KR20070055004A - Method and apparatus for transmitting/receiving scheduling grants of uplink data transmission in mobile telecommunications system - Google Patents

Abstract

The present invention provides a method for determining a scheduling grant used for scheduling reverse data transmission in a mobile communication system supporting a reverse packet data service, and a method and apparatus for operating a terminal according to the scheduling grant. The terminal receives a scheduling grant indicating a maximum power ratio of the enhanced dedicated physical data channel (E-DPDCH) to the power controlled dedicated physical control channel (DPDCH) allocated for reverse data transmission from the base station, and the scheduling grant, If it is an absolute grant representing a value in a scheduling grant table having predetermined values of the maximum power ratio, the value indicated by the absolute grant is determined as a serving grant. On the other hand, if the scheduling grant is a relative grant indicating an increase or decrease of the maximum power ratio, the terminal is not less than the power ratio just used in the HARQ process, which is currently to be transmitted, in the scheduling grant table. A minimum value is set as a reference value, and the serving grant is determined as a value that is increased or decreased by one step in the scheduling grant table according to the relative grant. Enhanced Dedicated Transport Channel (E-DCH) data is then transmitted using a power ratio that does not exceed the determined serving grant.

UPLINK DATA TRANSMISSION, E-DCH, SCHEDULING GRANT, ABSOLUTE GRANT, RELATIVE GRANT

Description

TECHNICAL AND APPARATUS FOR TRANSMITTING / RECEIVING SCHEDULING GRANTS OF UPLINK DATA TRANSMISSION IN MOBILE TELECOMMUNICATIONS SYSTEM}

1 is a block diagram illustrating a radio access network (UTRAN) of a typical UMTS system.

2 is a diagram illustrating a hierarchical interface between a UE and a radio network controller (RNC).

3 illustrates the transmission of data over an E-DCH in a typical radio link.

4 illustrates a typical E-DCH transmission and reception procedure.

5 illustrates the structure of physical channels associated with a reverse link in accordance with a preferred embodiment of the present invention.

6 is a diagram illustrating timing of a terminal and a base station related to scheduling of an E-DCH according to a preferred embodiment of the present invention.

7 illustrates a transmission structure of an absolute grant according to a preferred embodiment of the present invention.

8 is a flowchart illustrating the operation of a terminal according to an exemplary embodiment of the present invention.

9 is a block diagram showing the structure of a terminal according to an embodiment of the present invention.

10 is a flowchart illustrating the operation of a base station according to a preferred embodiment of the present invention.

11 is a block diagram showing the structure of a base station according to a preferred embodiment of the present invention.

The present invention relates to a mobile communication system supporting reverse data transmission, and more particularly, to a method and apparatus for transmitting and receiving a scheduling grant indicating a reverse resource allocated by a base station for controlling reverse packet data transmission of a terminal.

The third generation, based on the European mobile system Global System for Mobile Communications (GSM) and General Packet Radio Services (GPRS), using asynchronous wideband code division multiple access (WCDMA). 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.

FIG. 1 is a block diagram showing a UMTS Terrestrial Radio Access Network (hereinafter referred to as UTRAN) of a typical UMTS system.

Referring to FIG. 1, the UTRAN 12 is composed of radio network controllers (hereinafter referred to as RNCs) 16a and 16b and base stations Node Bs 18a, 18b, 18c, and 18d. The user equipment (UE) 20 is connected to the core network (Core Network: CN) 10. There may be a plurality of cells below the base stations 18a, 18b, 18c, 18d, and each of the RNCs 16a, 16b controls the corresponding base stations 18a, 18b, 18c, 18d, Each base station 18a, 18b, 18c, 18d controls the corresponding lower cells. The base stations and cells controlled by one RNC are collectively referred to as a Radio Network Subsystem (hereinafter referred to as RNS) 14a and 14b.

The RNCs 16a and 16b allocate or manage radio resources of the base stations 18a to 18d that they control. The base stations 18a to 18d serve to provide actual radio resources. The radio resources are configured for each cell, and the radio resources provided by the base stations 18a to 18d mean radio resources of cells managed by the base stations 18a to 18d. The terminal 20 may configure a radio channel and perform communication by using a radio resource provided by a specific cell of a specific base station. From the standpoint of the terminal 20, the distinction between the base station and the cell is meaningless, and since only the physical layer configured for each cell is recognized, the base stations 18a to 18d and the cells will be referred to as the same meaning.

