KR20090098272A - Apparatus and method for using guard band as data subchannel in communication system based frequency overlay - Google Patents

Abstract

A method and an apparatus for using protection band as data subcarrier for transmitting the signal in a communication system are provided to increase frequency efficiency by utilizing protection band as data subcarrier. A frequency synchronization is obtained through preamble about a first FA(300). The information about a first addition radio resource is received(302). By using the whole radio resource including the first addition radio resource, the first network entry procedure is performed(304). Among the first network entry process execution, the frequency overlay decided operation is negotiated(306). The information about the second addition radio resource is received(308). By using the whole radio resource including the second addition radio resource, the secondary network entry procedure is performed(310).

Description

A method and apparatus for using a guard band as a data subcarrier in a communication system supporting frequency overlay {APPARATUS AND METHOD FOR USING GUARD BAND AS DATA SUBCHANNEL IN COMMUNICATION SYSTEM BASED FREQUENCY OVERLAY}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a broadband wireless communication system supporting frequency overlay, and more particularly, to an apparatus and method for using a guard band as a data subcarrier, which is not used for interference mitigation between FAs. It is about.

In general, a guard band is defined in a wireless communication system to prevent interference between channels (or frequency assignments), for example, in an Orthogonal Frequency Division Multiplexing (OFDM) based system. The purpose of the guard band is to make the spectrum of the OFDM signal have a 'brick wall' shape. When the Fourier transform is performed by transmitting '0' to left and right subcarriers (no signal), the signal acts as an interference to adjacent frequency bands. To make the ingredients smaller.

1 illustrates a frequency domain in an OFDM based communication system according to the prior art.

Referring to FIG. 1, an OFDM-based communication system performs communication using FAs (that is, 5 MHz, 10 MHz, and 20 MHz bandwidths) which are allocated channel frequency units, and a plurality of FAs 101 and 111 are allocated. Here, each of the FAs 101 and 111 is composed of a plurality of subcarriers 102 and 112, the center frequency of the FA 101 is f _c1 (100), and the center frequency of the FA 111 is f _c2 (110). to be. In addition, the guard band 130 is configured to prevent interference between the FA 101 and the FA 111.

On the other hand, communication systems are evolving by changing standards and providing high-speed data or solving implementation issues. In this evolution, various systems can coexist in the same region, depending on the degree of compatibility with existing systems. For example, a new system using an 20 MHz FA that has evolved from an existing system using a 10 MHz FA may be installed in an area in which an OFDM-based wireless communication system is installed. Existing systems only support terminals with a single bandwidth in one FA. That is, the existing 10MHz system has a structure that can support only 10MHz terminal. Therefore, in order to support a new terminal having a larger bandwidth, such as a terminal using a 20 MHz FA, a new FA having a 20 MHz bandwidth is required.

Accordingly, research on frequency overlay technology using existing multi-FAs without newly assigning frequency bands has been on the rise. The frequency overlay technology is a technology for servicing a new required FA by using several existing FAs simultaneously. For example, when two 10MHz FAs are used, 20MHz FAs can be used without additional frequency allocation by frequency overlaying two 10MHz FAs. In this case, a guard band defined to prevent interference between two 10 MHz FAs may increase bandwidth efficiency if used as a data region during frequency overlay.

In this case, as shown in FIG. 1, the interval between the center frequencies f _c1 and f _c2 (100,110) of two adjacent FAs 101 and 111 may not be an integer multiple of the subcarrier spacing. For example, in the IEEE 802.16e standard, when the FA is 10 MHz, the sampling frequency is 11.2 MHz, and the subcarrier spacing is 10.9375 kHz. When the spacing between two adjacent FAs is 10 MHz, this does not become an integer multiple of the subcarrier spacing, thus causing a mismatch between rasters between adjacent FAs. In such a case, when the subcarriers in the guard band 130 located between the two FAs are used, the guard band 130 is necessary because interference effects are caused to each other. Accordingly, since the guard band is not used in the frequency overlay, the frequency efficiency is lowered.

