KR20050119067A - A method for controlling uplink data rate for reducing the downlink signaling overhead in mobile telecommunication system - Google Patents

Abstract

The present invention provides a method and apparatus for controlling an uplink transmission rate without increasing downlink signaling overhead in a base station and a terminal supporting a packet data service through an enhanced uplink dedicated transport channel in an asynchronous code division multiple access communication system. will be. The base station determines transmission rate information to be transmitted to the terminals, selects a common signaling method or a dedicated signaling method to be used according to a situation, and transmits the transmission rate information by the selected signaling method. The terminal first attempts to receive the rate information by the dedicated signaling method, and if it is not successfully received, the terminal receives the rate information by the common signaling method. This invention has the effect of reducing the downlink signaling overhead for transmitting the rate information allocated by the base station to the terminal.

Description

A method for controlling uplink transmission rate to reduce downlink signaling overhead in a mobile communication system

The present invention relates to a wideband code division multiple access (WCDMA) communication system, and in particular, an uplink rate control method for performing base station control scheduling in an enhanced uplink dedicated channel. Relates to a device.

Third generation, based on the European mobile system Global System for Mobile Communications (GSM) and General Packet Radio Services (GPRS), and using Wideband Code Division Multiple Access (CDMA) UMTS (Universal Mobile Telecommunication Service) system, a mobile communication system, is a consistent service that enables mobile phone or computer users to transmit packet-based text, digitized voice or video, and multimedia data at high speeds of 2 Mbps or more anywhere in the world. To provide. UMTS uses the concept of virtual access, which is a packet-switched connection that uses a packet protocol such as Internet Protocol (IP), and can always be connected to any other end in the network.

In particular, in the UMTS system, the uplink from the user equipment (UE) to the base station (BS or Node B), that is, the uplink (uplink: UL) communication in order to further improve the performance of packet transmission in the uplink (UL) communication A transport channel called an Enhanced Uplink Dedicated Channel (hereinafter referred to as EUDCH or E-DCH) is used. E-DCH supports Adaptive Modulation and Coding (AMC), Hybrid Automatic Retransmission Request (HARQ), and Base Station Control Scheduling (Node B Controlled) to support more stable high-speed data transmission. Technology, such as Scheduling).

AMC is a technology that determines the modulation method and coding method of the data channel according to the channel state between the base station and the terminal, thereby increasing the resource usage efficiency. The combination of modulation scheme and coding scheme is called MCS (Modulation and Coding Scheme), and various MCS levels can be defined according to the supported modulation scheme and coding scheme. AMC adaptively determines the level of the MCS according to the channel state between the terminal and the base station, thereby increasing the resource usage efficiency.

HARQ refers to a technique for retransmitting a packet to compensate for the error packet when an error occurs in an initially transmitted data packet. The complex retransmission technique includes a chase combining technique (hereinafter referred to as CC) that retransmits packets of the same format as the initial transmission when an error occurs, and an incremental increment technique that retransmits packets having a different format than the initial transmission when an error occurs. (Incremental Redundancy: referred to as IR hereinafter).

In the base station control scheduling, if the base station determines whether to transmit the uplink data through the E-DCH and the upper limit of the possible data rate, and transmits the determined rate information to the terminal, the terminal can refer to the rate information to enable uplink E -Means a method of determining the data rate of the DCH.

1 is a diagram illustrating uplink packet transmission through an E-DCH in a typical mobile communication system. Here, reference numeral 110 denotes a base station supporting a E-DCH, that is, a Node B, and reference numerals 101, 102, 103, and 104 denote terminals that use the E-DCH. As shown, the terminals 101 to 104 transmit data to the base station 110 through the E-DCHs 111, 112, 113, and 114, respectively.

The base station 110 informs whether or not EUDCH data can be transmitted for each terminal by using the data buffer status, request data rate, or channel state information of the terminals 101 to 104 using the E-DCH, or provides the EUDCH data rate. Transmit rate information to adjust. Scheduling assigns low data rates to terminals far away from the base station (e.g., 103 and 104) while ensuring that the measured noise rise of the base station does not exceed the target value to increase system-wide performance. Terminals (eg, 101, 102) are performed in a manner of allocating a high data rate. The terminals 101 to 104 determine the maximum allowable data rate of the E-DCH data according to the rate information, and transmit the E-DCH data at the determined data rate.

Uplink signals transmitted from different terminals in uplink are not orthogonal because they are not kept in synchronization with each other, and thus act as interference. As a result, as the uplink signals received by the base station increase, the amount of interference with respect to the uplink signal of a specific terminal also increases, thereby reducing reception performance. In order to overcome this problem, although the uplink transmission power of the specific terminal may be increased, this again acts as interference to other uplink signals, thereby reducing reception performance. As a result, the total power of the uplink signal that the base station can receive while guaranteeing reception performance is limited. Rise Over Thermal (ROT) represents a radio resource used by the base station in the uplink, and is defined as in Equation 1 below.