An interface between the terminal 20 and the RNCs 16a and 16b is called a Uu interface, and a detailed hierarchical structure is illustrated in FIG. 2. The Uu interface is divided into a control plane used to exchange control signals between the terminal 20 and the RNCs 16a and 16b and a user plane used to transmit actual data.

The control plane signal 30 includes a radio resource control (RRC) layer 34, a radio link control (RLC) layer 40, a media access control (MAC) layer 42, and a physical (hereinafter, referred to as PHY) layer. And the user plane information 32 includes a packet data control protocol (PDCP) layer 36, a broadcast / multicast control (BMC) layer 38, an RLC layer 40, and a MAC layer 42. Processing through the physical layer 44. Among the layers shown here, the physical layer 44 is located in each cell, and the MAC layer 42 to the RRC layer 34 are located in the RNC. The terminal has all layers.

The physical layer 44 is a layer that provides an information transmission service using a radio transfer technology, and corresponds to a first layer of an Open Systems Interconnection (OSI) model. The physical layer 44 and the MAC layer 42 are connected by transport channels, and transport channels are defined by the manner in which specific data is processed in the physical layer.

The MAC layer 42 and the RLC layer 40 are connected via logical channels. The MAC layer 42 delivers the data delivered by the RLC layer 40 through the logical channel to the physical layer through the appropriate transport channel, and the data delivered by the physical layer 44 through the transport channel through the appropriate logical channel. It serves to convey to 40. In addition, by inserting additional information into the data received through the logical channel or the transmission channel or by analyzing the inserted additional information, it takes appropriate action and controls the random access operation. The part related to the user plane in this MAC layer 42 is called MAC-d (MAC-data), and the part related to the control plane is called MAC-c (MAC control).

The RLC layer 40 is responsible for establishing and releasing logical channels. The RLC layer 40 may operate in one of three operation modes, namely, an acknowledgment mode (AM), an unacknowledged mode (UM), and a transparent mode (TM), and provide different functions for each operation mode. In general, the RLC layer 40 is responsible for dividing or assembling a service data unit (hereinafter referred to as SDU) from an upper layer into an appropriate size, and an error correction function.

The PDCP layer 36 is located above the RLC layer 40 in the user plane, and has a function of compressing and restoring headers of data transmitted in the form of IP packets, and an RNC for providing a service to a specific terminal with mobility. It is responsible for lossless transmission of data under the circumstances.

The characteristics of a transport channel connecting the physical layer 44 and upper layers include physical layer processing such as convolutional channel encoding, interleaving, and service-specific rate matching. It is determined by the TF (Transport Format).

In particular, the UMTS system uses an enhanced uplink dedicated channel (hereinafter referred to as E-DCH) to further improve the performance of packet transmission in uplink (UL) communication from the terminal to the system. E-DCH supports technologies such as Hybrid Automatic Retransmission Request (hereinafter referred to as HARQ) and Node B controlled scheduling to support more stable high-speed data transmission.

3 illustrates transmission of reverse packet data over an E-DCH in a typical radio link. Here, reference numeral 100 denotes a base station supporting the E-DCHs 111, 112, 113, and 114, and 101 to 104 denote terminals that transmit the E-DCHs 111 to 114. The base station 100 determines the channel status of the terminals 101 to 104 using the E-DCH and schedules data transmission of each terminal. The scheduling allocates a low data rate to the terminal 104 far from the base station 100 while keeping the measured noise rise value of the base station 100 from exceeding a target value in order to increase the performance of the entire system. The terminal 101 is located in a manner of assigning a high data rate.

4 is a diagram illustrating a transmission and reception procedure through a typical E-DCH.

Referring to FIG. 4, in step 202, the base station and the terminal configure an E-DCH. Step 202 includes a process of delivering messages on a dedicated transport channel. When the E-DCH is configured, the terminal informs the base station of scheduling information indicating the terminal state in step 204. The scheduling information may be terminal transmission power information indicating the reverse channel state, extra power information, and the amount of data to be transmitted in the buffer of the terminal.

In step 206, the base station monitors scheduling information of the plurality of terminals in order to schedule data transmission of each terminal. In step 208, the base station determines to allow the reverse packet transmission to the terminal, and transmits a scheduling grant indicating scheduling allocation information to the terminal. The scheduling allocation information may include an allowed data rate and an allowable timing.

