KR20090099321A - Apparatus and method for device identification broadcasting in cognitive radio communication system - Google Patents

Abstract

An apparatus and a method for device identification broadcasting in a cognitive wireless communication system and a device thereof are provided to spread a PN code through fixed resources to broadcast an equipment identifier, thereby detecting the equipment identifier without complex synchronization in a detection device. A scheduling unit(508) schedules IDB(ID Broadcasting) according to a rule. A controller(504) unicasts or multicasts an IDB request message to at least one terminal. The IDB request message includes at least one of an index of a PN(Pseudo Noise) code assigned per a terminal or a cluster, an index of an assigned slot and start and end time points of IDB.

Description

Method and apparatus for broadcasting device identifier in cognitive radio communication system {APPARATUS AND METHOD FOR DEVICE IDENTIFICATION BROADCASTING IN COGNITIVE RADIO COMMUNICATION SYSTEM}

The present invention relates to a cognitive radio system, and more particularly, to a method and apparatus for broadcasting device identifiers to easily solve interference not only with a primary system but also with other cognitive radio systems.

Rapidly developing various forms of wireless communication technologies are becoming more closely used in everyday life. After the Code Division Multiple Access ("CDMA") communication technology called the second generation, it uses a third generation wireless communication technology called IMT-2000 (International Mobile Telecommunication-2000), Can also send data information quickly. This rapidly developing wireless communication system requires a different frequency due to coexistence of existing technologies and technologies, and almost all frequencies are currently allocated. This limits the use of several GHz bands, especially low frequency bands.

In order to solve this problem, Cognitive Radio (hereinafter referred to as "CR") technology has been introduced that can detect frequencies that are allocated but are not actually used and are vacant and efficiently shared.

In a cognitive radio system that coexists with one or several primary systems and is constrained to interference, the cognitive radio system may transmit power to avoid interference directed to the one or several primary systems. In addition, the operating frequency band must be adjusted. The existing system is a system that can occupy and use the licensed frequency band at any time, and the cognitive radio system is a system that checks whether the licensed frequency band is used and shares an empty frequency band.

Therefore, a mechanism for preventing any one of the devices (eg, terminal, base station) of the cognitive radio system from causing interference with the existing system should be provided. For example, the IEEE 802.22 Working Group recommends special monitoring devices. The special monitoring device is not a component of the cognitive radio system, but a device for monitoring which devices in the cognitive radio system cause interference to the existing system. The monitoring apparatus will be described in FIG. 1.

FIG. 1 illustrates an example of monitoring a unique identifier (eg, MAC ID) of a terminal causing interference in a monitoring apparatus when interference occurs in a wireless recognition system according to the related art.

Referring to FIG. 1, after the cognitive wireless base station 100 and the terminals 110 to 114 perform channel sensing, the cognitive wireless base station 100 and the terminals 110 to 114 for an empty frequency band. The channel band to be operated is determined through negotiation. Here, it is assumed that the cognitive radio base station 100 and the terminals 110 to 114 detect an unused TV channel band among the TV channel bands and perform communication using a part thereof.

At this time, when the TV receiver 120 of the existing system (ie, the TV system) uses the TV channel band used in the cognitive radio system at the same time, interference will occur. It is assumed that the TV receiver 120 receives interference from the terminal 114 over the distance and does not interfere with other terminals 110, 112, and 113.

The monitoring device 130 is located around the TV receiver 120 and the cognitive radio system, and detects a MAC ID, which is a unique identifier of the terminal 114 that interferes with an existing system (eg, the TV receiver 120).

By allowing other cognitive radio systems to quickly know which device is operating on a given channel, the unique identifier (MAC ID) information can be usefully used to coexist with a peer cognitive radio system.

Conventionally, a cognitive radio system broadcasts the unique device identifier by using a burst control header (hereinafter referred to as "BCH"). The BCH is special header information transmitted for every uplink burst. When uplink resources are allocated to the UE, the BCH should be transmitted before other payloads in the allocated uplink bursts.

