KR100985396B1 - Apparatus and method for selecting frame structure in broadband wireless access communication system using multi-hop relay method - Google Patents

Abstract

The present invention relates to an apparatus and method for selectively using a frame structure suitable for a system environment in a broadband wireless access communication system using a multi-hop relay method, the process of performing an initial access procedure with a predetermined relay station, Transmitting a control signal including the frame information to the relay station during the initial access procedure and using a frame structure suitable for a system environment, and having a transmission delay and over for each frame structure. The advantage is that the trade off between the heads can be freely selected.

Multi-hop relay method, frame structure, frame structure change, relay station, control message

Description

Apparatus and method for selecting frame structure in broadband wireless access communication system using multi-hop relay method {APPARATUS AND METHOD SELECTTING FRAME STRUCTURE IN MULTI-HOP RELAY BROADBAND WIRELESS ACCESS COMMUNICATION SYSTEM}

1 is a diagram showing the configuration of a broadband wireless access communication system using a general multi-hop relay method;

2 is a diagram illustrating a frame configuration of a broadband wireless access communication system according to the prior art;

3 is a diagram illustrating a frame configuration of a broadband wireless access communication system using a multi-hop relay method according to an embodiment of the present invention;

4 is a diagram illustrating a frame operation procedure of a broadband wireless access communication system using a multi-hop relay method according to an embodiment of the present invention;

5 is a diagram illustrating a frame configuration of a broadband wireless access communication system using a multi-hop relay method according to another embodiment of the present invention;

6 is a diagram illustrating a frame operation procedure of a broadband wireless access communication system using a multi-hop relay method according to another embodiment of the present invention;

7 is a diagram illustrating an operation procedure of a base station in a broadband wireless access communication system using a multi-hop relay method according to an embodiment of the present invention;

8 is a diagram illustrating a relay station operation procedure of a broadband wireless access communication system using a multi-hop relay method according to an embodiment of the present invention;

9 is a diagram illustrating an operation procedure of a base station in a broadband wireless access communication system using a multi-hop relay method according to another embodiment of the present invention;

10 is a diagram illustrating a relay station operation procedure of a broadband wireless access communication system using a multi-hop relay method according to another embodiment of the present invention; and

11 is a block diagram of a base station in a broadband wireless access communication system using a multi-hop relay method according to the present invention.

The present invention relates to a broadband wireless access communication system using a multi-hop relay method, and provides an apparatus and method for selectively using a frame structure suitable for a system environment in a broadband wireless access communication system using the multi-hop relay method. Is in.

In the fourth generation mobile communication system, which is a next generation communication system, cells having a very small radius are installed to enable high speed communication and to accommodate more call volume. In this case, centralized design using the current wireless network design method will be impossible. That is, while the wireless network of the fourth generation mobile communication system is distributed and controlled, it must be able to actively cope with environmental changes such as the addition of a new base station. Accordingly, the fourth generation mobile communication system must be configured as a self-configurable wireless network capable of providing a mobile communication service by autonomously and distributedly configuring a wireless network without control of a central system.

In order to implement the autonomous adaptive wireless network required in the fourth generation mobile communication system, a relaying technique for transmitting data in a multi-hop form using a relay station may be applied.

In general, since the communication is performed through a direct link between a base station and a mobile station, a wireless communication link having high reliability can be easily configured between the terminal and the base station. However, since the location of the base station is fixed, it is difficult to provide an efficient service in a wireless environment in which the traffic distribution or the call demand is changed due to low flexibility of the wireless network configuration.

In order to overcome such drawbacks, the fourth generation mobile communication system may apply a relaying method of transferring data in a multi-hop form using several terminals or relay stations in the vicinity. The relay technique can quickly reconfigure the network in response to changes in the surrounding environment, and more efficiently operate the entire wireless network. In addition, the relay scheme may provide a radio channel having a better channel state to the terminal by configuring a multi-hop relay path through the relay station by installing a relay station between the base station and the terminal. In addition, by using the multi-hop relay path, a high-speed data channel can be provided to terminals in a region where communication with the base station is not possible, such as a shaded region, thereby expanding a cell region.

1 illustrates a configuration of a broadband wireless access communication system using a general multi-hop relay method.

As shown in FIG. 1, the base station 100 is directly connected to the terminal 110 included in the service area 101. On the other hand, the base station 100 is located outside the service area 101 and is connected to the relay link through the terminal 120 and the relay station 130 having a poor channel state.

That is, the base station 100 uses the relay station 130 when the terminal 120 is located in a shaded area where shielding is severe due to the outside of the service area 101 or a building, and the channel state is poor. It is possible to provide a better wireless channel to the terminal 120. Accordingly, the base station 100 can provide a high-speed data channel to a cell boundary region having a poor channel state by applying the multi-hop relay scheme, and can expand the cell service region. In this case, since the broadband wireless access communication system relays a signal between the base station and the terminal using the relay station, not only the base station and the terminal link but also the base station and the relay station link and the relay station and the terminal link are configured.

