KR101542519B1 - Apparatus and method for processing the change of preamble of a relay system in a multi-hop relay broadband wireless access communication system - Google Patents

Abstract

The present invention relates to an apparatus and method for processing a preamble change of a relay station in a wireless communication system using a multi-hop relay scheme. A method of operating a base station according to the present invention includes the steps of providing a relay service through a relay station, determining whether a preamble change of the relay station is necessary, and transmitting a preamble change instruction And transmitting the preamble change notification message to at least one lower node of the relay station when the preamble of the relay station is changed.

Relay communication system, multi-hop, mobile relay station, preamble

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a preamble change processing apparatus and method for a relay station in a broadband wireless access communication system using a multi-

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a broadband wireless access communication system using a multi-hop relay scheme, and more particularly, to an apparatus and method for processing a preamble change of a relay station (RS).

The 4G (4th generation) communication system, which is a next generation communication system, desires to provide various quality of service (QoS) services having a transmission speed of about 100 Mbps. Particularly, the 4G communication system has mobility in a broadband wireless access (BWA) communication system such as a wireless local area network (LAN) system and a wireless metropolitan area network (MAN) system. And QoS (Quality of Service). The representative communication system is IEEE (Institute of Electrical and Electronics Engineers) 802.16d communication system and IEEE 802.16e communication system.

The IEEE 802.16d communication system and the IEEE 802.16e communication system use an Orthogonal Frequency Division Multiplexing (OFDM) / Orthogonal Frequency Division Multiple Access (OFDMA) method for a physical channel use. The IEEE 802.16d communication system does not consider the mobility of a subscriber station (SS), and assumes a single cell structure. Alternatively, the IEEE 802.16e communication system considers the mobility of the terminal, and the terminal having mobility is called a mobile station (MS).

1 is a diagram schematically showing a structure of a general IEEE 802.16e communication system.

1, the IEEE 802.16e communication system includes a base station (BS) 110 having a multi-cell structure, that is, having a cell 100 and a cell 150 and managing the cell 100, A base station 140 managing the cell 150 and a plurality of MSs 111, 113, 130, 151 and 153. The signal transmission / reception between the BSs 110 and 140 and the MSs 111, 113, 130, 151 and 153 is performed using the OFDM / OFDMA scheme. The MS 130 of the MSs 111, 113, 130, 151 and 153 is located in a boundary region between the cell 100 and the cell 150, i.e., a handover region. Accordingly, when the MS 130 moves to the cell 150 managed by the BS 140 during transmission and reception of signals with the BS 110, the serving BS transmits, to the BS 110, The base station 140 is changed.

In the general IEEE 802.16e communication system, a signaling transmission / reception is performed through a direct link between a fixed base station and an MS as shown in FIG. 1, so that a reliable wireless communication link between the base station and the MS can be easily established. However, since the IEEE 802.16e communication system has a fixed base station location, flexibility in the wireless network configuration is low, and thus it is difficult to provide an efficient communication service in a wireless environment where the traffic distribution and the call demand change are severe.

In order to overcome such a disadvantage, a multi-hop relay data transmission method using a fixed relay station or a mobile relay station or general MSs is applied to a general cellular wireless communication system such as the IEEE802.16e communication system . The wireless communication system using the multi-hop relay scheme can quickly reconfigure the network in response to a change in the communication environment, and can efficiently operate the entire wireless network. For example, the wireless communication system using the multi-hop relay scheme can expand the cell service area and increase the system capacity. That is, when the channel state between the BS and the MS is poor, a relay station is provided between the BS and the MS to configure a multi-hop relay path through the RS, thereby providing the MS with a better channel state. Further, by using the multi-hop relay scheme in a cell boundary region where the channel state is poor from the base station, a higher-speed data channel can be provided and the cell service area can be expanded.

FIG. 2 is a diagram schematically illustrating a structure of a broadband wireless communication system using a multi-hop relay scheme for expanding a coverage area of a base station.