I ₀ denotes a power spectral density for the entire reception band of the base station and represents the total amount of uplink signals received by the base station. N ₀ is the thermal noise power spectral density of the base station. Thus, the maximum allowable ROT is the total radio resource that the base station can use on the uplink.

The total ROT of the base station is represented by the sum of inter-cell interference, voice traffic and E-DCH traffic. If base station control scheduling is used, it is possible to prevent a plurality of terminals from transmitting packets of a high data rate at the same time, so that the reception ROT can be maintained at the target ROT to ensure reception performance at all times. That is, the base station control scheduling prevents the reception ROT from increasing beyond the target ROT by not allowing the other terminal with a high data rate when allowing a specific data rate.

In case of base station control scheduling, the overhead of downlink signaling should be considered due to signaling of rate information when there are many terminals performing E-DCH service in one cell. For example, if the number of terminals is very large, the base station consumes downlink transmission power for transmitting the rate information, or otherwise, many downlink channel codes are required for transmitting the rate information. This may cause a problem of reducing downlink capacity in the entire cell. Therefore, there is a need for a technique for reducing downlink signaling overhead in transmitting rate information for base station control scheduling.

Accordingly, an object of the present invention, which is designed to solve the problems of the prior art operating as described above, is to provide a method for reducing signaling overhead while the base station individually schedules the terminals.

An object of the present invention is to provide a method for transmitting uplink rate information by a base station providing a packet service through a reverse transport channel while reducing downlink signaling overhead.

An object of the present invention is to provide a method for a user equipment to receive uplink rate information transmitted by a base station while reducing downlink signaling overhead.

Hereinafter, with reference to the accompanying drawings will be described in detail the operating principle of the preferred embodiment of the present invention. In the following description of the present invention, detailed descriptions of well-known functions or configurations will be omitted if it is determined that the detailed description of the present invention may unnecessarily obscure the subject matter of the present invention. Terms to be described later are terms defined in consideration of functions in the present invention, and may be changed according to intentions or customs of users or operators. Therefore, the definition should be made based on the contents throughout the specification.

The present invention to be described later, in the packet service supporting base station control scheduling, such as the E-DCH service of the WCDMA system, the base station transmits the transmission rate information to the terminals through the downlink without increasing the downlink signaling overhead as much as possible To receive the rate information.

First, two base station control scheduling methods applied to the present invention will be described. One is rate scheduling for increasing or decreasing only the data rate of the terminal, and the other is time and rate scheduling for controlling up to a transmission / reception point of time with the data rate of the terminal.

In the rate scheduling scheme, the UE can transmit data at each transmission time interval (hereinafter, referred to as a TTI), and since the data rate is controlled by the base station, the base station should inform all terminals of the transmission rate information at every TTI. do. In this case, if the absolute value of the data rate is reported, the signaling overhead is so large that the base station signals rate allowance information indicating an increase or decrease of the rate instead of the absolute value of the rate. In general, the rate allowance information is two bits of information indicating the increase / decrease / sustainment of the rate. In this case, the amount of change in the transmission rate that can be controlled by the base station at a moment for one terminal is limited. In other words, even if the terminal requires a very high transmission rate, the base station incrementally increases the transmission rate of the terminal through multiple signaling. Therefore, the time delay for obtaining the desired transmission rate is large.

Physical channels for signaling the rate grant information include a typical dedicated channel and a common channel. Since the rate scheduling scheme informs scheduling information of all terminals at every point in time, all terminals must receive rate tolerance information. Therefore, in case of using a common channel, a code division multiplex for allocating a terminal-specific channelization code to identify each terminal or a time division multiplex for allocating a transmission timing unique to a terminal TDM) can be used. Channel codes for the CDM scheme have orthogonal characteristics to distinguish terminals.

In the time rate scheduling scheme, the UE transmits E-DCH traffic according to the rate information received from the base station, and does not transmit the E-DCH traffic when the rate information is not received. To this end, the base station informs the absolute value of the rate every time. Since the base station uses the absolute rate, it is possible to assign a random rate among the possible rates at every transmission point to the terminal. For example, if the terminal supports transmission rates of 8kbps ~ 1Mbps, the base station may allocate 8kbp at one transmission time and 1Mbps at the next transmission time. Alternatively, the E-DCH transmission is blocked by not transmitting the rate information. Unlike rate scheduling, the rate scheduling can change up to the maximum data rate through one scheduling operation, thereby reducing time delay due to scheduling.

The absolute rate is carried over the shared channel and identified by the terminals using a UE-id. Since the terminal identifier is masked with error detection information such as Cyclic Redundancy Codes (CRC), the rate information includes a unique CRC and an absolute rate value according to the terminal identifier. The UE performs a CRC check on the rate information received through the common channel at every scheduling time point. If the UE is not for the UE, the CRC check fails and discards the rate information. If the CRC check is successful, the terminal adjusts the transmission rate according to the transmission rate information.

In the following cases, the number of terminals to which the base station should transmit rate information is greatly increased.

