KR20080076262A - Method and system for allocating resource in a communication system - Google Patents

Abstract

A resource allocation method and system in a communication system are provided to provide a communication service to a user stably and improve a usage efficiency of resources. A BS(Base Station) receives search information including information about a frequency band that can be used by an MS of a sub-system from the MS(301). The BS allocates the available frequency band, namely, resources, to the MS(303) and receives CSI(Channel State Information), namely, energy measurement information of each frequency band, from the MS(305). The BS checks whether a main system wants to use the frequency band allocated to the MS(307). If the main system wants to use the frequency band, the BS checks whether a certain portion of the frequency band can be used(311). If the certain portion of the frequency band can be used, the BS allocates the certain portion of the frequency band to the MS(313).

Description

METHOD AND SYSTEM FOR ALLOCATING RESOURCE IN A COMMUNICATION SYSTEM}

1 is a view schematically showing the structure of a CR communication system according to an embodiment of the present invention;

2 illustrates an example of resource allocation in a CR communication system according to an embodiment of the present invention.

3 is a diagram illustrating an operation process of a secondary system BS in a CR communication system according to an embodiment of the present invention.

4 is a flowchart illustrating an operation of a secondary system MS in a CR communication system according to an exemplary embodiment of the present invention.

5 is a diagram schematically illustrating a transmitter structure of a sub system in a CR communication system according to an embodiment of the present invention.

The present invention relates to a communication system, and more particularly, to a method and system for allocating resources by selecting a frequency band in a Cognitive Radio (CR) communication system.

In the next generation communication system, active researches are being conducted to provide users with services having high quality of service (QoS: Quality of Service, hereinafter referred to as 'QoS'). In particular, in the current next generation communication system, a wireless local area network (LAN) system and a wireless metropolitan area network (MAN) system Researches are being actively conducted to support high-speed services in a form of guaranteeing mobility and QoS in a broadband wireless access (BWA) communication system.

The BWA communication system efficiently uses the limited resources because a plurality of cells constituting the communication system divide a limited resource, that is, a frequency resource, a code resource, a time slot resource, and the like. Should be used. In particular, the demand for wireless resources is increasing day by day due to the rapid development of wireless communication systems and the emergence of various services. However, due to the allocation of almost all frequency bands that are currently commercially available, there is a very shortage of frequency resources for new wireless platforms. Given the current frequency usage, few GHz bands, especially low frequency bands, have little room for use. In order to solve such a frequency shortage problem, a CR communication system based on the CR method has been proposed. The CR communication system detects a frequency band to which a frequency is allocated but is not actually used, and efficiently shares and uses the frequency band. This CR communication system is a communication system that can be used in conjunction with the next generation communication system currently being studied. A representative communication system of such a CR communication system is an IEEE 802.22 WRAN (Wireless Regional Area Networks) system. The IEEE 802.22 WRAN system adopts CR technology in a TV frequency band, and intends to use an unused TV band for data transmission and reception. will be.

However, in a CR communication system, even if a secondary system secures a resource, that is, a frequency band and uses it, if the primary system intends to use the frequency band used by the CR communication system, The secondary system must immediately empty the frequency band to the primary system. Here, the main system means a communication system having a right to use a legal frequency band. In addition, the sub-system measures the strength of the received signal in the frequency band selected by the sub-system itself to select and use a frequency band not used by the main system as described above.

That is, the secondary system measures the intensity of the received signal in the frequency band, eg spectrum, in order to detect a frequency band in which the frequency is assigned to the primary system but is not actually used. Then, the sub system detects that the main system is not used in the predetermined frequency band through the measured strength of the received signal, and selects and uses the detected frequency band. In this case, the signal received by the sub system may include not only a transmission / reception signal of the main system but also an interference signal, for example, a transmission / reception signal of another sub system. That is, it is determined that the other system uses a predetermined frequency band in which the signal strength is measured for use by the sub system.

In addition, when the sub system uses a frequency band not used by the main system as described above, the sub system may vary due to a variable situation between the sub system and the main system, that is, the frequency bands used by the two systems are variable. In order to provide services with QoS to users, it is necessary to stably allocate resources. In particular, the sub-system immediately emptyes the frequency band to the main system when the main system intends to use the frequency band that the sub-system is using while using resources not used by the main system, that is, the frequency band, Accordingly, there is a problem that the secondary system cannot provide a communication service stably to the user.

