KR100923159B1 - Packet Data Transmission and Receiving in Packet based Mobile Communication System - Google Patents

Abstract

The present invention relates to a packet data transmission and reception method for minimizing the amount of scheduling information transmitted through a radio resource in a packet-based wireless communication system and reducing the case of transmitting additional control information through a radio resource. A packet data transmission method in a communication system, comprising: (a) setting a radio resource block identifier indicating a coding scheme of a radio resource block for packet data transmission; (b) encoding the radio resource block identifier including a CRC masking a control signal block for transmitting scheduling information by using a group identifier of a terminal; And (c) encoding the radio resource block for transmitting the packet data in a manner indicated by the radio resource block identifier.

Packet, communication, system, wireless, LTE, resource, control, block, data, packet, transmission

Description

Packet Data Transmission and Receiving in Packet based Mobile Communication System}

The present invention relates to packet data transmission in a packet-based wireless communication system, and more particularly, to minimize the amount of scheduling information transmitted through a radio resource in a packet-based wireless communication system and to transmit additional control information through a radio resource. It relates to a packet data transmission and reception method that can reduce the.

The present invention is derived from the research conducted as part of the IT new growth engine core technology development project of the Ministry of Information and Communication and the Ministry of Information and Communication Research and Development. [Task Management Number: 2005-S-404-12, Title: 3G Evolution Wireless Transmission Technology Development] ].

In order to provide various packet services, the packet-based wireless communication system (for example, Long Term Evolution (LTE) system), which is currently being standardized, aims to provide pure packet services, and seeks a more efficient and variable method of utilizing radio resources. It is becoming.

Packet-based wireless communication system is a technology that implements high-speed packet-based communication of about 100Mbps with the aim of commercialization around 2010. Currently, packet-based wireless communication systems (LTE systems) consider Orthogonal Frequency Division Multiplexing (OFDMA). The OFDMA scheme has a two-dimensional radio resource distinguished by frequency and time, unlike the CDMA scheme in which a code is allocated to distinguish radio resources for respective terminals. That is, in the OFDMA scheme, radio resources consisting of time and frequency are divided and transmitted for downlink and uplink physical channels, and radio resources are divided into transmission time interval (TTI) and subcarrier (subcarrier) groups. Use resource blocks. A radio frame constituting such a radio resource consists of a slot (or TTI) of 1 millisecond size. Therefore, in case of 10 millisecond radio frame, 10 slots constitute one radio frame.

In such a packet-based wireless communication system, a plurality of terminals share radio resources for transmitting packet data. In a packet-based wireless communication system, radio resources are allocated according to whether a data is required to be transmitted or received and a wireless channel situation of a terminal that is dynamically changed according to time. Therefore, according to a period in which radio resources are allocated, control information such as scheduling information is provided through a radio resource shared by various terminals so that each terminal can access and demodulate the radio resource allocated to each terminal according to a period in which the radio resource is allocated. What can be done is required.

The scheduling operation for allocating radio resources to transmit packet data is basically performed in TTI units, which are transmission periods. Accordingly, terminals receiving a packet service search for a control signal block (L1 / L2 control signal resource block) in which scheduling information is transmitted every TTI in order to transmit or receive data. In this case, the control signal information addresses the radio resource block allocated for packet data transmission. In addition, a terminal identifier (C-RNTI) and a group identifier (group C-RNTI) for identifying a terminal or a group of terminals in a base station for scheduling may be inserted into control signal information or not. It may not.

Currently, in the packet-based wireless communication system, different radio resource allocation schemes are considered according to the type of packet service and quality of service (QoS). For example, in the case of a real time service, a persistent or semi-static radio resource allocation method that allocates radio resource blocks fixedly at regular intervals in time is considered. In the case of a non-real time service, a dynamic allocation method in units of TTIs is considered. In particular, the VoIP (Voice of IP) service, which is a typical real-time service, continuously allocates a radio resource block in a radio resource controller (RRC) of the base station layer 3, and at the corresponding TTI in order to reduce the amount of transmission of control signal information. It is also contemplated not to transmit separate control signal information for scheduling.