-If the interference suddenly increases in the cell and the RoT level increases

-When a terminal with a higher priority requests a higher data rate and reduces the rate of many other terminals at once

When there is enough cell load, it is possible to schedule many terminals at once

Both scheduling schemes described above should consider the overhead of downlink signaling due to signaling of scheduling information when the number of terminals supporting E-DCH service in one cell increases. In the rate scheduling scheme, since terminals always have code channels for receiving rate tolerance information, new channel codes are not required even when the number of terminals increases, but signaling of rate tolerance information when the number of terminals that must be signaled at the same time increases. The ratio of the downlink transmission power for the large becomes. In the case of the time rate scheduling scheme, when the number of terminals to be scheduled at the same time increases, many new channel codes to be allocated are required, and thus, downlink code resources may be insufficient. Since the code resources available in the entire cell are limited, this reduces the downlink capacity of the entire cell.

Another scheduling scheme for reducing such downlink signaling overhead is common control scheduling for signaling all terminals at once. The common control scheduling scheme signals common rate information of the entire cell. The base station transmits rate information that reduces data rate to all terminals when the RoT level of the cell is higher than the RoT level for the E-DCH. If not, the transmission rate information for increasing the transmission rate is transmitted to all terminals. This method reduces signaling overhead because it requires less signaling channel and transmit power, but cannot individually schedule each UE according to priority or QoS of data to be serviced.

In the present invention, the rate information is transmitted by using a common signaling scheme and a dedicated scheduling scheme. That is, the base station determines the transmission rate of each terminal based on the transmission rate request information of each terminal in every scheduling period and determines how to transmit the scheduling information. The scheduling information and the scheduling signaling scheme of each terminal are transmitted to the corresponding terminals. In this case, the scheduling information is transmitted using a dedicated signaling scheme or a common signaling scheme. The terminal first checks whether there is scheduling information given to the user through the dedicated channel, and if there is no dedicated scheduling information transmitted to the corresponding terminal, the terminal reads the shared scheduling information through the shared channel.

2A and 2B illustrate a case in which transmission rate information is individually transmitted to all terminals and a case in which transmission rate information is integrally transmitted to some terminals according to an exemplary embodiment of the present invention.

Referring to FIG. 2A, the base station 210 transmits rate information through a shared control channel (EU-SCCH) 202 in order to schedule an E-DCH service. In this case, since there are five terminals UE1 203 to UE5 207 performing the E-DCH service, the EU-SCCH 202 may have five separate channels having unique channel codes or time intervals. To EU-SCCH5. do. In every scheduling period, the base station 210 determines the transmission rates for the UE1 203 through the UE5 207 and transmits the rate information including the respective transmission rates to the respective channels for each of the UE1 203 through the UE5 207 EU. -Transmit via SCCH1 to EU-SCCH5. Therefore, up to five channels are required for transmitting each scheduling information at each transmission point.

If a high priority terminal, for example, UE5 207, requires a high data rate, the base station 210 assigns a high data rate to the UE5 207, but the other terminals UE1 203 to UE4 206. ) Is commonly assigned a low data rate. In this case, since the rate information transmitted to the terminals UE1 203 to UE4 206 are all the same, a common signaling method is used. Signaling in this case is shown in Figure 2b.

Referring to FIG. 2B, the base station 210 allocates a high transmission rate to the UE5 214 having a high priority through the dedicated signaling channel EU-SCCH5 209 and to the remaining UE1 203 to UE4 206. Allocate low data rates on the common signaling channel EU-SCCH 208 collectively. In this way, if the transmission rate is notified collectively, the number of channels to be transmitted simultaneously is reduced to two compared to five of FIG. 2A.

In the following, embodiments for the preferred embodiment of the present invention will be described.

<< first embodiment >>

In a system for controlling uplink transmission rate of a terminal by transmitting absolute value information of an allocated transmission rate, a Radio Network Controller (RNC) is a common UE-ID and a dedicated UE-ID to terminals. ID), and the base station transmits transmission rate information to a specific terminal using a dedicated identifier or transmission rate information using a common identifier as necessary.

3 illustrates a data structure of an enhanced reverse common control channel (hereinafter referred to as EU-SCCH) for carrying absolute scheduling information according to the first embodiment of the present invention.

Referring to FIG. 3, the scheduling assignment information (hereinafter, referred to as SA) 302 includes allocated transmission rate information, and the CRC 304 includes a CRC masked by a terminal identifier. Since the CRC 304 includes a specific terminal identifier, it is only decoded by the terminal having the terminal identifier and ignored by the CRC error in the terminal having another terminal identifier.

In addition to the method of determining whether the corresponding UE is signaled through the CRC check method using the CRC masked by the UE-id as described above, the CRC may be used in common but UE-id information may be added in the PDU. In this case, there is also a method of determining whether or not the terminal is signaling information transmitted to the terminal by reading data and checking the UE-id field after the CRC check.