Accordingly, an object of the present invention is to provide a method and system for allocating resources in a communication system.

Another object of the present invention is to provide a resource allocation method and system for stably providing a communication service to a user in a radio-cognitive communication system.

A method of the present invention for achieving the above objects comprises a first system having a right to use a first frequency band and a second system not having a right to use the first frequency band. In the allocating method, the mobile terminal of the second system searches for a second frequency band usable in the first frequency band and transmits search information to a base station, and corresponds to the search information. And a fourth frequency band excluding the third frequency band from the second frequency band when the use of the first system is detected by the base station and the third frequency band of a predetermined portion of the second frequency band. It includes receiving a process.

Another method of the present invention for achieving the above objects is a communication system comprising a first system having a right to use a first frequency band, and a second system not having a right to use the first frequency band. In the resource allocation method, the base station of the second system receiving the search information of the second frequency band usable in the first frequency band from the mobile terminal, and the second frequency band corresponding to the search information; Allocating to the mobile terminal, and confirming the use of the first system with respect to a third frequency band of a predetermined portion of the second frequency band, a fourth frequency band excluding the third frequency band from the second frequency band It includes the process of assigning.

A system of the present invention for achieving the above objects comprises a first system having a right to use a first frequency band and a second system not having a right to use the first frequency band. In an allocation system, a search is performed for a second frequency band usable in the first frequency band to transmit search information to a base station, and the second frequency band is allocated from the base station according to the search information. And detecting a use of the first system for a third portion of a predetermined frequency band in a frequency band, and receiving a fourth frequency band other than the third frequency band from the second frequency band, and the first frequency. When receiving the search information of the second frequency band usable in the mobile station from the mobile terminal, the second frequency corresponding to the search information Assigning a plurality of bands to the mobile terminal and confirming the use of the first system for a third portion of the predetermined frequency band in the second frequency band, the fourth frequency other than the third frequency band in the second frequency band And the base station for allocating a frequency band.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that in the following description, only parts necessary for understanding the operation according to the present invention will be described, and descriptions of other parts will be omitted so as not to distract from the gist of the present invention.

The present invention proposes a resource allocation method and system in a communication system. Here, in the embodiment of the present invention to be described later, IEEE 802.16 communication system which is an Institute of Electrical and Electronics Engineers (IEEE) 802.22 communication system and a broadband wireless access (BWA) communication system. Orthogonal Frequency Division Multiplexing (OFDM) or Orthogonal Frequency Division Multiple Access (OFDMA) Although a Cognitive Radio (CR) communication system is described as an example, the resource allocation method and system proposed by the present invention can be applied to other communication systems.

In addition, the present invention provides the use of the predetermined frequency band when the first system having a right to use a predetermined resource, for example, the frequency band, that is, the primary system does not use the predetermined frequency band. In a communication system that allows a second system that does not have a right to a second system, that is, a secondary system to use the predetermined frequency band, a frequency band not used by the primary system, which is the first system, may be used. We propose a method and system for retrieving and allocating resources. In an embodiment of the present invention to be described later, a receiver of the secondary system, for example, a mobile terminal (MS), searches for a frequency band not used by the main system and searches for the frequency band. A method and system for allocating the resource of the found frequency band to the receiver by a transmitter, for example, a base station (BS), which provides a communication service to the receiver to use a frequency band. Suggest.

In the embodiment of the present invention to be described later, the right to use the predetermined frequency band described above, that is, when the main system having the use right does not use the predetermined frequency band, A communication system that allows a non-privileged sub-system to use the predetermined frequency band is called a CR communication system. In addition, in the following embodiment of the present invention, for convenience of description, a frequency band in which the main system, which is a first system, has a right to use in the CR communication system is referred to as a first frequency band, and the first frequency band In FIG. 2, a frequency band not actually used by the main system is referred to as a second frequency band. That is, the present invention proposes a method and system for the sub-system to search for the second frequency band and allocate resources of the searched second frequency band.

Here, as described above, the right to use the first frequency band has only a main system that is the first system, and after the sub-system that is the second system searches for the second frequency band, The allocation and use of resources is possible only when the first system does not use the second frequency band. In an embodiment of the present invention to be described later, the sub-system searches for a second frequency band that is not used by the main system. We propose a method and system for allocating them.

