KR100953568B1 - Downlink scheduling method in wireless communication system - Google Patents

Abstract

Disclosed is a downlink scheduling method of a frame in a TR-MMR system. The control data for the data burst area of the DAZ section of the frame and the control data for the data burst area of the OTZ section are configured in the MAP of the frame, and the data to be transmitted from the relay station to the mobile station in the next frame is transmitted to the relay station in advance through the current frame. In addition, accurate and fast data transmission via relay stations is possible.

Description

Downlink scheduling method in wireless communication system

The present invention relates to a downlink scheduling method in a wireless communication system, and more particularly, to a downlink scheduling method of a base station and a relay station in a TR (Mobile Multi-hop Relay) system.

The present invention is derived from the research conducted as part of the IT growth engine technology development project of the Ministry of Information and Communication and the Ministry of Information and Communication Research and Development. [National Management No .: 2006-S-011-02, Task name: relay / mesh for multi-hop WiBro] Communication system development].

In general, a mobile multi-hop relay (MMR) system includes a non-transparent (NTR) -transmitter that transmits a separate preamble and MAP information from a relay station, and a TR (transparent) that does not transmit separate preamble and MAP information from a relay station. It is divided into MMR system. In the TR-MMR system, the downlink section of a frame is divided into a downlink access zone (DAZ) and an optional transparent zone (OTZ).

Therefore, when the conventional WiMax Time Division Duplexing (TDD) frame structure is applied to the TR-MMR system, there is a problem in that burst information of the DAZ section and burst information of the OTZ section cannot be configured as one dl_map_ie.

An object of the present invention is to provide a scheduling method for a mobile station to receive accurate data from a base station or a relay station in a TR-MMR system using a frame composed of a downlink period (DAZ) and an optional transmission period (OTZ). There is.

One embodiment of a downlink scheduling method in a base station according to the present invention for achieving the above technical problem, in the downlink scheduling method of the base station in a wireless communication system consisting of a base station, a relay station and a mobile station, the current frame 1, first control data for a data burst region of a downlink access interval in which data is transmitted from the base station to the relay station, and second control data for a data burst region of a selective transmission interval in which data is transmitted from the relay station to the mobile station. Assigning to the control data area of the current frame; And in the next frame, allocating a relay packet including data to be transmitted by the relay station to the mobile station and third control data required for transmitting the relay packet through the selective transmission period of the next frame to the first data burst region. It includes.

In order to achieve the above technical problem, an embodiment of a downlink scheduling method in a relay station according to the present invention, in the downlink scheduling method of the relay station in a wireless communication system consisting of a base station, a relay station and a mobile station, the base station A first control data for a data burst region of a downlink access interval in which data is transmitted to the relay station and a second control data for a data burst region of a selective transmission interval in which data is transmitted from the relay station to the mobile station in Receiving a frame from the base station; And allocating data to be transmitted from the relay station to the mobile station through the data burst region of the downlink access interval of the previous frame to the data burst region of the selective transmission interval of the current frame.

According to the present invention, the control data for the burst of the downlink access interval and the information about the burst of the selective transmission interval are configured in one frame in the MAP area of the frame so that the data via the relay station can be accurately and quickly transmitted to the mobile station. Can be.

Hereinafter, a method of scheduling a frame according to the present invention will be described in detail with reference to the accompanying drawings.

1 is a diagram illustrating an example of a frame structure of a WiMax TDD system.

Referring to FIG. 1, a frame 100 of a WiMax Time Divison Duplexing (TDD) system based on Orthogonal Frequency Division Multiplexing (OFDM) is generally a downlink that transmits data from a base station to a mobile station. A downlink (DL) section 110 and an uplink (UL) section 150 for transmitting data from the mobile station to the base station are divided.

The DL section 110 includes general data from the base station to the mobile station and the DL_MAP 116 including control data such as the preamble 112, the FCH 114 indicating the characteristics of the control data, dl_map_ie including information of the DL burst, and the like. DL burst 118 for transmission, UL section 150 is for transmitting the general data from the mobile station to the base station and the area 152 for the transmission of control data, such as ranging (ranging) from the mobile station to the base station UL burst 154 or the like.

