KR100977243B1 - Method for making map in broadband wireless communication system - Google Patents

Abstract

PURPOSE: A method for generating a map in a broadband mobile communication system is reduce a total processing time by efficiently performing a map generation process, an allocated section for downlink data calculating process. CONSTITUTION: Uplink data burst is respectively generated(S201). An uplink data information is generated(S202). Uplink controlling information is generated for the uplink data information(S203). The length of an uplink map is stored(S204). The length of the uplink map is verified by generating the uplink map(S205). The types of a map is determined(S206). The total length of the map is calculated(S207). The total length of the map is compared with a basic allocated symbol region(S208). A starting symbol position is regulated(S209). A downlink map is generated by generated downlink data information(S210). Based on the types of the map, the final map is generated by considering the uplink map and the downlink map(S211).

Description

Map generation method in broadband mobile communication system {Method for making MAP in Broadband Wireless Communication System}

The present invention relates to a method for generating a map (MAP) in a broadband mobile communication system. Before the downlink map (DL-MAP) is generated, the entire length of the map (MAP) is determined and applied to the generation of the downlink map. It's about how to do it.

Broadband Wireless Communication System (MAC) is a medium access control layer (MAC layer) and a physical layer (PHY layer) for point-to-multipoint connection between a base station and a mobile station. ) Protocol.

The physical layer (PHY layer) of the broadband mobile communication system is largely divided into a single carrier (Single Carrier) and a multiple carrier (Multiple Carrier). Among them, a multiple carrier method is an access method for allocating resources in subchannel units in which a part of a carrier is grouped. Orthogonal Frequency Division Multiple Access (OFDMA) method. Etc.

In the orthogonal frequency division multiple access (OFDMA) system, a base station (BS) generates bandwidth allocation information for downlink and uplink physical layers as a map and generates a mobile station (MS). Send to. The map MAP includes a downlink map DL-MAP for a download link and an uplink map UL-MAP for an uplink.

The map MAP includes not only information on the data allocation interval but also various control information such as a multiple-input multiple-output (MIMO) or a hand-over. In general, the map MAP transmits data by allocating two symbols after the preamble used for synchronization, so that the length of the map MAP becomes longer than the size of the data corresponding to the two symbols. If the downlink data transmission interval is reduced, data is preferentially allocated to the map MAP.

This is not a problem for a general OFDMA system using a wide bandwidth, but a problem for an OFDMA system using a relatively narrow bandwidth.

For example, in a typical OFDMA system using a wide bandwidth such as 8.75 MHz or 10 MHz, since there is enough data area allocated to the map, the MAP section is generated when the map is generated. In many cases, we don't consider much about the recalculation of the data and the length of the map. Therefore, the start symbol position of the downlink data section is fixed to the next symbol after the end of the map section, the downlink data burst is generated, and then the downlink map (DL-MAP) is generated.

However, in the OFDMA system using a relatively small bandwidth, such as 3.5MHz, the data area allocated to the map (MAP) is reduced by more than half compared to the 8.75MHz or 10MHz profile. Since the amount of information to be generated by the MAP is the same but the size of data allocated is reduced, there is a relatively high possibility that a variation may occur in the downlink data allocation interval according to the MAP length.

That is, in an OFDMA system using a relatively small bandwidth, when the length of the generated map (MAP) is longer than that of the basic map transmission interval and the downlink data transmission interval is changed, the map (MAP) is regenerated according to these changes. You're more likely to have to do double work.

Even in an OFDMA system using a wide bandwidth, if the length of the MAP increases by more than two symbols basically allocated, there is a problem of generating the MAP again as above.

The technical problem of the present invention is to solve the duplex task of regenerating the map by changing the downlink data transmission interval due to a length of the map generated in the broadband mobile communication system. In addition, the technical problem of the present invention is to calculate the changed start symbol position before generating the downlink map to generate a downlink map reflecting this.