An object of the present invention is to provide an apparatus and method for using a guard band located between two adjacent FAs as a data subcarrier in a communication system supporting frequency overlay.

According to a first aspect of the present invention for achieving the above object, in a method of using a guard band as a subcarrier for signal transmission in a communication system supporting a frequency overlay, the intermediate frequency between FA (Frequency Assignment) is the subcarrier spacing And setting the number of subcarriers usable in the guard band between FAs, and allocating subcarriers for data transmission, including the subcarriers usable in the guard band. do.

According to a second aspect of the present invention for achieving the above object, in a terminal operating method using a guard band as a subcarrier for signal transmission in a communication system supporting a frequency overlay, the frequency for the first FA through a preamble Acquiring synchronization, acquiring information on a first additional radio resource after acquiring the frequency synchronization, and performing a first network entry procedure using all radio resources including the first additional radio resource Characterized in that it comprises a.

According to a third aspect of the present invention for achieving the above object, in a method for operating a base station using a guard band as a subcarrier for signal transmission in a communication system supporting a frequency overlay, after the first preamble transmission, Transmitting a first additional radio resource for the FA to a corresponding terminal, performing a first network entry procedure with the corresponding terminal, negotiating whether or not a frequency overlay operation is performed during a first network entry procedure; When operating in the frequency overlay mode, transmitting a second additional radio resource for a second FA to the corresponding terminal after transmitting a second preamble, and performing a second network entry procedure with the corresponding terminal. Characterized in that.

According to a fourth aspect of the present invention for achieving the above object, in an apparatus using a guard band as a subcarrier for signal transmission in a communication system supporting frequency overlay, the intermediate frequency between FA (Frequency Assignment) is the subcarrier spacing A control unit configured to set an integer multiple of the subcarrier, a guard band resource allocation unit for calculating the number of subcarriers usable in the guard band between the FAs, and a MAC processor for allocating subcarriers for data transmission, including a subcarrier usable in the guard band. It is characterized by including.

According to a fifth aspect of the present invention for achieving the above object, in a terminal using a guard band as a subcarrier for signal transmission in a communication system supporting frequency overlay, frequency synchronization is performed for the first FA through a preamble. And a MAC processing unit for receiving information on a first additional radio resource after acquiring the frequency synchronization, and a controller for performing a first network entry procedure using all radio resources including the first additional radio resource. It is characterized by.

According to a sixth aspect of the present invention for achieving the above object, in a base station using a guard band as a subcarrier for signal transmission in a communication system supporting a frequency overlay, after the first preamble transmission, A first MAC processor for transmitting a first additional radio resource to a corresponding terminal, a process of performing a first network entry procedure with the corresponding terminal, a controller negotiating whether or not a frequency overlay operation is performed during a first network entry procedure; When operating in the frequency overlay mode, it characterized in that it comprises a second MAC processing unit for transmitting the second additional radio resources for the second FA to the corresponding terminal after transmitting the second preamble.

As described above, the present invention uses a guard band located between two FAs as a data subcarrier for data transmission by making the interval of the center frequency between FAs an integer multiple of the subcarrier spacing in a communication system supporting frequency overlay. There is an advantage that can increase the efficiency.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In describing the present invention, when it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted. Terms to be described later are terms defined in consideration of functions in the present invention, and may be changed according to intentions or customs of users or operators. Therefore, the definition should be made based on the contents throughout the specification.

Hereinafter, the present invention provides a guard band as a data subcarrier by allowing each center frequency interval of adjacent FAs to be an integer multiple of subcarrier spacing in a broadband wireless communication system supporting frequency overlay. The apparatus and method to be used will be described. By assigning FAs so that each center frequency interval is an integer multiple of the subcarrier interval, the guard band between the two FAs is made an integer multiple of the subcarrier interval.

