult to set a precise broadcasting service protection standard in the domestic wireless communication area where the GPS position estimation function is impossible.

In this regard, Korean Patent Laid-Open Publication No. 2012-0139747 entitled " System and Method for Spectrum Sharing Between Multiple Wireless Networks " refers to a system or method for sharing wireless communication between multiple networks or groups, Discloses systems and methods for facilitating simultaneous use of spectra.

Korean Patent Application Publication No. 2012-0132607 entitled " Resource Management System and Method in Communication System ") discloses a system in which a plurality of systems coexist in a frequency band usable in a frequency band already used in a communication system, And a resource management system and method for using the resource management system.

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems of the prior art, and it is an object of the present invention to provide a TV white space service for coping with menstrual interference phenomenon and accurate wireless communication at home, And a frequency allocation system and method for a wireless terminal that simultaneously operates the technology and the spectrum sensing technology.

According to a first aspect of the present invention, there is provided a frequency allocation system for a wireless terminal, including a storage unit storing user information of the wireless terminal and TV whitelist database information available to the wireless terminal, An interference reference setting unit for setting an interference reference by comparing an interference reference value based on the interference reference value of the TV white space database and the interference reference value based on the spectral sensing information received by the wireless terminal, And a frequency allocator configured to allocate a frequency of a TV whitespace available to the wireless terminal based on the emission mask reference, tablet When the interference reference value based on the beam is smaller than the interference reference value of the TV white space database, the interference reference value of the TV white space database is set as the interference reference.

A method for allocating a frequency of a wireless terminal using a frequency allocation system of a wireless terminal according to the second aspect of the present invention includes receiving a TV white space frequency allocation request of the wireless terminal, Setting an interference criterion by comparing an interference reference value based on the TV white space database and an interference reference value based on the spectrum sensing information, setting a radiation mask reference of the wireless terminal based on the set interference criterion And assigning a TV whitelist frequency that is available to the wireless terminal based on the set emission mask reference, wherein the setting of the interference criterion comprises: determining that the interference reference value based on the spectrum sensing information is less than the TV whitelist frequency Interference criterion If you set the reference value smaller than the interference of the TV white space database based on the interference.

According to the above-mentioned problem solving means of the present invention, in addition to the database technology of TV white space, it is possible to grasp the electric field intensity value of the minute radio wave exceeding the threshold value of the protection area of the TV technology of the TV white space when using the spectrum sensing technology .

Accordingly, it is possible to efficiently set the interference reference value for extending the detection range and protecting the broadcasting service.

In addition, it is possible to cope with the menstrual interference phenomenon by operating the database technology of TV white space and the spectrum sensing technology in parallel, and it is possible to set an accurate broadcasting service protection standard in a home wireless communication environment where GPS position estimation is difficult.

1 is a diagram for explaining a menstrual interference phenomenon.
FIG. 2 is a diagram comparing interference measurable ranges for DTV protection.
3 is a block diagram of a frequency allocation system for a wireless terminal in accordance with an embodiment of the present invention.
FIG. 4 is a diagram for comparing boundaries of a broadcast service protection area according to comparison of field strength values.
5 is a flowchart of a frequency allocation method of a wireless terminal according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, which will be readily apparent to those skilled in the art. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In order to clearly illustrate the present invention, parts not related to the description are omitted, and similar parts are denoted by like reference characters throughout the specification.

Throughout the specification, when a part is referred to as being "connected" to another part, it includes not only "directly connected" but also "electrically connected" with another part in between . Also, when an element is referred to as "comprising ", it means that it can include other elements as well, without departing from the other elements unless specifically stated otherwise. The word " step (or step) "or" step "used to the extent that it is used throughout the specification does not mean" step for.

3 is a block diagram of a frequency allocation system 300 of a wireless terminal in accordance with an embodiment of the present invention.

The frequency allocation system 300 of the wireless terminal according to the present invention includes a storage unit 310, a spectrum sensing information receiver 320, an interference criterion setting unit 330, and a frequency allocator 340.

3 refers to a hardware component such as software or an FPGA (Field Programmable Gate Array) or ASIC (Application Specific Integrated Circuit), and performs predetermined roles .

However, 'components' are not meant to be limited to software or hardware, and each component may be configured to reside on an addressable storage medium and configured to play one or more processors.

Thus, by way of example, an element may comprise components such as software components, object-oriented software components, class components and task components, processes, functions, attributes, procedures, Routines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables.