However, the broadband wireless access communication system according to the prior art performs communication using a frame configuration as shown in FIG. Here, FIG. 2 illustrates a frame structure of an Institute of Electrical and Electronics Engineers (IEEE) 802.16e system.

2 shows a frame configuration of a broadband wireless access communication system according to the prior art.

As shown in FIG. 2, the frame includes a downlink subframe 200 and an uplink subframe 210.

The downlink subframe 200 includes a synchronization channel, control information, and a downlink burst transmitted from the base station to the terminal. In addition, the uplink subframe 210 is configured to include control information and uplink bursts transmitted from the terminal to the base station.

As described above, in the frame structure of the conventional broadband wireless access communication system, only resources for the base station and the terminal link are allocated. Accordingly, when the multi-hop relay method is used in the broadband wireless access communication system, a frame structure for allocating resources to the base station and the relay station link and the relay station and the terminal link as well as the base station and the terminal link is required.

Accordingly, an object of the present invention is to provide an apparatus and method for constructing a frame for using a multi-hop relay method in a broadband wireless access communication system.

Another object of the present invention is to provide an apparatus and method for using a frame structure suitable for a system environment in a broadband wireless access communication system using a multi-hop relay method.

Still another object of the present invention is to provide an apparatus and method for transmitting frame structure information to each RS using control information in a BWA communication system using a multi-hop relay method.

Another object of the present invention is to provide an apparatus and method for providing frame structure information to a relay station initially connected in a broadband wireless access communication system using a multi-hop relay method.

Another object of the present invention is to provide an apparatus and method for providing frame structure change information to a relay station that is connected when a frame structure is changed in a broadband wireless access communication system using a multi-hop relay method.

According to a first aspect of the present invention for achieving the above object, a method for transmitting frame information in a serving node of a wireless communication system using a multi-hop relay method, the process of performing an initial access procedure with a predetermined relay station, And transmitting a control signal including frame information to the relay station during the initial access procedure.

According to a second aspect of the present invention, a method for selecting a frame structure in a relay station of a wireless communication system using a multi-hop relay method includes performing an initial access procedure with a serving node, and receiving frame information from the serving node. When the control signal is received, including the step of checking the frame structure and the relay service start time information included in the frame information, and performing the communication using the frame structure when the relay service start time It is characterized by.

According to a third aspect of the present invention, a method for selecting a frame structure in a relay station of a wireless communication system using a multi-hop relay method includes the steps of checking whether a control signal is received from a serving node and using the control signal. Synchronizing with the serving node and checking frame information, and requesting initial access to the serving node.

According to a fourth aspect of the present invention, a method for transmitting frame information in a serving node of a wireless communication system using a multi-hop relay method includes, when a frame structure is changed, a frame structure that is changed and relay stations connected to the frame are changed. And checking the time information for changing the structure, and transmitting a control signal including the changed frame structure and the changed time information to the relay station.

According to a fifth aspect of the present invention, a method for selecting a frame structure in a relay station of a wireless communication system using a multi-hop relay method includes: connecting to a serving node to perform communication, and changing a frame structure from the serving node; When a signal including information is received, checking a frame structure changed from the signal and change time information of the frame structure, and performing communication using the changed frame structure when the frame structure change time arrives. Characterized in that it comprises a.

According to a sixth aspect of the present invention, in a wireless communication system using a multi-hop relay method, a serving node device includes a frame structure checking unit for checking a frame structure of the serving node, and a control message including the frame structure information. And a transmitter for generating the message generator and a transmitter for transmitting the control message to the lower relay station.

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 subject matter of the present invention, the detailed description thereof will be omitted.

Hereinafter, the present invention describes a technique for selectively using a frame structure suitable for a system environment in a broadband wireless access communication system using a multi-hop relay method. In the following description, the broadband wireless access communication system will be described using the frame structure selectively according to a system environment (eg, frame length).

In addition, the following description will be exemplarily described for a broadband wireless access communication system using a time division duplex and orthogonal frequency division multiplexing access scheme, and another multiple access scheme and another divided duplex basis. The same applies to the communication system.

The broadband wireless access communication system supports a multi-hop relay method using a frame having a structure as shown in FIGS. 3 and 5.

3 illustrates a frame configuration of a broadband wireless access communication system using a multi-hop relay method according to an exemplary embodiment of the present invention.

As shown in FIG. 3, the frame includes a downlink subframe 300 and an uplink subframe 310. In this case, the downlink subframe 300 and the uplink subframe 310 are the first interval (301, 311), the second interval (303, 313), the third interval (305, 315) using time resources. Separated by.