Here, the FA is fixed so that the center frequency spacing of each FA is an integer multiple of the subcarrier spacing, or the center frequency of a fluidly adjacent FA is calculated so that the center frequency spacing of the FA adjacent to the center frequency of any reference FA is an integer multiple of the subcarrier spacing. It can also be applied. In the present invention, it is assumed that each center frequency interval of the FA is fixed to be an integer multiple of the subcarrier interval.

2 illustrates an example of using an inter-FA guard band according to the present invention as a data subcarrier.

Referring to FIG. 2, the UE supporting the frequency overlay receives a service simultaneously through two FAs f _c1 200 and f _c2 210. That is, the first FA, which is the center frequency (f _c1 ) 200, and the second FA, which is the center frequency (f _c2 ) 210, each include a plurality of subcarriers 230 and 250, and the terminal includes one FA. Alternatively, the service is provided using a plurality of FAs. For example, the UE serviced through the 10 MHz FA may be serviced with the 20 MHz FA by adding another available 10 MHz FA (220).

In this case, when the interval between the center frequencies between adjacent FAs is an integer multiple of the subcarrier spacing, the subcarriers 240 in the guard band can maintain orthogonality with each other, and thus can be used as data subcarriers.

At this time, if the interval of the center frequency between adjacent FAs is an integer multiple of the subcarrier spacing, the subcarriers 240 of each FA can maintain orthogonality with each other, so that even if a subcarrier in a guard band is used, no interference occurs. The subcarriers in the band can be used as data subcarriers.

3 is a flowchart illustrating an operation of a terminal for using a guard band as a data subcarrier in a broadband wireless communication system supporting frequency overlay according to an embodiment of the present invention.

For convenience of description, it is assumed that the FA size of the base station is determined based on 5 MHz (using 512 FFT), and the frequency overlay may be supported in units of 10 MHz and 20 MHz, for example, in addition to 5 MHz. Meanwhile, in a system that supports frequency overlay, whether to transmit a preamble for initial synchronization and a control channel (eg, MAP information and frame control header (FCH)) for transmitting broadcast information is limited to a specific FA as necessary or It can be transmitted from multiple FAs. When the preamble and the control channel are transmitted in multiple FAs, the UE can perform an initial access procedure in any FA, thereby reducing the processing time according to the initial access procedure. In the following description, it is assumed that the preamble and the control channel are transmitted in multiple FAs.

Referring to FIG. 3, the terminal performs scanning on all possible frequency positions within a specific range in step 300 to obtain frequency synchronization for the first FA. In this case, the terminal may detect the center frequency of the first FA through frequency synchronization.

Scanning is performed for all frequency positions, which may consume excessive time during initial synchronization acquisition. Therefore, in the current IEEE 802.16e system, the position of the center frequency in DL and UL is limited to a position that is necessarily an integer multiple of 250 kHz. In this case, the terminal may perform the scanning process in units of 250 kHz within a specific range, thereby reducing the burden on initial frequency synchronization acquisition.

On the other hand, the length of the cyclic prefix (CP) of the preamble used as the synchronization channel may vary according to the decision of the base station. In this case, the UE may consider not only the center frequency and the channel bandwidth but also a combination of the lengths of the CPs. Alternatively, the base station may fix the CP length to reduce the burden on the initial synchronization acquisition process of the terminal. And it is assumed that the terminal attempting initial access to the system knows in advance the number of data subcarriers N _Base used in the preamble.

The position of the center frequency corresponds to an integer multiple of the subcarrier spacing, where the subcarrier spacing is considered to be 10.9375 kHz when the sampling frequency is 11.2 MHz. The narrower the interval for the position of the center frequency, the greater the number of cases that the terminal needs to scan during the initial frequency acquisition process. Conversely, the wider the interval, the greater the degree of freedom for the service provider to adjust the position of the center frequency within its assigned band. It will fall, so consider these two factors and choose the appropriate value. In this case, it is assumed that the position of the center frequency corresponds to 16 times the subcarrier spacing and 175 kHz.