According to an embodiment of the present invention, a process of determining the total length of a map MAP, which is bandwidth allocation information for downlink and uplink physical layers, and the total length of the map MAP exceeds a predefined default allocation symbol region. Adjusting a start symbol offset of a downlink data allocation interval according to whether or not, and generating a downlink data information element (DL DATA IE) having the adjusted start symbol offset, and including the downlink map (DL-MAP) ), And generating a final map (MAP) according to a map type in consideration of a pre-generated uplink map (UL-MAP) and the generated downlink map (DL-MAP).

The process of determining the total length of the map MAP may include generating an uplink map UL-MAP having a location and use of a burst allocated for the uplink interval and storing the generated uplink map length. Determining a length of a downlink map (DL-MAP) having a variable length according to the number of downlink data information elements (DL DATA IE) to be transmitted; and a length of the uplink map (UL-MAP); Calculating the total length of the map MAP by adding the length of the downlink map DL-MAP.

The process of determining the length of a downlink map (DL-MAP) may include selecting a downlink data burst to be transmitted and a downlink interval usage (DIUC) different from the downlink data burst (DL data burst). Determining the number of downlink data bursts having a plurality of downlink data bursts, and determining the number of downlink data information elements by the number of downlink data bursts having different downlink interval usage codes (DIUCs). And determining the length of the downlink map including the element.

Adjusting the start symbol offset of the downlink data allocation interval, if the total length of the map (MAP) does not exceed the basic allocated symbol region, the next next of the basic allocated symbol region without changing the starting symbol offset position Placing the start symbol offset in a symbol, and when the total length of the map MAP exceeds the default allocated symbol region, the start symbol in a next symbol of an area where the length of the map MAP ends. The process of placing an offset is included.

According to an embodiment of the present invention, before generating the entire map MAP, the length of the map MAP is calculated by first calculating the length of the map MAP to be generated in advance, and then reflecting the generated length in the downlink map DL-MAP. If it is longer than the default allocated symbol region, it is not necessary to recalculate the downlink data interval. In addition, according to the embodiment of the present invention, not only can the map MAP be efficiently generated and the downlink data allocation interval can be calculated, but also the overlapping calculation can be avoided, thereby reducing the overall data processing time. The present invention can be used to efficiently generate a map in an OFDMA system using a relatively small bandwidth.

1 is a diagram illustrating an example of a frame structure of a physical layer of an OFDMA system, which is a broadband mobile communication system.
2 is a flowchart illustrating a map generation process in a broadband mobile communication system according to an embodiment of the present invention.
3 is an example of a downlink map (DL-MAP) configuration block in an OFDMA system.
4 is an example of a configuration field of each downlink map information element (DL-MAP IE).
5 is a diagram illustrating a frame generated without adjusting a symbol offset according to an embodiment of the present invention.
6 is a diagram illustrating a frame generated by adjusting a symbol offset according to an embodiment of the present invention.

Hereinafter, with reference to the accompanying drawings will be described an embodiment of the present invention in more detail. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various forms, and only the embodiments are intended to complete the disclosure of the present invention and to those skilled in the art to fully understand the scope of the invention. It is provided to inform you. Like numbers refer to like elements in the figures.

1 is a diagram illustrating a frame structure of a physical layer of an OFDMA system, which is a broadband mobile communication system.

In the OFDMA physical layer, active carriers are divided into groups and transmitted to different receivers for each group. The group of carriers transmitted to such a receiver is called a subchannel. Carriers constituting each subchannel may be adjacent to each other or at equal intervals. As such, by enabling multiple access in each subchannel unit, the complexity of implementation is increased, but there is an advantage that the frequency diversity gain, the gain due to the concentration of power, and the forward power control can be efficiently performed.

Slots assigned to each user are defined by a data region of a two-dimensional space as shown in FIG. 1, which is a set of consecutive subchannels allocated by a burst. In the OFDMA, one downlink data region is shown as a rectangle determined by symbol coordinates on the time axis and subchannel coordinates on the frequency axis. This data area may be allocated to a specific user in the downlink so that the base station transmits the data area.

To define such a data region in two-dimensional space, the number of OFDMA symbols in the time domain and the number of consecutive subchannels starting at a position separated by an offset from a reference point in the frequency domain should be given.