In step 210, the UE determines a transmission format (TF) of the E-DCH according to the scheduling allocation information, and in step 214, the dedicated physical data channel to which the E-DCH is mapped according to the transmission format (Enhanced-Dedicated Physical Data Channel): While transmitting UL packet data through the E-DPDCH, the TF information indicating the TF is transferred to the dedicated-dedicated physical control channel (E-DCH) associated with the E-DCH in operation 212. Called a DPCCH).

In step 216, the base station determines whether there is an error in the TF information and the packet data. In step 218, the base station transmits a non-acknowledge (NACK) to the terminal through any ACK / NACK channel if there is no error in any one of the determination result, . When the ACK is transmitted, the terminal transmits new user data through the E-DCH when packet data is completed, but when the NACK is transmitted, the terminal retransmits the packet data having the same contents through the E-DCH.

As described above, the E-DCH is mapped to the E-DPDCH for channel coding and demodulation of transmission data. Control information for the E-DCH is transmitted through the E-DPCCH or E-DPDCH. Control information for the E-DCH includes the aforementioned scheduling information and TF information. The scheduling information indicates a terminal state and is information required by the base station to schedule reverse data transmission of the terminal. The scheduling information includes buffer state information of the terminal and reverse channel state information. As another control information, there is a "happy bit" indicating the current state of the terminal. The TF information includes a data rate of the transmitted E-DCH data, HARQ operation information, QoS information, and the like, and is always transmitted together when the E-DCH data is transmitted.

A scheduling grant determined through scheduling is generally expressed by using a power ratio of the E-DPDCH to a dedicated physical control channel (DPCCH), which is a power-controlled reference channel, and the base station is a scheduling grant that represents an absolute value of the power ratio. (Absolute Grant (AG)) or a relative grant (RG) indicating an increase (UP) / decrease (DOWN) / hold (HOLD) of the power ratio can be transmitted. The UE determines a Serving Grant (SG) indicating a maximum allowable power ratio that can be used for the E-DCH with reference to the absolute grant or the relative grant, and the E-DCH within the range not exceeding the serving grant. Select the data rate.

As such, the absolute grant informs the UE of the power ratio value of the E-DPDCH to the DPCCH serving as the serving grant. In order to improve transmission efficiency of the scheduling grant, it is necessary to clearly define values that can be indicated by the absolute grant. There is. In addition, in the case of the relative grant, the UE determines the serving grant by adding or subtracting a predetermined value according to the relative grant based on the power ratio of the E-DPDCH to the previously used DPCCH. There is a need.

The present invention provides a method and apparatus for setting and interpreting control information related to an E-DCH according to a condition in which a reverse packet is transmitted.

The present invention provides a method and apparatus for efficiently transmitting and receiving a scheduling grant of a base station for scheduling reverse data transmission.

The present invention provides a method and apparatus for efficiently setting and interpreting a happy bit transmitted by a terminal in transmitting reverse data.

In a preferred embodiment of the present invention, in a method for receiving a scheduling grant for controlling reverse data transmission in a mobile communication system,

Receiving a scheduling grant indicating a maximum power ratio of the enhanced dedicated physical data channel (E-DPDCH) to the power controlled dedicated physical control channel (DPDCH) allocated for reverse data transmission from the base station;

If the scheduling grant is an absolute grant representing a value in a scheduling grant table having predetermined values of the maximum power ratio, determining a value indicated by the absolute grant as a serving grant;

If the scheduling grant is a relative grant that indicates an increase or decrease in the maximum power rate, then the minimum value in the scheduling grant table that is not less than the power rate just previously used in the complex automatic retransmission request (HARQ) process to be transmitted currently is determined. Setting a reference value and determining, by the serving grant, a value that is increased or decreased by one step in the scheduling grant table according to the relative grant;

And transmitting enhanced dedicated transport channel (E-DCH) data using a power ratio that does not exceed the determined serving grant.

Another embodiment of the present invention, in the method for receiving a scheduling grant for controlling reverse data transmission in a mobile communication system,

Allocating a maximum power ratio of the enhanced dedicated physical data channel (E-DPDCH) to the terminal, the power-controlled dedicated physical control channel (DPDCH);

Determining whether a value indicating the allocated maximum power ratio can be directly instructed by the terminal from a scheduling grant table having predetermined values of the maximum power ratio;

Generating a value representing the allocated maximum power ratio as an absolute grant if directly indicating a value representing the allocated maximum power ratio;

If the value indicating the allocated maximum power ratio cannot be directly indicated, the minimum value in the scheduling grant table, which is not smaller than the previously used power ratio of the terminal, is set as a reference value, and the allocated maximum power for the reference value is set. Generating a relative grant indicating a change in ratio,

And transmitting the absolute grant or the relative grant to the terminal.