Therefore, in the case of supporting such a radio resource allocation method in a packet-based wireless communication system, it is necessary to minimize the amount of scheduling information transmitted through a radio resource for transmitting control information and to transmit additional control information through a radio resource. What is needed is a way to reduce it.

Accordingly, the present invention has been proposed to solve the above problems of the prior art, and minimizes the amount of scheduling information transmitted through radio resources in the packet-based next generation wireless communication system and transmits additional control information through radio resources. It is an object of the present invention to provide a method for transmitting and receiving packet data that can reduce cases.

Other objects and advantages of the present invention can be understood by the following description, and will be more clearly understood by the embodiments of the present invention. Also, it will be readily appreciated that the objects and advantages of the present invention may be realized by the means and combinations thereof indicated in the claims.

A packet data transmission method according to the present invention for achieving the above object, in the packet data transmission method in a packet-based wireless communication system, (a) a radio resource block indicating a coding method of a radio resource block for packet data transmission Setting a delimiter; (b) encoding and applying a CRC masked with a group identifier of a terminal, wherein the radio resource block identifier is included and a control signal block for transmitting scheduling information is masked; And (c) encoding the radio resource block for transmitting the packet data in a manner indicated by the radio resource block identifier.

Preferably, before the step (a), (d) assigning a unique identifier and a group identifier for the terminals while performing a radio resource control (RRC) connection setup; And (e) designating a scheduling characteristic for each terminal to notify each terminal.

Preferably, the radio resource block identifier identifies whether the radio resource block is encoded using common information to indicate that it is transmitted to all terminals in the group or the terminal unique information to indicate that it is transmitted to a specific terminal. Contains information for

Preferably, the common information is any one of a common CRC and a CRC masked with a group identifier, and the terminal specific information is any one of a CRC masked with a terminal unique identifier and a terminal unique scrambling code.

In addition, the packet data receiving method according to the present invention for achieving the above object, in the packet data receiving method in a packet-based wireless communication system, (a) a radio resource block identifier is included, a control signal for transmitting scheduling information Decoding the block by applying a CRC masked with the group identifier of the terminal; (b) confirming radio resource block information allocated to itself for packet data transmission from the decoded control signal block; And (c) decoding the radio resource block identified through the radio resource block information in a manner indicated by the radio resource block identifier.

Preferably, the receiving method according to the present invention, before the step (a), (d) receiving a terminal unique identifier and a group identifier from the base station while performing the radio resource control (RRC) connection setup; And (e) receiving scheduling characteristics from the base station.

In addition, another embodiment of the present invention for achieving the above object, in a packet data transmission method in a packet-based wireless communication system, (a) performing a radio resource control (RRC) connection setup and unique identifiers for the terminals; Assigning a group identifier; (b) setting an attribute of a radio resource block including information related to allocation of at least a radio resource block and location information of the radio resource block for each terminal; And (c) encoding and transmitting the radio resource block for packet data transmission to the terminal according to the set attribute of the radio resource block.

Preferably, the radio resource block may be encoded using a CRC masked with a unique identifier of each terminal or encoded using a unique scrambling code of each terminal.

In addition, another embodiment of the present invention for achieving the above object, in a packet data receiving method in a packet-based wireless communication system, (a) assigning a terminal unique identifier and a group identifier through the radio resource control (RRC) connection settings Receiving step; (b) receiving an attribute of a radio resource block including at least information related to allocation of a radio resource block and location information of the radio resource block; And (c) searching for and decoding the radio resource block for packet data transmission according to the property of the received radio resource block.

In the present invention as described above, when a radio resource block is allocated permanently or semi-statically for a real-time service, it is transmitted to the terminals by managing terminals to be scheduled as a group through RRC connection establishment. Control signal information can be reduced. In addition, the present invention can reduce the load according to the scheduling of the base station by managing the scheduling by group while improving the sharing property of the radio resource for the burst characteristics of the packet in the case of real-time service. In addition, the present invention, by transmitting the control signal information for the addressing of the radio resource block in the corresponding TTI according to the scheduling information set through the RRC connection configuration by notifying the encoding method of the radio resource block using a radio resource block identifier, The utilization of radio resources can be improved.

