KR20090016291A - Method for transmitting channel measurement result in wirelss communication system - Google Patents

Abstract

A method for transmitting a channel measurement result in a wireless communications system for efficiently using wireless resource and reducing signaling overhead is provided to report CQI(Channel Quality Indicator) based on the radio environment and transmit a channel report message. A measurement control message including a base station is the measurement configuration table is transmitted to the terminal(S210). According to the channel condition, the measurement configuration type is determined(S220). The notify message which informs the base station that the measurement configuration type A is determined is transmitted from the terminal(S230). The base station reports the ACK message allowing the use of the measurement configuration type received to the response about the notify message(S240).

Description

Method for transmitting channel measurement result in wirelss communication system

The present invention relates to wireless communication, and to a method for transmitting a channel measurement result in a wireless communication system.

3rd generation partnership project (3GPP) mobile communication systems based on wideband code division multiple access (WCDMA) wireless access technology are widely deployed around the world. High Speed Downlink Packet Access (HSDPA), which can be defined as the first evolution of WCDMA, provides 3GPP with a highly competitive wireless access technology in the mid-term future. However, as the demands and expectations of users and operators continue to increase, and the development of competing wireless access technologies continues to progress, new technological evolution in 3GPP is required to be competitive in the future. Reduced cost per bit, increased service availability, the use of flexible frequency bands, simple structure and open interface, and adequate power consumption of the terminal are demanding requirements.

The measurement procedure provides a variety of information needed to support appropriate network management and resource allocation in consideration of the wireless environment. In general, in the measurement procedure, the base station sends measurement configuration information to the terminal. The terminal sends the measurement result to the base station when the measurement reporting criteria (Measurement Reporting Criteria) is satisfied while proceeding the measurement procedure based on the measurement configuration information.

The channel environment between the terminal and the base station varies in various ways. Therefore, if the measurement procedure is performed without considering such a channel environment, it may be inefficient.

For efficient use of radio resources, there is a need for a method that can flexibly perform measurement procedures according to channel conditions.

An object of the present invention is to provide a method for transmitting channel measurement results in consideration of channel conditions and wireless environments.

The present invention provides a method for transmitting a channel measurement result, which is a measurement result of a channel state, in a wireless communication system. Receive a measurement control message including a measurement configuration table that defines a format for reporting the channel measurement results. One of the measurement configuration types included in the channel configuration table is selected to transmit channel measurement results according to the selected measurement configuration type.

The present invention provides a method for transmitting a channel measurement result, which is a measurement result of a channel state, in a wireless communication system. Receive a configuration message that includes a measurement configuration table that defines a format for reporting the channel measurement results. One of the measurement configuration types included in the channel configuration table is selected to transmit channel measurement results according to the selected measurement configuration type.

When a channel report message or channel quality indicator (CQI) is reported while a connection is established between a terminal and a base station, the reporting configuration is determined differently based on a wireless environment. Since the terminal can immediately reflect the measurement result for the wireless environment, it is possible to reduce the signaling overhead and to efficiently use the radio resources.

1 is a block diagram illustrating a wireless communication system. This may be a network structure of an Evolved-Universal Mobile Telecommunications System (E-UMTS). The E-UMTS system may be referred to as a Long Term Evolution (LTE) system. Wireless communication systems are widely deployed to provide various communication services such as voice, packet data, and the like.

Referring to FIG. 1, an Evolved-UMTS Terrestrial Radio Access Network (E-UTRAN) includes a base station (BS) 20 that provides a control plane and a user plane.

The UE 10 may be fixed or mobile and may be called by other terms such as a mobile station (MS), a user terminal (UT), a subscriber station (SS), a wireless device, and the like. The base station 20 generally refers to a fixed station communicating with the terminal 10, and may be referred to as other terms such as an evolved-NodeB (eNB), a base transceiver system (BTS), and an access point. have. One or more cells may exist in one base station 20. An interface for transmitting user traffic or control traffic may be used between the base stations 20. Hereinafter, downlink means communication from the base station 20 to the terminal 10, and uplink means communication from the terminal 10 to the base station 20.