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 main subject of the present invention to be described later, in the mobile communication system that transmits the reverse data based on the base station control scheduling, to give a clear definition of the scheduling grant, that is, the value assigned by the absolute grant and the relative grant determined through the scheduling, The terminal receiving the scheduling grant provides an operation required in the process of transmitting the E-DCH.

In the following description, the UMTS system, which is an asynchronous WCDMA communication method, will be used. However, the method of transmitting and receiving control information for reverse data transmission, which is a basic object of the present invention, is applicable to other mobile communication systems having a similar technical background and channel form with a slight modification without departing from the scope of the present invention. This will be possible in the judgment of a person skilled in the art of the present invention.

5 illustrates a structure of physical channels used in a reverse link according to a preferred embodiment of the present invention. In this case, the dedicated physical data channel (hereinafter referred to as DPDCH) is for conventional reverse data transmission, and the high speed dedicated physical control channel (high speed DPCCH: referred to as HS-DPCCH) is HSDPA (High Speed Downlink Packet). Access) is used to support services.

)(505)에 의해 해당 전력값으로 설정되어 다중화기(550)로 입력된다. DPCCH 생성기(511)에서 생성된 DPCCH 정보는 확산기(512)에서 확산부호 C_c(513)를 이용하여 확산되고, 이득 조정기(514)에서 DPCCH의 이득 인자인 베타값(beta_c, 즉

)(515)에 의해 해당 전력값으로 설정되어 다중화기(550)로 입력된다.Referring to FIG. 5, the DPDCH data generated by the DPDCH generator 501 is spread using the spreading code C _d 503 in the spreader 502, and the beta value (beta_d) which is a gain factor of the DPDCH in the gain adjuster 504. , In other words

505 is set to the corresponding power value and input to the multiplexer 550. The DPCCH information generated by the DPCCH generator 511 is spread using the spreading code C _c 513 in the spreader 512, and a beta value (beta_c, i.e., a gain factor of the DPCCH in the gain adjuster 514).

515 is set to the corresponding power value and input to the multiplexer 550.

)(525)에 의해 해당 전력값으로 설정되어 다중화기(550)로 입력된다. E-DPDCH 생성기(531)에서 생성된 E-DPDCH 데이터는 확산기(532)에서 확 산부호 C_ed(533)를 이용하여 확산되고, 이득 조정기(534)에서 E-DPDCH의 이득 인자인 베타값(beta_ed, 즉

)(535)에 의해 해당 전력값으로 설정되어 다중화기(550)로 입력된다. 마지막으로 E-DPCCH 생성기(541)에서 생성된 E-DPCCH 정보는 확산기(542)에서 확산부호 C_ec(543)를 이용하여 확산되고, 이득 조정기(544)에서 E-DPCCH의 이득 인자인 베타값(beta_ec, 즉

)(545)에 의해 해당 전력값으로 설정되어 다중화기(550)로 입력된다. The HS-DPCCH information generated by the HS-DPCCH generator 521 is spread using the spreading code C _hs 523 in the spreader 522 and the beta value (beta_hs) which is a gain factor of the HS-DPCCH in the gain adjuster 524. , In other words

525 is set to the corresponding power value and input to the multiplexer 550. The E-DPDCH data generated by the E-DPDCH generator 531 is spread using the spread code C _ed 533 in the spreader 532 and the beta value, which is a gain factor of the E-DPDCH, in the gain adjuster 534. beta_ed, i.e.

535 is set to the corresponding power value and input to the multiplexer 550. Finally, the E-DPCCH information generated by the E-DPCCH generator 541 is spread using the spreading code C _ec 543 in the spreader 542, and the beta value, which is a gain factor of the E-DPCCH, in the gain adjuster 544. (beta_ec, i.e.

545 is set to a corresponding power value and input to the multiplexer 550.

The spread physical channel signals are orthogonal because they are spread with the spreading codes that are orthogonal to each other, and thus are multiplexed together (ie, summed) together in the multiplexer 550. The physical channel signal multiplexed by the multiplexer 550 is converted into a spread signal having a random number by the scrambling code S 552 in the scrambler 551 and transmitted as shown by reference numeral 553.