First, the first intervals 301 and 311 include a subframe for the base station and the terminal link and a subframe for the relay station and the terminal link.

Next, the second section 303, 313 includes a subframe for the base station and the terminal link, a subframe for the relay station and the relay station link, and a subframe for the odd hop end relay station and the terminal link.

Finally, the third section 305, 315 includes a subframe for the base station and the 1-hop relay station, a subframe for the relay station and the relay station link, and a subframe for the even-hop terminal relay station and the terminal link.

In the frame structure, a TTG (Transmit / receive Transmission Gap), which is a time protection region, exists between the downlink subframe 300 and the uplink subframe 310. In addition, there is a Receive / Transmit Transmission Gap (RTG) that is a time protection region between the frame and the frame.

Using the frame structure configured as described above, the base station and the relay station operate as shown in FIG.

4 illustrates a frame operation procedure of a broadband wireless access communication system using a multi-hop relay method according to an exemplary embodiment of the present invention.

As shown in FIG. 4, the i-th frame 400 includes a downlink subframe 410 and an uplink subframe 420. In this case, the downlink subframe 410 and the uplink subframe 420 use a time resource to use a first section 411 and 421, a second section 413 and 423, and a third section 415 and 425. It is divided into two parts.

When the broadband wireless communication system communicates using the frame structure, first, the base station 430 firstly divides the first intervals 411 and 421 of the downlink subframe 410 and the uplink subframe 420 from each other. The terminal 1 communicates with the terminal 1 included in the service area during the two sections 413 and 423. In addition, the base station 430 communicates with the one-hop relay station during the third periods 415 and 425.

Next, the odd-hop relay station 440 communicates with the terminal 2 included in the service area during the first intervals 411 and 421.

The odd hop relay station 440 communicates with the next even hop relay station 450 during the second period 413 and 423. Here, when the odd hop relay station 440 is an end hop relay station, the relay station communicates with the terminal 2 during the second intervals 413 and 423.

The odd hop relay station 440 communicates with a previous even hop relay station during the third interval 415, 425. Here, when the odd-hop relay station 440 is a one-hop relay station, the relay station 440 communicates with the base station during the third periods 415 and 425.

Finally, the even-hop relay station 450 communicates with the terminal 3 included in the service area during the first intervals 411 and 421.

The even-hop relay station 450 communicates with the previous odd-hop relay station 440 during the second intervals 413 and 423.

The even-hop relay station 450 communicates with the next odd-hop relay station during the third period 415, 425. Here, when the even-hop relay station 450 is an end hop relay station, the relay station 450 communicates with the terminal 3.

5 illustrates a frame configuration of a broadband wireless access communication system using a multi-hop relay method according to another embodiment of the present invention.

As shown in FIG. 5, the frame includes a downlink subframe 500 and an uplink subframe 510. In this case, the downlink subframe 500 and the uplink subframe 510 are divided into a first section 501 and 511 and a second section 503 and 513 using time resources.

First, the first intervals 501 and 511 are configured to include a subframe for the base station and the terminal link and a subframe for the relay station and the terminal link.

Next, the second intervals 503 and 513 include a subframe for the base station and the 1-hop relay station link, a subframe for the relay station and the relay station link, and a subframe for the end relay station and the terminal link.

In the frame structure, there is a TTG (Transmit / receive Transmission Gap) that is a time protection region between the downlink subframe 500 and the uplink subframe 510. In addition, there is a Receive / Transmit Transmission Gap (RTG) that is a time protection region between the frame and the frame.

When using the frame structure as shown in FIG. 5 in the broadband wireless access communication system, when the system is configured with three or more hops, two frames are configured as one super frame as shown in FIG. The base station and the relay station operate.

6 illustrates a frame operation procedure of a broadband wireless access communication system using a multi-hop relay method according to another exemplary embodiment of the present invention.

As shown in FIG. 6, the i-th frame 600 and the (i + 1) -th frame 630 include downlink subframes 611 and 631 and uplink subframes 613 and 633. In this case, the subframes 611, 613, 631, and 633 are divided into first sections 621, 625, 641, and 645 and second sections 623, 627, 643, and 647 using time resources. do.

When the broadband wireless communication system communicates using the frame structure, the base station 650 first communicates with the terminal 1 included in the service area during the first period 621, 625, 641, and 645. . In addition, the base station 650 communicates with the 1-hop relay station during the second intervals 623 and 627 of the i-th frame 600, and the second interval (i + 1) -th frame 630 ( 633, 637 and communicates with the terminal 1.