When communication of one terminal is started, the radio network controller allocates both a common identifier for public signaling and a dedicated identifier for dedicated signaling to the terminal through higher layer signaling. At this time, the wireless network controller sets one common identifier to all the terminals in the cell in consideration of the environment such as the scheduling method of the base station and the E-DCH service type of the terminal, or the common identifier for each group of terminals classified according to the service type. Set them up. If public identifiers are set to some or all terminals of a cell through such higher layer signaling, the base station performs public signaling based on the public identifiers to increase scheduling efficiency.

In addition, when the base station needs to restrict the transmission / reception operation of the terminal in addition to the identifier for transmitting the scheduling information, the radio network controller may set a common control identifier indicating that the control information is signaled. That is, the RNC grasps the situation of each base station and, if necessary, allocates a UE-id as shown in Table 1 below.

ID Type Information contained in E-SCCH Explanation Dedicated scheduling ID Transfer rate Used by the base station to control only the transmission rate of the terminal Public scheduling ID Transfer rate Used by the base station to control the transmission rate of the entire terminals to which the common scheduling ID is assigned Public control ID Control information Used by a base station to control a terminal assigned a common control ID in a cell

Here, the control information is to control the operation of the terminal in accordance with the situation of the Node-B, not the rate information for the E-DCH transmission of the terminal may be configured as shown in Table 2 below. Table 2 below shows an example of the control content according to the value of the common control information field when the common control information is 5 bits.

Control information fields Control information Control content 00000 ONLY_MINSET_ID Instructs to lower the transmission rate of all terminals to the lowest transmission rate 00001 REQ_NOT_ALLOWED Instructed not to request transmission because cell could not be scheduled due to heavy load 00010 DATA_RATE_SCALE_DOWN Instruction to lower all baud rates 00011 DATA_RATE_SCALE_UP Instruction to increase the transmission rate of all terminals by one step 00100 DATA_RATE_SCALE_TWO DOWN Instruction to lower the transmission rate of all terminals by two steps 00100 DATA_RATE_SCALE_TWO UP Instruction to increase the transmission rate of all terminals by two steps

The base station determines the signaling scheme with the SA of the terminal communicating for the E-DCH service at every scheduling time. The criteria for determining the signaling scheme is determined according to the system design and implementation. In one embodiment, the base station simply selects a common signaling scheme for transmitting the SA when the number of terminals having the same SA commonly assigned in one cell is more than a predetermined number. In another embodiment, the base station allocates the same SA to a group and decides to transmit the SA to the terminals of the group using a common signaling scheme. A dedicated signaling scheme is selected for the remaining terminals. When the SA and the signaling scheme are determined, the base station transmits the CRC masked with the terminal identifier according to the determined signaling scheme together with the determined SA.

Hereinafter, the operation of the terminal according to the first embodiment of the present invention will be described in detail with reference to FIG. 4.

In FIG. 4, the UE has a public identifier and a dedicated identifier, and when both the common UE-id and the dedicated UE-id are set. In this case, when the Node-B transmits SA to the UE and transmits control information to the UE through the common UE-id for a plurality of other UEs, the UE receives the two information at the same time, thereby determining the reception priority. do. That is, since the common control information signaled by the Node-B to control the operation of the terminal may control the transmission operation of the terminal in an emergency situation, the terminal may control the common control UE before other UE-ids indicating the scheduling information. Check whether the information exists using -id. For the above investigation, the terminal reads common control information using a common control UE-id.

Referring to FIG. 4, in step 400, the UE receives EU-SCCH data including a CRC masked with an SA and a UE identifier in every scheduling period.

In step 401, the UE checks the CRC using the common control UE-id, and proceeds to step 402 to determine whether the CRC check is successful. If the CRC check succeeds, it means that the common control information exists, the terminal proceeds to step 403. In step 403, the UE interprets the control information field of the demodulated information field by checking the CRC using the dedicated UE-id to determine what control information is signaled. That is, in step 410, the UE reverse-masks the CRC using a public identifier to perform a CRC check. If the CRC check fails, the UE proceeds to step 405.

In step 404, the terminal examines the content of the common control information. If the contents of the common control information transmit transmission restriction information such as a request to change all transmission rates by one step or change the minimum transmission rate to a minimum transmission rate, in step 407, the terminal restricts transmission according to the control information. Proceed to 408. In step 408, the UE does not attempt to receive a dedicated UE-id or a public UE-id, and transmits E-DCH data at the maximum allowable transmission rate allocated according to the SA. If the result of the investigation in step 404 does not receive common control information or the common control information is information that is not related to the E-DCH transmission rate such as the limitation of the transmission request of the terminal, the terminal reverse masks the CRC using a dedicated identifier in step 405. Performs a CRC check. In step 406, it is determined whether the CRC check is successful, and if it is successful, the process proceeds to step 408, and if it fails, the process proceeds to step 409.

In step 409, the UE performs a CRC check using the common identifier. In step 410, it is determined whether the CRC check in step 410 is successful, and if successful, in step 411, the UE transmits E-DCH data at the maximum allowable transmission rate allocated according to the SA. If the CRC check fails in step 410, the UE stops transmitting data in step 412.