In FIG. 5, the gain factors of the physical channels are defined as follows.

와 DPCCH를 위한 이득 인자인

를 설정하여 단말과 기지국에게 전달한다. 단말은

와

의 상대적인 차이, 즉 비율을 이용하여, DPDCH와 DPCCH의 전력값들을 설정한다.When establishing a dedicated channel (DCH) between the terminal and the base station, the RNC is a gain factor for the DPDCH, one for each transmission type combination (TFC) available for the DCH.

And gain factor for DPCCH

Set to deliver to the terminal and the base station. The terminal

Wow

Power values of DPDCH and DPCCH are set using the relative difference, i.

,

,

자체를 단말에게 시그널링해주지 않고

에 대한 상대적인 옵셋 값들을 시그널링해주게 된 다. 일 예로 HS-DPCCH를 통해 HARQ 정보로서 ACK/NACK가 전송되는 슬롯에서와 채널품질 정보(Channel Quality Information: CQI)가 전송되는 슬롯에서, 상기 HS-DPCCH에 대해 시그널링되는 옵셋 값들을 Δ_ACK, Δ_NACK, 그리고 Δ_CQI라고 하면,

는 상기 시그널링 변수들을 이용하여 하기 <수학식 1>와 같이 정의되게 된다. On the other hand, for HS-DPCCH, E-DPDCH and E-DPCCH, RNC is

,

,

Without signaling itself to the terminal

Signals offset values relative to. For example, in the slot in which ACK / NACK is transmitted as HARQ information on the HS-DPCCH and in the slot in which Channel Quality Information (CQI) is transmitted, offset values signaled for the HS-DPCCH are Δ _ACK , Δ. _NACK and Δ _CQI ,

Is defined as in Equation 1 using the signaling variables.

Δ _{HS - DPCCH} in a slot in which ACK / NACK information is transmitted is as follows.

Δ _{HS - DPCCH} = Δ _ACK (if HARQ information is ACK)

Δ _{HS - DPCCH} = Δ _NACK (if HARQ information is NACK)

Δ _{HS - DPCCH} = Δ _ACK and Δ _{NACK, which} is a large value (when HARQ information is PRE or POST), where PRE or POST is HARQ information, which means transmission start or transmission end of ACK / NACK.

In addition, Δ _{HS - DPCCH} in a slot for transmitting CQI information is as follows.

Δ _{HS - DPCCH} = Δ _CQI

와

는 하기 <수학식 2>로 결정될 수 있다.In addition, the E-DPDCH and E-DPCCH in order to set the power offset value, which are related to the transmission format (TF) of the E-DCH Δ _{E- DPDCH,} Δ _{E- DPCCH} is used, the _{E- DPDCH} Δ, Δ _{E- DPCCH} May be delivered to the terminal through signaling from the RNC, or may be directly obtained by the terminal through a predetermined formula and a predetermined formula. then

Wow

May be determined by Equation 2 below.

,

,

는

가 존재하는 경우에 한해서 상기

에 대한 상대적인 값으로 정해지게 된다.That is, the transmission power of the HS-DPCCH, E-DPCCH, and E-DPDCH

,

,

Is

Only if

It is set relative to.

는 개발의 복잡성을 줄이기 위하여 임의의 실수값을 가질 수 없으며, 양자화된 제한된 값만을 취하도록 정해진다. 일 예로서, E-DPDCH의 한 코드 채널에 대해 사용될 수 있는 전력값들이 아래의 <표 1>과 같이 정의된다. 하기 <표 1>에서 양자화된 진폭 비율이라 함은, 전력비의 제곱근(root)을 의미하는 것으로서, 결과적으로 DPCCH 대비 E-DPCCH의 진폭 비율을 의미하게 된다.remind

Cannot have any real value in order to reduce the complexity of development, it is decided to take only quantized limited values. As an example, power values that can be used for one code channel of the E-DPDCH are defined as shown in Table 1 below. In Table 1, the quantized amplitude ratio refers to the root of the power ratio, and consequently, the amplitude ratio of the E-DPCCH to the DPCCH.