Next, the odd-hop relay station 660 communicates with the terminal 2 included in the service area during the first period 621, 625, 641, 645. In addition, the odd-hop relay station 660 communicates with the previous even-hop relay station during the second intervals 623 and 627 of the i-th frame 600, and transmits the first of the (i + 1) th frames 630. Communicate with the next even hop relay station during two intervals (633, 637).

In this case, when the odd-hop relay station 660 is the one-hop relay station, the relay station 660 communicates with the base station during the second periods 623 and 627 of the i-th frame 600. In addition, the relay station 660 communicates with the two-hop relay station during the second periods 633 and 637 of the (i + 1) th frame 630.

When the odd-hop relay station 660 is an end hop relay station, the relay station 660 communicates with the terminal 2 during the second intervals 633 and 637 of the (i + 1) th frame 630.

Finally, the even-hop relay station 670 communicates with the terminal 3 included in the service area during the first period 621, 625, 641, 645. In addition, the even-hop relay station 670 communicates with the next odd-hop relay station during the second intervals 623 and 627 of the i-th frame 600, and performs the first of the (i + 1) th frame 630. Communicate with the previous odd hop relay station during two intervals (633, 637).

In this case, when the even-hop relay station 670 is an end hop relay station, the relay station 670 communicates with the terminal 3 during the second periods 623 and 627 of the i-th frame 610.

The frame structures shown in FIGS. 3 and 5 defined for using the multi-hop relay scheme in the broadband wireless access communication system have different characteristics.

First, in the frame structure configured as shown in FIG. 3, a relay station receives a signal from a base station or an upper relay station for one frame and transmits the signal to a lower relay station.

Therefore, the relay station can relay a signal for one frame, thereby reducing the transmission delay. However, the relay station performs operation switching while switching from the second section to the third section of the frame. Accordingly, an operation switching resource for operation switching of the relay station is required between the second interval and the third interval of the frame.

Next, in the frame structure configured as shown in FIG. 5, the RS receives a signal from a base station or an upper RS during a first frame and transmits the signal to a lower RS during a second frame.

Thus, the relay station relays the signal over two frames, causing a transmission delay. However, since the signal is received in the first frame and the signal is transmitted in the second frame, resources required for switching the operation of the relay station can be reduced.

The broadband wireless access communication system may use frames having different lengths for different systems. For example, a frame of a specific length may be used within 2 ms to 20 ms for each system. In this case, the frame length and structure defined in the system are commonly used by all nodes included in the system. That is, although the systems can communicate using different frame lengths and frame structures, all nodes included in the same system communicate using the same frame length and structure.

If the broadband wireless access communication system uses a frame having a short length (for example, 2 ms), since the frame length is short, the operation switching resource of the frame structure configured as shown in FIG. 3 is a large overhead for the system. Works. That is, in the t system, the operation switching resource has a greater impact on the performance of the system than the transmission delay shown in the frame structure shown in FIG.

Therefore, when the broadband wireless access communication system uses the short frame, it is more efficient to support the relay service using the frame structure of FIG. 5 than the frame structure of FIG. 3.

On the other hand, when the broadband wireless access communication system uses a frame having a long length (for example, 20 ms), since the frame length is long, the operation switching resource of the frame structure configured as shown in FIG. 3 does not significantly affect the system. . That is, the transmission delay shown in the frame structure configured as shown in FIG. 5 in the system has a greater impact on the performance of the system than the operation switching resource.

Therefore, when the broadband wireless access communication system uses the long frame, it is more efficient to support the relay service using the frame structure of FIG. 3 than the frame structure of FIG. 5.

As described above, in the broadband wireless access communication system using the multi-hop relay method, it is more efficient to selectively use a frame structure suitable for a system environment (eg, frame length). Therefore, the following description describes the operation of the base station and the relay station for selectively using a frame structure suitable for a system environment in the broadband wireless access communication system. In the following description, an example of transmitting frame structure information from a base station to a relay station is described. However, the same applies to the case of transmitting frame structure information from the upper relay station to the lower relay station.

In the following description, FIGS. 7 and 8 describe operations of a base station for providing frame information of a system at initial access in the broadband wireless access communication system and a relay station for receiving the frame information. In this case, the frame information transmitted by the base station includes a frame structure selected by a system environment (for example, a frame length) and a frame number to start a relay service using the frame structure. In another embodiment, the frame information may include start position information of area information for the RS to communicate with a higher node to perform a relay service after initial access. Here, when the relay station performs initial access to the base station, the relay station performs initial access using an area for the base station to communicate with the terminal. For example, when the broadband wireless access communication system uses the frame structure of FIG. 3, the RS performs initial access with the base station using the first intervals 301 and 311.

If the broadband wireless access communication system uses the frame structure of FIG. 5, the RS performs initial access with the base station using the first sections 501 and 511.