5 shows an apparatus for transmitting a base station according to the first embodiment of the present invention. Here, the base station transmitter transmits EU-SCCH data.

Referring to FIG. 5, the scheduler 502 allocates a transmission rate to a terminal that wants to perform an E-DCH service. The scheduler 502 allocates the transmission rate of the terminal based on the buffer state and the power state reported by the terminal, and the RoT level of the cell, and also determines a signaling method together with the transmission rate, and the terminal according to the determined signaling method. An identifier (UE-ID), that is, a dedicated identifier or a public identifier, is passed to the CRC generator 504. For example, the scheduler 502 determines to use a common signaling method when the number of other terminals having the same transmission rate as the allocated transmission rate is greater than or equal to a predetermined number. In other cases, the scheduler 502 assigns the same transmission rates to terminals of a specific group, and determines to use a common signaling scheme for the terminals of the group.

CRC generator 504 generates a CRC masked with the passed dedicated or public identifier. The rate information generator 506 generates rate information according to the assigned rate, and the CRC adder 508 adds the masked CRC to the rate information. The masked CRC is also called a UE-specific CRC (UE-specific CRC) because it includes a terminal identifier of the terminal. The masked CRC and the data rate information are encoded by the encoder 510 and then modulated by the modulator 512 in order to increase reliability _, and multiplied by the channel code C _{e, c} of the EU-SCCH by the spreader 514. To become EU-SCCH data. The multiplexer 516 multiplexes and transmits the EU-SCCH data with data of other channels.

6 shows a receiving device of a terminal according to the first embodiment of the present invention. Here, the receiver of the terminal receives EU-SCCH data.

Referring to FIG. 6, the received signal is despread by multiplying by the despreader 612 with the channel codes C _{e and c} of the EU-SCCH, demodulated by the demodulator 610, and then decoded by the decoder 608. Input to the CRC detector 606. The CRC detector 606 extracts the masked CRC from the decoded data and delivers it to the CRC checker 614. The CRC checker 614 receives both a dedicated identifier and a public identifier of the terminal from the E-DCH controller 612, performs a CRC check by reverse masking the masked CRC with the dedicated identifier first in every scheduling period, If an error occurs as a result of the CRC check, a CRC check is performed by reverse masking the masked CRC with a common identifier.

The CRC checker 614 determines the CRC result by the terminal identifiers and transmits the CRC result to the CRC detector 606. The CRC detector 606 transmits, to the rate information determiner 604, the rate information other than the CRC of the decoded data to the rate information determiner 604 when the CRC check succeeds with any one terminal identifier. Discard. The rate information determiner 604 determines the maximum allowable transmission rate from the rate information, and transmits the determined maximum allowable transmission rate to the E-DCH controller 602 to transmit the E-DCH data.

<< 2nd Example >>

In a system for controlling an uplink transmission rate of a terminal by transmitting rate allowance information for increasing, decreasing, or maintaining a transmission rate, the radio network controller allocates a common code and a dedicated code to the terminals. The base station transmits transmission rate information using a dedicated code or a transmission rate information using a common code as needed.

A UE that performs an E-DCH service and uses a common signaling scheme for base station control scheduling is assigned a unique orthogonal code, and rate allowance information for the terminal is spread to the assigned orthogonal code. The terminal determines a correlation value between the received signal and the assigned orthogonal code and determines whether the received signal includes a rate allowance information for itself.

The radio network controller configures a dedicated code and a common code through higher layer signaling so as to receive rate allowance information in allocating orthogonal codes to terminals. At this time, the radio network controller sets one common code to all terminals of all cells, or sets one common code to one group of terminals classified according to a service type. In addition, the terminals basically have a dedicated code.

The base station determines a rate grant information (hereinafter referred to as RG) and a signaling scheme of a terminal communicating for an E-DCH service at every scheduling time point. The criteria for determining the signaling scheme is determined according to the system design and implementation. In one embodiment, the base station simply determines RG, which takes up a large portion of the increase / decrease / maintenance, by using a common signaling method. In another embodiment, the base station selects a common signaling scheme to increase or decrease transmission rates of all terminals in the cell. A dedicated signaling scheme is selected for the remaining terminals. When the RG and the signaling scheme are determined, the base station spreads and transmits the RG with an orthogonal code according to the determined signaling scheme.

7 is a flowchart illustrating the operation of a terminal according to the second embodiment of the present invention. Here, the terminal is assigned a dedicated orthogonal code and a common orthogonal code.

Referring to FIG. 7, in step 702, the UE receives EU-SCCH data including RG spread by an orthogonal code in every scheduling period. First, in step 704, the terminal analyzes the spread RG using a dedicated orthogonal code and determines the RG in step 706. In this case, the RG has the same meaning as in Table 3 in the prior art and the present invention.