The above objects, features and advantages will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, whereby those skilled in the art may easily implement the technical idea of the present invention. There will be. In addition, in describing the present invention, when it is determined that the detailed description of the known technology related to the present invention may unnecessarily obscure the gist of the present invention, the detailed description thereof will be omitted. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 illustrates an example of a configuration of a downlink radio frame and a TTI for allocating a radio resource block by scheduling in units of TTIs.

The radio frame 11 is defined as a predetermined time (eg, 10 ms) and a frequency bandwidth (eg, 10 MHz) including a broadcast channel (BCH) block 12 for transmitting system information. Each radio frame includes a TTI 13 representing an interval at which packet data is transmitted according to a scheduling operation period, and a control signal block 14 for allowing each terminal to access and decode a radio resource block through which packet data is transmitted for each TTI. It includes.

The control signal block 14 transmits scheduling information for uplink radio resources defined separately from the downlink (DL) control signal block 15 for transmitting scheduling information for downlink radio resources in the TTI including the control signal block. The uplink (UL) control signal block 16 is configured. A radio resource block (RB) 17 through which packet data is transmitted has a mapping relationship with a downlink (DL) control signal block 18 for a corresponding radio resource block.

As shown in FIG. 1, the allocation of a radio resource block (RB) for each terminal or group of terminals depends on the scheduling attribute, i.e. whether it is a persistent assignment (or semi-static assignment) or a dynamic assignment. For example, in FIG. 1, terminal 5 is continuously allocated a radio resource block (RB), and terminal 2 and terminal 11 are periodically allocated a radio resource block (RB) at regular intervals. Referring to FIG. 1, the terminal 19 and the terminal group 2 may be dynamically allocated a radio resource block according to a packet generation situation. In particular, in a special case of a real time service (eg, a VoIP service), a radio resource block (RB) may be allocated without a separate control signal block.

Due to the sharing of radio resources in packet-based wireless communication systems, a large number of terminals are expected to remain active. Here, the active state refers to a state in which a terminal and a base station maintain a connection relationship (for example, an RRC connection state) to transmit and receive packet data through radio resource request or allocation when necessary.

Scheduling for radio resource block (RB) allocation in a packet-based wireless communication system should be made in a terminal or group of terminals according to the characteristics of a packet service. In addition, in order for each terminal to access a radio resource block (RB) allocated by a base station and receive packet data transmitted thereto, each terminal searches for a control signal block that is scheduling information for the corresponding radio resource block (RB). Must be able to recognize the radio resource block (RB) assigned to it. Or, each terminal has an attribute (or subcarrier index) of a radio resource block (RB) including a generation position of a radio resource block (RB) allocated to it and no modulation and coding scheme (MCS) in the absence of scheduling information. Information, etc.) in advance.

To this end, a control signal block and a radio resource block for transmitting scheduling information are separately encoded. That is, each control signal block is encoded using a cyclic redundancy check (CRC) masked with a terminal identifier or a group identifier (eg, C-RNTI) allocated for scheduling. Accordingly, each terminal or a specific group of terminals are decoded using a CRC masked with an identifier (terminal identifier or group identifier), thereby recognizing that the terminal transmits control signal information for itself. The radio resource block for packet data transmission is encoded using a common CRC defined by a system, encoded using a CRC masked with an assigned identifier, or uses a unique scrambling code for a predetermined terminal or terminal group. To be encoded in units of radio resource blocks (RBs).

When scheduling for radio resource block allocation is performed on a terminal group basis, the control signal block is encoded using a CRC masked with a predetermined or assigned group identifier. The radio resource block for packet data transmission may be encoded using a common CRC, encoded using a CRC masked with a group identifier, or encoded using a scrambling code for a group.