7 is a flowchart illustrating a base station operation procedure of a broadband wireless access communication system using a multi-hop relay method according to an exemplary embodiment of the present invention.

Referring to FIG. 7, the base station first checks whether an initial access request signal is received from an arbitrary relay station in step 701.

When the initial access request signal is received from the relay station, the base station checks frame information of the broadband wireless access communication system in step 703. Here, the frame information includes a frame structure selected by a system environment (for example, a frame length) in the broadband wireless access communication system and a frame number to start a relay service using the frame structure. Here, for example, the base station checks the frame information before performing the initial access procedure. However, the base station may check the frame information during the initial access procedure. In addition, the base station may check the frame information before the initial access request signal is received.

After confirming the frame structure and the frame number, the base station proceeds to step 705 to determine its communication status (eg, load) to determine whether the relay station accepts the initial access. If the relay station accepts the initial access, the base station performs an initial access procedure with the relay station.

During the initial access, the base station proceeds to step 707 and transmits a control message including the frame structure and the frame number of the system to the relay station.
For example, the base station transmits the frame structure and the frame number to the relay station using a downlink channel descriptor (DCD) message. In another embodiment, the base station transmits the frame structure and frame number using the last control message of the initial access procedure. That is, when the last procedure of the initial access is a registration procedure, the base station includes the frame structure and the frame number in the registration response message and transmits it to the relay station. Here, the broadband wireless access communication system can assign a specific index for each supportable frame structure. In this case, the base station transmits an index of a frame structure used by the broadband wireless access communication system in the control message. If the base station includes only the start position information of an area for starting a service using the relay link in the control message may be transmitted. In this case, the base station transmits the frame structure and the frame number to the relay station by including the frame structure and the frame number in a control message of a region for starting a service using the relay link.

The base station then terminates this algorithm.

8 is a flowchart illustrating a relay station operation procedure of a broadband wireless access communication system using a multi-hop relay method according to an exemplary embodiment of the present invention.

Referring to FIG. 8, first, the RS acquires synchronization with the BS through a synchronization channel received from the BS in step 801.

After acquiring synchronization with the base station, the RS proceeds to step 803 to transmit an initial access request signal to the base station.

Thereafter, the RS proceeds to step 805 to check whether an initial access response signal is received from the base station.

If the initial access response signal is received, the RS proceeds to step 807 to perform an initial access procedure with the base station.

During the initial access procedure, the RS proceeds to step 809 to check whether a control message including frame information of the base station is received. Here, the frame information includes the frame structure information and the frame number. For example, the control message indicates a DCD message of the access link of FIG. 3 or 5 or a control message of the last procedure of the initial access procedure. In another embodiment, the frame information may include start position information of an area for the relay station to start a service using a relay link.

If the control message including the frame information is received, the RS proceeds to step 811 to determine a frame structure used by the base station included in the control message and a frame number for starting a relay service using the frame structure. Check it. Here, the frame number indicates a frame number for the relay station to start a service using a relay link instead of the first section (Access Link) of FIG. 3 or 5. When the control message includes a start position of an area for starting a service using the relay link, the RS may identify the frame structure and the frame number through a control message of the area according to the start position.

After checking the frame structure and the frame number, the RS proceeds to step 813 to perform communication using the frame structure from the time point at which the relay service is provided through the frame number.

The relay station then terminates this algorithm.

In the above-described embodiment, the base station transmits the frame information to the relay station using a DCD message or a control message when the lower relay station is initially connected. In another embodiment, the base station may include the frame information in a DCD message transmitted every predetermined period and transmit the same. Accordingly, according to the transmission period of the DCD message, the RS may check frame information included in the DCD message received from the base station before the initial access request. For example, the frame information included in the DCD message received in the process of acquiring the relay station with the base station is checked. Thereafter, an initial access request signal is transmitted to the base station.

The initial access procedure between the base station and the relay station indicates from the time when the relay station receives the broadcast message of the base station and acquires synchronization to the time when the initial connection is completed. Accordingly, the RS can check frame information by receiving a DCD message periodically transmitted by the BS during an initial access procedure. Here, the base station can provide frame information to the relay station using a separate message as well as the DCD message.

Next, FIG. 9 and FIG. 10 describe operations of a base station and a relay station for changing the frame structure according to the system environment by changing the system environment in the broadband wireless access communication system.

9 is a flowchart illustrating an operation of a base station in a broadband wireless access communication system using a multi-hop relay method according to another embodiment of the present invention.

Referring to FIG. 9, in step 901, the base station communicates with the relay station when the relay station is connected. For example, the base station communicates with the relay station using a frame structure as shown in FIG. 3 or 5.

Thereafter, the base station proceeds to step 903 to determine whether the environment of the system is changed to change the frame structure.