In a system using Orthogonal Frequency Division Multiple Access (OFDMA), the base station (BS) generates bandwidth allocation information for the downlink and uplink physical layers as a map (MAP), and displays the frames of the OFDMA physical layer as shown in FIG. And transmit to the mobile station MS.

The frame transmitted from the base station (BS) to the mobile station (MS) starts with a preamble used for synchronization in the physical layer, and then the location and purpose of the bursts allocated to the downlink and uplink. It is defined as a structure for the entire frame through a map (MAP) including a downlink map (DL-MAP) and an uplink map (UL-MAP) of a broadcasting type to be defined.

An embodiment of the present invention provides processes for generating the map (MAP), in particular, in generating a downlink map (DL-MAP), a map information element (MAP IE; MAP Information) of the downlink map (DL-MAP). The length of the elements is first estimated, the total length of the map is determined in advance, the map transmission interval is determined, and then a downlink map (DL-MAP) is generated. These map MAP generation processes will be described in detail with the flowchart of FIG. 2.

2 is a flowchart illustrating a process of generating a map in a broadband mobile communication system according to an embodiment of the present invention.

The map MAP is a downlink map (DL-MAP) having downlink information (location and use of downlink data burst) and an uplink map (UL-) having uplink information (location and use of uplink data burst). MAP). Among them, first, processes S201, S202, S203, and S204 of generating an uplink map UL-MAP having a location and a use of a burst allocated for an uplink period are included.

The uplink map information element (UL-MAP IE) constituting the uplink map (UL-MAP) includes an uplink data information element (UL DATA IE) having data allocation interval information and control information for uplink. It includes an uplink control information element (UL Ctrl IE).

For reference, the UL map information element (UL-MAP IE) is determined by an uplink interval usage code (UIUC) for each CID (connection ID), and the location of a corresponding section is defined by 'duration'.

The uplink map (UL-MAP) has a general uplink map generation process. The uplink map (UL-MAP) generates each uplink data burst (UL DATA Burst) to be allocated to the corresponding frame (S201), stores allocation information, and based on the uplink map. A link data information element (UL DATA IE) is generated (S202). After the generation process for the UL data information element (UL DATA IE) is finished, generates an uplink control information element (UL Ctrl IE) for uplink control information (S203), and combines the uplink map (UL-MAP). ) Generation is completed and the length is stored (S204). As described above, storing the length of the uplink map UL-MAP separately is for later use in calculating the total length of the map MAP.

After generating the uplink map (UL-MAP) as described above to determine the uplink map length (S205), there is a process of generating a downlink map (DL-MAP) (S206, S207, S208, S209, S210). . According to the embodiment of the present invention, unlike the UL-MAP generation process, the DL-MAP generation generates a downlink map after first determining the length of the variable DL-MAP and considering the DL-MAP first. Create a link map (DL-MAP).

Before describing the process of generating the downlink map DL-MAP, the structure of the downlink map DL-MAP will be briefly described to help understand the description.

Downlink map (DL-MAP) is defined as the use allocated for each burst for the downlink period in the burst mode physical layer.

Like the UL-MAP IE, the DL Map Information Element (DL-MAP IE) also has downlink data information element (DL DATA IE) having data allocation interval information and control information for downlink. Downlink control information element (DL Ctrl IE).

An example of a downlink map (DL-MAP) construction block in an OFDMA system is shown in FIG. 3. As shown in FIG. 3, a normal downlink map (DL-MAP) includes an 8-bit Management Message Type 310, a 32-bit PHY Synchronization Field 320, and an 8-bit Downlink Channel Descriptor Count (330), 48-bit Base Station ID (340), Base Station ID (340), 8-bit OFDMA Symbol Number (350; N_OFDMA Symbols), DL Map Information Element (360; DL-MAP IE) do.

In the above description, the DL-MAP IE (DL-MAP IE) includes a downlink interval usage code (DIUC), a connection ID (CID), and position information (subchannel offset, symbol offset, subchannel number, symbol number) of the burst. ), The downlink traffic section is identified to the user.

However, the total length of the DL-MAP IE is a field having a variable length, unlike other fields, and depends on the number of DL-MAP IEs included in the map MAP. Accordingly, the entire length of the map MAP varies and may include a control information element and a data information element.