Prior art The present invention +1 UP UP 0 KEEP Receive public signaling information -One DOWN DOWN

If the RG is increased (+1) or decreased (-1) in step 706, the UE increases or decreases the maximum allowable transmission rate of the current E-DCH by a predetermined value according to the RG in step 708. On the other hand, if the RG is 0, the UE reinterprets the spread RG using the common orthogonal code in step 710 and determines the RG in step 712. In step 714, the terminal increases, decreases, or maintains the current maximum allowable transmission rate according to the determination of step 712. That is, the UE increases the maximum allowable transmission rate when the RG interpreted using the common orthogonal code is +1, decreases it when -1, and maintains 0.

8 shows an apparatus for transmitting a base station according to a second embodiment of the present invention. Here, the base station transmitter transmits EU-SCCH data.

Referring to FIG. 8, the scheduler 802 allocates a transmission rate to a terminal to perform an E-DCH service. The scheduler 802 allocates a transmission rate of the terminal using a buffer state, a power state, and a RoT level of a cell reported by the terminal, and determines a signaling scheme according to the allocated transmission rate. The RG information generator 804 generates the RG information having a value of +1, 0 or -1 by comparing the allocated transmission rate with the current maximum allowable transmission rate of the terminal, and the RG information is generated by the modulator 806. Is modulated. Meanwhile, the RG code controller 814 selects an orthogonal code for the RG information according to the signaling method determined by the scheduler 802. That is, the orthogonal code is selected as a common orthogonal code in the case of a common signaling scheme and a dedicated orthogonal code in the case of a dedicated signaling scheme.

The modulated RG information is multiplied by the selected orthogonal code by the spreader 808 and then multiplied by the channel codes C _{e and c} of the EU-SCCH to become EU-SCCH data. The multiplexer 812 multiplexes and transmits the EU-SCCH data with data of other channels.

9 shows a receiving device of a terminal according to a second embodiment of the present invention. Here, the receiver of the terminal receives EU-SCCH data.

Referring to FIG. 9, the received signal is despread by the despreader 910 by multiplying with the channel codes C _{e and c} of the EU-SCCH _, and after being multiplied by the orthogonal code by the despreader 908, the demodulator 906. By demodulating the data into the RG information identifier 904. The RG code controller 912 receives both the dedicated orthogonal code and the common orthogonal code of the terminal from the E-DCH controller 902, and sets the dedicated orthogonal code to the despreader 908 first in every scheduling period and the RG information is set. If not, the common orthogonal code is set to the despreader 908.

The RG information identifier 904 determines whether the value of the RG information included in the demodulated data is 'maintain' ('0'), and if not, maintains an increase or decrease command according to the RG information. Forward to E-DCH controller 902. The E-DCH controller 902 increases or decreases the current maximum allowed data rate according to the increase or decrease command, and then transmits E-DCH data at the changed maximum allowed data rate.

If the RG information is identified with a dedicated orthogonal code and its value is 'maintain', the RG information identifier 904 requests the RG code controller 912 to set the dedicated orthogonal code. The RG code controller 912 sets a dedicated orthogonal code in the despreader 908 according to the request. The new RG information, which is then multiplied by the decoded orthogonal code by the despreader 908 and demodulated by the demodulator 906, is input to the RG information identifier 904, and the E-DCH controller 902 receives the RG. According to the identification result of the new RG information by the information identifier 904, the current maximum allowable transmission rate is increased, maintained or decreased.

<< third embodiment >>

According to the third embodiment, scheduling and control are performed separately by a terminal operating as in the aforementioned first embodiment, when the EU-SCCH containing the scheduling information is received, without distinguishing between the scheduling information and the control information through a CRC check. We propose a way to include identifiers that distinguish information in the header.

In the first embodiment, the number of UE-ids for which the UE has to perform CRC check is very large, such as dedicated scheduling, common scheduling, and common control channel UE-id. This may bring the complexity of the reception operation to the terminal that must read the scheduling information for every TTI. To compensate for this, the third embodiment reduces the CRC checking operation by transmitting information for determining whether the scheduling information or the control information is used as header information in the header portion of the data.

Hereinafter, the E-SCCH data structure according to the third embodiment of the present invention will be described in detail with reference to FIG. 10.

Referring to FIG. 10, reference numeral 1007 denotes a structure of data containing scheduling information (hereinafter referred to as 'scheduling data'), and reference numeral 1009 denotes data containing common control information (hereinafter referred to as 'public control data'). ) Is the structure. The scheduling data 1007 includes a dedicated or common indicator (D / C) 1001, scheduling information 1002, and CRC with UE-id 1003, and the common control data 1008 includes D / C ( 1004), common control information 1005, and CRC without UE-id CRC 1006.

The D / Cs 1001 and 1004 represent an identifier indicating whether the scheduling information or the common control information. For example, '0' represents common control information and '1' represents scheduling information. The scheduling information 1002 is information for informing scheduling information to each terminal or several terminals. The CRC with UE-id 1003 indicates a CRC generated by using a UE-id allocated exclusively or publicly. The common control information 1005 means that the Node-B signals using the field when the Node-B wants to control the operation of the UE in addition to the scheduling information, and the CRC without the UE-id 1006 is not masked as the UE-id. Is not a common CRC.