The components and functions provided within those components may be combined into a smaller number of components or further separated into additional components.

First, the storage unit 310 stores user information of a wireless terminal and information of a TV white space database available to the wireless terminal. At this time, the TV White Space database corresponds to a local TV white space database operated by a local business operator. Meanwhile, the user information of the wireless terminal corresponds to the serial information for identifying the wireless terminal user such as the ID information of the user.

The spectrum sensing information receiving unit 320 receives the spectrum sensing information transmitted from the wireless terminal. When spectrum sensing information is used, the detection limit of the existing TV whitespace database method can be exceeded. Hereinafter, the spectrum sensing information receiving unit 320 will be described with reference to FIG.

FIG. 4 is a diagram for comparing boundaries of a broadcast service protection area according to comparison of field strength values.

The table shown in FIG. 4 shows the broadcast service protection field strength value when using the standardized broadcast service protected field strength reference value, the broadcast service protected field strength reference value when applying the TV whitespace database operation method, and the spectrum sensing operation method The reference value is compared.

First, when using the TV whitespace database operation method, the wireless terminal based on the TV white space can operate the service at a point outside the range of at least 131 Km to 140 Km centered on the position of the DTV base station.

At this time, the TV white space database interference protection threshold includes the antenna height of the wireless terminal proposed by the FCC and the distance value required for the DTV driving frequency channel (same or adjacent channel).

However, in the case of the database system of TV whitespace, there is a limitation in terms of activation of TV white space service and improvement of efficiency of frequency utilization because the interference threshold is added to the standardized DTV protection domain field strength reference value and the separation distance is added.

Meanwhile, since the spectrum sensing technique can detect a field intensity value (19 dBuV) corresponding to the maximum -114 dBm value of the DTV receiving signal power detection threshold value of the FCC, it has a wider detection range than the conventional TV whitelist database operation method, Can be detected for a low DTV receive signal. Therefore, in the case of a wireless terminal based on TV whitespace capable of detecting -114 dBm (= 19 dBu), it can have a detection range extended by 175% of the electric field strength value of the conventional standardized broadcasting service, which is 41 dBu.

Accordingly, the frequency allocation system 300 of the wireless terminal according to the present invention receives the spectrum sensing information transmitted from the wireless terminal through the spectrum sensing information receiver 320 and combines the spectrum sensing scheme, It is possible to exceed the detection limit of the method. In addition, since the spectral sensing method utilizes the actually measured electric field strength values, it is advantageous in that the reliability is higher than that of the TV whitelist database method using the theoretical propagation propagation model.

Referring again to FIG. 3, the interference criterion setting unit 330 compares the interference reference value of the TV white space database with the interference reference value based on the spectrum sensing information to set an interference criterion. At this time, when the interference reference value based on the spectrum sensing information is smaller than the interference reference value of the TV white space database, the interference reference setting unit 330 sets the interference reference value of the TV white space database as the interference reference. The TV white space database interference protection reference value includes TV white space database information managed by the frequency management agency and emergency or public wireless communication information requiring protection in the service area.

In addition, the interference criterion setting unit 330 may convert the received power unit of the wireless terminal from dBm to dBuV. In order to calculate the boundary value of the interference protection area that can be acquired through the TV white space database technique and the spectrum sensing technique, it is necessary to uniformize the intensity in dBuV. One of the reasons for converting the received power reference value in dBm to the dBuV unit applied to the spectrum sensing technique is that the dBuV unit is generally accepted by the existing broadcasting company and the US FCC. Hereinafter, the process of converting the reception power unit of a TV-based space-based wireless terminal from dBm to dBuV will be described.

Equation (1) is for measuring the received power of a wireless terminal including a power density incident on a receiving antenna of a TV-based white space-based wireless terminal and an effective area capable of measuring an electric field intensity.

[Equation 1]

In this case, S denotes the power density incident on the reception antenna of the wireless terminal, and the unit uses a Watt / square meter. And, A _E means the effective area where the electric field intensity can be measured, and the unit is a square meter.

At this time, the power density S is calculated by the following equation (2), and the effective area A _E is calculated by the following equation (3). In Equation (2), E denotes a field strength value, and Volt / meter is used as a unit. And, R _FS means an impedance value affecting the propagation in free space, and corresponds to a value of about 377 Ω. In Equation (3), G _R denotes a gain value of the reception antenna.