4 shows an example of a configuration field of each DL-map information element (DL-MAP IE). For reference, FIG. 4 describes only fields related to MAP message generation.

Referring to FIG. 4, a downlink interval usage code (DIUC) is generally used for the purpose of downlink data information element (DL DATA IE) in the case of 4 bits having a value of 0 to 12. The remaining values are used for control purposes and are used for the downlink control information element (DL Ctrl IE).

Therefore, when selecting a data burst to be transmitted in downlink and sorting it by downlink interval use code (DIUC), it is determined how many DL DATA IEs are to be sent in this frame. The total length of the downlink map information element DL-MAP IE located in the map DL-MAP is determined.

According to the embodiment of the present invention, by identifying the total length of the DL-MAP IE as described above, the length of the DL-MAP including the DL-MAP can be determined as a result. The total length of the map MAP including the downlink map DL-MAP and the uplink map UL-MAP may be known.

Hereinafter, a process of generating a downlink map (DL-MA) will be described with reference to the above contents.

As shown in FIG. 3, the downlink map (DL-MAP) has an 8-bit Management Message Type, a 32-bit PHY Synchronization Field, and an 8-bit Downlink Channel Descriptor Count. It includes a 48-bit base station ID, a 8-bit OFDMA symbol number (N_OFDMA symbols), and a variable length downlink map information element (DL-MAP IE).

The length of the DL-MAP IE among the various fields in the DL-MAP, unlike other fixed-length fields, is the DL DATA IE that enters the MAP. The length varies depending on the number of.

Therefore, in order to know the total length of the downlink map DL-MAP, it is necessary to have a process of determining the length of the downlink map information element DL-MAP IE having a variable length (S205).

Determining the length of the downlink map information element (DL-MAP IE) (S205), selecting a downlink data burst (DL DATA Burst) to be transmitted in the frame, different from the downlink data burst to be transmitted in this frame Determine how many DL DATA Bursts have downlink interval usage codes (DIUCs).

Thereafter, the number of downlink data information elements (DL DATA IE) is determined by the number of downlink data bursts having different DIUCs, so that the downlink map (DL−) including each downlink data information element (DL DATA IE) is determined. The length of the MAP) can be determined. As a result, since the DL data IE is generated for each DIUC, the length of the total downlink map DL-MAP can be calculated without actually generating the DL data IE.

If a map type to be transmitted is determined based on the length of the UL map generated in step S204 and the length of the downlink map DL-MAP determined in step S205, the map MAP is determined. The total length of the map to be transmitted in the transmission interval may be calculated (S207).

After calculating the total length of the map MAP as described above (S207), the start symbol offset of the downlink data allocation interval is determined according to whether the total length of the map MAP exceeds a predefined basic allocation symbol region. It has a process of adjustment.

That is, it is determined whether the total length of the map MAP has exceeded a predefined basic allocated symbol region (S208), and when the total length of the map MAP exceeds the basic allocated symbol region (S208a), And a start symbol offset positioning process of placing a downlink data allocation start symbol offset in a next symbol of an area where the length of the map MAP ends.

On the other hand, when the total length of the map MAP does not exceed the basic allocated symbol region (S208b), the start symbol offset is placed in the next symbol of the basic allocated symbol region without adjusting the start symbol offset position. .

For example, assuming that the default allocated symbol region is two symbol regions, if the total length of the map MAP is less than or equal to two symbol regions, the symbol offset is generated when DL data IE is generated. There is no need to adjust the position. For reference, as shown in FIG. 5, the symbol offset is not positioned and is in the original position.

However, if the total length of the map MAP is larger than two symbol regions, the symbol offset must be positioned when generating the DL data IE. That is, when the total length of the map MAP is larger than two symbol regions, the start symbol offset that is a reference when generating the DL data IE is not the start symbol offset of the basic downlink data interval, but is transmitted. It should be updated with the starting symbol offset reflecting the total length of the map to be mapped. For reference, FIG. 6 illustrates a state in which the start symbol offset is adjusted as described above.

Through the above processes, a symbol and a subchannel interval for a data region that actually transmits downlink data may be defined.