The BCH message should normally carry the MAC address of the base station as well as the terminal. The MAC address of the device (base station or terminal) is 48 bits, and the length of the BCH message is at least 96 bits plus the number of Cyclic Redundancy Check (CRC) bits.

However, there are some problems in detecting device identifiers through BCH in uplink burst based transmission.

1. Detection Complexity: Since any supervisor must acquire the uplink burst position before decoding the information, the BCH supervisor 130 must synchronize with the cognitive radio base station 100 and provide uplink burst position information. The UL-MAP message must be decoded to know the uplink burst position. The supervisor 130 then decodes all possible uplink bursts and decodes the BCH portion of the bursts to find out whether they are valid.

2. Burst time misalignment: In cognitive radio communication systems based on Orthogonal Frequency Division Multiplexing Access (hereinafter referred to as " OFDMA "), terminals 110 to 114 are each a base station in a cell. Because of the different distance from 100, the terminals 110-114 are allocated by the base station 100 at different time offsets for uplink transmission. Thus, all bursts from the other terminals 110 to 114 may arrive aligned with the base station 100. However, since the location of the possible BCH supervisor 130 is random, the arrival of the burst from the other terminals 110 to 114 in the BCH supervisor 130 is not aligned at one point in time. Accordingly, based on the uplink burst allocation, the other bursts overlap each other in the time and frequency domains, and a part of the uplink burst may not be decoded for the BCH.

An apparatus and method for efficient device identification broadcasting using Pseudo Noise (PN) codes in a cognitive radio communication system are proposed to solve the above problems.

According to a first aspect of the present invention for achieving the above object, in a method of operating a base station for device identifier broadcasting in a cognitive radio communication system, scheduling device identifier broadcasting (IDB) in accordance with a predefined rule And unicasting or multicasting IDB_REQ messages to the scheduled one or more terminals.

According to a second aspect of the present invention for achieving the above object, a method for operating a terminal for broadcast device identifier in a cognitive radio communication system, the method comprising: receiving a device identifier broadcast request message (IDB_REQ) from the station, and the IDB_REQ message The method may include generating an IDB signal by mapping a Pseudo Noise (PN) code and data symbols with at least one or more subcarriers, and broadcasting the IDB signal at an IDB scheduling time. It is done.

According to a third aspect of the present invention for achieving the above object, a method for monitoring device identifier broadcasting in a cognitive wireless communication system, the method comprising: receiving an IDentification Broadcasting (IDB) signal, and the IDB Performing a correlation on the signal using the corresponding PN code, and detecting the PN code from the correlation result and predicting an IDB start time.

According to a fourth aspect of the present invention for achieving the above object, in a base station apparatus for device identifier broadcasting in a cognitive radio communication system, scheduling for scheduling device identifier broadcasting (IDB) according to a predefined rule And a controller for unicasting or multicasting IDB_REQ messages to the scheduled one or more terminals.

According to a fifth aspect of the present invention for achieving the above object, a terminal device for broadcast device identifier in a cognitive radio communication system, the receiving unit for receiving a device identifier broadcast request message (IDB_REQ) from a base station and the IDB_REQ message A PN code generator for generating an IDB signal by mapping a Pseudo Noise (PN) code and data symbols with at least one subcarrier, and a controller for broadcasting the IDB signal at the time of the IDB scheduling. It is characterized by.

According to a sixth aspect of the present invention for achieving the above object, there is provided a monitoring apparatus for broadcasting device identifier in a cognitive radio communication system, comprising: a receiver for receiving an IDentification Broadcasting (IDB) signal, and the IDB signal; And a PN code detector for detecting a PN code from the correlation result and predicting an IDB start time.