In this case, in the communication system according to the embodiment of the present invention, the main system is assigned to the sub system while the second frequency band which is not used by the main system among the first frequency band and the second frequency band is allocated to the sub system. If a frequency band of a predetermined portion of the second frequency band, that is, the third frequency band is to be used, the third frequency to be used by the main system among the second frequency bands without allocating the entire second frequency band to the main system. Only bands are allocated to the primary system after band comparison, and the usable fourth frequency band is allocated to the secondary system except for the third frequency band in the second frequency band. Then, a frequency band having a magnitude corresponding to the third frequency band in the second frequency band is searched for in a frequency band not used by the main system and allocated to the sub system.

That is, the present invention is intended to be used by a second system that does not have a right to use the second frequency band when a first system having a right to use the first frequency band and the second frequency band uses only the first frequency band. If the first system intends to use a third frequency band within the second frequency band, the second system allocates only a third frequency band, so that the second system transmits a third frequency band from the second frequency band. Allocates resources to continuously use the fourth frequency band except for In addition, the present invention searches for a frequency band of a size corresponding to the third frequency band, that is, a fifth frequency band, in another frequency band not used by the first system, and allocates the same to the upper second system. Next, a CR communication system according to an exemplary embodiment of the present invention will be described with reference to FIG. 1.

1 is a view schematically showing the structure of a CR communication system according to an embodiment of the present invention.

Referring to FIG. 1, a CR communication system includes cell 1 110, which is a primary system cell, and cell 2 150, which is a secondary system cell, and has a right to use a predetermined resource, that is, a frequency band, in cell 1 110. That is, when the main system and the main system does not use the predetermined frequency band in the cell 2 (150), the sub system does not have a right to use the predetermined frequency band but can use the predetermined frequency band. It includes a system. The primary system includes BS1 112, which is a primary BS, and MS1 114, which is a primary MS that receives communication service from the BS1 112, and the secondary system is a secondary BS. BS2 152, which is a secondary BS, and MS2 154, which is a secondary MS that receives communication service from the BS2 152.

BS1 112 of the main system provides the MS's current location information and channel state information (CSI: Channel State) from MS1 114 while providing communication service to MS1 114 through a predetermined frequency band as described above. Information, hereinafter referred to as 'CSI'). At this time, the MS2 154 of the secondary system measures the interference information according to its communication environment, for example, noise and interference conditions, so that the frequency band which is not occupied at the position where it is present, that is, the main system has a right to use it. In the predetermined frequency band having a frequency band BS1 (112) and MS1 (114) of the main system is selected that is not used. That is, the MS2 154 of the secondary system senses the spectrum of a signal received in a predetermined frequency band, that is, the first frequency band and the second frequency band, to which the main system has authority to use, so that the MS2 154 can use it. That is, the second frequency band is scanned.

Then, the MS2 154 transmits search information, that is, information on the second frequency band, which is an available frequency band, to the BS2 152, and the BS2 152 that has received the search information transmits the available frequency band. That is, the second frequency band not used by the main system is allocated to the MS2 154. In this case, the MS2 154 measures the channel state of the allocated second frequency band, for example, by measuring energy for each frequency band to confirm whether the main system is used for the allocated frequency band. That is, the MS2 154 checks whether the main system intends to use the frequency band allocated thereto. As a result of the check, when the main system wants to use a predetermined frequency band or a third frequency band in the frequency band allocated to the MS2 154, that is, the second frequency band, the second allocated to the MS2 154 After allocating the third frequency band that the main system intends to use in the frequency band to the main system, the MS2 154 is available in a size corresponding to the third frequency band in a frequency band not used by the main system. Search for the frequency band, that is, the fourth frequency band.

Next, the MS2 154 transmits search information, that is, information about a fourth frequency band, which is an available frequency band, to the BS2 152, and the BS2 152 that has received the search information transmits the available frequency band. That is, the fourth frequency band not used by the main system is allocated to the MS2 154. Here, when the main system wants to use the entire frequency band, that is, the second frequency band in the frequency band assigned to the MS2 154 by the main system, that is, the second frequency band, the MS2 154 determines the main system. The system detects a spectrum of a signal received in a predetermined frequency band, that is, a first frequency band and a second frequency band, to which the system has a right to use, and scans a frequency band usable by the system. Next, resource allocation in the CR communication system according to an embodiment of the present invention will be described in detail with reference to FIG. 2.

