KR20090022138A - Method and system for handshaking in wireless communication system - Google Patents

Abstract

A method and system for performing handshaking in a wireless telecommunications system in which a terminal efficiently responses a request which the base station initiates are provided to transmit the request message and data authentication information in the wireless communications system of the IEEE 802.16d/e. A terminal transmits a response message from a next frame. A controller includes burst service information and burst position information into map information element(S710). An uplink map or a down link map is comprised by using the recorded map information elements(S720). A map configuration part assigns the map information element comprised by the controller. The down link map and uplink map are comprised. The burst configuration part maps require-message in the downlink burst(S730). In the burst configuration part is the physical layer require-message, it maps the downlink burst domain determined by the controller.

Description

Method and System for Handshaking in Wireless Communication System

The present invention relates to handshaking between a base station and a terminal. More particularly, the present invention relates to a method for performing handshaking in a wireless communication system for efficiently responding to a request initiated by a base station in a wireless communication system. It is about the system.

In IEEE 802.16d / e, in order for a terminal to transmit something through an uplink channel to a base station, a ranging process and a bandwidth request (BWR) / approval process are performed with the base station before transmitting a burst to the base station. Should be done. In addition, when the terminal receives the request message from the base station, the response message to the request message can be transmitted only after completing the bandwidth request / approval process with the base station. However, if the base station wants to request the terminal to respond to this request message within the next frame or just a few frames, this bandwidth request / approval process becomes inefficient. This will be described in more detail.

1 and 2 illustrate a general request-response process, in which FIG. 1 illustrates a process of transmitting a response from a base station to a request initiated by a terminal, and FIG. 2 illustrates a response of a terminal to a request initiated by a base station. It shows the process until sending.

In FIG. 1, according to IEEE 802.16d / e, the base station may immediately respond to a request initiated by the terminal in the next frame as in the general request-response process. On the contrary, in FIG. 2, the terminal may respond to a request initiated by the base station only after receiving a grant from the base station. That is, when the base station transmits a BS-initiated Request message to the terminal (n), the terminal transmits a ranging message to the base station (n + 1), and the base station transmits a CDMA code and allocation information (Allocation IE). ) Is transmitted to the terminal (n + 2). Subsequently, the terminal transmits bandwidth request (BWR) information to the base station (n + 3), the base station receiving the bandwidth request transmits data grant (Grant) information necessary for initialization to the terminal (n + 4), and the terminal finally receives Only after receiving a data grant from the base station can transmit a response message (n + 5) for the request initiated by the base station.

The biggest problem of this prior art is that the base station initiation request-response process takes too long because the terminal can receive the response only at least the fifth frame for the request initiated by the base station.

In addition, since the base station processes the contention request for this bandwidth request (n + 3) of the terminal, it does not necessarily guarantee that the terminal obtains a data grant in the next frame (n + 4). In addition, even if the above-described bandwidth request / approval process fails at the base station, the terminal may not transmit a response to the request initiated by the base station at all.

In addition, the base station does not give a special priority to such a bandwidth request and thus does not know what the purpose of the bandwidth request received from the terminal is. Accordingly, if the bandwidth request initiated by the base station is very urgent, it may be in a serious situation. Accordingly, there is a need for an appropriate handshaking method that can solve the above-described problems with the request initiated by the base station.

The present invention was devised to meet the above demands, and an object of the present invention is to provide a handshaking method and system for efficiently responding to a request initiated by a base station in a wireless communication system.

Another object of the present invention is to provide an apparatus and method for configuring a frame so that a terminal can respond without performing a bandwidth request / approval process to a request initiated by a base station in a wireless communication system.

For the above purposes, a handshaking method of a base station for initialization in a wireless communication system of one embodiment of the present invention includes: (a) a base station-initiation request including data grant information and response burst information for the initialization; Transmitting a first frame including a BS-initiated Request to a terminal; And (b) receiving, from the terminal, a second frame including a response to the base station-initiation request in an uplink burst region designated by the response burst information.

Further, in a wireless communication system of one embodiment of the present invention, a handshaking method of a terminal for initialization includes (a) receiving a first frame for a base station-start request from a base station, and the first frame is data for the initialization. Determining whether to include grant information; And (b) if the determination result includes the data grant information, includes a response message to the base station-initiation request in the response burst region of the second frame designated by the uplink map of the first frame to form the second frame. And transmitting to the base station.

On the other hand, in the wireless communication system of one embodiment of the present invention, a base station performing handshaking for initialization includes a BS-initiated Request including data grant information and response burst information for the initialization. A scheduler constituting a first frame including; A transmitter for transmitting the first frame to a terminal; And a receiver configured to receive, from the terminal, a second frame including a BS-initiated response in an uplink burst region designated by the response burst information.