2 is a flowchart illustrating an example of a frame scheduling method of a base station in a WiMax TDD system.

Referring to FIG. 2, the base station classifies packets to be transmitted to a plurality of mobile stations every frame (for example, 5 msec) into packets having the same Modulation & Coding Scheme (MCS) level (S200), and packets of the same MCS level. It consists of one burst (S210). That is, the base station classifies packets into groups having the same Modulation Order and Coding Order, and configures one or more all packets having the same MCS level into one DL burst.

The base station allocates resources for the DL burst (S220). That is, the base station allocates two-dimensional resources consisting of a specific subchannel section and a specific symbol section in a frame to the DL burst. The base station configures dl_map_ie including two-dimensional resource allocation information and a CID (Call ID) for distinguishing a receiving mobile station of a packet included in a specific DL burst.

The base station performs the same process for all packets to be transmitted in a specific frame to configure one or more DL bursts and one or more dl_map_ie to configure a downlink period of a frame composed of preamble, FCH, DL_MAP, and DL burst. . That is, the base station transmits a preamble, an FCH, one or more dl_map_ie, and one or more DL bursts during the DL period.

However, in the TR-MMR system, the DL section of the frame is divided into a downlink access zone (DAZ) section and an optional tramsparent zone (OTZ) section, so that the base station can transmit data to the mobile station only in the DAZ section, and the relay station can use the OTZ. Data can be transmitted to the mobile station only in the section. In addition, DL bursts having the same MCS level may exist in the DAZ section and the OTZ section, respectively. In this case, DL burst information of the same MCS level may exist in the DAZ section and the OTZ section of the DL section using one dl_map_ie. It cannot be provided.

3 is a flowchart illustrating a flow of an embodiment of a frame receiving method of a mobile station in a WiMax TDD system.

Referring to FIG. 3, when a mobile station receives a frame from a base station, the mobile station receives a specific burst including a packet transmitted to the mobile station based on the CID included in the control data dl_map_ie.

Specifically, when the mobile station receives the dl_map_ie of the frame from the base station (S300), it first checks whether the dl_map_ie includes the CID assigned to the mobile station (S310). If its CID is included, the mobile station grasps resource allocation information of the DL burst corresponding to the CID from dl_map_ie, receives the corresponding burst (S320), and acquires a packet corresponding to the CID from the received burst (S330). ).

4 is a diagram illustrating an example of a structure of dl_map_ie used in a WiMax TDD system.

Referring to FIG. 4, dl_map_ie exists for each DL burst configured for each MCS level. dl_map_ie includes resource allocation information (symbol, subchannel) in a frame of a DL burst and CIDs of packets included in the corresponding DL burst. A plurality of DL bursts and a plurality of dl_map_ie may be transmitted through one frame.

5A is a diagram illustrating an example of a frame structure of a TR-MMR system according to the present invention, and FIG. 5B is a diagram briefly showing an overall configuration of a TR-MMR system to which the present invention is applied.

5A and 5B, the frame 500 of the TR-MMR system according to the present invention is characterized in that the base station 560 transmits data to the relay station 565 or the mobile station 575 from the viewpoint of the base station 560. The DL section 510 and the mobile station 575 or the relay station 565 are configured as a UL section 550 for transmitting data to the base station 560.

The DL interval 510 is a DAZ (Dlownlink Access Zone) section 520 in which the base station 560 transmits data to the relay station 565 or the mobile station 575 and the mobile station 570 in which the relay station 565 belongs to its own area. ) Is divided into an optional transparent zone (OTZ) section 530 for transmitting data.

The DAZ section 520 includes a preamble 521, an FCH 522 indicating a characteristic of control data, a dl_map_ie 523 providing information about a DL burst of a DAZ section, and a DL burst of an OTZ section. dl_map_ie2 528, which consists of a DL burst for transmitting data from a base station to a relay station or a mobile station.

The relay station 565 acts like a mobile station during the DAZ period. The relay station 565 sets synchronization using the received preamble and receives a packet transmitted to itself in a frame based on the CID included in the received dl_map_ie 523. In addition, if there is data to be retransmitted to the mobile station 570 belonging to its own area among the received packets, the RS 565 may retransmit the data using the OTZ section 530 of the current frame 500. In general, since processing time is required, the UE retransmits the data to the mobile station 570 through the OTZ section of the next frame.