As described above, in the cognitive radio communication system, by spreading the PN code through a fixed resource to broadcast the device (eg, base station, terminal) identifier, there is an advantage that the detection device detects a unique device identifier without complicated synchronization. In addition, the detection device can compensate for the propagation delay to detect a unique device identifier.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, detailed descriptions of related well-known functions or configurations will be omitted if it is determined that the detailed description of the present invention may unnecessarily obscure the subject matter of the present invention. 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 refers to device identification broadcasting (IDB) through a plurality of fixed subcarriers using a pseudo noise (PN) code in a cognitive radio communication system. Will be described.

Hereinafter, the present invention will be described a method and apparatus for device identification broadcasting (hereinafter referred to as "IDB") through a plurality of subcarriers fixed using a pseudo preset code in a cognitive radio communication system. Let's do it. Here, as the preset code, a pseudo noise (hereinafter referred to as "PN") code will be described as an example. Of course, the preset code may use a predetermined orthogonal sequence or a code to replace the PN code.

2 is a flowchart illustrating an operation of a base station for broadcast device identifier in a cognitive radio communication system according to an embodiment of the present invention.

Referring to FIG. 2, the base station schedules the IDB according to a rule defined in step 200. For example, according to the location of the terminals, the terminals located in adjacent locations are grouped or clustered and then prioritized and scheduled.

Thereafter, the base station unicasts or multicasts the IDB_REQ message to at least one or more terminals scheduled in step 202. The IDB_REQ message includes an index of an allocated PN code, an index of an allocated slot, and an IDB start and end time point.

Syntax Size Notes IDB-REQ_Message_Format () { Management Message Type 8 bits Transaction ID 16 bits The connection ID of a terminal or a cluster Confirmation Needed 1 bit Indicates whether or not the terminal is required by the BS to confirm, with a IDB-RSP message, the receipt of this message. 0 = No confirmation needed (default) 1 = Confirmation needed Starting Super-frame Index 8 bits The index of super-frame from the beginning of which IDB starts. Ending Super-frame Index 8 bits The index of super-frame at the end of which IDB ends. PN Sequence Index 8 bits The index of PN sequence used for IDB Pilot Pattern (optional) 4 bits Type of pilot insertion pattern if any. Reserved 3 bits }

Referring to <Table 1>, the IDB message includes Transaction ID, Confirmation Needed, Starting Super-frame Index, Ending Super-frame Index, PN Sequence Index, and Piot Pattern information. The Transaction ID information is a connection ID of a terminal or a cluster, and the Confirmation Needed information is information for determining whether an IDB_REQ message is received. If Confirmation Needed = 0, the IDB_RSP message is not received. If Confirmation Needed = 1, it is received. According to another embodiment, if it is not necessary whether the IDB_REQ message is confirmed, the Confirmation Needed information may be omitted. The Starting Super-frame Index information is an index of an IDB start frame, and the Ending Super-frame Index information is an index of an IDB end frame. The PN Sequence Index is PN code information for IDB. The PN Sequence Index is an index of a PN code allocated to a corresponding UE among PN codes previously promised, and the Pilot Pattern is pilot insertion pattern information if any. Although not shown in Table 1, a repetition pattern of a PN code transmission may be further added to the IDB message.

Thereafter, the base station determines whether IDB scheduling is necessary in step 204, and proceeds to step 200 to perform IDB scheduling if necessary. If IDB scheduling is not needed, the IDB scheduling procedure is terminated.

3 is a flowchart illustrating an operation of a terminal for broadcast device identifier in a cognitive radio communication system according to an embodiment of the present invention.

Referring to FIG. 3, when the terminal receives the IDB_REQ message from the base station in step 300, the terminal proceeds to step 302, and if Confirmation Needed = 0 of information included in the IDB_REQ message (see Table 1), the IDB_RSP message is received. Instead of sending, if Confirmation Needed = 1, send IDB_RSP message. According to another embodiment, upon receiving the IDB_REQ message, it may directly enter step 304 without transmitting the IDB_RSP message.

The IDB_RSP message format is shown in Table 2 below.