If the frame structure is changed, the base station proceeds to step 905 and checks the changed frame structure and the frame number for applying the frame structure. Here, all nodes included in the broadband wireless access communication system including the base station communicate using the same frame at the same time. Accordingly, the base station transmits the changed frame structure information to all nodes over multiple hops by transmitting a frame number, so that all the nodes can communicate using the changed frame structure at the same time.

After checking the changed frame structure and frame number, the base station proceeds to step 907 and transmits a frame structure change control message including the frame structure and the frame number to the relay station. For example, the base station transmits the frame structure and the frame number in the DCD message included in the relay link of FIG. 3 or 5. In addition, the base station transmits the frame structure and the frame number in the relay station DL (MA) included in the relay link of FIG. 3 or 5. In this case, when the base station uses the relay station DL-MAP, the frame structure and frame number are included as IE (Information Element) information of the relay station DL-MAP. The base station may include the frame structure and the frame number as one field in the relay station DL-MAP or as a field in PHY synchronization of the relay station DL-MAP.

The base station then terminates this algorithm.

In the above-described embodiment, the base station selects a frame structure for communicating with the relay station from among the frame structure of FIG. 3 and the frame structure of FIG. 5 according to a system environment, and transmits the frame information to the relay station.

In another embodiment, when a two-hop broadband wireless communication system is extended to three or more hops by connecting a lower relay station to a relay station, the system may change the frame structure.

The two-hop broadband wireless communication system uses a frame structure configured by dividing a subframe into a section for a direct link and a section for a relay link. At this time, when the broadband wireless access communication system is extended to more than three hops, the system performs communication using a super frame including two frames as shown in FIG.

That is, when the broadband wireless access communication system uses two hops, communication is performed through one frame, and when extended to three or more hops, the communication is performed using two frames.

Therefore, the base station or the upper relay station generates the relay station DL-MAP including the frame information in the form of Table 1 and transmits it to the lower relay station.

Syntax Size Notes Frame_Type_IE () Extended DUIUC 4bits Frame_Type = 0xxx Length 4bits Length = 0x03 Frame unit change 1 bit '1' indicate the start that enable 2 frame unit
'0' indicate the start of that enable 1 frame unit Frame number 7bits Frame number that enable 2 frame unit

Here, the Frame_Type_IE includes frame unit change information indicating frame structure information to be used in the system and frame number information indicating a frame number to which the frame structure is to be applied. That is, when the frame unit change information is 1, two frames are used, and thus the frame structure when the frame unit change information is extended to three or more hops is shown. In addition, when the frame unit change information is 0, since one frame is used, a frame structure having a two hop structure is shown.

10 is a flowchart illustrating a relay station operation procedure of a broadband wireless access communication system using a multi-hop relay method according to another embodiment of the present invention.

Referring to FIG. 10, first, the RS accesses a base station in step 1001 to perform communication with the base station. For example, the relay station communicates with the base station using the frame structure shown in FIG. 3 or 5.

In step 1003, the RS checks whether a frame structure change message is received from the BS. Here, the frame structure change message is received in a DCD message or DL-MAP included in the relay link of FIG. 3 or 5.

If the frame structure change message is received, the RS proceeds to step 1005 to check the frame structure and frame number that are changed in the frame structure change message. Here, the frame number indicates viewpoint information for changing the frame structure.

After confirming the frame structure and the frame number, the RS proceeds to step 1007 to change the checked frame number from the checked frame structure to perform communication.

The relay station then terminates this algorithm.

In the above-described embodiment, the base station transmits the frame information to the relay station using the DCD message or DL-MAP during the relay link period. However, the base station may transmit the frame information to the relay station using a message defined separately for transmitting the frame information during the relay link period.

The following description describes a block structure for transmitting the frame structure and frame number of the broadband wireless access communication system from the base station to the relay station as described above. Here, since the upper relay station that transmits the frame structure and frame number to the lower relay station is configured in the same manner as the base station, a description thereof will be omitted.

11 is a block diagram of a base station in a broadband wireless access communication system using a multi-hop relay method according to the present invention.

As shown in FIG. 11, the base station includes an RF processor 1101 and 1123, an analog / digital convertor 1103, an OFDM demodulator 1105, a decoder 1107, and a message processor 1109. Control unit 1111, frame structure checker 1113, message generator 1115, encoder 1117, OFDM modulator 1119, digital / analog converter 1121, switch 1125 And a time controller 1127.

First, the time controller 1127 controls the switching operation of the switch 1125 based on frame synchronization. For example, if a signal is received, the time controller 1127 controls the switch 1125 so that the antenna and the RF processor 1101 of the receiver are connected to each other. In addition, when the signal transmission period, the switch 1125 is controlled to connect the antenna and the RF processor 1123 of the transmitting end.