For example, the base station classifies the terminals into groups based on channel quality measured for terminals receiving a real-time service such as VoIP service, terminal identifier, terminal capability, network access point, and the like. Scheduling may be considered. In this case, there is a terminal that receives a plurality of VoIP services in one group. The base station periodically allocates radio resources by scheduling in group units. In addition, the terminal searches for a control signal block according to an allocation period of radio resources on a group basis to check whether there is a radio resource block allocated to its own group, and if the allocated radio resource block exists, the corresponding radio resource. Decrypt the block. In this case, the terminal decodes the radio resource block using a CRC (or group scrambling code) masked with a group identifier according to the radio resource block identifier, or uses terminal specific data (for example, terminal unique identifier) for a specific terminal. The radio resource block is decoded using a masked CRC or a terminal specific scrambling code.

2A is a flowchart illustrating a process of a base station for packet data transmission according to the present invention described above.

The base station broadcasts system information on the broadcast channel, including system scheduling information and general attributes for persistent allocation (or semi-static allocation) and dynamic allocation according to a service supported by the base station (201).

In the process of establishing a call between the base station and the terminal in order to start a real-time service (for example, RRC connection establishment process), the base station designates a corresponding group of the terminal and assigns the terminal to the terminal along with a unique terminal identifier. (202). In this case, the base station specifies scheduling characteristics for the corresponding terminal through an RRC connection establishment process (203). For example, in case of persistent allocation (or semi-static allocation), the base station designates information on the period in which the control signal block is generated and informs the terminal.

When the RRC connection is made between the base station and the terminal by the RRC connection establishment process, the base station allocates a radio resource block for downlink packet data transmission, and a radio resource block (RB) identifier indicating an encoding method of the radio resource block. After setting (204), the control signal block is transmitted to the terminal according to the scheduling pattern specified in the RRC connection establishment process (205). At this time, the base station encodes the control signal block using the CRC masked by the group identifier.

Here, the radio resource block (RB) identifier indicates whether packet data transmitted in the allocated radio resource block is encoded using a common CRC (or a CRC masked by a group identifier) as information transmitted to all terminals in a group, or a specific terminal. For the purpose of indicating whether the encoding is performed by a terminal-specific method (eg, CRC masking or terminal-specific scrambling code using a terminal unique identifier). For example, if the radio resource block identifier is set to '0', it means that the radio resource block is encoded using a common CRC. If the radio resource block identifier is set to '1', the radio resource block is encoded by a terminal-specific method. It means. Using such a radio resource block identifier, it is possible to transmit control information to be transmitted to the entire group in the allocated radio resource block. Such a radio resource block identifier may be configured as an information field in control information. Alternatively, the radio resource block identifier is not inserted into an information field in control information, and a part of a scheduling identifier in the system is allocated as a common information scheduling identifier for a certain service or a separate mapping relationship with a corresponding group identifier is provided. It can be configured through a method using a group scheduling identifier.

Thereafter, the base station transmits downlink packet data using the allocated radio resource block (206). When the service is terminated, the base station and the terminal release radio resource allocation information that has been allocated for packet service through an RRC connection release process (207). At this time, the terminal returns the group identifier (C-RNTI) to the base station, and the scheduling attribute for the corresponding service is also changed.

2b is a flowchart illustrating a processing procedure in a terminal for packet data transmission according to the present invention.

The terminal receives the system information including the scheduling policy according to the service supported by the base station and the general attributes of the persistent allocation (or semi-static allocation) and the dynamic allocation through the broadcast channel (211).

In order to start a real-time service, the terminal is assigned a group identifier with a unique terminal identifier from the base station through a process of attempting to establish a call with the base station (for example, an RRC connection establishment process), and is informed of scheduling characteristics set by the base station. 212). For example, in case of persistent allocation (or semi-static allocation), the terminal receives information from the base station about the period in which the control signal block is generated.

After the RRC connection is established between the base station and the terminal by the RRC connection setup as described above, the terminal receives the control signal block at a specified timing according to the scheduling information obtained through the RRC connection procedure in order to receive the downlink packet data (213). The control signal block is decoded using the CRC masked with the identifier of the group to which the group belongs (214). Accordingly, the terminal checks the existence of the radio resource block allocated to its group (215), and checks the radio resource block identifier indicating the attribute of packet data of the radio resource block (216).