In addition, a terminal for performing handshaking for initialization in a wireless communication system according to one embodiment of the present invention includes: a receiving unit for receiving a first frame for a BS-initiated Request; After determining whether the data grant information for the initialization is included in the first frame, and if the data grant information is included, the base station is included in the response burst region of the second frame designated by the uplink map of the first frame. A control unit including a response message to the start request; And a transmitter for transmitting the second frame to the base station.

According to the present invention, a quick response of a terminal to a request initiated by a base station by transmitting a request message and data acknowledgment information together in an IEEE 802.16d / e-based wireless communication system so that the terminal can transmit a response message in the next frame. This has a possible effect.

In addition, according to the present invention, by transmitting the allocation information of the uplink burst to the request information element in the IEEE 802.16d / e-based wireless communication system, and transmits the information to the request message without going through the bandwidth request / approval process A quick response is possible.

In addition, according to the present invention, by efficiently configuring the frame for the base station-initiated request (BS-initiated Request) according to the channel environment in the IEEE 802.16d / e-based wireless communication system efficient handshaking between the base station and the terminal There is a possible effect.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings and preferred embodiments. For reference, in the following description, detailed descriptions of well-known functions and configurations that may unnecessarily obscure the subject matter of the present invention are omitted.

3 shows a frame structure in a wireless communication system based on IEEE 802.16d / e.

Referring to FIG. 3, the frame represents data transmission units in a frequency and time domain as subchannels and symbols, respectively, and a minimum data unit that can be transmitted to a terminal includes one subchannel and one symbol. In this case, the vertical axis represents a subchannel index which is a frequency resource allocation unit, and the horizontal axis represents an OFDM symbol index that is a time resource allocation unit. A TTG (Transmit / receive Transition Gap), which is a guard region, exists between the downlink and the uplink.

Meanwhile, the above-described frame is divided into a downlink subframe configured to transmit data from the base station to the terminal and an uplink subframe configured to transmit data from the terminal to the base station. The downlink subframe includes a preamble, a frame control header (FCH), a downlink map (DL MAP), an uplink map (UL MAP), and a downlink burst (DL burst). Control symbols (ranging, ACK, CQICH) and uplink bursts (UL Burst).

The preamble is used to provide time and frequency synchronization and cell information to the terminal. The FCH contains frame information and information for decoding the downlink map. In the downlink map, information about the location and use of downlink bursts transmitted by the base station is recorded through a downlink map information element (DL MAP IE). In addition, in the uplink map, information on the location and use of uplink bursts transmitted by the terminals is recorded through an uplink map information element (UL MAP IE).

The base station broadcasts the frame thus configured to the terminal. The terminal receives the frame, decodes each map, checks whether there is a data burst assigned to it, and if so, references the map to decode its data burst.

4 is a diagram illustrating a configuration of an IEEE 802.16d / e based base station according to the present invention.

As shown in FIG. 4, the base station includes an interface 110, a band signal processor 120, a transmitter 130, a receiver 160, a scheduler 150, and an antenna 140. The base station supports TDD and may be divided into a reception path and a transmission path.

In the reception path, the receiver 160 receives one or more radio signals transmitted by the terminals through the antenna 140 and converts them into baseband signals. For example, the receiver 160 removes and amplifies noise from the above-described signal for data reception of the base station, down-converts the amplified signal to a baseband signal, and digitizes the down-converted baseband signal. The band signal processor 120 extracts information or data bits from the digitized signal to perform demodulation, decoding, and error correction processes. The received information is transmitted to the adjacent wired / wireless network via the interface 110 or transmitted to other terminals serviced by the base station through the transmission path.

In the transmission path, the interface 110 receives voice, data, or control information from a control station or a wireless network, and the band signal processor 120 encodes voice, data, or control information and outputs the encoded information to the transmitter 130. do. The transmitter 130 modulates the encoded voice, data, or control information into a carrier signal having a desired transmission frequency or frequencies, amplifies the modulated carrier signal to a level suitable for transmission, and propagates to the air through the antenna 140. do.

On the other hand, the scheduler 150 controls the operation of the reception path and the transmission path and each component. In particular, in connection with the present invention, the scheduler 150 configures a frame to be transmitted to each terminal, and the frame is configured such that an appropriate handshaking method that can solve the conventional problems is applied. That is, the scheduler 150 configures a frame such that the terminal transmits a response in the next frame to the request initiated by the base station. To this end, the present invention proposes a method of transmitting a data grant with a request message (Data Grant with Request message) and a method of transmitting a request information element with burst allocation (Request IE with Burst Allocation).