During the reception period, the RF processor 1101 frequency down converts a radio frequency (RF) signal received through an antenna into a baseband analog signal. The analog-to-digital converter 1103 converts an analog signal from the RF processor 1101 into sample data and outputs the sample data. The OFDM demodulator 1105 performs fast Fourier transform on the sample data output from the analog / digital converter 1103 and outputs data in a frequency domain.

The decoder 1107 selects data of subcarriers to be actually received from data in the frequency domain from the OFDM demodulator 1105, demodulates the selected data according to a predetermined modulation level (MCS level), and Decode and output

The message processor 1109 decomposes a control message input from the decoder 1107 and provides the result to the controller 1111. For example, as shown in FIG. 7, an initial access request signal of a relay station is extracted and provided to the controller 1111.

The controller 1111 performs a corresponding process on the information provided from the message processor 1109 and provides the result to the message generator 1115. In this case, when the initial connection or frame structure of the relay station is changed, the controller 1111 checks the frame structure of the broadband wireless access communication system from the frame structure checking unit 1113 to the message generating unit 1115. to provide.

The frame structure checking unit 1113 confirms the frame structure of the broadband wireless access communication system including the base station.

During the transmission period, the message generator 1115 generates a message with various types of information provided from the controller 1111 and outputs the message to the encoder 1117 of the physical layer. For example, when the RS is initially connected, the message generator 1115 includes the frame structure and the frame time in the DCD message of the access link section of FIG. 3 or 5 and outputs the frame structure and the frame time to the encoder 1117. . In addition, the frame structure and the frame time may be included in the control message of the last procedure of the initial access procedure of the relay station and output to the encoder 1117.

If the frame structure is changed while the relay station is connected, the message generator 1115 transmits the frame structure and the frame to the DCD message or DL-MAP included in the relay link section of FIG. 3 or 5. The time is included and output to the encoder 1117.

The encoder 1117 codes and modulates the data from the message generator 1115 according to a predetermined modulation level (MCS level) and outputs the encoded data. The OFDM modulator 1119 performs inverse fast Fourier transform on the data from the encoder 1117 and outputs sample data (OFDM symbols). The digital-to-analog converter 1121 converts the sample data into an analog signal and outputs the analog signal. The RF processor 1123 frequency-converts the baseband analog signal from the digital-to-analog converter 1121 to a high frequency signal and transmits the same through an antenna.

In the above configuration, the controller 1111 is a protocol controller, and controls the message processor 1109, the message generator 1115, and the frame structure checker 1113. That is, the controller 1111 may perform the functions of the message processor 1109, the message generator 1115, and the frame structure checker 1113. In the present invention, it is separately configured to describe each function separately. Therefore, in actual implementation, all of them may be configured to be processed by the controller 1111, and only some of them may be configured to be processed by the controller 1111.

The above-described embodiment has been described with an example of performing communication by selecting one frame structure among the two frame structures shown in FIGS. 3 and 5 according to a system environment in the broadband wireless access communication system. However, the same applies to selecting other types of frame structures that can be supported in the broadband wireless access communication system.

If the base station or the upper relay station is changed due to the handover of the relay station having the mobility, the relay station must grasp in advance the frame structure of the target base station or the target higher relay station that performed the handover. Therefore, the serving base station or the serving upper relay station includes the frame structure information in the neighbor base station or neighbor upper relay station information and transmits the information. That is, the RS can grasp the frame structure of the neighbor BS or the neighbor RS through the neighbor BS or the neighbor RS received from the serving BS or the serving RS.

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.

As described above, in a broadband wireless access communication system using a multi-hop relay method, a frame structure suitable for a system environment (for example, frame length) is selected, and the selected frame structure information is informed to a lower relay station, thereby making it suitable for a system environment. There is an advantage in that a frame structure can be used, and the trade-off between transmission delay and overhead that each frame structure has can be freely selected.

Claims (40)