Figure 4 shows a detailed flowchart for obtaining information about the center frequency of the base station and the channel bandwidth being used.

Referring to FIG. 4, the terminal attempting initial access performs an initial frequency acquisition process based on the 512 FFT size corresponding to the minimum channel bandwidth of the system in step 400. In step 402, a variable n = 0 for scanning at a subcarrier interval is set.

Thereafter, the terminal proceeds to step 400 when the FFT size (N _FFT ) is greater than the maximum FFT size (FFT_MAX) in step 404, and proceeds to step 406 when the FFT size (N _FFT ) is set to F _c = n * 175KHz. F _c is the center frequency of the preamble to be searched and n is a variable for scanning the subcarrier spacing.

Then, the UE proceeds to step 410 when F _c is greater than F _HI in step 408 to set the FFT size N _FFT = (N _FFT ) * 2, and performs steps 402 to 406 according to the changed NFFT size do.

On the other hand, if F _c is less than or equal to F _HI , the terminal proceeds to step 412 and searches for a preamble for F _c .

Thereafter, if the preamble is detected in step 414, the terminal terminates the synchronization procedure. If the preamble is not detected, the terminal sets n = n + 1 in step 416 and proceeds to step 406.

In summary, it is assumed that the UE knows the F _LO and F _HI , the allowable position information of the center frequency, and attempts the preamble search process from a position corresponding to an integer multiple of 175 kHz (which may vary depending on the implementation) that is not smaller than F _LO . Done. If the preamble is not found within the defined range (F _LO ~ F _HI ), the above process is repeated by doubling the FFT size. If the preamble is successfully found within the given range, the terminal terminates the initial frequency synchronization acquisition process and attempts to enter the initial network through the FA serving the corresponding frequency band.

In step 302, the terminal acquires broadcast information on the number of subcarriers n ₁ and n ₂ usable in the guard band.

After acquiring the initial frequency synchronization through the preamble search, the UE determines the number of subcarriers used as data subcarriers in the data area through broadcast channels (eg, MAP information, FCH, BCH). Since the terminal that should initially receive the broadcast channel may still not know the number of data subcarriers, the broadcast channel uses the data _base carrier of N _Base like the preamble. Referring to the frame structure of FIG. 5, the preamble 500 and the broadcast channel 502 use N _Base 508 data subcarriers. The terminal receiving the broadcast channel, in addition to the N _Base 508 subcarriers in the data area, determines the number of subcarriers 504 used as data subcarriers within the guard band. Accordingly, data transmission may be performed using N _total (510) subcarriers for the data burst region 506 of the frame.

In general, the size of the guard band required for each FA may vary depending on the presence of other systems in adjacent frequency bands, the out-of-band emission regulations determined by the system, and the transmit / receive filter design requirements. The number of available subcarriers may vary. In this case, the broadcast channel may directly inform the number of subcarriers 504 to be additionally used in the guard band, the value of n1 and n2, or the size of n1 (or n2) together with the sum of n1 and n2. Do. In addition, if n1 and n2 have the same size, it is possible to notify only n values with n = n1 = n2. In another embodiment, n = n1, n2 = 0, or n = n2, n1 = 0. In this case, the base station may be applied in such a manner as to inform the number n of the number of subcarriers to be used in the guard band and information indicating which guard band the subcarrier is to be used in. In this case, the information may have three pieces of information, 'left', 'right' or 'both'. If the information is 'left' or 'right', the number of additionally used subcarriers is n, while in case of 'both', the number of additionally used subcarriers is 2n.

Meanwhile, as shown in FIG. 6, when the subchannelization scheme to be used in the data area is configured by a specific resource block unit, the sum of n ₁ and n ₂ is configured by the size unit of the resource block. More efficient in terms of subchannel configuration. For example, when the size of the resource block is 18 subcarriers, n ₁ + n ₂ = 18 * n, and the broadcast channel only needs to transmit a value for n. In this case, the overhead can be reduced compared to the method of directly indicating both sizes of n ₁ and n ₂ .