Hereinafter, the detailed configuration and operation of the above-described scheduler, and also the frame configured by the scheduler will be described in more detail.

5 is a diagram illustrating a configuration of a scheduler according to an embodiment of the present invention.

As shown in FIG. 5, the scheduler 150 includes a control unit 151, a map constructing unit 152, and a burst constructing unit 153.

The control unit 151 configures map information elements recorded in the uplink map and the downlink map, respectively, and also determines areas to which an uplink burst and a downlink burst are allocated. Specifically, the controller 151 includes burst usage information, terminal information (CID information), and burst position information for the base station start-request message in the map information element. In addition, the controller 151 may map the terminal information and the burst position information to a map information element (eg, UL MAP IE) so that a response message for the request may be carried in an uplink subframe. To record. More specific operations of the controller 151 will be described in the following embodiments.

The map construction unit 152 configures the downlink map and the uplink map by allocating the map information elements configured by the control unit 151 to specific regions of the time-frequency resources.

The burst configurator 153 assigns a burst to the downlink burst allocation region determined by the controller 151.

FIG. 6 is a diagram illustrating a frame according to an embodiment of the present invention, for explaining a method of transmitting a data acknowledgment along with a request message. For reference, since it is similar to the frame structure of FIG. 3 described above, its detailed configuration will be omitted and only the difference will be described.

Referring to FIG. 6, in the frame, a request message (REQ) for a base station-initiation request is allocated to a downlink burst region, and burst use information, terminal information (CID information), and burst position information for the request message are allocated. Is configured to be included in the downlink map information element (DL MAP IE). In addition, the frame may include a terminal information and burst position information such as a map information element (eg, an uplink map information element) so that the terminal may load a response message to the base station-initiation request in an uplink subframe. UL MAP IE).

7 is a flowchart illustrating a frame configuration method according to an embodiment of the present invention.

Referring to FIG. 7, the scheduler 150 records burst usage information, terminal information, and burst location information for a request message in a downlink map information element, and receives terminal information, for receiving a response message for the request message. And uplink burst position information is recorded in the uplink map information element (S710). Subsequently, the scheduler 150 includes the downlink map information element and the uplink map information element in the downlink map and the uplink map, respectively (S720), and then includes the request message with a downlink burst (ie, downlink control data). ) To configure the frame (S730).

Specifically, in step 710, the controller 151 includes the burst usage information, the terminal information (CID information), and the burst location information for the request message in the map information element (downlink map information element: DL MAP IE). That is, the control unit 151 determines which terminal the request message is assigned to (CID), what the request message is for (use), and what position is the burst in the downlink subframe (location). To record. In addition, the controller 151 records terminal information and burst position information in a map information element (eg, UL MAP IE) so that a response message for the request can be carried in an uplink subframe.

In operation S720, the map construction unit 152 constructs an uplink map or a downlink map using the recorded map information elements. That is, the map configuration unit 152 configures the downlink map and the uplink map by allocating the map information elements configured by the controller 151 to specific regions of the time-frequency resources.

In step S730, the burst constructing unit 153 maps the request message to a downlink burst. That is, the burst constructing unit 153 maps the request message to a downlink burst region determined by the controller 151 in the physical layer.

However, when the frame is configured as described above, even if the terminal receives the frame and decodes the downlink map, the uplink map, and the downlink burst, the uplink burst region allocated for the response message to the request message is not determined. It is not known whether it is a use. Accordingly, in the next frame, an uplink burst for another use may be allocated to an area where the terminal should carry the response message.

To this end, the controller 151 adds an "Allocated Response Region Indication" field to the request message, and the terminal carries the response message for the request message in the corresponding uplink burst region in the next frame. To help.

8 illustrates a request message format according to an embodiment of the present invention.

Referring to FIG. 8, the request message format adds the above-mentioned "assigned response region indication" field to the general request message format. The request message of this format is carried by the scheduler 150 in the payload of the MAC PDU, which is mapped to downlink bursts of the physical layer and transmitted to the terminal. For example, if the terminal decodes this field and the field is set to 1, the terminal may transmit a response message to the base station through the designated uplink burst region in the next frame. However, if it is set to 0, the terminal may transmit a response message to the base station through a data grant process through the bandwidth request.

Thus, when the base station broadcasts the frame configured as described above, the terminal transmits a response message for the request message in the uplink subframe to the base station in the next frame. Thus, the terminal may transmit a response message in the next frame with respect to the request message initiated by the base station.

FIG. 9 is a diagram illustrating a frame according to another embodiment of the present invention to describe a method of transmitting a request information element with burst allocation.