2 is a diagram illustrating an example of resource allocation in a CR communication system according to an embodiment of the present invention.

Referring to FIG. 2, resource allocation in the CR communication system uses a first frequency band 202 and a fifth frequency band 210 in a predetermined frequency band 200 in which a main system has a use authority. When not using the frequency bands, i.e., the second frequency band 204, the third frequency band 206, the fourth frequency band 208, and the sixth frequency band 212, the MS of the secondary system is determined to be the primary system. This searches for unused frequency bands, that is, frequency bands that can be used by them. As a result of the search, the MS provides search information indicating that the available frequency bands are the second frequency band 204, the third frequency band 206, the fourth frequency band 208, and the sixth frequency band 212. The BS of the secondary system transmits the second frequency band 204 and the third frequency band 206 to the MS of the secondary system in a frequency band available to the secondary system.

In this case, while the MS is using the frequency band assigned to the MS, the BS of the main system or the MS of the main system may use the frequency band without notice. Then, the MS of the secondary system collects the state of the channel through resource search at a predetermined frame time and transmits the state of the channel to the BS of the secondary system using the collected information. In this case, in the communication system according to the embodiment of the present invention, since the frequency band is occupied by the main system, after allocating the frequency band to the main system, a communication service is not provided using another resource, that is, another frequency band. The secondary system allocates a portion of the frequency being used by the secondary system to the primary system by comparing the frequency band currently being used with the magnitude of the frequency band which is interfering with the primary system.

That is, in the communication system according to the embodiment of the present invention, even if the secondary system allocates resources to the primary system, the secondary system allocates resources after the band comparison of the size of the resources that are infringed by the primary system, that is, the frequency band that the primary system intends to use. Assign. As a result, the secondary system can continue to use resources and continue to use some frequency bands for seamless data transmission. As described above, the communication system according to the embodiment of the present invention can support various resources in the CR communication system by comparing the bandwidth of the resource infringed by the primary system with the bandwidth size of the resource invaded by the secondary system and allocating only as necessary. At this time, after the secondary system allocates resources to the primary system, the secondary system checks the usefulness of other frequency bands through frequency band search.

In more detail, when the MS is in the second frequency band 204 and the third frequency band 206 in the available frequency band of the sub-system, the MS or other sub-system is currently present during the search period of the predetermined frame time. Search for the use of the second frequency band 204 and the third frequency band 206 in use, for example, by measuring the channel state of the second frequency band 204 and the third frequency band 206 to search for use. When the main system wants to use the third frequency band 206 as a result of the search, the MS allocates the third frequency band 206 allocated to the main system to the main system for use by the main system. In the unused frequency bands, that is, the fourth frequency band 208 and the sixth frequency band 212, a usable frequency band having a size corresponding to the third frequency band 206 is searched for. As a result of the search, the MS transmits search information indicating that the sixth frequency band 212 is an available frequency band to the BS of the secondary system. The BS then allocates the sixth frequency band 212 to the MS.

Here, when the MS transmits search information including information on the frequency band not used by the main system, that is, the fourth frequency band 208 and the sixth frequency band 212, to the BS, the BS transmits the fourth frequency. A sixth frequency band 212 having a size corresponding to the third frequency band 206 may be allocated among the band 208 and the sixth frequency band 212. In other words, the MS transmits all of the available frequency bands, that is, the information about the fourth frequency band 208 and the sixth frequency band 212, to the BS by including the information in the search information or the third frequency band ( The information on the usable frequency band, ie, the sixth frequency band 212, of the size corresponding to 206 is included in the search information and transmitted to the BS. Next, the BS operation of the secondary system in the CR communication system according to the embodiment of the present invention will be described in detail with reference to FIG. 3.

3 is a diagram illustrating an operation process of a secondary system BS in a CR communication system according to an embodiment of the present invention.