A method for transmitting frame information in a serving node of a wireless communication system using a multi-hop relay method, Generating a control signal including the frame information; Transmitting the control signal to a lower relay station, The frame information includes structure information of the frame and time point at which the relay station starts a relay service using the frame structure. The method of claim 1, And the serving node is a base station or an upper relay station. delete The method of claim 1, The frame structure is a super frame comprising a single frame or at least one single frame consisting of one frame. The method of claim 1, The frame structure is characterized in that divided into the number of sub-frames constituting the frame. The method of claim 1, And the frame structure is determined according to system environment information of the wireless communication system. The method of claim 6, The system environment information includes length information of a frame used in the wireless communication system. The method of claim 1, The process of generating the control signal, Performing an initial access procedure with a predetermined relay station, Generating a control signal including the frame information during the initial access procedure. The method of claim 8, The control signal is characterized in that for transmitting using the interval for performing communication with the terminals in the frame. The method of claim 8, In case of generating a control signal including start position information of a section for communicating with the relay station for a relay service, After the initial access, generating a control signal including frame structure information and information on when the relay station starts the relay service using the frame structure; Transmitting the control signal in a section for communicating with the relay station. The method of claim 8, The initial access procedure, Method using a period for performing communication with the terminals in the frame. The method of claim 1, The control signal may include a downlink channel descriptor (DCD) message or a control message of the last procedure in the initial access procedure. A method for selecting a frame structure in a relay station of a wireless communication system using a multi-hop relay method, Performing an initial access procedure with the serving node, When a control signal including frame information is received from the serving node, checking a frame structure and relay service start time information included in the frame information; And when the relay service starts, communication is performed using the frame structure. The method of claim 13, And the serving node is a base station or an upper relay station. The method of claim 13, The control signal may include a downlink channel descriptor (DDC) message or a control message of a last procedure in the initial access procedure. A method for selecting a frame structure in a relay station of a wireless communication system using a multi-hop relay method, Checking whether a control signal is received from the serving node; Synchronizing with the serving node and checking frame information using the control signal; Requesting initial access to the serving node; The frame information includes a structure of the frame and relay service start time information. The method of claim 16, And the serving node is a base station or an upper relay station. The method of claim 16, The control signal, characterized in that it comprises a Downlink Channel Descriptor (DCD) message. delete The method of claim 16, Performing an initial access procedure with the serving node; And when the start time of the relay service included in the frame information, communicating using the frame structure included in the frame information. A method for transmitting frame information in a serving node of a wireless communication system using a multi-hop relay method, When the frame structure is changed, checking the time frame at which the changed frame structure and accessing relay stations change the frame structure; And transmitting a control signal including the changed frame structure and the changed time point information to the relay station. The method of claim 21, And the serving node is a base station or an upper relay station. The method of claim 21, And the frame structure is changed according to system environment information of the wireless communication system. 24. The method of claim 23, The system environment information includes length information of a frame used in the wireless communication system. The method of claim 21, And the control signal is transmitted using the predetermined interval allocated for communicating with a destination through the relay station in the frame. The method of claim 21, The control signal is any one of a downlink channel descriptor (DDC) message, a downlink MAP message, and a frame structure change message. The method of claim 26, The frame structure and the change time point information may include one field value of the downlink MAP message, one information element (IE) information of the downlink MAP message, and one of PHY synchronization of the downlink MAP message. Method included in the downlink MAP in the form of any one of the field values. The method of claim 26, The downlink MAP is characterized in that it comprises the changed frame structure to be divided into the number of frames to use for communication. A method for selecting a frame structure in a relay station of a wireless communication system using a multi-hop relay method, Connecting to the serving node to perform communication; When a signal including frame structure change information is received from the serving node, checking a frame structure changed in the signal and change time information of the frame structure; And when the frame structure change time is reached, communicating using the changed frame structure. The method of claim 29, And the serving node is a base station or an upper relay station. The method of claim 29, The signal is received over a predetermined interval allocated for communicating with a destination via the relay station in the frame. The method of claim 29, The signal may be any one of a downlink channel descriptor (DCD) message, a downlink MAP message, and a frame structure change message. 33. The method of claim 32, The frame structure and the modification time point information may include any one field value of the downlink MAP message, one IE information of the downlink MAP message, and one field value of PHY synchronization of the downlink MAP message. The method characterized in that included in the downlink MAP in one form. 33. The method of claim 32, The downlink MAP is characterized in that it comprises the changed frame structure to be divided into the number of frames to use for communication. A serving node device in a wireless communication system using a multi-hop relay method, A frame structure checking unit for checking a frame structure of the serving node; A message generator for generating a control message including the frame structure information; And a transmitter for transmitting the control message to a lower relay station. 36. The method of claim 35, And the serving node is a base station or an upper relay station. 36. The method of claim 35, The frame structure confirmation unit, And identifying a frame structure selected according to a system environment of the wireless communication system. 36. The method of claim 35, The message generator, When the relay station initially accesses, the apparatus comprises generating a downlink channel descriptor (DCD) message including the frame structure information and the relay service start time information or a control message of the last procedure in the initial access procedure. 36. The method of claim 35, The message generator, And when the frame structure is changed, generating a downlink channel descriptor (DCD) message or a downlink MAP message or a frame structure change message including the changed frame structure information and the frame structure change time information. 40. The method of claim 39, The message generating unit may include one field value of the downlink MAP message, one IE information of the downlink MAP message, and one of PHY synchronization of the downlink MAP message. Apparatus characterized by including in the form of any one of the field values.

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