Syntax Size Note IDB-RSP_Message_Format () { Management Message Type 8 bits Transation ID 16 bits Connection code 8 bits }

The IDB_RSP message includes management message type information, connection ID information, and confirmation code information.

In step 304, the terminal maps the allocated PN code and data symbol. The data symbol is device identifier (eg, MAC address of base station / terminal) information. The PN code is generated through the PN code generator shown in FIG. 7 with reference to the PN code index received from the base station.

Referring to FIG. 7, the length of the PN code is output by a predetermined function, for example, the number of fixed subcarriers by the polynomial 1 + x ¹ + x ⁴ + x ⁷ + x ¹⁵ . In other words, the length of the PN code is equal to the number of fixed subcarriers allocated for the IDB.

The generated PN code is modulated according to a predetermined modulation scheme and mapped to a subcarrier. For example, when the PN code length is 28 bits and the fixed number of subcarriers is 28, the 28-bit PN code has one-to-one mapping with 28 subcarriers. In one-to-one mapping, bits in the low index are modulated to subcarriers in the low frequency index in ascending order of frequencies. Alternatively, the low index bits are modulated onto the high frequency index subcarriers in descending order of frequency. Alternatively, depending on the implementation, 28 bits of the PN code are randomly one-to-one mapping with 28 subcarriers.

An example of the PN code and data symbol mapping allocated in FIGS. 8 to 9 will be described.

8 illustrates an example of PN code and data symbol mapping according to an embodiment of the present invention. Here, it is assumed that the uplink frame includes 7 OFDM symbols. Assume that 28 fixed subcarriers (or one subchannel) 810 are used for device identifier broadcast.

An OFDM frame is composed of a plurality of subcarriers (vertical axis) and a plurality of slots (or symbols) (horizontal axis), and device identifier information is mapped and transmitted with a PN code during an uplink OFDM frame period. In FIG. 8, the downlink frame is not shown in the section. 8 (a) and 8 (b) are enlarged views of the subcarriers (or one subchannel) 810.

만이 전송된다. 2번째 OFMA 심볼(801), 3번째 OFMA 심볼(803), 5번째 OFDM 심볼(805), 6번째 OFDM 심볼(807) 심볼구간에서는

심볼 벡터가 전송된다. 상기

는 i 번째 데이터 심볼로써 장치 식별자 정보를 구성하는 데이터 심벌들 중 하나를 나타낸다.Referring to FIG. 8A, in the 1st OFMA symbol 800, the 4th OFMA symbol 802, and the 7th OFDM symbol 804, a plurality of subcarriers and a PN code are spread by one-to-one mapping. At this time, the PN code symbol vector in the 1st OFMA symbol 800, 4th OFMA symbol 802, and 7th OFDM symbol 804 interval.

Only is sent. In the second OFMA symbol 801, the third OFMA symbol 803, the fifth OFDM symbol 805, and the sixth OFDM symbol 807 symbol intervals,

The symbol vector is sent. remind

Represents one of the data symbols constituting the device identifier information as the i-th data symbol.

If the data of the device identifier information is assumed to be 96 bits, the number of cyclic redundancy check (CRC) bits may be about 128 bits. As an example, the device identifier information may be a medium access control (MAC) ID.

를 QPSK(Quadrature Phase Shift Keying) 변조방식으로 변조하게 되면, 상향링크의 7개 OFDM 심볼 중 2번째 OFMA 심볼(801), 3번째 OFMA 심볼(803), 5번째 OFDM 심볼(805), 6번째 OFDM 심볼(807)을 전송할 시, 한 프레임을 통해 8비트(4*2)를 전송할 수 있다. 따라서, 상기 장치 식별자 정보가 128 비트라고 가정하면, 하나의 장치 식별자 정보를 전송하기 위해서는 총 16(8*16=128)개의 프레임이 필요하다.Since the device identifier information cannot be transmitted through one frame, data symbols constituting the device identifier information must be transmitted through a plurality of frames. For example,

Is modulated by Quadrature Phase Shift Keying (QPSK) modulation, the second OFMA symbol 801, the third OFMA symbol 803, the fifth OFDM symbol 805, and the sixth OFDM among seven OFDM symbols of uplink. When transmitting the symbol 807, 8 bits (4 * 2) can be transmitted through one frame. Therefore, assuming that the device identifier information is 128 bits, a total of 16 (8 * 16 = 128) frames are required to transmit one device identifier information.

