KR100684323B1 - Ap of wireless communication system and scheduling method of sounding channel information thereof - Google Patents

Abstract

An AP of a wireless communication system and a sounding channel information scheduling method thereof are provided to search an AT which has transmitted sounding information through a sounding channel at the current frame by using stored sounding channel-related control information, and transmit sounding channel information of the searched AT to a scheduler, thereby reducing CPU throughput of the scheduler for generally performing a scheduling function. An AP(Access Point)(120) of a wireless communication system comprises the followings: a modem(121) which measures sounding channel information according to each AT(Access Terminal)(110) and stores the measured information; a scheduler(123) for transmitting a sounding channel assigning command on an AT(110) to which sounding information has to be transmitted through a sounding channel; and an MAC DSP(Media Access Control Digital Signal Processor)(122) which stores and manages sounding channel-related control information, included in the sounding channel assigning command transmitted from the scheduler(123), according to the ATs(110), and performs scheduling of the sounding channel information by using the sounding channel-related control information before reporting the scheduled information to the scheduler(123).

Description

A base station and a sounding channel information scheduling method of a wireless communication system {AP OF WIRELESS COMMUNICATION SYSTEM AND SCHEDULING METHOD OF SOUNDING CHANNEL INFORMATION THEREOF}

1 is a diagram illustrating a WiBro communication system to which the present invention is applied.

2 is a diagram illustrating a frame structure considering a sounding channel in a WiBro communication system according to an exemplary embodiment of the present invention.

3 is a diagram illustrating a base station shown in FIG. 1.

4 is a diagram illustrating a DB structure of the MAC DSP shown in FIG. 3.

FIG. 5 is a diagram illustrating an operation process for managing sounding channel related control information for each terminal in the MAC DSP shown in FIG. 3.

FIG. 6 is a diagram illustrating an operation process for scheduling sounding channel information in the MAC DSP illustrated in FIG. 3.

The present invention relates to a base station and a sounding channel information scheduling method of a wireless communication system.

Among the wireless communication systems, WiBro (Wireless Broadband Internet) communication system, which is currently the domestic mobile Internet standard, is located in the middle of the mobile phone and wireless LAN, and uses wireless transmission technology that guarantees spectrum use efficiency in the 2.3 GHz frequency band. It is a 3.5 generation mobile communication system that provides video and high-speed packet data transmission of various types of IP-based wireless data services (for example, streaming video, FTP, mail, chat, etc.) provided by the wired Internet. The service range may cover a range of about 1 km from the AP, which provides much wider coverage than the range of about 100 m, which is the range of the WLAN AP. WiBro adopts mobility guarantee, handover function, cell-based engineering, and portable terminal use, which are technologies used by existing mobile phones. MIMO (Multi Input Multi Output) technology is the core technology of 4G, the next generation mobile communication, and it is an essential technology for improving frequency efficiency.

Here, smart antenna technology is typically applied as an adaptive antenna system (AAS) mode in a mobile communication system based on the OFDMA scheme. In the AAS mode, the beam pattern is adaptively used in a cell, thereby increasing cell capacity and cell coverage. In this case, in order to form a beam in the terminal in the base station supporting the smart antenna, channel information on the terminal is required. Accordingly, in order to improve the performance of the adaptive antenna in the WiBro communication system supporting the AAS mode terminal, the scheduler in the base station transmits a command for periodically receiving the predetermined information from the terminal through the sounding channel through the sounding channel. In response to the request, the terminal periodically transmits sounding information determined to the base station through an uplink sounding channel. However, at present, there is no disclosure about the scheduling method for such a sounding channel.

The scheduler in the base station currently performs many functions such as resource allocation, map information generation, power control, and ARQ. However, if the scheduling function for the sounding channel is performed, a problem may occur in that the scheduler's CPU process throughput increases and the scheduler's processing function is degraded.

SUMMARY OF THE INVENTION The present invention has been made in an effort to provide a base station and a method for scheduling sounding channel information thereof which can reduce CPU processing throughput of a scheduler in a base station in a wireless communication system.

According to an aspect of the present invention, there is provided a base station for scheduling sounding channel information in a wireless communication system supporting a terminal in an adaptive antenna system (AAS) mode. The base station includes: a modem measuring and storing sounding channel information for each terminal; A scheduler for transmitting a sounding channel allocation command for a terminal to which sounding information is to be transmitted through a sounding channel; And store and manage sounding channel related control information included in a sounding channel allocation command transmitted from the scheduler for each terminal, and schedule the sounding channel information using the sounding channel related control information to the scheduler. It includes a reporting MAC Media Access Control Digital Signal Processor (DSP).