In the TR-MMR system, all mobile stations 570,575 operate the same as the mobile stations of the WiMax system. In particular, the mobile stations 570 belonging to the relay station 565 are controlled data such as FCH 522, dl_map_ie2 528, and the like. Is received from the base station 560 via the DAZ interval 520 and the general data burst is received from the relay station 565 via the OTZ interval 530.

6 is a flowchart illustrating an embodiment of a frame scheduling method of a base station in a TR-MMR system according to the present invention.

Referring to FIG. 6, a base station determines (a) whether a relay station has data to be transmitted to a mobile station through a next frame (# n + 1), and (b) the base station determines a relay station or a mobile station through a current frame (#n). The current frame is scheduled by determining whether there is data to be transmitted to the mobile station, and (c) determining whether there is data to be transmitted to the mobile station through the current frame (#n). Hereinafter, each process will be described in detail.

(a) Determining whether there is data to be transmitted to the mobile station through the next frame (# n + 1) (S600)

First, the base station determines whether there is data to be transmitted (ie, relayed) by the relay station to the mobile station belonging to its area through the next frame (# n + 1) (S600). The base station configures a separate relay packet for transmitting one or more data packets to be transmitted from the relay station to the mobile station (S610), and transmits the data packet from the relay station to the mobile station through the OTZ section of the next frame (# n + 1). A dl_map_ie2 (# n + 1) or relay information (# n + 1) that provides parameters such as an MCS level, a subchannel interval, a symbol interval, and the like is configured and stored (S620). The base station configures a relay message for transmitting dl_map_ie2 (# n + 1) or relay information (# n + 1) from the base station to the relay station (S620). The configured relay packet and relay message are transmitted from the base station to the relay station through the current frame (#n). At this time, the base station and the relay station utilizes a preset MCS.

(b) determining whether there is data to be transmitted to the relay station or the mobile station through the current frame (#n) (S630).

If there is data to be transmitted from the base station to the relay station or the mobile station through the current frame (S630), the base station classifies all packets according to the MCS level (S640), and forms a data burst composed of the packets classified according to the MCS level. In operation S650, resources are allocated from the frame, and dl_map_ie (#n) is configured for the current frame (S660).

(c) determining whether there is data to be transmitted from the relay station to the mobile station through the current frame (#n) (S670).

Finally, the base station determines whether there is data to be transmitted from the relay station to the mobile station during the OTZ period of the current frame (S670). The presence of data to be transmitted may be determined based on whether dl_map_ie2 (#n) or relay information (#n) related thereto is configured in the previous frame # n-1. When there is data to be transmitted from the relay station to the mobile station through the OTZ section of the current frame, the base station uses the dl_map_ie2 (#n) or relay information (#n) configured and stored in the scheduling process of the previous frame to control the current data frame. Frame scheduling is performed to include the FCH, dl_map_ie, and dl_map_ie2 (#n) in operation S680.

7 is a flowchart illustrating a flow of an embodiment of a frame relay method of a relay station in a TR-MMR system according to the present invention.

Referring to FIG. 7, if a relay station receives dl_map_ie, which is control data through a current reception frame, and dl_map_ie includes an ID assigned to the relay station (S700), the relay station checks resource allocation information corresponding to the ID in dl_map_ie. A DL burst is received and a corresponding data packet is received in the received DL burst (S710).

The relay station determines whether the relay packet and the relay message are included in the received packet (S720). When the relay packet and the relay message are included, the relay message is interpreted to detect the relay information for transmission in the OTZ section of the next frame, and the relay packet is stored (S730).

The RS also determines whether there is a packet for the RS to transmit to the mobile station through the OTZ section of the current frame (S740). If there is a packet to be transmitted, data is transmitted to the mobile station through the OTZ section using the relay message and the stored relay packet received in the previous frame (S750).