In this case, the device identifier transmission and the uplink data burst 809 are simultaneously transmitted. If the terminal transmits at the same power, the power density of the IDB subcarrier may change due to the uncertainty of the uplink burst allocation. Meanwhile, the device identifier information may be scrambled by bit randomization in a predefined pattern.

만이 전송된다. 2번째 OFMA 심볼(821), 4번째 OFMA 심볼(823), 6번째 OFDM 심볼(825) 심볼구간에서는

심볼 벡터가 전송된다.Depending on the implementation, the pattern of PN code transmission may be configured as shown in FIG. 8 (b). In the intervals of the first OFMA symbol 820, the third OFMA symbol 822, the fifth OFDM symbol 824, and the seventh OFDM symbol 826, a plurality of subcarriers and PN codes are mapped one-to-one and spread. At this time, the PN code symbol vector in the 1st OFMA symbol 820, the 3rd OFMA symbol 822, the 5th OFDM symbol 824, and the 7th OFDM symbol 826.

Only is sent. In the period of the second OFMA symbol 821, the fourth OFMA symbol 823, and the sixth OFDM symbol 825,

The symbol vector is sent.

Referring to FIG. 8 (c), identifier information of two terminals may be transmitted through one subchannel (which is composed of a plurality of fixed subcarriers).

For example, two slots are required to broadcast identifier information for two terminals, and the number of fixed subcarriers can be divided by 1/2 to implement two slots in one subchannel. That is, if there are 28 fixed subcarriers, 14 subcarriers constitute one slot. According to another embodiment, different PN codes may be assigned to each of the terminals, and thus, identifier information of the two terminals may be transmitted through two subchannels (56 subcarriers).

9 illustrates an example of PN code and data symbol mapping according to another embodiment of the present invention. It is assumed that the uplink frame includes 7 OFDM symbols. And, it is assumed that 28 fixed subcarriers (or one subchannel) are used for device identifier transmission.

만이 전송된다. 2번째 OFMA 심볼, 3번째 OFMA 심볼, 5번째 OFDM 심볼, 6번째 OFDM 심볼 구간에서는

심볼 벡터가 전송된다. 상기

는 데이터 심볼로 장치 식별자 정보의 심벌이다. 상기 도 8 (a)에서는 2번째 OFMA 심볼, 3번째 OFMA 심볼, 5번째 OFDM 심볼, 6번째 OFDM 심볼 구간에서 PN 코드와

이 곱해져서 전송되지만, 상기 도 9에서는

심볼 벡터만 전송된다. 이때 한 프레임 동안에

데이터 심벌이 전송되어 112 비트를 전송할 수 있다.Referring to FIG. 9, 14 subcarriers of 28 subcarriers are allocated to UE 1 (900), and a PN code symbol vector is allocated in a 1st OFMA symbol, a 4th OFMA symbol, and a 7th OFDM symbol interval.

Only is sent. In the second OFMA symbol, the third OFMA symbol, the fifth OFDM symbol, and the sixth OFDM symbol interval,

The symbol vector is sent. remind

Is a symbol of device identifier information as a data symbol. In FIG. 8 (a), the PN code and the second OFMA symbol, the third OFMA symbol, the fifth OFDM symbol, and the sixth OFDM symbol interval are shown.

Is multiplied and transmitted, but in FIG.

Only symbol vectors are transmitted. For one frame

Data symbols can be transmitted to transmit 112 bits.