Referring to FIG. 3, in step 301, the BS receives search information from the MS, including information on a frequency band that the secondary system can use, that is, the MS of the secondary system can use as described above. Then, in step 303, the BS checks the search information, allocates a usable frequency band, that is, a resource, to the MS, and then proceeds to step 305. In step 305, the BS receives from the MS CSI, for example, energy measurement information for each frequency band, to confirm whether the main system is used for the frequency band allocated to the MS.

Next, in step 307, the BS determines whether the frequency band allocated to the current MS is still available through the measurement information for each frequency band received from the MS, that is, whether the main system intends to use the frequency band allocated to the MS. . As a result of the check in step 307, if the allocated frequency band is not used by the main system, the allocated frequency band is available. In step 309, the allocated frequency band is allocated to the MS. On the other hand, as a result of the check in step 307, if the main system wants to use the allocated frequency band, the process proceeds to step 311. In step 311, the entire frequency band to which the main system intends to use the current frequency band is used. Check whether or not you want to use, that is, whether a predetermined portion of the frequency band is available in the currently allocated frequency band.

As a result of the checking in step 311, if the use of the predetermined frequency band in the currently allocated frequency band is available to proceed to step 313, and in step 313 allocates the available frequency band of the predetermined part to the MS. Then, in step 315, search information of another frequency band available from the MS is received. In this case, the search information includes frequency band information having a size corresponding to a frequency band excluding a frequency band of a predetermined portion from a currently allocated frequency band.

On the other hand, if it is determined in step 311 that the use of the frequency band of a predetermined portion in the currently allocated frequency band, that is, if the main system uses the entire frequency band currently assigned, proceed to step 315, step 315 Receives search information of other frequency bands available from the MS. In this case, the search information includes frequency band information having a size as large as the currently allocated frequency band. In operation 303, the available frequency band is allocated to the MS. Hereinafter, an MS operation of a sub system in a CR communication system according to an exemplary embodiment of the present invention will be described with reference to FIG. 4.

4 is a diagram illustrating an operation process of a sub system MS in a CR communication system according to an exemplary embodiment of the present invention.

Referring to FIG. 4, in step 401, the MS detects a spectrum as described above to search for a frequency band not used by the main system, that is, a frequency band that is available for itself, and then, in step 403, the MS detects the spectrum. The search information indicated is transmitted to the BS. Then, in step 405, the MS receives the available frequency band corresponding to the search information, that is, the resource is allocated, and then, in step 407, the MS measures the channel state to check whether the main system is used for the frequency band allocated to the MS. For example, the energy of each frequency band is measured.

Next, in step 411, the MS checks whether the frequency band allocated to itself is continuously available through the measured frequency band energy, that is, whether the main system intends to use the frequency band allocated to the MS. As a result of the checking in step 411, if the main system does not use the frequency band allocated to itself, the process proceeds to step 413 and the MS receives the available frequency band allocated to itself from the BS.

On the other hand, as a result of the check in step 411, if the main system wants to use the allocated frequency band, the process proceeds to step 415, and in step 415 the entire frequency band to which the frequency band intended to be used by the main system is currently allocated. Check whether it is to be used, that is, whether a predetermined portion of the frequency band is available in the currently allocated frequency band. As a result of the checking in step 415, if the use of the predetermined frequency band in the currently allocated frequency band is available, the process proceeds to step 417, and in step 417, the frequency band of the available predetermined part is allocated. Then, the process proceeds to step 401 to search for available frequency bands in other frequency bands not used by the main system. In this case, the MS searches for an available frequency band having a size equal to that of the frequency band excluding a frequency band of a predetermined portion from the currently allocated frequency band.

If it is determined in step 415 that the use of a predetermined frequency band is not available in the currently allocated frequency band, that is, if the main system uses the entire currently allocated frequency band, the process proceeds to step 401, and in step 401 Search for available frequency bands in other frequency bands not used by the system. At this time, the MS searches for an available frequency band having a magnitude equal to that of the currently allocated frequency band.

5 is a diagram schematically illustrating a transmitter structure of a sub system in a CR communication system according to an exemplary embodiment of the present invention. 5 is a diagram illustrating a transmitter structure of a secondary system BS or MS in a CR communication system.