The base stations 20 may be connected to each other through an X2 interface. The base station 20 is connected to an Evolved Packet Core (EPC), more specifically, a Mobility Management Entity (MME) / System Architecture Evolution (SAE) gateway 30 through the S1 interface. The S1 interface supports a many-to-many-relation between the base station 20 and the MME / SAE gateway 30.

2 is a block diagram illustrating a functional split between an E-UTRAN and an EPC.

Referring to FIG. 2, the hatched block represents a radio protocol layer and the empty block represents a functional entity of the control plane.

The base station performs the following functions. (1) Radio resource management such as radio bearer control, radio admission control, connection mobility control, and dynamic resource allocation to a terminal RRM), (2) Internet Protocol (IP) header compression and encryption of user data streams, (3) routing of user plane data to SAE gateways, and (4) paging messages. Scheduling and transmission, (5) scheduling and transmission of broadcast information, and (6) measurement and measurement report setup for mobility and scheduling.

The MME performs the following functions. (1) distribution of paging messages to base stations, (2) Security Control, (3) Idle State Mobility Control, (4) SAE Bearer Control, (5) NAS (Non-Access) Stratum) Ciphering and Integrity Protection of Signaling.

The SAE gateway performs the following functions. (1) termination of user plane packets for paging, and (2) user plane switching to support terminal mobility.

Meanwhile, the layers of the radio interface protocol between the terminal and the network are based on the lower three layers of the Open System Interconnection (OSI) model, which is widely known in a communication system. , L2 (second layer), and L3 (third layer) can be divided. Among them, the physical layer belonging to the first layer provides an information transfer service using a physical channel, and is a radio resource control (RRC) layer located in the third layer. The role of controlling the radio resources between the terminal and the network. To this end, the RRC layer exchanges RRC messages between the UE and the network.

3 is a block diagram illustrating a radio protocol architecture for a user plane. 4 is a block diagram illustrating a radio protocol structure for a control plane. This shows the structure of the air interface protocol between the terminal and the E-UTRAN. The data plane is a protocol stack for user data transmission, and the control plane is a protocol stack for control signal transmission.

3 and 4, a physical layer, which is a first layer, provides an information transfer service to a higher layer by using a physical channel. The physical layer is connected to the upper Media Access Control (MAC) layer through a transport channel, and data between the MAC layer and the physical layer moves through this transport channel. Data moves between physical layers between physical layers, that is, between physical layers of a transmitting side and a receiving side. The physical channel is modulated by an orthogonal frequency division multiplexing (OFDM) scheme, and may use time and frequency as radio resources.

The MAC layer of the second layer provides a service to a radio link control (RLC) layer, which is a higher layer, through a logical channel. The RLC layer of the second layer supports reliable data transmission. In the RLC layer, there are three operation modes according to a data transmission method: transparent mode (TM), unacknowledged mode (UM), and acknowledged mode (AM). The AM RLC provides a bidirectional data transmission service, and supports retransmission when an RLC Protocol Data Unit (PDU) fails to transmit.

The Packet Data Convergence Protocol (PDCP) layer of the second layer contains relatively large and unnecessary control information in order to efficiently transmit packets in a wireless bandwidth having a low bandwidth when transmitting an Internet Protocol (IP) packet such as IPv4 or IPv6. Perform header compression to reduce the IP packet header size.

The radio resource control (RRC) layer of the third layer is defined only in the control plane. The RRC layer is responsible for the control of logical channels, transport channels, and physical channels in connection with configuration, re-configuration, and release of radio bearers (RBs). RB means a service provided by the second layer for data transmission between the UE and the E-UTRAN. If there is an RRC connection (RRC Connection) between the RRC of the terminal and the RRC of the network, the terminal is in the RRC Connected Mode, otherwise it is in the RRC Idle Mode.

The non-access stratum (NAS) layer located above the RRC layer performs functions such as authentication, SAE bearer management, and security control.

The RRC layer defines various RRC procedures to exchange configuration information necessary for radio resource management. Most of the RRC procedures are used for the purpose of setting and controlling the function of the terminal. Among them, the measurement procedure provides various information necessary to support proper network management and resource allocation considering the wireless environment. The network conveys measurement-related information through system information or measurement control messages.