만이 전송된다. 2번째 OFMA 심볼, 3번째 OFMA 심볼, 5번째 OFDM 심볼, 6번째 OFDM 심볼 구간에서는

심볼 벡터가 전송된다. 다른 실시예에 따라서, 단말들 각각에 서로 다른 PN 코드를 할당하여, 두 개의 부채널(sub-channel)을 통해 각각 두 단말의 식별자 정보를 전송할 수도 있다.Similarly, the remaining 14 subcarriers are allocated to UE 2 (910) and PN code symbol vectors in the first OFMA symbol, the fourth OFMA symbol, and the seventh OFDM symbol interval.

Only is sent. In the second OFMA symbol, the third OFMA symbol, the fifth OFDM symbol, and the sixth OFDM symbol interval,

The symbol vector is sent. According to another embodiment, different PN codes may be allocated to each of the terminals, and thus, identifier information of the two terminals may be transmitted through two sub-channels.

In step 306, the terminal broadcasts the IDB signal generated by FIG. 8 or 9 at the IDB scheduling time.

Thereafter, the terminal terminates the procedure for broadcasting the device identifier of the present invention.

4 is a flowchart illustrating an operation of a monitoring device for broadcasting a device identifier in a cognitive radio communication system according to an embodiment of the present invention.

Referring to FIG. 4, the monitoring apparatus converts the received RF signal into a baseband signal, performs sampling on the baseband signal received in the time domain, and performs correlation using a PN code.

Thereafter, the monitoring apparatus detects the PN code from the correlation result in step 402 to predict the IDB start time.

In step 404, the monitoring apparatus performs a fast fourier transform (FFT) operation from the start of the IDB signal.

In step 406, the monitoring apparatus performs channel estimation in the frequency domain using a pilot symbol. Here, the division of the pilot symbol and the data symbol can be found through a pre-scheduled mapping relationship between the PN code and the device identifier information defined according to the embodiments related to FIGS. 8 and 9 and a subchannel (or subcarrier). have.

Thereafter, the monitoring apparatus demodulates IDB data using the channel gain estimated in step 408 and performs decoding.

Thereafter, the monitoring apparatus terminates the device identifier detection procedure.

5 illustrates a terminal device for broadcast device identifier in a cognitive radio communication system according to an embodiment of the present invention.

The terminal device includes an OFDM receiver 500, a frame processor 502, a controller 504, a PN code generator 506, an IDB scheduling unit 508, a frame generator 510, and an OFDM transmitter 512. It is configured by.

The OFDM receiver 500 converts an RF signal into a baseband signal, samples the baseband signal, and performs an FFT operation to convert a signal in a time domain into a signal in a frequency domain. Then, demodulation and decoding are performed according to the modulation scheme.

The frame processor 502 processes a control message and a data message on a frame basis and outputs the control message to the controller 504.

The controller 504 performs overall control of the terminal according to a cognitive radio communication method.

The PN code generator 506 generates a PN code by the number of fixed subcarriers according to a predetermined function, for example, polynomial 1 + x ¹ + x ⁴ + x ⁷ + x ¹⁵ , and provides the PN code to the controller 504. . The initial seed value of the PN code is determined by the device identifier. In addition, the length of the PN code is equal to the number of fixed subcarriers allocated for IDB.

The IDB scheduling unit 508 checks the IDB start time and the end time from the IDB_REQ message information received from the base station, and informs the controller 504 at the IDB start time and the IDB end time.

The frame generator 510 maps the PN code and device identifier information allocated from the controller 504 to a predefined pattern (see FIGS. 8 to 9) and outputs the same to the OFDM transmitter 512.

The OFDM transmitter 512 maps data from the frame generator 510 to a fixed subcarrier, performs an FFT operation, and performs an FFT operation to convert a signal in the frequency domain into a signal in the time domain. In addition, the baseband signal is converted into an RF signal and transmitted.

6 illustrates a monitoring apparatus for broadcast device identifier in a cognitive radio communication system according to an embodiment of the present invention.