According to another aspect of the present invention, a method for scheduling sounding channel information in a lower MAC layer in a base station of a wireless communication system supporting a terminal in an adaptive antenna system (AAS) mode is provided. According to this method, a) storing and managing sounding channel related control information included in a sounding channel allocation command transmitted from a scheduler, which is a higher layer in a base station, in a DB for each terminal; b) searching for a terminal that has transmitted sounding information through a sounding channel in a current frame by using the stored sounding channel related control information; And c) delivering sounding channel information of the searched terminal to the scheduler.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification. In addition, when a part is said to "include" a certain component, this means that it may further include other components, except to exclude other components unless otherwise stated.

Now, a base station and a sounding channel information scheduling method thereof in a wireless communication system according to an exemplary embodiment of the present invention will be described in detail with reference to the accompanying drawings.

First, the WiBro communication system of the wireless communication system to which the present invention is applied will be described in detail with reference to FIG. 1.

1 is a diagram illustrating a WiBro communication system to which the present invention is applied.

As shown in FIG. 1, the WiBro communication system includes an access terminal (AT) 110, an access point (AP) 120, a packet access router (PAR) 130, and an AAA (Authentication). Authorization Accounting (140) server 140 and HA (Home Agent) (150).

The terminal 110 is mobile to a terminal used by a subscriber to receive a portable Internet service, and has a mobile channel transmission / reception function according to a wireless access standard at a frequency of 2.3 GHz in order to access and transmit high-speed packet data by accessing the base station 120. Perform.

The base station 120 is a device for connecting a wireless network and a wired network, and provides a wireless packet data service directly to the terminal 110 through a wireless interface at a wired network end. That is, it receives a radio signal from the terminal 110 and transmits it to the packet access router 130 or vice versa converts various information received from the packet access router 130 to a radio signal and delivers it to the terminal 110. .

Packet access router 130 has a structure that is connected to a plurality of base stations 120 by IP-based wired and connected to the operator IP network and integrated access to the public Internet, the authentication function, mobile IP function, handover control between packet access routers Function, handover control between packet access routers, and quality of service (QoS) control.

The AAA server 140 is connected to the operator IP network and performs the AT 110 and user authentication and service authority verification.

The HA 150 is connected to the operator IP network to perform a mobile IP service function.

In the WiBro communication system, data transmission may efficiently use frequency bandwidth by using an Iime Division Duplex (TDD) method that separates downlink and uplink by time. In order to enable high-speed data service while the user is moving, OFDM signal transmission method is used, and OFDM-based multiple access method is used based on OFDM so that multiple users can receive internet service at the same time. have. In a WiBro communication system using an OFDMA / TDD scheme, data transmission and reception are performed on a subchannel basis composed of subcarrier groups.

2 is a diagram illustrating a frame structure considering a sounding channel in a WiBro communication system according to an exemplary embodiment of the present invention.

As shown in FIG. 2, the downlink frame 210 is largely a downlink-mobile application part (DL-MAP) region 211 and a UL-MAP (uplink) in an external communication system using the OFDMA / TDD scheme. Mobile Application Part) area 212 and down burst data area 213, the uplink frame 220 is largely the control symbol area 221, AAS preamble area 222, up burst data area 223 Sounding zone region 224.

The DL-MAP area 211 is an area including a control message for downlink burst data allocated to the AT 110, and the UL-MAP area 212 is an uplink to be used for sending data to the AT 110 in uplink. This area contains link control information. The downlink burst data area 213 is an area including data to be actually transmitted.

The control symbol region 221 is a symbol region allocated from the AT 110 to the AP 120 to use a ranging code channel, a CQICH channel, an H-ARQ channel, and the like, and the AAS preamble region 222 is an uplink. When the AT 110 transmits data, the AT 110 is an area allocated to add and transmit the AAS preamble to the corresponding symbol. In this case, the AP 120 may measure a signal-to-noise ratio (SNR) of the AT 110 using the AAS preamble. However, the AAS preamble may measure the SNR of the AT 110 when there is data to be actually transmitted by the AT 110. The uplink burst data area 223 is an area including data to be actually transmitted, and the sounding zone area 224 is an area allocated to allocate a sounding channel.

3 is a diagram illustrating a base station shown in FIG. 1.

As shown in FIG. 3, the base station 120 includes a modem 121, a MAC Media Access Control Digital Signal Processor (DSP) 122, and a scheduler 123.

The modem 121 wirelessly transmits data through channel coding, interleaver modulation, ADC, etc., and measures sounding channel information and stores the sounding channel information in a corresponding sounding channel register. Here, the sounding channel information means the SNR value of the sounding channel through which the AT 110 transmits the sounding information.

The MAC DSP 122 is a lower MAC layer that generates actual MAP in bits, generates downlink burst data, and classifies uplink burst data. In addition, the MAC DSP 122 schedules an uplink sounding channel and transmits the sounding channel information measured from the modem 121 to the scheduler 123.