In operation 217, the terminal decodes the radio resource block allocated to itself through the decoding of the control signal block according to a method indicated by the radio resource block identifier.

Meanwhile, the terminal searches for an uplink control signal block at a specified timing according to scheduling information obtained through an RRC connection procedure for uplink packet data transmission. The terminal identifies the uplink radio resource block allocated to itself in the decoded control signal block and transmits uplink packet data using the uplink radio resource block assigned thereto.

When the service is terminated, the terminal releases radio resource allocation information that has been allocated for packet service through an RRC connection release process (218). At this time, the terminal is released from the group belonging to the service and returns the group identifier (C-RNTI) to the base station, and also changes the scheduling properties for the service.

On the other hand, in the method for allocating radio resources in a persistent or semi-static allocation method, the radio resource control unit (RRC) of the base station presets the radio resource allocation information and does not transmit scheduling information of the control signal block in the corresponding TTI. There may be a method of transmitting packet data through a pre-allocated radio resource block. 3 is a flowchart illustrating a packet transmission method according to another embodiment of the present invention.

The base station broadcasts system information including a scheduling policy according to a service supported by the base station, and general information on persistent allocation (or semi-static allocation) and dynamic allocation through a broadcast channel (301).

In the process of establishing the RRC connection between the base station and the terminal to start the real-time service, the base station designates a corresponding group of the terminal and gives the terminal a group identifier along with the terminal unique identifier (302). In addition, the base station sets scheduling properties in advance so that the terminal can receive packet data by decoding the allocated radio resource block without transmitting control signal information in the corresponding TTI through scheduling of the corresponding terminal through the RRC connection process (303). , 304). For example, in case of persistent allocation (or semi-static allocation), the base station sets attributes of a radio resource block such as a radio resource block allocation period and period, a location of the radio resource block, and a modulation and coding scheme (304). . Alternatively, the base station may provide the terminal with a radio resource block allocation period and interval, a location of the radio resource block, an attribute set of possible radio resource blocks for the modulation and encoding scheme, etc. (304). Accordingly, the terminal can select any one of the attribute sets of the provided radio resource block.

Thereafter, the base station transmits the packet data using the designated radio resource block according to the scheduling information notified to the terminal through the RRC connection establishment process (305). The UEs decode packet data by searching for a radio resource block designated for a corresponding real-time service without searching for a control signal block in a corresponding TTI according to scheduling information obtained in advance through the RRC connection establishment process. At this time, the terminal decodes the encoded packet data by using a CRC masked with an identifier assigned to the terminal or a method using a terminal-specific scrambling code.

When the service is terminated, the base station and the terminal release the radio resource allocation information, etc. which have been allocated for the packet service through the RRC connection release process (306).

On the other hand, the method of the present invention as described above can be written in a computer program. And the code and code segments constituting the program can be easily inferred by a computer programmer in the art. In addition, the written program is stored in a computer-readable recording medium (information storage medium), and read and executed by a computer to implement the method of the present invention. The recording medium may include any type of computer readable recording medium.

The present invention described above is capable of various substitutions, modifications, and changes without departing from the technical spirit of the present invention for those skilled in the art to which the present invention pertains. It is not limited by the drawings.

1 is a view for explaining a configuration example of a radio frame and TTI for radio resource allocation;

2a is a flowchart illustrating a processing procedure in a base station for packet data transmission according to an embodiment of the present invention;

2b is a flowchart illustrating a process of a terminal for receiving packet data according to an embodiment of the present invention;

3 is a flowchart illustrating a processing procedure in a base station for packet data transmission according to another embodiment of the present invention.