2, the multi-hop relay wireless communication system includes a base station (BS) 210 having a multi-cell structure, i.e., a cell 200 and a cell 240, A plurality of MSs 211 and 213 located in the cell area 200 and a plurality of MSs 211 and 213 located in the cell area 200, Hop relay paths between the MSs 221 and 223 existing in the area 230 outside the area 230 and between the MSs 221 and 223 located in the area 210 and the BS 210, A plurality of MSs 251, 253 and 255 located in an area of the cell 240 and a plurality of MSs 250 managed by the BS 250 but located in an area 270 outside the cell 240 And a relay station 260 for providing a multi-hop relay path between the MSs 261 and 263 and the MSs 261 and 263 existing in the BS 270 and the BS 250. [ The signal transmission and reception between the BSs 210 and 250 and the RSs 220 and 260 and the MSs 211, 213, 221, 223, 251, 253, 255, 261 and 263 are performed by the OFDM / OFDMA .

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3 is a diagram schematically illustrating a structure of a broadband wireless communication system using a multi-hop relay scheme for increasing system capacity.

3, the multi-hop relay wireless communication system includes a base station 310, a plurality of MSs 311, 313, 321, 323, 331 and 333, a base station 310 and MSs 311 and 313 And relay stations 320 and 330 that provide a multi-hop relay path between the BSs 321, 323, 331, and 333. Signals are exchanged between the BS 310 and the RSs 320 and 330 and the MSs 311, 313, 321, 323, 331 and 333 using the OFDM / OFDMA scheme. The BS 310 manages the cell 300 and the MSs 311, 313, 321, 323, 331 and 333 included in the cell 300 region and the RSs 320 and 330 communicate with the BS 300 310 and the signal can be directly transmitted and received.

When the MS 300 is located near the edge of the cell 300 as in the case of the partial MSs 321, 323, 331 and 333, the direct link between the BS 310 and the MSs 321, 323, 331, The signal-to-noise ratio (SNR) may be low. At this time, the RSs 320 and 330 provide a high-speed data transmission path to the MSs 321, 323, 331, and 333, thereby increasing the effective data rate of the MSs and increasing the system capacity.

In the broadband wireless communication system using the multi-hop relay shown in FIG. 2 or FIG. 3, the relay stations 220, 260, 320 and 330 are installed in the service providers, An infrastructure relay station for knowing and managing in advance, or a client relay station operating as a subscriber terminal (SS or MS) or a relay station depending on circumstances. The relay stations 220, 260, 320, and 330 may be fixed relay stations having no mobility, nomadic relay stations having nomadic characteristics (e.g., notebooks), mobile relay stations Lt; / RTI >

As described above, a relay station that relays communication between a terminal and a base station can have mobility. In case of a mobile relay station, it may be out of the service area of the base station or the upper relay station. In this way, when the mobile relay station moves to the service area of a new upper relay station or a neighboring base station, a terminal or a lower relay station connected to the mobile relay station can perform handover together with the mobile relay station.

Meanwhile, when the mobile relay station moves to a service area of a new target node (relay station or neighboring base station), the preamble used by the mobile relay station may interfere with the service area of another neighboring base station or another relay station. In this case, the preamble of the mobile relay station must be changed. When the preamble of the mobile relay station is changed, the mobile station in the service area of the mobile relay station recognizes the mobile relay station as a new node. Therefore, the serving base station of the mobile station handover the mobile station to the mobile relay station, .

That is, the serving BS transmits a handover indication message including a preamble index to be changed in the mobile relay station to the lower terminals of the mobile relay station. The handover indication message may be, for example, an MOB_BSHO-REQ message with a forced handover indicator set to '1'. The MSs receiving the handover indication message determine handover to the target node (mobile relay station) having the preamble index, and perform a network re-entry procedure with the target node. Herein, the network re-entry procedure includes a RNG-REQ / RSP, a SBC-REQ / RSP authentication procedure, and a REG- REQ / RSP).

As described above, when the preamble of the mobile relay station is changed, the terminal forcibly handover the terminal in the service area of the mobile relay station to the changed preamble, so that the terminal can receive a continuous service from the node having the changed preamble . However, such a method has an overhead in which a mobile station that does not deviate from the service area of the mobile relay station unnecessarily performs a handover procedure (including a network re-entry procedure). Therefore, when the preamble of the mobile relay station is changed, a scheme for reducing the overhead is needed.