&Quot; (2) "

&Quot; (3) "

Next, Equation (4) shows a correlation between dBm and dBuV that can be calculated by using Equation (3) in Equations (1) and (2).

&Quot; (4) "

Next, Equation (5) represents the K value defined by the conversion constant of dBuV and dBm, and the antenna is assumed to be 0 dBi at this time.

&Quot; (5) "

Using these equations, the wavelength values λ and K that can be calculated when considering three specific center frequency values in the TV white space band can be expressed as follows.

Referring again to FIG. 3, the frequency assigning unit 340 sets the radiation mask reference of the wireless terminal based on the set interference criterion. And allocates the frequency of TV whitespace available to the wireless terminal based on the set emission mask criteria.

At this time, the frequency allocator 340 may allocate the frequency of the TV whitespace to the wireless terminal prior to requesting the wireless communication service to be used for emergency or public use. In the case of broadcasting service, commercial wireless communication service, and wireless microphone service in addition to urgent or public wireless communication service, the frequency of the TV white space can be allocated first if necessary.

Meanwhile, the frequency allocation system 300 of the wireless terminal according to the present invention may further include a wireless terminal identification unit 350, a reception unit 360, and an update unit 370.

The wireless terminal identification unit 350 can receive the user information of the wireless terminal stored in the storage unit 310 and identify the wireless terminal for user ID authentication and registration of the wireless terminal. That is, the wireless terminal identification unit 350 can approve the service use of the wireless terminal by identifying the wireless terminal based on the wireless terminal user information. When the service use is approved, the service use permission message may be transmitted to the frequency allocation unit 340.

The receiving unit 360 may receive TV whitelist database information available to the wireless terminal from the frequency management organization and store the information in the storage unit 310. That is, the reception unit 360 receives the database information of the TV whitespace managed by the domestic frequency management organization. The frequency management organization includes the broadcasting communication committee and the National Radio Research Laboratory.

The updating unit 370 may periodically update the changed frequency specification information and the TV whitespaces database information in the frequency management agency. Since the frequency management organization periodically changes the technical standard information, it is necessary to periodically update the data in order to perform the service according to the changed technical standard. At this time, the interval of updating is in accordance with the technical standard proposed by the frequency management agency. In addition, the update unit 370 may update the frequency management agency's request or an urgent or public-purpose radio communication service to be protected in the area.

5 is a flowchart of a frequency allocation method of a wireless terminal according to an embodiment of the present invention.

First, a TV whitelist frequency allocation request (S510) of the wireless terminal is received. At this time, the wireless terminal transmits the identifier information and the spectrum sensing information to the wireless terminal frequency allocation system.

Next, the spectrum sensing information transmitted from the wireless terminal is received (S520). When spectrum sensing information is used, the detection limit of the existing TV whitespace database method can be exceeded. Since the contents related to the spectrum sensing information have been described with reference to FIG. 4, the description will be omitted.

Next, an interference reference is set by comparing the interference reference value of the TV white space database and the interference reference value based on the spectrum sensing information (S530). The interference criterion is set as the interference criterion value of the TV whitespace database when the interference criterion value based on the sensing information is smaller than the interference criterion value of the TV whitespace database. At this time, in setting the interference criterion, the reception power unit of the wireless terminal can be converted from dBm to dBuV.

In order to calculate the threshold value of the interference protection area that can be acquired through the TV white space database technology and the spectrum sensing technology, it is necessary to uniformize the electric field intensity (dBuV) unit, and the reception power unit of the TV white space based wireless terminal is changed from dBm to dBuV Since the conversion process is described with reference to FIG. 4, a detailed description thereof will be omitted.

Next, in step S540, a radiation mask reference of the wireless terminal is set based on the set interference criterion, and the TV whitelest frequency available in the wireless terminal is allocated based on the set radiation mask reference in step S550. At this time, the frequency allocating step may allocate the frequency of the TV whitespace to the wireless terminal prior to requesting the wireless communication service to be used for emergency or public use. In addition to emergency or public wireless communication services, in the case of broadcasting service, commercial wireless communication service, and wireless microphone service, the frequency of the TV white space can be allocated as necessary.

In addition, the wireless terminal may further include receiving information on available TV whitelist database from the frequency management agency. That is, it receives the database information of the TV whitespace managed by the domestic frequency management organization, and the frequency management organization includes the broadcasting communication committee and the National Radio Research Laboratory.