Referring to FIG. 9, the scheduler 150 includes a base station-initiation request as an uplink map information element (ie, "Request IE" in the present embodiment) rather than as downlink control data in the uplink map. Construct a frame. This Request Information Element (Request IE) includes an uplink burst profile, which is a characteristic of a physical layer (eg, physical transmission characteristics such as encoding and modulation information) used for an uplink burst to which a terminal will respond. Define.

To this end, the control unit 151 configures the request information element in the form of "UL MAP Extended-2 UIUC IE" as shown in FIG. 10 to be described later. The map constructing unit 152 constructs an uplink map using this request information element. That is, the map configuration unit 152 configures the uplink map by allocating the request information element configured by the control unit 151 to a specific region of the time-frequency resource.

10 illustrates a request information element format according to another embodiment of the present invention.

Referring to FIG. 10, the request information element includes the following fields, and the base station describes the burst profile for the response message through these fields. First, the Extended UIUC (Uplink Interval Usage Code) field is composed of 4 bits to map 16 types of request information, and the Length field is composed of variable bits as length information, and the length can be variably assigned. The "Request Type" field is composed of 2 bits and can be divided into 4 request types. The "Response Included" field is composed of 1 bit and used as data approval information, indicating whether a response to this request is required or not. Encoded Information ”field may be variably configured to indicate an attribute of the request information element. In particular, when the "Response Included" field is set to 1, it indicates that the terminal needs to respond to the request.

The request information element also includes a "duration" field, a "UIUC" field, and a "Repetition Coding Indication" field, and the base station describes a burst profile for the response message in these fields. Here, the "duration" field is composed of 6 bits to indicate the allocation period of the OFDM slot, the "UIUC" field is composed of 4 bits to indicate the modulation information (for example, FEC encoding type and modulation type) of the burst to be allocated, and "Repetition Coding". Indication "field consists of 2 bits and represents the repetition code information of the burst to be allocated.

In this way, when the base station constructs a "request" as an uplink map information element as described above and broadcasts a frame, the corresponding terminal transmits a response to the request message in an uplink subframe to the base station in a next frame. do. Thus, the terminal may transmit a response message in the next frame with respect to the request message initiated by the base station.

On the other hand, the method of transmitting a data grant with the request message according to an embodiment of the present invention (Data Grant with Request message) maps the request message to the downlink burst, the terminal is downlink again after the map decoding process Bursts must also be decoded.

In contrast, in the method of transmitting a request information element with burst allocation according to another embodiment of the present invention, the terminal decodes only an uplink map but may have a larger map size. That is, in the request message form of the previous embodiment, the base station may transmit the request message (which is in the form of downlink burst) according to the channel state by applying the MCS level of 64 QAM 5/6. Since the map is modulated to the MCS level of QPSK 1/2 repetition 6, the map size using the request information element becomes relatively large.

Therefore, it is desirable to selectively apply the above schemes according to the channel environment (eg QoS) for the terminal. For example, the terminal having a good channel environment transmits a frame applying a method of transmitting a data acknowledgment together with the request message, and the terminal having a good channel environment transmits a frame applying a method of transmitting a request information element with burst allocation. You may.

Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art to which the present invention pertains can implement the present invention in other specific forms without changing the technical spirit or essential features, The examples are to be understood in all respects as illustrative and not restrictive.

In addition, the scope of the present invention is specified by the appended claims rather than the detailed description, and all changes or modifications derived from the meaning and scope of the claims and their equivalent concepts are included in the scope of the present invention. Should be interpreted as

1 is a diagram illustrating a process of transmitting a response from a base station in response to a request initiated by a terminal.

2 is a diagram illustrating a process until a terminal transmits a response to a request initiated by a base station.

3 is a diagram illustrating a frame structure in an IEEE 802.16d / e based wireless communication system.

4 is a diagram illustrating a configuration of an IEEE 802.16d / e based base station.

5 is a diagram illustrating a configuration of a scheduler according to an embodiment of the present invention.

6 illustrates a frame according to an embodiment of the present invention.

7 is a flowchart illustrating a frame configuration method according to an embodiment of the present invention.

8 illustrates a request message format according to an embodiment of the present invention.

9 illustrates a frame according to another embodiment of the present invention.