The service provider can adjust the values of n ₁ and n ₂ appropriately in consideration of its allocated bandwidth, frequency spacing between adjacent providers, and spectral mask requirements.

In step 304, the terminal performs a first network entry procedure with the base station for the first FA.

After determining the total subcarriers N _Total available through the broadcast channel, the terminal can receive downlink control information and data transmitted from the corresponding first FA. Thereafter, the terminal performs an initial network entry process as in the existing IEEE 802.16e system. In addition, the UE, which is to be serviced in the frequency overlay mode, transmits and receives additional information necessary for the overlay operation through the capability negotiation process. The base station informs the information on the neighboring FA that can be supported for the terminal to operate as the frequency overlay, and the terminal operates in the frequency overlay mode after a brief network entry process if necessary for the neighboring FA through the corresponding information.

Thereafter, the terminal checks whether the frequency overlay operation is performed in step 306, and proceeds to step 308 when the frequency overlay operation is performed to obtain usable subcarrier information in the guard band for the second FA, and in step 310, the second FA for the second FA. Perform network entry procedure.

Here, if necessary during the frequency overlay operation, the base station may operate by designating a specific FA as a primary FA among the FAs allocated as the frequency overlay. The primary FA corresponds to an FA in which connection management messages transmitted and received between the base station and the terminal are transmitted, and in this case, the terminal can reduce the burden of unnecessarily receiving all of the plurality of FAs to receive the management message unnecessarily.

In addition, the traffic burst transmitted to the user terminal in the frequency overlay mode may be transmitted limited to a specific FA or may be transmitted overlayed in a plurality of FAs. The UE receives the MAP and data burst by performing subchannel configuration according to the number of subcarriers used as data subcarriers in each FA.

Thereafter, the terminal terminates the guard band use procedure of the present invention.

7 is a flowchart illustrating an operation of a base station for using a guard band as a data subcarrier in a communication system supporting frequency overlay according to an embodiment of the present invention.

Referring to FIG. 7, in step 700, the base station transmits a preamble for synchronous detection, and in step 702, transmits information on the available data subcarriers in the guard band to the terminal, in step 704. A first network entry procedure is performed with a corresponding terminal using a total subcarrier including a subcarrier.

In step 706, the base station determines whether the frequency overlay operation is performed. In operation 708, the base station transmits the preamble to the second FA and transmits available data subcarrier information to the terminal. 2 Perform network entry procedure. Here, whether to operate the frequency overlay is determined through a function negotiation during the first network entry procedure.

Thereafter, the base station terminates the guard band use procedure of the present invention.

In some implementations, additional subcarriers n ₁ and n ₂ may be identified in consideration of a guard band between two FAs during the frequency overlay operation. In the present invention, additional subcarriers are considered for each FA.

8 illustrates a terminal or base station apparatus for using a guard band as a data subcarrier in frequency overlay according to an embodiment of the present invention.

Referring to FIG. 8, the base station or the terminal includes a control unit 800, a first MAC processing unit 802-1, a second MAC processing unit 802-2, a first transmission / reception modem 804-1, and a second transmission / reception modem. 804-2, a multiplexer / demultiplexer 806, and an RF transceiver 808.

Looking at the transmission operation, first, the controller 800 controls the overall operation of the terminal or the base station. That is, in the case of a terminal, the controller 800 acquires frequency synchronization for the FA and performs a network entry procedure. The frequency overlay operation is controlled to transmit and receive data bursts through a plurality of FAs. In case of a base station, the controller 800 transmits a broadcast channel including a preamble and additional subcarrier information, and performs a network entry procedure with a corresponding terminal.