The system information includes system information for the terminal in the idle mode to access the network, and various information for supporting mobility, measurement, and the like for the terminal in the connected mode. In order to systematically transmit system information, the RRC layer forms a system information block (SIB) by combining system information having similar characteristics. System information belonging to different SIBs has different characteristics not only in the content but also in characteristics such as transmission repetition period.

Measurement control messages contain a wide variety of specific measurement control information. When the UE progresses the measurement procedure based on the measurement control information and an event that satisfies the Measurement Reporting Criteria occurs or a predetermined time elapses by a timer, the terminal transmits the channel measurement result through the measurement report message. To send. Table 1 shows an example of information included in the measurement report message.

Information Explanation 1.Message Type Type of measurement report message 2. UE Information Elements  2.1. Integrity Check Info Message Authentication Code, RRC Message Sequence Number 3. Measurement Information Elements  3.1. Measurement identity Integer from 1 to 16  3.2. Measured results CHOICE Measurement (Intra-Frequency Measured Results List / Inter-Frequency Measured Results List / Inter-RAT Measured Results List / Traffic Volume Measured Results List / Quality Measured Results List / UE-Internal Measured Results List / UE Positioning Measured Results List)  3.3. Measured results on RACH Measurement Result for Current Cell, Measurement Result for Monitored Cells on Used Frequency, Measurement Result for on Non-used Frequency  3.4. Additional Measured Results 1 to <MaxAdditionalMeas>  3.5. Measured results CHOICE Measurement (Intra-Frequency Measured Results List / Inter-Frequency Measured Results List / Inter-RAT Measured Results List / Traffic Volume Measured Results List / Quality Measured Results List / UE-Internal Measured Results List / UE Positioning Measured Results List)  3.6. Event results CHOICE Event Result (Intra-Frequency Measurement Event Results / Inter-Frequency Measurement Event Results / Inter-RAT Measurement Event Results / Traffic Volume Measurement Event Results / Quality Measurement Event Results / UE-Internal Measurement Event Results / UE Positioning Measurement Event Results  3.7. Inter-RAT (Radio Access Technology) cell Info Indication Integer from 0 to 3

The measurement control information may be delivered to the terminal through another path according to the RRC state of the terminal. The UE in the idle mode obtains information by receiving SIB # 11 transmitted to the BCH, and the UE in CELL_FACH, CELL_PCH, and URA_PCH states receives measurement control information using SIB # 12. When the terminal is in the CELL_DCH state, it receives a measurement control message over the DCCH. Table 2 shows an example of information included in the measurement control message.

Information Explanation 1.Message Type Type of measurement control message 2. UE Information Elements  2.1. UE Transaction Identifier Transaction Identification Number  2.2. Integrity Check Info Message Authentication Code, RRC Message Sequence Number 3. Measurement Information Elements  3.1. Measurement identity The network is used as identification information of a corresponding measurement procedure for correcting or releasing a specific measurement procedure, and the terminal is used as identification information of a measurement procedure for reporting a measurement result. There may be a total of 16 measurement procedures.  3.2. Measurement command Indicate whether to set up, modify, or release specific measurement procedures.  3.3. Measurement Reporting Mode Indicate the RLC mode (UM RLC or AM RLC) and Reporting Criteria used to report the measurement results.  3.4. CHOICE Measurement Type Intra-Frequency Measurement / Inter-Frequency Measurement / Inter-RAT Measurement / UE Positioning Measurement / Traffic Volume Measurement / Quality Measurement / UE-Internal Measurement 4. Physical Channel Information Elements  4.1. DPCH Compressed Mode Status Info Compressed Mode status information needed to perform Inter-frequency, Inter-RAT measurement

5 is a flowchart illustrating a general measurement procedure.

Referring to FIG. 5, the base station informs the UE of measurement control information through an RRC CONNECTION message and / or a MEASUREMENT CONTROL message in an RRC idle mode or an RRC connected mode (S110). The RRC connection message includes a channel, a period required for the terminal to transmit a channel quality indicator (CQI), a time point at which the CQI transmission starts, an offset, the number of retransmissions, and the like. The measurement control message includes measurement configuration information including measurement parameters.

If the UE satisfies the measurement reporting criteria while performing the measurement procedure based on the measurement control information, and transmits a measurement report (MEASUREMENT REPORT) message to the network (S120). The measurement report message includes a channel measurement result performed by the terminal.