According to the third embodiment, in order for the terminal to interpret the EU-SCCH, the terminal determines whether the scheduling information or the control information by using the D / C (1001, 1004) of the E-SCCH. As a result of the determination, when the D / C is the D / C 1001 set as the scheduling information, the terminal performs a CRC check using the CRC with UE-id 1003. If the D / C is set to D.C 1004 as common control information, the CRC check is performed using the CRC without UE-id 1006. At this time, the D / C field should be interpreted before the CRC check.

Subsequently, when the scheduling information is signaled, the terminal interprets the given information according to a rule for reading the scheduling information field, and in the case of the common control information, interprets the common information as the common control information corresponding to the data field.

Meanwhile, in the detailed description of the present invention, specific embodiments have been described, but various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined not only by the scope of the following claims, but also by those equivalent to the scope of the claims.

In the present invention operating as described in detail above, the effects obtained by the representative ones of the disclosed inventions will be briefly described as follows.

According to the present invention, when a packet service is performed through an E-DCH, a common signaling scheme and a dedicated signaling scheme are used in a mixed manner according to the situation of the transmission rate information to be transmitted. There is an effect of reducing link signaling overhead.

1 illustrates uplink packet transmission over an E-DCH in a typical wireless communication system.

2A and 2B are diagrams illustrating a case in which transmission rate information is individually transmitted to all terminals and a case in which transmission rate information is integrally transmitted to some terminals according to an exemplary embodiment of the present invention.

3 illustrates a data structure of an enhanced reverse common control channel (EU-SCCH) for conveying absolute scheduling information according to a first embodiment of the present invention.

4 is a flowchart illustrating the operation of a terminal according to the first embodiment of the present invention.

5 is a structural diagram showing an apparatus for transmitting a base station according to the first embodiment of the present invention;

6 is a structural diagram showing a receiving device of a terminal according to the first embodiment of the present invention;

7 is a flowchart illustrating the operation of a terminal according to a second embodiment of the present invention.

8 is a structural diagram showing an apparatus for transmitting a base station according to a second embodiment of the present invention;

9 is a structural diagram showing a receiving device of a terminal according to a second embodiment of the present invention;

10 is a data structure diagram for transmitting scheduling assignment information according to the third embodiment of the present invention.

Claims (23)