Claims (20)

In the packet data transmission method in a packet-based wireless communication system, (a) setting a radio resource block identifier indicating a coding scheme of a radio resource block for packet data transmission; (b) encoding the radio resource block identifier including a CRC masking a control signal block for transmitting scheduling information by using a group identifier of a terminal; And (c) encoding the radio resource block for transmitting the packet data according to a method indicated by the radio resource block identifier. Packet data transmission method comprising a. The method of claim 1, Before step (a) above, (d) assigning a unique identifier and a group identifier to the terminals while performing a radio resource control (RRC) connection establishment; And (e) specifying scheduling characteristics for each terminal and notifying each terminal Packet data transmission method further comprising. The method of claim 2, In step (b), the control signal block is transmitted by applying the CRC masked with the group identifier of the terminal according to the scheduling characteristic specified in step (e) and transmitting the encoded signal to the terminal. The method of claim 2, The radio resource block identifier is Packet data transmission, characterized in that it is information for identifying whether a radio resource block is encoded using common information to indicate transmission to all terminals in a group or whether to encode using terminal specific information to indicate transmission to a specific terminal. Way. The method of claim 4, wherein The common information is any one of a CRC masked by a common CRC and a group identifier. The method of claim 4, wherein The terminal specific information is any one of a CRC masked with a terminal unique identifier and a terminal unique scrambling code. A packet data receiving method in a packet based wireless communication system, (a) including a radio resource block identifier and decoding the control signal block for transmitting scheduling information by applying a CRC masked with a group identifier of a terminal; (b) confirming radio resource block information allocated to itself for packet data transmission from the decoded control signal block; And (c) decoding the radio resource block identified through the radio resource block information in a manner indicated by the radio resource block identifier; Packet data receiving method comprising a. The method of claim 7, wherein Before step (a) above, (d) receiving a terminal unique identifier and a group identifier from a base station while performing a radio resource control (RRC) connection establishment; And (e) receiving scheduling characteristics from a base station Packet data receiving method further comprising. The method of claim 8, In the step (a), the control signal block is transmitted according to the scheduling characteristic specified in the step (e). The method of claim 8, The radio resource block identifier is Packet data reception, characterized in that it is information for identifying whether a radio resource block is encoded using common information to indicate transmission to all terminals in a group or whether to encode using terminal specific information to indicate transmission to a specific terminal. Way. The method of claim 10, The common information is any one of a common CRC and a CRC masked by a group identifier. The method of claim 10, The terminal specific information is any one of a CRC masked with a terminal unique identifier and a terminal unique scrambling code. In the packet data transmission method in a packet-based wireless communication system, (a) assigning a unique identifier and a group identifier to terminals while performing a radio resource control (RRC) connection establishment; (b) setting an attribute of a radio resource block including information related to allocation of at least a radio resource block and location information of the radio resource block for each terminal; And (c) encoding and transmitting the radio resource block for packet data transmission to the terminal according to the set attribute of the radio resource block. Packet data transmission method comprising a. The method of claim 13, In step (b), transmitting a set of attributes of a configurable radio resource block including information related to the allocation of a radio resource block and location information of the radio resource block to each terminal, and among the set of attributes of the configurable radio resource block. Packet data transmission method characterized in that it is set to any one set. The method of claim 13, The radio resource block is encoded using a CRC masked with a unique identifier of each terminal. The method of claim 13, The radio resource block is encoded using a unique scrambling code of each terminal. A packet data receiving method in a packet based wireless communication system, (a) receiving a terminal unique identifier and a group identifier through a radio resource control (RRC) connection establishment; (b) receiving an attribute of a radio resource block including at least information related to allocation of a radio resource block and location information of the radio resource block; And (c) searching for and decoding the radio resource block for packet data transmission according to the property of the received radio resource block Packet data receiving method comprising a. The method of claim 17, In step (b), a set of attributes of the configurable radio resource block including information related to the allocation of the radio resource block and position information of the radio resource block is received, and any one of the set of attributes of the configurable radio resource block is received. A method for receiving packet data, characterized by setting attributes of a radio resource block in a set. The method of claim 17, And (c) decoding the radio resource block retrieved using the CRC masked with the unique identifier of each terminal in step (c). The method of claim 17, Packet data receiving method, characterized in that in step (c) to decode the found radio resource block using a unique scrambling code of each terminal.

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