The first MAC processing unit 802-1 processes the MAC data from an upper layer (eg, an IP layer unit) and transfers the data to the first transmission modem 804-1. In addition, the first MAC processing unit 802-1 performs a function of generating and interpreting a control message for signaling. For example, the first MAC processor 802-1 generates and outputs a MAP message for the additional subcarrier information of the controller 800.

The first transmission modem 804-1 encodes and outputs data (burst data) from the first MAC processing unit 802-1 according to the additional subcarrier information of the controller 800. For example, the first transmission modem 804-1 includes a channel code block, a modulation block, and the like, and outputs the baseband modulated signal from the first MAC processor 304-1. Here, the channel code block is composed of a channel encoder, an interleaver, a modulator, and the like, and the modulation block is an inverse fast fourier transform (IFFT) for loading transmission data on a plurality of orthogonal subcarriers. It may be configured with a calculator.

The first MAC processing unit 802-1 and the first transmission modem 804-1 are components for performing communication using a first FA, and are operated under the control of the controller 200.

Meanwhile, the second MAC processing unit 802-2 and the second transmission modem 804-2 are components for performing communication using the second FA, and are operated under the control of the controller 200.

The multiplexer 806 multiplexes the signal of the first FA from the first transmission modem 804-1 and the signal of the second FA from the second transmission modem 804-2. Here, the multiplexer 806 may multiplex signals having different frame structures using time division multiplexing or frequency division multiplexing. The multiplexer 806 selects a signal from the first transmission modem 804-1 to the RF transmitter 808 during the service interval of the first FA under the control of the controller 800, and provides a second FA. The signal from the second transmission modem 804-2 is selected and provided to the RF transmitter 808 during the service interval of. As another example, when using frequency division multiplexing, the multiplexer 806 converts, for example, the baseband signal from the first transmission modem 804-1 into a first intermediate frequency band signal and transmits the second transmission. The baseband signal from the modem 804-2 may be converted into a second intermediate frequency band signal, and frequency division multiplexing may be performed by combining the converted two signals.

The RF transmitter 808 converts a signal from the multiplexer 806 into a signal of an RF band that can be actually transmitted and transmits the signal through an antenna. Since the physical layer encoding schemes performed by the first transmission modem 304-1 and the second transmission modem 804-2 are similar, the first transmission modem 804-1 and the second transmission modem ( 804-2) may be implemented as one device.

Referring to the reception operation, the RF receiver 800 first converts a signal received through an antenna into a baseband signal and outputs the signal.

The demultiplexer 806 simultaneously transmits a signal from the RF receiver 800 to the first receiving modem 804-1 and the second receiving modem 804-2 under the control of the upper control unit 800, or the first receiving unit 806. One of the modem 804-1 and the second receiving modem 804-2 is outputted.

The first receiving modem 804-1 decodes and outputs a signal from the demultiplexer 806 according to a MAP received in a frame preceding section. Here, the first receiving modem 804-1 may include a modulation block, a channel decoding block, and the like. Assuming an OFDMA system, the modulation block includes an FFT operator for extracting data carried on each subcarrier, and the channel decoding block includes a demodulator, a deinterleaver, and a channel decoder. And the like.

The first MAC processing unit 802-1 processes the MAC layer data from the first receiving modem 804-1 to the upper layer. In addition, the first MAC processing unit 802-1 performs a function of generating and interpreting a control message for signaling. For example, the first MAC processor 802-1 interprets the MAP message of the first FA received from the base station and provides the same to the controller 800.

The first receiving modem 804-1 and the first MAC processing unit 802-1 are components for performing communication according to a first FA, and are operated under the control of the controller 600.

Meanwhile, the second receiving modem 804-2 and the second MAC processing unit 802-2 are components for performing communication according to the second FA, and are operated under the control of the controller 508.

Referring to the operation of the base station / terminal for the use of the subcarriers in the guard band, in a system supporting the frequency overlay, the terminal determines the number of subcarriers used as data subcarriers in the guard band through an initial system access process and then uses the corresponding data subcarriers to provide services. To be provided.