Accordingly, it is an object of the present invention to provide an apparatus and method for processing a preamble change of a relay station in a wireless communication system using a multi-hop relay scheme.

It is another object of the present invention to provide an apparatus and method for a lower node of a relay station to recognize a preamble change of the relay station in a wireless communication system using a multi-hop relay scheme.

It is another object of the present invention to provide an apparatus and method for notifying a preamble change of a relay station to a lower node belonging to a service area of the relay station in a wireless communication system using a multi-hop relay scheme.

It is still another object of the present invention to provide an apparatus and method for a lower node to maintain a connection with a relay station without a handover procedure when a preamble of a relay station is changed in a wireless communication system using a multi-hop relay scheme.

According to one aspect of the present invention, there is provided a method of operating a base station in a multi-hop relay wireless communication system, the method comprising: providing a relay service through a relay station; Transmitting a preamble change indication message to the relay station, the preamble change indication message indicating a change in the preamble, when the preamble of the relay station is changed; To the at least one lower node of the relay station.

According to another aspect of the present invention, there is provided a method of operating a terminal in a wireless communication system using a multi-hop relay scheme, the method comprising: communicating with a base station via a relay station; Acquiring new preamble information of the relay station from the received message if the preamble change notification message is received; and receiving a new preamble signal of the relay station according to the obtained information And a control unit.

According to another aspect of the present invention, there is provided a method of operating a relay station in a multi-hop relay wireless communication system, the relay method comprising: providing a relay service; checking whether a preamble change indication message is received from a base station Acquiring new preamble information from the received message when the preamble change instruction message is received; changing a preamble signal according to the new preamble information; and transmitting the changed preamble signal And a control unit.

According to another aspect of the present invention, there is provided a base station apparatus in a multi-hop relay wireless communication system, the base station apparatus comprising: a controller for determining whether a preamble change of a relay station is necessary; And generating a preamble change indication message by physical layer processing and transmitting the preamble change indication message to the relay station and performing physical layer processing on the preamble change notification message to transmit the preamble change indication message to a lower node of the relay station And a transmitting unit.

According to another aspect of the present invention, in a terminal apparatus in a multi-hop relay wireless communication system, when a preamble change notification message is received from an upper node during communication through a relay station, And a preamble demodulator for receiving a preamble signal changed from the relay station under the control of the control unit, characterized by comprising: a preamble demodulator for obtaining new preamble information of the relay station; a preamble demodulator for changing a preamble of the relay station according to the new preamble information; .

 According to another aspect of the present invention, in a relay station apparatus in a multi-hop relay wireless communication system, when a preamble change indication message is received from a base station during a relay service, new preamble information is acquired from the received message A controller for changing a preamble signal according to the new preamble information, and a preamble signal generator for generating the changed preamble signal.

As described above, the present invention proposes a scheme in which, when a preamble of a relay station is changed in a wireless communication system using a multi-hop relay scheme, a lower node can maintain a connection with the mobile relay station without a handover procedure. As described above, the present invention can provide a service to a lower node of a mobile relay station without interruption, and there is an advantage that overhead can be reduced because a handover procedure is not needed.

Hereinafter, the operation principle of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. The following terms are defined in consideration of the functions of the present invention, and these may be changed according to the intention of the user, the operator, or the like. Therefore, the definition should be based on the contents throughout this specification.

Hereinafter, a method for processing a preamble change of a relay station in a broadband wireless communication system using a multi-hop relay scheme will be described.

For example, if the mobile relay station moves out of the coverage area of the base station or the upper relay station and moves to the service area of a new upper relay station or a neighbor base station, the preamble of the mobile relay station may be changed. In this way, when the mobile relay station moves to a new service area, the preamble of the mobile relay station can be changed when a preamble of the mobile station is collided with an existing node in the new service area. As another example, It is possible. As another example, if the base station or the relay station is newly plugged in, the preamble of the existing node may be changed, or the preamble of the specific node may be changed during operation due to a change in the operator policy. As described above, if the preamble of the relay station (mobile relay station or fixed relay station) can be changed in various situations, and the preamble of the relay station is changed, a method by which the child node can maintain the connection with the relay station without a handover procedure do.