In this case, once the measurement configuration is determined, the UE transmits the CQI and the measurement report message in the same configuration regardless of the current channel state. Therefore, efficient use of radio resources requires flexible selection of measurement configurations according to channel conditions.

6 is a flowchart illustrating a method of transmitting a channel measurement result according to an embodiment of the present invention.

Referring to FIG. 6, the base station transmits a measurement control message including a measurement configuration table to the terminal (S210). The measurement configuration table is a table showing different measurement configuration formats according to channel conditions.

Table 3 shows an example of information for determining the channel state.

Information Explanation CPICH Ec / No Signal size received against noise CPICH RSCP Code Received Power Measured at Primary CPICH Pathloss Signal loss rate carrier Received Signal Strength Indication (RSSI) The total power received by the UE (for Inter-frequency Measurement GSM carrier RSSI Receive power measured on GSM channel (for Inter-RAT (GSM) measurement)

The terminal divides the channel state into groups based on the values in Table 3. For example, when the magnitude of the received signal is smaller than the first specific value or the magnitude of the interference is greater than the second specific value, the current channel state corresponds to the index N. N: 1,2,3,…)

Table 4 shows an example of information for determining the measurement configuration.

Information Explanation Measurement Type Indicates the type of measurement procedure that the terminal should measure. (Intra-Frequency Measurement / Inter-Frequency Measurement / Inter-System Measurement / Traffic Volume Measurement / Quality Measurement / UE-Internal Measurement / UE Positioning Measurement) Measurement objects The UE indicates information about a measurement target or a corresponding measurement target to be measured. Measurement quantity Indicate the value to be measured for the measurement object. (CPICH, Ec / No, CPICH Received Signal Code Power, Pathloss, etc.) Reporting Quantity It indicates the measurement value to be included when the terminal reports the channel measurement result to the network. Measurement Reporting Criteria The terminal presents the criteria for reporting channel measurement results to the network. There may be two types of event-causing reports and periodic reporting. Event triggering report is a method of observing a measured value when a certain condition is met, and a periodic report is a method of periodically reporting a measurement result by the operation of a timer. Measurement Reporting Mode Indicate the RLC mode (UM RLC or AM RLC) and measurement reporting criteria used to report the measurement results.

The terminal determines a discrimination equation according to the measurement report criteria included in the measurement control message, and determines a measurement configuration type according to the channel state (S220). Measurement reporting criteria include event-triggered reporting and periodic reporting. The event triggering report is a method in which a terminal transmits a channel measurement result to a base station according to a specific condition. The periodic report is a method in which the terminal periodically transmits a channel measurement result every time determined by the timer. The two methods transmit the channel measurement result according to the discrimination criterion of an event or a period, respectively. In this example, it is assumed that measurement configuration type A is determined.

The terminal transmits a notification message notifying that the measurement configuration type A has been determined to the base station (S230). When the index of the determined channel state is referred to as 'index 1', the notification message includes 'index 1'.

The base station sends an ACK message to permit the use of the received measurement configuration type in response to the notification message (S240). The ACK message may include an index of the channel state received via the notification message.

The terminal transmits a measurement report message having a predetermined period and form according to the determined measurement configuration type (S250).

The terminal determines the measurement configuration type again according to the channel state (S260). In this example, it is assumed that measurement configuration type C is determined.

The terminal transmits a notification message informing that the measurement configuration type C is determined to the base station (S270). Subsequently, the base station transmits a response to the notification message to the terminal. The terminal transmits a measurement report message having a predetermined period and shape according to the determined measurement configuration type.

When the terminal transmits a measurement report message or CQI to the base station, different measurement configuration types are applied based on the channel state and the wireless environment. The measurement configuration information includes information included in a measurement report message including a reporting period and information necessary for transmitting a CQI, that is, a channel, a period, an offset at which the CQI transmission is started, the number of retransmissions, and the like.

7 is a flowchart illustrating a method of transmitting a channel measurement result according to another embodiment of the present invention.

Referring to FIG. 7, the base station transmits a measurement control message including a measurement configuration table to the terminal (S310).

The terminal determines a measurement configuration type according to the channel state (S320). In this example, it is assumed that measurement configuration type A is determined.