10 illustrates a request information element format according to another embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

110: interface 120: band signal processing unit

130: transmitter 140: antenna

150: scheduler

151: control unit 152: map configuration unit

153: burst component

160: receiver

Claims (21)

A handshaking method of a base station for initialization in a wireless communication system, (a) transmitting to the terminal a first frame including a BS-initiated Request including data grant information and response burst information for initialization; And and (b) receiving from the terminal a second frame including a response to the base station-initiation request in an uplink burst region specified in the response burst information. The method of claim 1, wherein step (a) comprises: (a-1) The downlink map information element including the data approval information and the base station-initiation request recorded with the location information of the message is included in the downlink map of the first frame, and the uplink in which the response burst information is recorded. Including a map information element in an uplink map of the first frame; And and (a-2) including the message for the base station-initiation request in a downlink burst region designated by the downlink map information element and transmitting the message to the terminal. The message of claim 2, wherein the message for the base station-initiation request is: And an indicator field indicating whether the data grant information is included. The method of claim 1, wherein step (a) comprises: (a-1) configuring an uplink burst profile including the data grant information and the response burst information; And and (a-2) including the uplink map information element in which the uplink burst profile is recorded in an uplink map and transmitting the uplink map information element to the terminal. The method of claim 4, wherein the uplink burst profile, And a physical transmission characteristic applied to an uplink burst in which the response message to the base station-initiation request is to be located. The method of claim 1, wherein the response burst information, And uplink burst information in which a response message to the base station-initiation request is to be located. According to claim 1, wherein step (b), The terminal determines whether the data grant information for the initialization is included in the first frame, and if the data grant information is included in the first frame, the terminal determines whether the base station is located in the response burst region designated by the uplink map of the second frame. And including a response message for the start request to the base station so that the base station receives the second frame. The method according to any one of claims 1 to 7, wherein the second frame, And a next frame (n + 1) of the first frame (n). A handshaking method of a terminal for initialization in a wireless communication system, (a) receiving a first frame for a BS-initiated Request from a base station and determining whether the first frame includes data grant information for the initialization; And (b) if the determination result includes the data grant information, the second frame is included in the base station-start request by including a response message to the base station-initiation request in the response burst region of the second frame designated by the uplink map of the first frame. Handshaking method comprising the step of transmitting to. The method of claim 9, wherein step (a) comprises: If the indicator field for the data grant (Grant) is set to a set in the downlink burst of the first frame, it is determined that the first frame includes data grant information (Grant). How to do handshaking. The method of claim 9, wherein step (a) comprises: In the request information element included in the uplink map of the first frame, if the response field for the data grant is set to set, the first frame includes data grant information. Handshaking method, characterized in that judging. The method of claim 11, wherein the request information element, And recording an uplink burst profile for designating the response burst area. The method of claim 9, wherein step (b) comprises: And according to the physical transmission characteristics of the burst profile included in the uplink map information element, including the base station-initiated response message in the response burst region. The method according to any one of claims 9 to 13, wherein step (b) comprises: And the next frame (n + 1) of the frame (n) for the base station-initiation request. A base station performing handshaking for initialization in a wireless communication system, A scheduler constituting a first frame including a BS-initiated Request including data grant information and response burst information for initialization; A transmitter for transmitting the first frame to a terminal; And And a receiver configured to receive, from the terminal, a second frame including the BS-initiated response in an uplink burst region designated by the response burst information. The method of claim 15, wherein the scheduler, A control unit constituting a downlink map information element including data grant information for the initialization and message information for the base station-initiation request, and an uplink map information element including the response burst information; A map constructing unit configured to construct a downlink map and an uplink map using the downlink map information element and the uplink map information element, respectively; And And a burst constructing unit configured to construct a message for the base station-initiation request into a burst of the first frame in a downlink burst region designated by the downlink map information element. The method of claim 16, wherein the control unit, And an indicator field indicating whether the data grant information is included in the message for the base station-initiation request. The method of claim 15, wherein the scheduler, A controller configured to construct an uplink burst profile including the data grant information and the response burst information, and to record the uplink burst profile in the uplink map information element; And And a map constructing unit configured to construct an uplink map using the uplink map information element. The method according to any one of claims 15 to 18, wherein the receiving unit, And a second frame including the BS-initiated response in the next frame (n + 1) of the frame (n) transmitted by the transmitter. A terminal for performing handshaking for initialization in a wireless communication system, A receiver configured to receive a first frame for a BS-initiated Request; After determining whether the data grant information for the initialization is included in the first frame, and if the data grant information is included, the base station is included in the response burst region of the second frame designated by the uplink map of the first frame. A control unit including a response message to the start request; And And a transmitter for transmitting the second frame to the base station. The method of claim 20, wherein the control unit, In the downlink burst of the first frame for the base station-initiation request, the indicator field for the data grant is set to set or in the request information element included in the uplink map of the first frame. And if the response field for data grant is set to set, determine that the base station-initiation request frame includes data grant information.

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