In the following description, a broadband wireless communication system using a multi-hop relay scheme is a communication system using, for example, an OFDM / OFDMA scheme. Since the OFDM / OFDMA scheme is used, a plurality of sub- Speed data transmission is possible by transmitting a physical channel signal using a multi-cell structure, and the mobility of a terminal can be supported through a multi-cell structure.

Hereinafter, the present invention will be described by taking a broadband wireless access communication system as an example. However, the present invention can be similarly applied to a cellular-based communication system using a multi-hop relay scheme.

FIG. 4 illustrates a signal exchange procedure for processing a preamble change of a relay station in a wireless communication system using a multi-hop relay scheme according to an embodiment of the present invention.

4, in step 401, the base station 40 first transmits the relay service of the mobile relay station 41 to the first mobile station 42-1, the second mobile station 42-2 to the terminal n (42-n) Data is transmitted and received. In this way, while the relay service is being provided, the BS 40 checks whether the preamble transmitted by the mobile relay station 41 needs to be changed. If it is necessary to change the preamble of the mobile relay station 41, the base station 40 transmits a preamble change indication message to the mobile relay station 41 in step 403. [ The base station 40 may be a serving base station managing the serving cell of the mobile relay station 41 or a target base station managing neighboring cells. The preamble change indication message may have the information shown in Table 1 below.

Preamble change command () { New preamble index Newly assigned preamble index for the mobile RS Action time the time (frame number) when the mobile RS transmits the new preamble }

As shown in Table 1, the preamble change indication message may include a new preamble index of a preamble to be newly allocated to the mobile relay station 41, an action time to transmit a new preamble, and the like .

In step 405, the BS 40 transmits the MS 2 to the MS 1 (42-1), the MS 2 (42-2) to the MS n (42-n) in the service area of the mobile relay station 41 to the new preamble change notification message. The preamble change notification message may include information of Table 2 below.

Preamble change notification () { New preamble index New preamble index of the mobile RS Action time the time when the new preamble is transmitted }

As shown in Table 2, the preamble change notification message includes a new preamble index of the mobile relay station 41 and an action time of the mobile relay station 41 transmitting the new preamble, And the like.

If the preamble of the mobile relay station 41 is changed when handing over to the target base station, information on the changed preamble using the handover control message may be transmitted instead of the preamble change indication message.

The preamble change notification message may be transmitted from the base station 40 as shown in FIG. The mobile relay station 41 which has received the preamble change indication message from the base station 40 transmits the preamble change indication message to the terminal 1 42-1, the terminal 2 42-2 to the terminal n 42- And may transmit the preamble change notification message.

Meanwhile, the MSs 42-1 to 42-n analyze the preamble change notification message received from the BS 40 in steps 407 to 411, and transmit a preamble of the mobile relay station 41 after a predetermined time Will be changed.

In step 413, the mobile relay station 41 checks whether an action time has been reached in the preamble change indication message, and if the action time is reached, the mobile relay station 41 changes the preamble and transmits the changed preamble. In step 413, the MSs 42-1 to 42-n check whether the preamble change alerting message has been received within the predefined time. If the preamble has been reached, .

In step 415, the BS 40 continues the data service with the MSs 42-1 to 42-n using the relay service of the mobile relay station 41 that transmits the changed preamble.

If the base station 40 is a target base station managing neighboring cells. In other words, when the mobile relay station 41 performs handover to the target base station, the connection identifier of the terminal 1 (42-1) to the terminal n (42-n) receiving the relay service of the mobile relay station 41 identifier can be changed. The mobile relay station 41 exchanges a previous CID with a new CID in place of transmitting new CID information to the MSs 42-1 through 42-n when the CID needs to be changed Can be performed.

For example, when a packet including the previous connection identifier is received from the terminal 42, the mobile relay station 41 exchanges a previous connection identifier of the packet with a new connection identifier, send. In addition, when a packet including the new CID is received from the BS, the MRI 41 may exchange the new CID of the packet with the previous CID and transmit the new CID to the MS 42.