Referring to FIG. 6, the IDB monitoring apparatus includes an RF processor 600, a sampler 602, a correlator 604, a PN code detector 606, an FFT operator 608, a demodulator 610, and a decoder 612. And a channel estimator 614.

The RF processor 600 converts the received RF signal into a baseband signal, and the sampler 602 samples the baseband signal received in the time domain according to a sampling period and outputs the result to the correlator 604. do.

으로 상관을 수행한다. 상기

는

의 IFFT 연산에 의해 PN 코드이다.The correlator 604 is coupled to the output signal from the sampler 602.

Perform correlation with remind

Is

Pn code by the IFFT operation.

The PN code detector 606 detects the PN code from the correlation result and determines the starting point of the IDB signal and the IDB transmission pattern. For example, when 16 frames are called super frames, the IDB transmission pattern includes IDB information in odd-numbered frames (1, 3, 5, 7, 9, 11, 13, and 15), and the even-numbered frames are transmitted. Frames 0, 2, 4, 6, 8, 10, 12, and 14 do not contain IDB information.

Referring to FIG. 10, when the base station of the cognitive radio system determines the IDB pattern and informs the terminal, in step 1000, the terminal performs IDB broadcasting in units of super frames, but the odd number of super frames are considered in consideration of overhead and the like. IDB information is transmitted to only (3,5,7,9,11,13,15).

The monitoring apparatus performs correlation with each of 16 frames constituting the superframe according to the length of the PN code defined at any time in step 1020. In this case, the correlation coefficient becomes maximum for each frame in the IDB sections 1010_1, 1010_2, and 1010_3, and the correlation coefficient becomes the minimum in the remaining sections (sections other than the IDB section) (1030).

The FFT operator 608 performs an FFT operation to convert a signal in the time domain into a signal in the frequency domain, the demodulator 610 performs modulation according to a modulation scheme, and the decoder 612 is the demodulator. The device demodulated information is output by decoding the demodulated data from 610. The channel estimator 614 extracts a pilot symbol from the FFT operator 608 to perform channel estimation.

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 an exemplary diagram of monitoring a unique identifier (eg, MAC ID) of a terminal causing interference in a monitoring apparatus when interference occurs in a wireless recognition system according to the prior art;

2 is a flowchart illustrating an operation of a base station for broadcast device identifier in a cognitive radio communication system according to an embodiment of the present invention;

3 is a flowchart illustrating an operation of a terminal for broadcasting a device identifier in a cognitive radio communication system according to an embodiment of the present invention;

4 is a flowchart for detecting a device identifier in a cognitive radio communication system according to an embodiment of the present invention;

5 is a terminal device for broadcast device identifier in a cognitive radio communication system according to an embodiment of the present invention;

6 is a device diagram for detecting a device identifier in a cognitive radio communication system according to an embodiment of the present invention;

7 is a PN code generator according to the present invention,

8 is a diagram illustrating PN code and identifier information, subcarriers, mapping relationships, and frame structures according to a selection pattern according to an embodiment of the present invention;

9 is a diagram illustrating PN code and identifier information, subcarriers, mapping relationships, and frame structures according to a selection pattern according to an embodiment of the present invention;

10 is a diagram illustrating IDB detection according to an IDB transmission pattern according to an embodiment of the present invention.

Claims (26)