The scheduler 123 performs resource allocation, MAP information generation, power control, and ARQ functions as a higher layer. In particular, the scheduler 123 transmits a sounding channel allocation command to the MAC DSP 122 and transmits a UL Sounding Command IE (Information Element) to the AT 110 through the modem 121. In this case, the UL Sounding Command IE includes the sounding channel position and period information to be used in the sounding zone region 224 to the AT 110 and is carried in the UL-MAP region 212 and transmitted to the AT 110. Then, the AT 110 periodically transmits the sounding data through the sounding channels UE # 0, UE # 1, and UE # 2 in the sounding zone region 224 after analyzing the UL Sounding Command IE.

4 is a diagram illustrating a DB structure of the MAC DSP shown in FIG. 3.

As shown in FIG. 4, the MAC DSP 122 includes N DB arrays having respective DB numbers for storing sounding channel related control information for each UE, and the number of DBs stored in the current current frame. It has a parameter of Total Active DB Count.

In detail, the MAC DSP 122 transmits basic CID information, period information, subchannel allocation offset information, and an active flag through a sounding channel allocation command from the scheduler 123. Receives sounding channel related control information such as Flag) information and stores it in the relevant DB. In this case, the basic access ID is information for distinguishing the terminal, and the period information is information indicating the interval at which the terminal transmits the sounding information through the sounding channel, and the active flag information is the sounding information transmission related information. Information indicating when to send ding information.

FIG. 5 is a diagram illustrating an operation process for managing sounding channel related control information for each terminal in the MAC DSP shown in FIG. 3.

As shown in FIG. 5, the MAC DSP 122 initializes Total Active DB Count and N DBs in order to store sounding channel related control information delivered through the sounding channel allocation command delivered from the scheduler 123. (S510).

The MAC DSP 122 checks whether a sounding channel allocation command exists from the scheduler 123 in the current frame (S520). At this time, if the sounding channel allocation command does not exist from the scheduler 123, the mobile station moves to the scheduling routine for the sounding channel information of the terminal 110 stored in N DBs. If there is a sounding channel assignment command from the scheduler 123, it is checked whether the periodic value in the DB in which the basic CID included in the sounding channel assignment command is stored is 0 or not (S530). At this time, if the period value in the DB where the basic access ID (Basic CID) is stored is not 0, the DB in which the active flag (1) and the same basic access ID (Basic CID) in the DB is present is searched (S512). If the DB where the active flag in the DB is 1 and the same basic CID exists is found, it is requested to update the period value for the terminal 110 with the period values included in the sounding channel allocation command. Since the command, the period value for the terminal 110 in the DB is updated to the period value included in the sounding channel allocation command (S570). If the DB where the active flag in the DB is 1 and the same basic CID exists is not found, it is recognized as a new sounding channel allocation command for the basic CID. The control information included in the sounding channel allocation command is stored in the next DB number of the stored DB (S580). The total Active DB Count is increased by one and then the Active Flag is set to 1 (S590).

If the period value in the DB in which the basic CID included in the sounding channel allocation command is stored in step S530 is not 0, the active basic flag in the DB is 1 and the same basic access ID is defined. Search for the DB where the CID) exists (S540). At this time, since the period value is a command to stop the transmission of the sounding channel information to the corresponding terminal, the active flag of the searched DB is set to 0, the total active DB count is decreased by one, and the searched DB is initialized ( S550).

Through such steps S510 to S590, the MAC DSP 122 processes the sounding channel allocation command from the scheduler 123, thereby managing sounding channel related control information of each terminal 110.

On the other hand, apart from this processing step, the MAC DSP 122 searches for sounding channel related control information of each terminal 110 stored in the current DB every frame and sounds which terminal 110 is sounding in the current frame. Make sure you sent the information. This can be known by finding a terminal having an active flag set to 1 in the DB. Thereafter, the MAC DSP 122 transmits the basic access ID (Basic CID) of the terminal that has transmitted the sounding information in the current frame and the SNR value for the sounding channel to the scheduler 123. Hereinafter, an operation process thereof will be described in detail with reference to FIG. 6.

FIG. 6 is a diagram illustrating an operation process for scheduling sounding channel information in the MAC DSP illustrated in FIG. 3.

As shown in FIG. 6, the MAC DSP 122 temporarily stores Total Active DB Count in Tmpcount (S610), and then performs the following operations by the number of Tmpcount. Here, Tmpcount is a temporary storage variable with Total Active DB Count value.