As another example, if there is a tunnel connection between the base station and the mobile relay station, the mobile station can change the connection identifier of the mobile station by changing the tunnel connection identifier of the mobile relay station. That is, when the mobile relay station 41 moves to the target cell managed by the target base station 40, the target base station 40 transmits the relayed service to the mobile station The relay station 41 may allocate a new tunnel connection identifier that is mapped to the previous tunnel connection identifier.

If the STID (station identifier) of the MS is allocated to each BS, the STID of the MS managed by the MS can be changed when the MS moves to the target BS. If the STID of the UE changes, the changed STID information may be included in the preamble change notification message of Table 2 and transmitted. Also, when a service mapped to the FID (flow identifier) of the UE is changed in the target BS, information on the changed service can be transmitted in the preamble change notification message. At this time, information such as the changed service flow and the FID mapped to the service flow may be included in the preamble change notification message.

If a STID (STID) is allocated to each BS, the STID of the MS managed by the MTR can be changed when the MTR performs handover to the target BS. If the STID of the UE changes, the changed STID information may be included in the preamble change notification message of Table 2 and transmitted. Also, when a service mapped to a flow identifier (FID) of the UE is changed in the target BS, information on the changed service may be included in the preamble change notification message. At this time, information such as the changed service flow and the FID mapped to the service flow may be included in the preamble change notification message.

FIG. 5 illustrates an operation procedure of a base station in a wireless communication system using a multi-hop relay scheme according to an embodiment of the present invention.

Referring to FIG. 5, in step 501, the BS provides data services to the MS using relay communication. In step 503, the BS determines whether it is necessary to change the preamble transmitted from the RS through the RS. If a preamble of a mobile relay station that has moved from another cell collides with a preamble of another relay station, the base station can change the preamble of the mobile relay station. Here, it is assumed that a collision of the preamble can be detected by the BS or the MS, but the determination of the preamble change is performed by the BS.

If it is necessary to change the preamble of the RS, the BS generates a preamble change indication message in step 505 and transmits the preamble change indication message to the RS. Here, the preamble change indication message may include index information of a new preamble and information on an operation time (e.g., frame number) to which the new preamble is applied.

In step 507, the BS generates a preamble change notification message informing the RS of the preamble change, and transmits the preamble change notification message to the lower nodes of the RS. At this time, the preamble change notification message may include new preamble index information of the RS, operation time information to which the new preamble is applied, and the like.

FIG. 6 illustrates an operation procedure of a relay station in a wireless communication system using a multi-hop relay scheme according to an embodiment of the present invention.

Referring to FIG. 6, in step 601, the RS relays data between the BS and the MS. In this manner, during the provision of the relay service, the RS determines whether a preamble change indication message is received from the BS in step 603. Upon receiving the preamble change indication message, the RS checks the index of the new preamble and the operation time information to which the new preamble is to be applied, in step 605.

If the RS needs to inform the lower nodes of the preamble change, the RS generates a preamble change notification message in step 607 and transmits the preamble change notification message to the lower nodes of the RS. At this time, the preamble change notification message may include new preamble index information of the RS, operation time information to which the new preamble is applied, and the like.

In step 609, the RS determines whether a new preamble has reached an operation time. If the operation time is reached, the RS changes the preamble according to the preamble index information in the preamble change indication message in step 611, and transmits the changed preamble signal.

7 illustrates an operation procedure of a UE in a multi-hop relay wireless communication system according to an embodiment of the present invention.

Referring to FIG. 7, in step 701, a terminal communicates with a base station through a relay station. During the communication via the RS, the MS determines in step 703 whether a preamble change notification message informing of the preamble change of the RS is received. Upon receiving the preamble change notification message, the terminal checks index information of a new preamble and operation time information to which a new preamble is to be applied, from the received message in step 705.

In step 707, the MS determines whether the new preamble has reached the operation time. In step 709, the MS changes the preamble of the RS according to the preamble index information in the preamble change notification message, and receives the preamble of the changed RS.