The terminal transmits a notification message notifying that the measurement configuration type A is determined to the base station (S330). When the index of the determined channel state is referred to as 'index 1', the notification message may include the 'index 1'.

The base station sends a NACK message disallowing use of the measurement configuration type received in response to the notification message (S340). The NACK message may include an index of the channel state received through the notification message. That is, unlike the embodiment of Figure 6, the base station does not allow the use of the measurement configuration type requested by the terminal.

Upon receiving the NACK message from the base station, the terminal determines other measurement configuration types except the disallowed measurement configuration type (S350). In this example, it is assumed that measurement configuration type B is determined.

The terminal transmits a notification message informing that the measurement configuration type B is determined to the base station (S360).

The base station sends an ACK message to permit the use of the received measurement configuration type in response to the notification message (S370).

The terminal transmits a measurement report message having a period and a shape determined according to the determined measurement configuration type (S380).

The base station may disallow this in consideration of the channel state or relationship with other terminals for the measurement configuration type requested by the terminal. The terminal selects a new measurement configuration request.

8 is a flowchart illustrating a method of transmitting a channel measurement result according to another embodiment of the present invention.

Referring to FIG. 8, the base station transmits a measurement control message including a measurement configuration table to the terminal (S410).

The terminal determines a measurement configuration type according to the channel state (S420). In this example, it is assumed that measurement configuration type A is determined.

The terminal transmits a notification message notifying that the measurement configuration type A is determined to the base station (S430).

The base station sends a NACK message disallowing use of the measurement configuration type received in response to the notification message (S440).

The terminal first transmits a measurement report message according to the previously selected measurement configuration type A (S450).

The terminal determines other measurement configuration types except the allowed measurement configuration type (S460).

If the selection of the new measurement configuration type fails, the terminal transmits a measurement report message according to the previously selected measurement configuration type A (S470).

The terminal determines other measurement configuration types except the disallowed measurement configuration type (S480). In this example, it is assumed that measurement configuration type B is determined.

The terminal transmits a notification message indicating that the measurement configuration type B is determined to the base station (S490).

The base station sends an ACK message to permit the use of the measurement configuration type received in response to the notification message (S492).

The terminal transmits a measurement report message having a predetermined period and form according to the determined measurement configuration type (S494).

Even if the new measurement configuration type is determined, the UE may immediately transmit a measurement report message according to the new measurement configuration type without a separate notification message. Alternatively, a measurement report message according to a new measurement configuration type may be directly transmitted without a notification message and an acknowledgment message.

9 is a flowchart illustrating a method of transmitting a channel measurement result according to another embodiment of the present invention.

9, the base station transmits a measurement control message including a measurement configuration table to the terminal (S510).

The base station transmits an indication message indicating the measurement rectangle type to the terminal (S520). That is, the terminal may not determine the measurement configuration type, but the base station may determine the measurement configuration type and inform the terminal of the measurement configuration.

The terminal transmits a measurement report message according to the indicated measurement configuration type (S530).

The terminal determines the measurement configuration type according to the channel state (S540). In this example, a measurement configuration type C is determined.

The terminal transmits a notification message notifying that the measurement configuration type C is determined to the base station (S550). The base station may send an ACK message or a disallowed NACK message to permit use of the received measurement configuration type in response to the notification message.

10 is a flowchart illustrating a method of transmitting a channel measurement result according to another embodiment of the present invention.

Referring to FIG. 10, the base station transmits a measurement control message including a measurement configuration table to the terminal (S610).

The terminal determines a measurement configuration type according to the channel state (S620). In this example, it is assumed that measurement configuration type A is determined.

The terminal transmits a notification message notifying that the measurement configuration type A is determined to the base station (S630).

The terminal transmits a measurement report message according to the selected measurement configuration type A (S640). The terminal does not wait for a response to the notification message from the base station, but directly uses the measurement configuration type selected by the terminal. .

The terminal determines a new measurement configuration type according to the channel state (S650). In this example, it is assumed that measurement configuration type C is determined.

The terminal transmits a notification message informing that the measurement configuration type C is determined to the base station (S660). The terminal may wait for a response to the notification message from the base station, or may directly use the type of measurement configuration selected by the user without waiting for a response.