A method for controlling uplink transmission rate for terminals in a mobile communication system supporting base station control scheduling, Setting up dedicated identifiers for the dedicated signaling of the base station control scheduling and common identifiers for the common signaling to the terminals; Allocating transmission rates for uplink packet transmission to the terminals at every scheduling time point and determining a signaling scheme for each of the terminals; Transmitting rate information indicating a corresponding transmission rate to terminals determined by a common signaling method using a corresponding common identifier; And transmitting transmission rate information indicating a corresponding transmission rate to terminals determined by a dedicated signaling method using corresponding dedicated identifiers. The method of claim 1, wherein the setting process comprises: The method of claim 1, wherein the common identifiers are set for each group of terminals. The method of claim 1, wherein the determining of the signaling scheme comprises: The method according to claim 1, wherein the same transmission rates are determined by the common signaling scheme for the terminals assigned and the remaining signaling is determined by the dedicated signaling scheme. The method of claim 1, wherein each of the transmitting steps is performed by: And masking the error detection information of the transmission rate information with a corresponding public identifier or a corresponding dedicated identifier, and transmitting the transmission rate information and the masked error detection information to the terminals. The method of claim 1, wherein the rate information, Said absolute value of said assigned rate. A method of controlling uplink transmission rate in a mobile communication system supporting base station control scheduling, Receiving rate information and masked error detection information of the rate information; Demasking the masked error detection information using the corresponding dedicated identifier and checking whether an error is detected; If no error is detected as a result of the check by the dedicated identifier, transmitting uplink data at a transmission rate according to the transmission rate information If an error is detected as a result of the check by the dedicated identifier, reverse masking the masked error detection information by using the set common identifier and checking whether the error is detected; If an error is detected as a result of the check by the common identifier, ignoring the rate information and transmitting uplink data at a previous rate; And if no error is detected as a result of the check by the common identifier, transmitting uplink data at a transmission rate according to the transmission rate information. The method of claim 6, wherein the rate information, Said absolute rate of said assigned rate. A base station transmitter for controlling uplink transmission rate in a mobile communication system supporting base station control scheduling, Manage a terminal having a dedicated identifier for the dedicated signaling of the base station control scheduling and a common identifier for public signaling, and assigns a transmission rate for uplink packet transmission to the terminal at every scheduling time and determines a signaling scheme for the terminal. With the scheduler A rate information generator for generating rate information indicating the assigned rate; An error detection information generator for generating error detection information masked with the public identifier or the dedicated identifier according to the determined signaling scheme; And an error detection information adder for transmitting the masked error detection information to the transmission rate information. The method of claim 8, wherein the scheduler, And if the number of other terminals allocated the same transmission rates as the allocated transmission rate is equal to or greater than a predetermined number, determining by a common signaling method, otherwise determining by a dedicated signaling method. The method of claim 8, wherein the rate information, And the absolute value of the assigned transmission rate. A terminal receiver for controlling uplink transmission rate in a mobile communication system supporting base station control scheduling, Upon receiving the rate information and the masked error detection information of the rate information, the masked error detection information is first reverse masked using the set dedicated identifier, and if the detection result error by the dedicated identifier is detected, the masked error An error detector for reverse masking detection information using the set common identifier; An error checker that determines whether an error is detected by the error detection information demasked by the dedicated identifier or the public identifier; And a transmission rate information determiner for determining a transmission rate for transmitting uplink data according to the transmission rate information when no error is detected by the dedicated identifier or the common identifier. The method of claim 11, wherein the rate information, And the receiving device is characterized in that it represents an absolute value of the assigned transmission rate. A method of controlling uplink transmission rate in a mobile communication system supporting base station control scheduling, Setting common orthogonal codes for common signaling to terminals having dedicated orthogonal codes for dedicated signaling of the base station control scheduling; Allocating transmission rates for uplink packet transmission to the terminals at every scheduling time point and determining a signaling scheme for each of the terminals; Transmitting and transmitting rate allowance information indicating a corresponding transmission rate to the terminals determined by the common signaling scheme in a corresponding orthogonal code; And spreading transmission rate allowance information indicating a corresponding transmission rate to corresponding dedicated orthogonal codes to terminals determined by a dedicated signaling scheme. The method of claim 13, wherein the assigning process comprises: The method characterized in that for setting the common orthogonal codes for each group of terminals. The method of claim 13, wherein the determining of the signaling scheme comprises: The method as claimed in the common signaling scheme for the terminal to transmit the same rate allowance information, and the remaining signaling to the dedicated signaling method. The method of claim 13, wherein the rate tolerance information, Wherein the corresponding allocated rate is increased, decreased or maintained compared to a previous rate. A method of controlling uplink transmission rate in a mobile communication system supporting base station control scheduling, Receiving spread rate tolerance information, Despreading the spread rate permission information with a corresponding dedicated orthogonal code to determine the despread rate permission information; When the rate allowed information despread with the dedicated orthogonal code indicates an increase or decrease, transmitting or decreasing uplink rate and transmitting uplink data at the increased or decreased rate; Determining that the despread rate allowed information is despread by despreading the spread rate allowed information to a corresponding set common orthogonal code when the rate allowed information despread with the dedicated orthogonal code indicates maintenance; And adjusting a previous transmission rate according to the transmission rate allowance information despread with the common orthogonal code, and transmitting uplink data at the adjusted transmission rate. The method of claim 17, wherein the rate tolerance information, Wherein the allocated transmission rate is increased, decreased or maintained compared to the previous transmission rate. A base station transmitter for controlling uplink transmission rate in a mobile communication system supporting base station control scheduling, Manage a terminal having a dedicated orthogonal code for dedicated signaling of the base station control scheduling and a common orthogonal code for common signaling, and assigns a transmission rate for uplink packet transmission to the terminal at every scheduling time and according to the allocated transmission rate A scheduler for determining a signaling scheme for the terminal; A rate tolerance information generator for generating rate tolerance information by comparing the allocated rate with a previous rate of the terminal; And a spreader configured to spread and transmit the rate tolerance information with the common orthogonal code or the dedicated orthogonal code according to the determined signaling scheme. The method of claim 19, wherein the scheduler, And if the number of other terminals to transmit the same rate allowance information as the rate allowance information is equal to or greater than a predetermined number, determine using a common signaling method, and otherwise determine using a dedicated signaling method. The method of claim 19, wherein the rate allowed information, And wherein the allocated transmission rate is increased, decreased, or maintained compared to a previous transmission rate. A terminal receiver for controlling uplink transmission rate in a mobile communication system supporting base station control scheduling, When receiving the spread rate allowance information, the spread rate allowance information is first despread to the corresponding dedicated orthogonal code, and when the request signal is input, the spread rate allowance information is despread to the set common orthogonal code. Diffuser, An identifier for determining the rate tolerance information despread by the dedicated orthogonal code and the common orthogonal code; A controller for managing the dedicated orthogonal code and the common orthogonal code and inputting the request signal to the despreader when the rate allowed information despread by the dedicated orthogonal code indicates maintenance; If the rate allowed information despread with the dedicated orthogonal code indicates an increase or decrease, the previous rate is increased or decreased according to the rate allowed information despread with the dedicated orthogonal code, and the rate allowed information despread with the dedicated orthogonal code is decoded. And a transmission controller for adjusting the previous transmission rate according to the transmission rate allowance information despread with the common orthogonal code, and transmitting uplink data according to the adjusted transmission rate. The method of claim 22, wherein the rate allowed information, And the received transmission rate is indicative of whether the corresponding transmission rate is increased, decreased or maintained compared to the previous transmission rate.