FIG. 8 shows a block configuration of a base station (or a relay station or a terminal) according to an embodiment of the present invention. Here, since the base station, the relay station and the terminal having the same interface module (communication module) have the same block configuration, the operation of the base station, the relay station and the terminal will be described below with reference to FIG. Hereinafter, a description will be given assuming a TDD-OFDMA system. However, the present invention can be easily applied to an FDD-OFDMA system, a hybrid system using TDD and FDD together, and a cellular-based system using another resource partitioning scheme.

A base station (or a relay station or a terminal) according to the present invention includes a controller 800, a message generator 802, an encoder 804, an OFDM modulator 806, a digital to analog converter (DAC) 808 , An RF transmitter 809, a duplexer 810, an RF receiver 811, an ADC (Analog to Digital Converter) 812, an OFDM demodulator 814, a decoder 816, and a message analyzer 818 . The BS may further include a preamble signal generator 820 in the case of a base station and a preamble signal generator 820 and a preamble signal demodulator 822 in the case of a relay station. (822).

Referring to FIG. 8, the controller 800 controls the overall operation of a corresponding node (a base station or a relay station or a terminal). The message generator 802 generates a control message (a signaling message or a MAC management message) under the control of the controller 800 and provides the generated control message to the physical layer encoder 804. [

The encoder 804 codes and modulates data from the message generator 802 according to a predetermined modulation level (MCS level) and outputs the modulated data. The OFDM modulator 806 performs Inverse Fast Fourier Transform (IFFT) on the data from the encoder 804 and outputs sample data (OFDM symbol). The DAC 808 converts the sample data into an analog signal and outputs the analog signal. The RF transmitter 809 converts an analog signal from the DAC 808 into a radio frequency (RF) signal and transmits the RF signal to the duplexer 810.

The duplexer 810 transmits a transmission signal from the RF transmitter 809 through the antenna according to the duplexing scheme and provides a reception signal from the antenna to the RF receiver 811. For example, in the case of TDD (Time Division Duplex), the duplexer 810 transmits a signal from the RF transmitter 809 through the antenna when it is in a transmission interval, Signal to the RF receiver 811.

The RF receiver 811 converts an RF (Radio Frequency) signal received through an antenna into a baseband analog signal. The ADC 812 converts the analog signal from the RF receiver 811 into sample data and outputs it. The OFDM demodulator 814 performs FFT (Fast Fourier Transform) of the sample data from the ADC 812 to convert the data into frequency domain data, and selects and outputs data of subcarriers to be actually received in the frequency domain data.

The decoder 816 demodulates and decodes the data from the OFDM demodulator 814 according to a predetermined modulation level (MCS level) and outputs the demodulated and decoded data. The message analyzing unit 818 analyzes the control message from the decoder 816 and provides the result to the controller 800. [

In the above-described configuration, the control unit 800 controls the message processing unit 802 and the message generation unit 818 as a protocol control unit. That is, the controller 800 may perform the functions of the message processor 802 and the message generator 818. In the present invention, these are separately configured to distinguish the respective functions. Therefore, in a real implementation, all of them can be processed by the control unit 800, and only a part of them can be processed by the control unit 800. [ In addition, the controller 800 receives information necessary for performing protocol processing from a corresponding component of the physical layer or generates a control signal to a corresponding component of the physical layer.

Hereinafter, operations of the base station, the relay station, and the terminal according to the present invention will be described with reference to FIG. Hereinafter, the signaling process performed in the MAC (Media Access Control) layer will be described.

First, the operation of the base station will be described.

During providing the data service to the terminal through the RS, the controller 800 determines whether the preamble of the RS needs to be changed. If it is necessary to change the preamble of the RS, the controller 800 instructs the message generator 802 to generate a preamble change indication message. Then, the message generator 802 generates the preamble change indication message and delivers the generated message to the physical layer. The message transferred to the physical layer unit is processed in the physical layer and transmitted to the relay station. The preamble change indication message may include index information of a new preamble and operation time information to which a new preamble is to be applied.

Also, when the preamble change of the RS is required, the controller 800 instructs the message generator 802 to generate a preamble change notification message. The message generator 802 generates the preamble change notification message and transmits the generated message to the physical layer unit. The preamble change notification message includes index information of a new preamble and operation time information to which a new preamble is to be applied, and is transmitted to the lower nodes of the relay station.

Next, the operation of the relay station will be described.