First, the MAC DSP 122 checks whether an active flag of the first DB is 1 or not (S620). In this case, if the active flag is 1, the period of the corresponding UE is calculated using a BFN value that increases from 0 to 4095 every frame (S630). Here, BFN is a parameter necessary for synchronization between MACs having a value of 0 to 4095 and increasing by 1 every 5 ms. At this time, if the modulo has a value of 0, the corresponding terminal 110 transmits the sounding information through the sounding channel in the current frame, so that the scheduler 123 may know which sounding information of the terminal 110. The MAC DSP 122 transmits the basic access ID (Basic CID) of the terminal 110 and the SNR value of the sounding channel for the terminal measured by the modem 121 to the scheduler 123 (S640). Thereafter, after decreasing one Tmpcount value (S650), after checking whether the value of Tmpcount is 0 (S660), the above procedure is performed for all terminals 110 stored in the DB until the value of Tmpcount becomes 0. do.

The embodiments of the present invention described above are not implemented only through an apparatus and a method, but may be implemented through a program for realizing a function corresponding to the configuration of the embodiment of the present invention or a recording medium on which the program is recorded. From the description of the above-described embodiment can be easily implemented by those skilled in the art.

The above embodiments are intended to illustrate the present invention, the scope of the present invention is not limited to the embodiments, it can be modified or modified by those skilled in the art within the scope of the invention defined by the appended claims.

According to the above-described configuration, it is possible to expect an effect of reducing CPU throughput of a scheduler which is a higher layer. In addition, effective control for the modem of the base station specifying only the SNR value for each sounding channel without storing information about the terminal is possible. In addition, it is possible to increase the memory efficiency of the lower MAC layer by using only the DB information about the actually connected terminal and have an effective load distribution effect of the scheduler, MAC DSP and modem in the base station.

Claims (11)

A base station for scheduling sounding channel information in a wireless communication system supporting an AAS (Adaptive Antenna System) mode terminal, A modem measuring and storing sounding channel information for each terminal; A scheduler for transmitting a sounding channel allocation command for a terminal to which sounding information is to be transmitted through a sounding channel; And Stores and manages sounding channel related control information included in the sounding channel allocation command transmitted from the scheduler for each terminal, and schedules the sounding channel information using the sounding channel related control information to report to the scheduler. MAC Media Access Control Digital Signal Processor (DSP) A base station of a wireless communication system comprising a. The method of claim 1, The MAC DSP is a base station of a wireless communication system having a plurality of DBs for storing the sounding channel-related control information for each terminal and a parameter indicating the number of the DB. The method of claim 2, The sounding channel allocation command includes a base access ID information, period information, subchannel allocation offset information, and active flag information related to sounding information transmission of the terminal. The method according to any one of claims 1 to 3, The MAC DSP, the base station of the wireless communication system for transmitting the basic connection ID of the terminal that transmitted the sounding information and the sounding channel information of the terminal to the scheduler as a result of the scheduling. The method of claim 4, wherein And the sounding channel information is a signal to noise ratio (SNR) value of the sounding channel. A method for scheduling sounding channel information in a lower MAC layer in a base station of a wireless communication system supporting a terminal in an adaptive antenna system (AAS) mode, a) storing and managing sounding channel related control information included in a sounding channel allocation command transmitted from a scheduler which is a higher layer in the base station in a DB for each terminal; b) searching for a terminal that has transmitted sounding information through a sounding channel in a current frame by using the stored sounding channel related control information; And c) delivering sounding channel information of the searched terminal to the scheduler; Sounding channel information scheduling method of a base station in a wireless communication system comprising a. The method of claim 6, In the step c), the sounding channel information is measured from a modem in the base station. The method of claim 7, wherein The sounding channel related control information, the basic connection ID, period information, the sounding channel information scheduling method of the base station in a wireless communication system including active flag information related to the transmission of sounding information. The method of claim 8, Step a) is If the sounding channel allocation command exists from the scheduler, checking whether the period information for the basic access ID of the terminal included in the sounding channel allocation command is 0; Searching for a DB having the basic access ID equal to 1 and the same as the basic access ID included in the sounding channel allocation command when the period information is not 0; Updating period information in the searched DB with period information included in the sounding channel allocation command when the DB is searched; And If the DB is not found, storing the sounding channel related control information in a next DB number and setting the active flag information to 1; Sounding channel information scheduling method of a base station in a wireless communication system comprising a. The method of claim 9, If the period information is 0, setting the active flag information to 0 in a DB having the same basic access ID as 1 and the basic access ID included in the sounding channel allocation command. Sounding channel information scheduling method of a base station in a wireless communication system further comprising. The method of claim 8, Step b), b-1) checking whether the active flag information is 1 in the DB of any one terminal; b-2) calculating a period in which the terminal transmits sounding information using the BFN of the current frame; b-3) finding a terminal transmitting the sounding information through a sounding channel in a current frame from the calculated period; b-4) transmitting a basic access ID of the terminal that has transmitted sounding information in the current frame and sounding channel information of the terminal to the scheduler; And b-5) repeating the steps b-1) to b-4) with respect to the DBs of the remaining terminals among the DB for each terminal; Sounding channel information scheduling method of a base station in a wireless communication system comprising a.

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