First, in operation of the terminal, after obtaining frequency synchronization, information necessary for accessing a system is transmitted through a broadcast channel, which includes information on the number of data subcarriers used in data symbols. In this case, since the UE must know in advance the number of data subcarriers in a symbol including a broadcast channel, the corresponding symbol does not use a guard band subcarrier. When the UE recognizes the number of data subcarriers used in the remaining data area except for the preamble and the broadcast channel for initial synchronization acquisition and broadcast channel, the UE can perform subchannelization through this. Thereafter, the terminal performs an initial network access process with the base station based on this. The initial network access process also determines whether the terminal operates in the frequency overlay mode through a capability negotiation process, and the base station transmits information on the neighboring FA to the terminal accordingly. In case of receiving the frequency overlay mode operation, the UE may perform an additional initial network access process for the neighboring FA as needed. After this process is completed, the UE may receive a service through a plurality of allocated FAs. Initiate the overlay mode of operation.

In particular, in the operation of the present invention, a method of using a subcarrier in a guard band for data transmission is described for a case where a frequency overlay is applied, but an additional subcarrier is used in a guard band for data transmission regardless of whether a frequency overlay is applied. The present invention is applicable to the case where the intermediate frequency spacing of adjacent FAs is an integer multiple of subcarrier spacing.

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 determined not only by the scope of the following claims, but also by the equivalents of the claims.

1 is a frequency domain in an OFDM based communication system according to the prior art.

2 is an exemplary diagram using an inter-FA guard band according to the present invention as a data subcarrier;

3 is a flowchart illustrating an operation of a terminal for using a guard band as a data subcarrier in a broadband wireless communication system supporting frequency overlay according to an embodiment of the present invention;

4 is a detailed flowchart for obtaining information about a center frequency of a base station and a channel bandwidth being used;

5 is a frame structure according to the present invention,

6 is a subchannel configuration diagram to be used in the data area according to the present invention;

7 is a flowchart illustrating an operation of a base station for using a guard band as a data subcarrier in a broadband wireless communication system supporting frequency overlay according to an embodiment of the present invention;

8 is an apparatus diagram for using a guard band as a data subcarrier in a broadband wireless communication system supporting a frequency overlay according to an embodiment of the present invention.

Claims (30)