A method of operating a base station for broadcast device identifier in a cognitive radio communication system, Scheduling a device identification broadcasting (IDB) according to a predefined rule, And unicasting or multicasting IDB_REQ messages to the scheduled one or more terminals. The method of claim 1, The IDB_REQ message includes at least one index of an PN code allocated to each terminal or cluster, an index of an allocated slot, and an IDB start and end time point. The method of claim 1, The IDB scheduling is performed by grouping or clustering a plurality of terminals. A method of operating a terminal for broadcasting device identifier in a cognitive radio communication system, Receiving a device identifier broadcast request message (IDB_REQ) from a base station; Generating an IDB signal by mapping a pseudo noise (PN) code and data symbols with at least one subcarrier with reference to the IDB_REQ message; And broadcasting the IDB signal at the IDB scheduling time. The method of claim 4, wherein And transmitting a device identifier broadcast response message (IDB_RSP) to the IDB_REQ message. The method of claim 4, wherein And the PN code has orthogonality between codes. The method of claim 4, wherein The data symbol is device identifier information. The method of claim 4, wherein The device identifier information is characterized in that the MAC address of the terminal or the base station. The method of claim 4, wherein The process of generating an IDB signal by mapping a pseudo noise (PN) code and data symbols with at least one subcarrier with reference to the IDB_REQ message, Generating the PN code; Mapping the PN code to a subcarrier according to a predefined pattern, configuring a first slot region in which only the PN code information exists, and configuring a second slot region in which device identifier information exists; How to. The method of claim 9, Wherein the first slot area and the second slot area are determined according to a predefined pattern. A monitoring method for broadcasting device identifier in a cognitive radio communication system, Receiving a device identification broadcasting (IDB) signal; Performing correlation using the corresponding PN code on the IDB signal; Detecting a PN code from the correlation result and predicting an IDB start time. The method of claim 11, Outputting data symbols and pilot symbols in a frequency domain by performing a fast fourier transform (FFT) operation from a start point of the predicted IDB signal; Performing channel estimation in the frequency domain using the pilot symbol; And demodulating IDB data by using the estimated channel gain. The method of claim 11, The process of receiving an IDentification Broadcasting (IDB) signal, And converting the received RF signal into a baseband signal and sampling the baseband signal received in the time domain according to a sampling period. A base station apparatus for broadcasting device identifier in a cognitive radio communication system, A scheduling unit that schedules device identification broadcasting (IDB) according to a predefined rule; And a controller for unicasting or multicasting IDB_REQ messages to the scheduled one or more terminals. The method of claim 14, The IDB_REQ message includes at least one index of an PN code allocated to each terminal or cluster, an index of an allocated slot, and an IDB start and end time point. The method of claim 14, The IDB scheduling, characterized in that performed by grouping or clustering a plurality of terminals. A terminal device for broadcasting device identifier in a cognitive radio communication system, A receiving unit for receiving a device identifier broadcast request message (IDB_REQ) from the base station; A PN code generator for generating an IDB signal by mapping a pseudo noise (PN) code and data symbols with at least one subcarrier with reference to the IDB_REQ message; And a controller for broadcasting the IDB signal at the IDB scheduling time. The method of claim 17, And transmitting a device identifier broadcast response message (IDB_RSP) to the IDB_REQ message. The method of claim 17, And said PN code has orthogonality between codes. The method of claim 17, And the data symbol is device identifier information. The method of claim 17, Wherein the device identifier information is a MAC address of a terminal or a base station. The method of claim 17, Mapping the PN code to a subcarrier according to a predefined pattern, and configuring a first slot area in which only the PN code information exists, and further comprising a frame generation unit constituting a second slot area in which device identifier information exists Characterized in that the device. The method of claim 9, And the first slot area and the second slot area are determined according to a predefined pattern. A monitoring apparatus for broadcasting device identifier in a cognitive radio communication system, A receiver for receiving a device identification broadcasting (IDB) signal; A correlation unit for performing correlation on the IDB signal by using a corresponding PN code; And a PN code detector for detecting a PN code from the correlation result and predicting an IDB start time. The method of claim 24, An FFT calculator configured to output a data symbol and a pilot symbol in a frequency domain by performing a fast fourier transform (FFT) operation from a start point of the predicted IDB signal; A channel estimator for performing channel estimation in the frequency domain using the pilot symbol; And a demodulation / decoding unit for performing decoding after demodulating IDB data using the estimated channel gain. The method of claim 24, The receiving unit An RF processor for converting the received RF signal into a baseband signal; And a sampler for sampling the baseband signal received in the time domain according to a sampling period.

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