During relaying data between the BS and the MS, the message analyzing unit 818 analyzes the received message and determines whether a preamble change indication message has been received from the BS. If the preamble change instruction message is received, the message analyzer 818 extracts index information of a new preamble and operation time information to which a new preamble is to be applied, from the received preamble change indication message, do.

Then, the controller 800 checks the index of the new preamble and the operation time, and when the operation time is reached, instructs the preamble signal generator 820 to change the preamble. Then, the preamble signal generator 820 generates a preamble signal (or a preamble sequence) according to the index under the control of the controller 800, and provides the preamble signal to the OFDM modulator 806. The OFDM modulator 806 maps a signal from the preamble signal generator 802 to a corresponding subcarrier, and OFDM-modulates the signal. The OFDM-modulated preamble signal is transmitted for synchronization of the lower nodes.

Next, the operation of the terminal will be described.

During communication with the base station through the relay station, the message analyzing unit 818 analyzes the received message and determines whether a preamble change notification message informing the preamble change of the relay station has been received. If the preamble change notification message is received, the message analyzer 818 extracts index information of a new preamble and operation time information to which a new preamble is to be applied, from the received preamble change notification message, do.

Then, the controller 800 checks the index and the operation time of the new preamble of the RS, and when the operation time is reached, the preamble signal demodulator 822 instructs the preamble signal demodulator 822 to change the preamble. The preamble signal demodulator 822 changes the preamble to be received under the control of the controller 800 and demodulates the preamble channel signal from the OFDM demodulator 814 according to the changed preamble. This demodulated preamble signal can then be used to obtain synchronization (time and frequency synchronization).

In the above description, a preamble change notification message for informing the lower-layer mobile station or the lower-layer relay station of a preamble change of the mobile relay station is generated in the base station and is transmitted to the lower-layer mobile station or the lower-layer relay station through relay transmission of the mobile relay station. Respectively.

However, if the mobile relay station can directly construct a message to be transmitted to its lower-level terminal or lower-level relay station, the mobile relay station can generate the preamble change notification message and transmit it to the lower-level terminal or the lower relay station. At this time, the mobile relay station configures the preamble change notification message based on the control information included in the preamble change indication message received from the base station.

While the present invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments, but is capable of various modifications within the scope of the invention. Therefore, the scope of the present invention should not be limited by the illustrated embodiments, but should be determined by the scope of the appended claims and equivalents thereof.

1 schematically shows a structure of a general IEEE 802.16e communication system;

2 is a diagram schematically illustrating a structure of a broadband wireless communication system using a multi-hop relay scheme for expanding a base station service area.

3 is a diagram schematically illustrating a structure of a broadband wireless communication system using a multi-hop relay scheme for increasing system capacity.

4 is a diagram illustrating a signal exchange procedure for processing a preamble change of a relay station in a wireless communication system using a multi-hop relay scheme according to an embodiment of the present invention.

5 is a diagram illustrating an operation procedure of a base station in a wireless communication system using a multi-hop relay scheme according to an embodiment of the present invention.

6 is a diagram illustrating an operation procedure of a relay station in a wireless communication system using a multi-hop relay scheme according to an embodiment of the present invention.

FIG. 7 illustrates an operation procedure of a UE in a wireless communication system using a multi-hop relay scheme according to an embodiment of the present invention. FIG.

8 is a block diagram of a base station (or a relay station or a terminal) according to an embodiment of the present invention.

Claims (24)