Since the downlink data transmission interval is determined, a downlink data burst (DL DATA Burst) to be transmitted in a frame is generated based on this space, and this information is generated as a downlink data information element (DL DATA IE) to generate a downlink map ( DL-MAP) may be generated (S210).

When the downlink map DL-MAP is generated considering the entire length of the map MAP, the map type may be determined in consideration of the uplink map UL-MAP and the downlink map DL-MAP. Accordingly, the final map MAP is generated (S211). For example, the final map can be generated by determining a map type that can cover the corresponding map length in consideration of the total length of the UL map and the DL-MAP. .

Although the invention has been described with reference to the accompanying drawings and the preferred embodiments described above, the invention is not limited thereto, but is defined by the claims that follow. Accordingly, one of ordinary skill in the art may variously modify and modify the present invention without departing from the spirit of the following claims.

S204: Create uplink map and store its length
S205: grasp the length of the downlink map
S206: Map Type Determination
S207: Calculate the total length of the map
S208: Total length of map exceeds default allocation symbol area
S209: Starting Symbol Offset Adjustment
S210: downlink map generation
S211: Final Map Creation Complete

Claims (7)

Determining an entire length of a map MAP, which is bandwidth allocation information for downlink and uplink physical layers;
Adjusting a start symbol offset of a downlink data allocation interval according to whether the total length of the map MAP exceeds a predefined basic allocation symbol region;
Generating a downlink map information (DL-MAP) including the downlink data information element by generating a downlink data information element having the adjusted start symbol offset;
A process of generating a final map (MAP) according to a map type in consideration of a pre-generated uplink map (UL-MAP) and the generated downlink map (DL-MAP).
Map generation method in a broadband mobile communication system comprising a. The method of claim 1, wherein the process of determining the total length of the map MAP includes:
Generating an uplink map (UL-MAP) having a location and use of a burst allocated for an uplink period and storing the generated uplink map length;
Determining a length of a downlink map (DL-MAP) having a variable length according to the number of downlink data information elements (DL DATA IE) to be transmitted;
A process of calculating the total length of the map MAP by adding the length of the uplink map UL-MAP and the length of the downlink map DL-MAP.
Map generation method in a broadband mobile communication system comprising a. The method according to claim 2, the UL map (UL-MAP),
A method for generating a map in a broadband mobile communication system including an uplink data information element (UL DATA IE) having an uplink data allocation interval and an uplink control information element (UL Ctrl IE) having uplink control information . The method of claim 2, wherein the determining of the length of the downlink map DL-MAP comprises:
Selecting a downlink data burst to be transmitted;
Determining a number of downlink data bursts having different downlink interval usage codes (DIUCs) among the downlink data bursts;
A process of determining the length of a downlink map including each downlink data information element by determining the number of downlink data information elements by the number of downlink data bursts having different downlink interval usage codes (DIUCs).
Map generation method in a broadband mobile communication system comprising a. The method of claim 1, wherein the adjusting of the start symbol offset of the downlink data allocation interval comprises:
If the total length of the map MAP does not exceed the basic allocated symbol region, placing the starting symbol offset in a next symbol of the basic allocated symbol region without changing a starting symbol offset position;
When the total length of the map MAP exceeds the basic allocated symbol region, the starting symbol offset is placed in the next symbol of the region where the length of the map MAP is terminated.
Map generation method in a broadband mobile communication system comprising a. The method according to any one of claims 1 to 5, wherein the downlink map (DL-MAP),
Management Message Type, PHY Synchronization Field, Downlink Channel Descriptor Count, Base Station ID, Base Station ID, N_OFDMA Symbol, and Downlink Map Information Element (DL-) MAP IE) map generation method in a broadband mobile communication system. The method of claim 6, wherein the Management Message Type, PHY Synchronization Field, Downlink Channel Descriptor Count, Base Station ID, and N_OFDMA Symbol are designed in advance. The downlink map information element (DL-MAP IE) has a fixed length and generates a map in a broadband mobile communication system having a variable length according to the number of transmissions of downlink data bursts having different downlink interval usage codes (DIUCs). Way.

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