A method of using a guard band as a subcarrier for signal transmission in a wireless communication system, Setting the intermediate frequency between FA (Frequency Assignment) to be an integer multiple of the subcarrier spacing, Calculating the number of subcarriers (n ₁ , n ₂ ) usable in the guard band between FAs; Allocating subcarriers for data transmission by including subcarriers usable in the guard band. The method of claim 1, The guard band is an integer multiple of the subcarrier spacing. The method of claim 1, And wherein said wireless communication system supports frequency overlay. The method of claim 1, And the number of subcarriers n ₁ and n ₂ usable in the guard band between FAs is the same or different. A terminal operating method using a guard band as a subcarrier for signal transmission in a communication system supporting frequency overlay, Acquiring frequency synchronization with respect to the first FA through the preamble; Receiving information on a first additional radio resource after acquiring the frequency synchronization; And performing a first network entry procedure using all radio resources including the first additional radio resource. The method of claim 5, And wherein the first additional radio resource is some subcarrier in the guard bands of both sides of the first FA. The method of claim 5, The guard band is an integer multiple of the subcarrier spacing. The method of claim 5, Negotiating whether or not a frequency overlay operation is performed during the first network entry procedure; When operating in the frequency overlay mode, obtaining frequency synchronization with a second FA and receiving information on a second additional radio resource; And performing a second network entry procedure using all radio resources including the second additional radio resource. The method of claim 8, And wherein the second additional radio resource is some subcarrier in the guard bands of both sides of the second FA. The method of claim 5, The process of obtaining the frequency synchronization Searching for a preamble within a predetermined range from a position corresponding to N integer multiples of a subcarrier, If the preamble is not found, increasing the size to twice the FFT size and searching for the preamble again. The method of claim 5, The information on the first radio resource includes as information on both subcarriers (n1, n2) of the first FA, wherein n1 and n2 are the same or different. The method of claim 5, The first radio resource is applied to the resource block unit size when received in the resource block unit when configuring the sub-channel to be used in the data area, characterized in that received. A method of operating a base station using a guard band as a subcarrier for signal transmission in a communication system supporting frequency overlay, Transmitting the first additional radio resource for the first FA to the corresponding terminal after transmitting the first preamble, Performing a first network entry procedure with the corresponding terminal; Negotiating whether to operate the frequency overlay while performing the first network entry procedure; When operating in the frequency overlay mode, transmitting a second additional radio resource for a second FA to the corresponding terminal after transmitting a second preamble; And performing a second network entry procedure with the corresponding terminal. The method of claim 13, Wherein the first preamble is a preamble for the first FA, and the second preamble is a preamble for the second FA. The method of claim 13, And wherein the first radio resource is a subcarrier on both sides of the first FA and the second radio resource is a subcarrier on both sides of the second FA. An apparatus using a guard band as a subcarrier for signal transmission in a wireless communication system, A control unit for setting the intermediate frequency between FA (Frequency Assignment) to be an integer multiple of the subcarrier spacing, Guard band resource allocation unit for calculating the number of sub-carriers available within the guard band between the FA, And a MAC processing unit including subcarriers usable in the guard band and allocating subcarriers for data transmission. The method of claim 16, The guard band is an integer multiple of the subcarrier spacing. The method of claim 16, And wherein said wireless communication system supports a frequency overlay. The method of claim 16, And the number of subcarriers n ₁ and n ₂ usable in the guard band between FAs is the same or different. A terminal using a guard band as a subcarrier for signal transmission in a communication system supporting frequency overlay, A MAC processor for acquiring frequency synchronization with respect to the first FA through the preamble, and receiving information on a first additional radio resource after acquiring the frequency synchronization; And a controller for performing a first network entry procedure using all radio resources including the first additional radio resource. The method of claim 20, And the first additional radio resource is some subcarriers in the guard bands of both sides of the first FA. The method of claim 20, The guard band is an integer multiple of the subcarrier spacing. The method of claim 21, The control unit Negotiating whether to perform a frequency overlay operation during the first network entry procedure and acquiring frequency synchronization with a second FA and receiving information on a second additional radio resource when operating in the frequency overlay mode; And performing a second network entry procedure using all radio resources including the second additional radio resource. The method of claim 23, wherein And wherein the second additional radio resource is some subcarrier in the guard bands of both sides of the second FA. The method of claim 20, The control unit And searching for the preamble within a predetermined range from a position corresponding to N integer multiples of the subcarrier and searching for the preamble again by increasing the size of the FFT to twice the size when the preamble is not found. The method of claim 20, The information on the first radio resource is included as information on both subcarrier counts (n1, n2) of the first FA, wherein n1 and n2 are the same or different. The method of claim 20, The first radio resource is characterized in that the terminal is applied in the size of the resource block when receiving the sub-channel configuration to be used in the data area, characterized in that the terminal is applied. A base station using a guard band as a subcarrier for signal transmission in a communication system supporting frequency overlay, A first MAC processor for transmitting a first additional radio resource for the first FA to the corresponding terminal after transmitting the first preamble; A control unit for negotiating whether to perform a frequency overlay operation while performing a first network entry procedure with the corresponding terminal and performing a first network entry procedure; And a second MAC processor for transmitting a second additional radio resource for a second FA to the corresponding terminal after transmitting the second preamble when operating in the frequency overlay mode. The method of claim 28, The first preamble is a preamble for the first FA, and the second preamble is a preamble for the second FA. The method of claim 28, And the first radio resource is a subcarrier on both sides of the first FA, and the second radio resource is a subcarrier on both sides of the second FA.

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