A method of operating a base station in a wireless communication system using a multi-hop relay scheme, Providing a relay service through a relay station, Determining whether a preamble change of the RS is necessary; Transmitting a preamble change indication message to the relay station indicating a change of the preamble; And transmitting a preamble change notification message informing the change of the preamble to at least one lower node of the relay station. The method according to claim 1, Wherein the preamble change indication message includes at least one of index information of a new preamble of the RS and operation time information to which the new preamble is to be applied. The method according to claim 1, Wherein the preamble change notification message includes at least one of new preamble index information of the relay station, operation time information to which the new preamble is to be applied, terminal identifier information, and flow identifier information. The method according to claim 1, Wherein the relay station is a mobile relay station and the base station is a serving base station or a target base station of the relay station. The method of claim 1, Checking whether a preamble of the relay station conflicts with a preamble of another node, And determining a preamble change of the RS if the collision occurs. A method of operating a terminal in a wireless communication system using a multi-hop relay scheme, Communicating with a base station through a relay station, Receiving a preamble change notification message informing a change of a preamble of the relay station from an upper node; Acquiring new preamble information of the relay station from the message; And receiving a new preamble signal of the relay station based on the information. The method according to claim 6, Wherein the preamble change notification message includes at least one of new preamble index information of the relay station, operation time information to which the new preamble is to be applied, terminal identifier information, and flow identifier information. 7. The method of claim 6, wherein the step of receiving the preamble signal comprises: Checking whether the set operation time has been reached, And receiving the new preamble signal from the relay station when the operation time has been reached. A method of operating a relay station in a wireless communication system using a multi-hop relay scheme, Providing a relay service, Receiving a preamble change indication message for instructing a change of a preamble of the relay station from a base station; Acquiring new preamble information from the message; Changing a preamble signal based on the information; And transmitting the changed preamble signal. 10. The method of claim 9, Wherein the preamble change indication message includes at least one of index information of a new preamble of the RS and operation time information to which the new preamble is to be applied. 10. The method of claim 9, Generating a preamble change notification message before changing the preamble signal; And transmitting the preamble change notification message to at least one lower node of the relay station. 12. The method of claim 11, Wherein the preamble change notification message includes at least one of index information of a new preamble of the RS, operation time information to which the new preamble is to be applied, terminal identifier information, and flow identifier information. A base station apparatus in a wireless communication system using a multi-hop relay scheme, A control unit for determining whether a preamble change of the relay station is necessary, A generating unit generating at least one of a preamble change instruction message for instructing the change of the preamble and a preamble change notification message for notifying the change of the preamble, And a transmitter for transmitting the preamble change indication message to the relay station and transmitting the preamble change notification message to at least one lower node of the relay station. 14. The method of claim 13, Wherein the preamble change indication message includes at least one of index information of a new preamble of the RS and operation time information to which the new preamble is to be applied. 14. The method of claim 13, Wherein the preamble change notification message includes at least one of new preamble index information of the relay station, operation time information to which the new preamble is to be applied, terminal identifier information, and flow identifier information. 14. The method of claim 13, Wherein the relay station is a mobile relay station and the base station is a serving base station or a target base station of the relay station. 14. The apparatus of claim 13, Determines whether a preamble of the relay station conflicts with a preamble of another node currently serving and determines whether to change the preamble of the relay station if the collision occurs. A terminal apparatus in a wireless communication system using a multi-hop relay scheme, An analysis unit for acquiring new preamble information of the relay station from the message when a preamble change notification message informing the change of the preamble of the relay station is received from an upper node during communication through the relay station; A control unit for changing a preamble of the relay station based on the information; And a preamble demodulator for receiving the changed preamble signal from the relay station under the control of the control unit. 19. The method of claim 18, Wherein the preamble change notification message includes at least one of new preamble index information of the relay station, operation time information to which the new preamble is to be applied, terminal identifier information, and flow identifier information. 19. The method of claim 18, Wherein the control unit instructs the preamble demodulator to change the preamble of the relay station at a set operation time. 1. A relay station apparatus in a wireless communication system using a multi-hop relay scheme, A message analyzer for acquiring new preamble information from the message when a preamble change indication message for instructing to change a preamble of the relay station is received from a base station during a relay service, A control unit for changing the preamble signal based on the information; And a preamble signal generator for generating the modified preamble signal. 22. The method of claim 21, Wherein the preamble change indication message includes at least one of index information of a new preamble of the RS, operation time information to which the new preamble is to be applied, terminal identifier information, and flow identifier information. 22. The method of claim 21, Further comprising a transmitter for transmitting a preamble change notification message to at least one lower node of the relay station when the preamble signal is changed. 24. The method of claim 23, Wherein the preamble change notification message includes at least one of index information of a new preamble of the RS, operation time information to which the new preamble is to be applied, terminal identifier information, and flow identifier information.

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