In addition, the frequency management organization may further include periodically updating the changed frequency specification information and the TV whitespaces database information. Since the frequency management organization periodically changes the technical standard information, it is necessary to periodically update the data in order to perform the service according to the changed technical standard. At this time, the interval of updating is in accordance with the technical standard proposed by the frequency management agency. In addition, updates may be made in the event of a request from a frequency management agency or an emergency or public wireless service to be protected in the area.

On the other hand, an embodiment of the present invention may also be realized in the form of a recording medium including instructions executable by a computer such as a program module executed by a computer. Computer readable media can be any available media that can be accessed by a computer and includes both volatile and nonvolatile media, removable and non-removable media. In addition, the computer-readable medium may include both computer storage media and communication media. Computer storage media includes both volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data. Communication media typically includes any information delivery media, including computer readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave, or other transport mechanism.

It will be understood by those skilled in the art that the foregoing description of the present invention is for illustrative purposes only and that those of ordinary skill in the art can readily understand that various changes and modifications may be made without departing from the spirit or essential characteristics of the present invention. will be. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. For example, each component described as a single entity may be distributed and implemented, and components described as being distributed may also be implemented in a combined form.

The scope of the present invention is defined by the appended claims rather than the detailed description and all changes or modifications derived from the meaning and scope of the claims and their equivalents are to be construed as being included within the scope of the present invention do.

300: Frequency allocation system of wireless terminal 310:
320: Spectrum sensing information receiver 330:
340: Frequency allocation unit 350:
360: Updating unit 370: Wireless terminal identification unit

Claims (11)

A frequency allocation system for a wireless terminal,
A storage unit for storing user information of the wireless terminal and TV whitelist database information available to the wireless terminal,
A spectrum sensing information receiver for receiving spectral sensing information transmitted from the wireless terminal,
An interference reference setting unit for setting an interference reference by comparing an interference reference value of the TV white space database and an interference reference value based on the spectrum sensing information;
And a frequency allocation unit for setting a radiation mask reference of the wireless terminal based on the set interference criterion and allocating a frequency of a TV whitespace available to the wireless terminal based on the radiation mask reference,
The interference criterion setting unit may include:
Wherein the interference reference value of the TV whitespace database is set as an interference reference when the interference reference value based on the spectrum sensing information is smaller than the interference reference value of the TV white space database. The method according to claim 1,
Wherein the interference criterion setting unit converts the reception power unit of the wireless terminal from dBm to dBuV. The method according to claim 1,
Further comprising a wireless terminal identification unit for receiving user information of the wireless terminal stored in the storage unit and identifying the wireless terminal through authentication and registration of the user ID of the wireless terminal. The method according to claim 1,
And a receiver for receiving TV whitelist database information available to the wireless terminal from a frequency management organization and storing the information in the storage unit. The method according to claim 1,
And an updating unit for periodically updating the changed frequency standard information and the TV whitelist database information in the frequency management organization. The method according to claim 1,
Wherein the frequency allocator allocates the frequency of the TV whitespace in preference to the wireless terminal when requesting a wireless communication service to be used for emergency or public use. A method of allocating a frequency of a wireless terminal using a frequency allocation system of a wireless terminal,
Receiving a TV white space frequency allocation request of the wireless terminal;
Receiving spectral sensing information transmitted from the wireless terminal,
Setting an interference criterion by comparing an interference reference value of the TV white space database and an interference reference value based on the spectrum sensing information,
Setting a radiation mask criterion of the wireless terminal based on the set interference criterion;
And allocating a TV whitelist frequency available to the wireless terminal based on the set emission mask criteria,
The step of setting the interference criterion comprises:
Wherein the interference reference value of the TV whitespaces database is set as an interference criterion when the interference reference value based on the spectrum sensing information is smaller than the interference reference value of the TV white space database. 8. The method of claim 7,
The step of setting the interference criterion comprises:
And converting the received power unit of the wireless terminal from dBm to dBuV. 8. The method of claim 7,
Further comprising the step of receiving from the frequency management agency TV whitelist database information available to the wireless terminal. 8. The method of claim 7,
And periodically updating the changed frequency specification information and the TV whitespaces database information in the frequency management organization. 8. The method of claim 7,
The step of allocating the TV white space frequency comprises:
And allocating the frequency of the TV whitespace to the wireless terminal when the wireless communication service to be used for emergency or public use is requested.

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