Referring to FIG. 5, the transmitter may include a modulator 510 for modulating data to be transmitted and an output data of the modulator 510 as an inverse fast Fourier transform (IFFT). IFFT input unit 520 for packing according to the size, IFFT unit 530 for IFFT the data input from the IFFT input unit 520, and output data of the IFFT unit 530 A filter unit 540 for filtering the digital-to-analog converter (DAC) for converting the digital data output from the filter unit 540 into analog data. 550, an RF unit 560 for processing radio frequency (hereinafter referred to as RF) output data of the DAC 550, and a current sub system. Comparator for comparing the available frequency band with the available frequency band 570.

When the transmitter transmits data using a frequency band usable in a frequency band not used by the main system, the IFFT unit 530 transmits data by performing IFFT through a full IFFT module (Full N IFFT). . In this case, when the main system wants to use a predetermined portion of the frequency band currently being used by the transmitter, the frequency band to be used is allocated to the main system, so that the comparator 570 is currently using the frequency band currently being used and the main system. After comparing the available frequency bands assigned to the system, the comparison result is transmitted to the IFFT input unit 520. Then, the IFFT input unit 520 packs the input data of the IFFT unit 530 according to the comparison result, that is, performs the IFFT through the sub IFFT module (1 / N IFFT) instead of the previous IFFT module.

That is, since the transmitter decreases the frequency band because the main system intends to use a predetermined portion of the frequency band in the currently used frequency band, the transmitter corresponds to an available frequency band except for the predetermined frequency band of the main system. IFFT is performed by reducing the IFFT size. Accordingly, when the main system wants to use a frequency band of a predetermined portion in the frequency band currently being used, the transmitter allocates only a frequency band of the predetermined portion to the main system and excludes the frequency band of the predetermined portion. Data is continuously transmitted over the remaining frequency bands.

Meanwhile, in the detailed description of the present invention, specific embodiments have been described, but various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined not only by the scope of the following claims, but also by the equivalents of the claims.

According to the present invention as described above, when the main system uses a predetermined portion of the frequency band in the frequency band being used by the sub-system in the radio-cognitive communication system, only the predetermined frequency band is allocated to the main system, thereby continuing to allocate data. By transmitting and receiving, a communication service can be stably provided to a user, and resource efficiency can be improved.

Claims (26)