The invention can also be embodied as computer readable code on a computer readable recording medium. The computer-readable recording medium includes all kinds of recording devices in which data that can be read by a computer system is stored. Examples of computer-readable recording media include ROM, RAM, CD-ROM, magnetic tape, floppy disk, optical data storage, and the like, and also in the form of a display by a carrier wave (for example, transmission over the Internet). It includes what is implemented. The computer readable recording medium can also be distributed over network coupled computer systems so that the computer readable code is stored and executed in a distributed fashion.

So far I looked at the center of the preferred embodiment for the present invention. Those skilled in the art will appreciate that the present invention can be implemented in a modified form without departing from the essential features of the present invention. Therefore, the disclosed embodiments should be considered in descriptive sense only and not for purposes of limitation. The scope of the present invention is shown in the claims rather than the foregoing description, and all differences within the scope will be construed as being included in the present invention.

1 is a diagram illustrating an example of a frame structure of a WiMax TDD system;

2 is a flowchart illustrating an example of a frame scheduling method of a base station in a WiMax TDD system;

3 is a flowchart illustrating an embodiment of a method for receiving a frame of a mobile station in a WiMax TDD system;

4 is a diagram illustrating an example of a structure of dl_map_ie used in a WiMax TDD system;

5A is a diagram illustrating an example of a frame structure of a TR-MMR system according to the present invention;

Figure 5b is a simplified view showing the overall configuration of the TR-MMR system to which the present invention is applied,

6 is a flowchart illustrating a flow of an embodiment of a frame scheduling method of a base station in a TR-MMR system according to the present invention;

7 is a flowchart illustrating a flow of an embodiment of a frame relay method of a relay station in a TR-MMR system according to the present invention.

Claims (9)

In the downlink scheduling method of the base station in a wireless communication system consisting of a base station, a relay station and a mobile station, In the current frame, first control data for a data burst region of a downlink access interval in which data is transmitted from the base station to the relay station and a second data burst region of a selective transmission interval in which data is transmitted from the relay station to the mobile station. Allocating control data to a control data area of the current frame; And Allocating a relay packet including data to be transmitted by the relay station to the mobile station in a next frame and third control data required to transmit the relay packet through a selective transmission interval of the next frame to the data burst region; Downlink scheduling method of a base station in a wireless communication system, characterized in that. The method of claim 1, wherein the step of allocating the control data area comprises: And storing the second control data. The downlink scheduling method of a base station in a wireless communication system, further comprising: storing the second control data. The method of claim 1, wherein the step of allocating the control data area comprises: And configuring the second control data based on control data for data to be transmitted from the relay station to the mobile station through the selective transmission interval of the current frame, stored in the scheduling of the previous frame. Downlink scheduling method of a base station in a communication system. The method of claim 1, wherein the data burst region allocation step comprises: Classifying, by the base station, packets to be transmitted to the relay station according to a modulation & coding scheme (MCS) level; Configuring packets having the same MCS level into one downlink burst and allocating them to a data burst region of the downlink access interval; And And configuring the first control data including resource allocation information for each downlink burst allocated to the data burst region and assigning the first control data to the control data region. Link Scheduling Method. The method of claim 1, The first control data, the second control data and the third control data, the downlink scheduling of the base station in the wireless communication system, characterized in that it comprises resource allocation information including MCS level, subchannel interval, symbol interval, respectively Way. The method of claim 1, The control data region is a MAP region, the downlink scheduling method of a base station in a wireless communication system. In the downlink scheduling method of the relay station in a wireless communication system consisting of a base station, a relay station and a mobile station, First control data for a data burst area of a downlink access period in which data is transmitted from the base station to the relay station and second control data for a data burst area of a selective transmission period in which data is transmitted from the relay station to the mobile station; Receiving the current frame from the base station; And Allocating data to be transmitted from the relay station to the mobile station through the data burst region of the downlink access interval of the previous frame to the data burst region of the selective transmission interval of the current frame. Downlink scheduling method of a relay station in a communication system. The method of claim 7, wherein And extracting and storing the data to be transmitted to the mobile station and the control data necessary for the data transmission through a next frame in a data burst region of the downlink access interval of the current frame. Downlink scheduling method of the relay station in the system. The method of claim 7, wherein And the first control data and the second control data include resource allocation information including an MCS level, a subchannel interval, and a symbol interval, respectively.

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