11 is a flowchart illustrating a method of transmitting a channel measurement result according to another embodiment of the present invention.

Referring to FIG. 11, the base station transmits a measurement control message including a measurement configuration table to the terminal (S710).

The terminal initially transmits a measurement report message according to a preset measurement configuration type (S720). That is, the terminal does not separately transmit a notification message notifying that the measurement configuration type A is determined to the base station, and directly uses the preset measurement configuration type. .

The terminal determines a new measurement configuration type according to the channel state (S730). In this example, it is assumed that measurement configuration type C is determined.

When the UE determines the new measurement configuration type, the UE transmits a notification message indicating that the measurement configuration type C is determined (S740). The terminal may wait for a response to the notification message from the base station, or may directly use the type of measurement configuration selected by the user without waiting for a response.

Meanwhile, the technical idea of the present invention can be applied as it is to CQI reporting. In the initial RRC connection step, the network transmits a CQI report table for CQI reporting to the UE. The terminal selects a CQI report type corresponding to the channel state from the CQI report table. By selecting the CQI report type suitable for the channel state, re-configuration suitable for the channel environment is possible. Whether the RRC layer, the MAC layer, or the physical layer indicates the reconfiguration of the channel according to the CQI report type, data transmission optimized for the wireless environment can be performed. The proposed scheme can be particularly effective where the cell boundary or the UE is free to move.

When the channel report message or the CQI is reported while the connection is established between the terminal and the base station, the reporting configuration is determined differently based on the wireless environment. Since the terminal can immediately reflect the measurement result for the wireless environment, it is possible to reduce the signaling overhead and to efficiently use the radio resources.

All of the above functions may be performed by a processor such as a microprocessor, a controller, a microcontroller, an application specific integrated circuit (ASIC), or the like according to software or program code coded to perform the function. The design, development and implementation of the code will be apparent to those skilled in the art based on the description of the present invention.

Although the present invention has been described above with reference to the embodiments, it will be apparent to those skilled in the art that the present invention may be modified and changed in various ways without departing from the spirit and scope of the present invention. I can understand. Therefore, the present invention is not limited to the above-described embodiment, and the present invention will include all embodiments within the scope of the following claims.

1 is a block diagram illustrating a wireless communication system.

2 is a block diagram illustrating a functional split between an E-UTRAN and an EPC.

3 is a block diagram illustrating a radio protocol structure for a user plane.

4 is a block diagram illustrating a radio protocol architecture for a control plane.

5 is a flowchart illustrating a general measurement procedure.

6 is a flowchart illustrating a method of transmitting a channel measurement result according to an embodiment of the present invention.

7 is a flowchart illustrating a method of transmitting a channel measurement result according to another embodiment of the present invention.

8 is a flowchart illustrating a method of transmitting a channel measurement result according to another embodiment of the present invention.

9 is a flowchart illustrating a method of transmitting a channel measurement result according to another embodiment of the present invention.

10 is a flowchart illustrating a method of transmitting a channel measurement result according to another embodiment of the present invention.

11 is a flowchart illustrating a method of transmitting a channel measurement result according to another embodiment of the present invention.

Claims (7)

In the method for transmitting a channel measurement result which is a measurement result of the channel state in a wireless communication system, Receiving a measurement control message including a measurement configuration table defining a format for reporting the channel measurement result; And Selecting one of the measurement configuration types included in the channel configuration table, and transmitting a channel measurement result according to the selected measurement configuration type. The method of claim 1, Selecting one of the measurement configuration types included in the channel configuration table, and then sending a notification message to the network comprising the selected measurement configuration type. The method of claim 2, After sending the notification message, receiving an ACK message permitting use of the selected measurement configuration type. The method of claim 2, After sending the notification message, receiving a NACK message disallowing use of the selected measurement configuration type. In the method for transmitting a channel measurement result which is a measurement result of the channel state in a wireless communication system, Receiving a configuration message including a measurement configuration table that defines a format for reporting the channel measurement results; And Selecting one of the measurement configuration types included in the channel configuration table, and transmitting a channel measurement result according to the selected measurement configuration type. The method of claim 5, wherein The configuration message is an RRC connection message. The method of claim 5, wherein The channel measurement result is a channel quality indicator (CQI).

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