A resource allocation method in a communication system comprising a first system having a usage right for a first frequency band and a second system having no use right for the first frequency band, Transmitting, by the mobile terminal of the second system, a search for a second frequency band usable in the first frequency band and transmitting search information to a base station; Allocating the second frequency band from the base station in response to the search information; If the use of the first system for the third frequency band of the predetermined portion in the second frequency band, resources comprising the step of assigning a fourth frequency band except the third frequency band in the second frequency band Assignment method. The method of claim 1, The step of assigning the fourth frequency band may include searching for an available fifth frequency band having a size corresponding to the third frequency band in the first frequency band, transmitting search information to the base station, and transmitting the search information. And correspondingly, allocating the fifth frequency band from the base station. The method of claim 1, The step of assigning the fourth frequency band may include: searching for a fifth frequency band usable in the first frequency band and transmitting search information to the base station, and corresponding to the transmitted search information in the fifth frequency band; And allocating a sixth frequency band of a size corresponding to a third frequency band from the base station. The method of claim 1, The searching of the second frequency band usable in the first frequency band and transmitting search information to the base station may include detecting the spectrum in the first frequency band to search for the second frequency band, and searching for the second frequency band. And transmitting search information including the information of. The method of claim 1, And detecting the use of the first system for the third frequency band by measuring a channel state of the second frequency band. The method of claim 1, And detecting the use of the first system with respect to the third frequency band by measuring the energy for each of the second frequency bands. The method of claim 1, After the mobile terminal converts an Inverse Fast Fourier Transform (IFFT) size corresponding to the difference between the second frequency band and the fourth frequency band, data is transmitted to the base station through the fourth frequency band. Resource allocation method further comprising the step of transmitting. A resource allocation method in a communication system comprising a first system having a usage right for a first frequency band and a second system having no use right for the first frequency band, Receiving, by a base station of the second system, search information of a second frequency band usable in the first frequency band from a mobile terminal; Allocating the second frequency band to the mobile terminal in response to the search information; A resource for allocating a fourth frequency band excluding the third frequency band from the second frequency band when the use of the first system is confirmed for a third frequency band of a predetermined portion of the second frequency band; Assignment method. The method of claim 8, The assigning of the fourth frequency band may include receiving, from the mobile terminal, search information of an available fifth frequency band having a size corresponding to the third frequency band in the first frequency band, and receiving the search information. And correspondingly allocating the fifth frequency band to the mobile terminal. The method of claim 8, The allocating of the fourth frequency band may include receiving, from the mobile terminal, search information of a fifth frequency band usable in the first frequency band and corresponding to the received search information in the fifth frequency band. And allocating a sixth frequency band having a size corresponding to three frequency bands to the mobile terminal. The method of claim 8, Receiving search information of the second frequency band usable in the first frequency band from the mobile terminal, the search information including the information of the second frequency band retrieved through the spectrum detection in the first frequency band received Resource allocation method, characterized in that. The method of claim 8, Detecting the use of the first system for the third frequency band, resource allocation, characterized in that for receiving and confirming the measurement information generated by the measurement of the channel state of the second frequency band from the mobile terminal Way. The method of claim 8, And confirming the use of the first system for the third frequency band comprises receiving and confirming measurement information generated by the energy measurement for each second frequency band from the mobile terminal. The method of claim 8, The base station converts an Inverse Fast Fourier Transform (IFFT) size according to the difference between the second frequency band and the fourth frequency band, and then transmits data to the mobile terminal through the fourth frequency band. Resource allocation method further comprising the step of transmitting. A resource allocation system in a communication system comprising a first system having a usage right for a first frequency band and a second system having no use right for the first frequency band, Search for a second frequency band usable in the first frequency band, and transmit search information to a base station; receive the second frequency band from the base station in correspondence with the search information; Detecting a use of the first system for a third frequency band, the mobile terminal being allocated a fourth frequency band excluding the third frequency band from the second frequency band; When receiving the search information of the second frequency band usable in the first frequency band from the mobile terminal, the second frequency band is allocated to the mobile terminal in correspondence with the search information, and a predetermined portion of the second frequency band is allocated. And identifying the use of the first system for a third frequency band, the base station for allocating a fourth frequency band excluding the third frequency band from the second frequency band. The method of claim 15, And the base station and the mobile terminal are included in the second system. The method of claim 15, After receiving the fourth frequency band, the mobile terminal searches for an available fifth frequency band having a size corresponding to the third frequency band in the first frequency band, and transmits search information to the base station. And the fifth frequency band is allocated from the base station according to the transmitted search information. The method of claim 15, After receiving the fourth frequency band, the mobile terminal searches for a fifth frequency band usable in the first frequency band and transmits search information to the base station, and corresponds to the transmitted search information. And a sixth frequency band having a size corresponding to the third frequency band in a frequency band from the base station. The method of claim 15, The mobile terminal detects the spectrum in the first frequency band, searches for the second frequency band, and transmits the search information including the information of the second frequency band to the base station. The method of claim 15, And the mobile terminal measures the channel state of the second frequency band to sense the use of the first system for the third frequency band. The method of claim 15, The mobile terminal measures the energy of the second frequency band and senses the use of the first system for the third frequency band. The method of claim 15, The base station, after allocating the fourth frequency band, receives search information of the fifth available frequency band of a size corresponding to the third frequency band from the first frequency band, and receives the received information from the mobile terminal. And allocating the fifth frequency band to the mobile terminal in response to search information. The method of claim 15, The base station, after allocating the fourth frequency band, receives search information of a fifth frequency band usable in the first frequency band from the mobile terminal, and corresponds to the received search information to the fifth frequency band. And allocating a sixth frequency band having a size corresponding to the third frequency band to the mobile terminal. The method of claim 15, The base station, the resource allocation system, characterized in that for receiving the search information including the information of the second frequency band retrieved through the spectrum detection in the first frequency band. The method of claim 15, And the base station receives the measurement information generated by the energy measurement for each second frequency band from the mobile terminal and confirms the use of the first system for the third frequency band. The method of claim 15, The base station and the mobile terminal converts an Inverse Fast Fourier Transform (IFFT) size according to a difference between the second frequency band and the fourth frequency band, and then transmits data through the fourth frequency band. Resource allocation system, characterized in that for transmitting and receiving.

Images