Δ _{E- DPDCH}

의 양자화된 진폭(amplitude) 비율

Quantized amplitude ratio of 29 168/15 28 150/15 27 134/15 26 119/15 25 106/15 24 95/15 23 84/15 22 75/15 21 67/15 20 60/15 19 53/15 18 47/15 17 42/15 16 38/15 15 34/15 14 30/15 13 27/15 12 24/15 11 21/15 10 19/15 9 17/15 8 15/15 7 13/15 6 12/15 5 11/15 4 9/15 3 8/15 2 7/15 One 6/15 0 5/15

6 illustrates timing of a terminal and a base station related to scheduling of an E-DCH according to a preferred embodiment of the present invention. In this case, the base station 601 performs scheduling for E-DCH transmission of the terminal 602 and informs the terminal 602 of an amount of reverse resources allowed, and informs the absolute value of the reverse resource as a scheduling grant. The Relative Grant Channel (RGCH) 604 transmits an Absolute Grant over an Absolute Grant Channel (AGCH) 603 or indicates a relative change to a predetermined reference value of a reverse resource. Send it. Arrows 620 indicate a previous HARQ process operation having the same process id among a plurality of HARQ processes used in parallel in the E-DCH.

As such, the base station 601 controls the E-DCH transmission of the terminal by using an absolute grant and a relative grant, and the terminal 602 receives the scheduling grants to determine a transmission rate of the E-DCH 605. Done. The scheduling grant may indicate an actual transmission rate of the E-DCH 605 or another value that may indicate a transmission rate other than the actual transmission rate. As described above, the E-DPDCH power ratio of the DPCCH is one of the ones. It can be an example.

Referring to FIG. 6, in step 606, the terminal 602 transmits E-DCH data using a predetermined data rate. Herein, the transmission rate actually used in step 606 is referred to as Last Used Power Ratio (hereinafter referred to as LUPR) 1, that is, LUPR_1. When the E-DCH data is transmitted, a happy bit may be transmitted through the E-DPCCH, and scheduling information such as buffer information and reverse channel information may be included in the E-DCH data. Thereafter, in steps 607 and 608, the UE transmits E-DCH data using transmission rates of LUPR_2 and LUPR_3, respectively.

In step 609, the base station 601 receives the E-DCH data, and in step 610, the base station 601 performs scheduling in consideration of other terminals. When the reverse resource for the E-DCH allocated to the terminal 602 is determined through the scheduling, the base station 601 uses the absolute grant 611 or the relative grant 612, 613, 614 terminal 602. ) Is informed of the amount of reverse resources determined. Specifically, the relative grants (612, 613, 614), the UP (612) command to raise a predetermined value for a predetermined reference transmission rate, the HOLD (613) command to keep the predetermined reference transmission rate the same, the predetermined reference transmission rate DOWN 614, which is a command to lower a certain value, is included.

When the terminal 602 receives the absolute grant 611, in step 615, the terminal 602 sets a value indicated by the absolute grant 611 as a serving grant and transmits E-DCH data using the set serving grant. . The serving grant is a value representing the maximum DPCCH to E-DPDCH power ratio currently allowed for the UE to transmit the E-DCH, and the UE transmits the E-DCH to the E-DCH within the limit not exceeding the serving grant in the E-DCH. The E-DCH transmission rate that satisfies the DPDCH power ratio is selected.

On the other hand, when the terminal 602 receives the relative grant 612 indicating the UP, in step 616, the UE adds a predetermined value Δ to the LUPR_1 of step 606, which is the previous transmission rate used in the corresponding HARQ process. LUPR_1 + Δ) is set as a serving grant, and E-DCH data is transmitted at a power and a transmission rate according to the serving grant. When the terminal 602 receives the relative grant 613 indicating HOLD, in step 617, the terminal 602 maintains the previous serving grant as it is regardless of the HARQ process, and at the transmission rate according to the serving grant. E-DCH data is transmitted. Finally, when the terminal 602 receives the relative grant 614 indicating DOWN, the terminal 602 in step 618 subtracts a predetermined value for LUPR_3 in step 608, which is the previous transmission rate used in the HARQ process ( LUPR_3-Δ) is set as a serving grant, and E-DCH data is transmitted at a transmission rate according to the serving grant.

Here, the serving grant, the absolute grant, and the relative grant both represent an E-DPDCH power ratio to the DPCCH, and an E-DPDCH power ratio to the DPDCH is determined according to a gain factor of the E-DPDCH. Values are limited by Table 1. The simplest example of values of the power ratio that can be expressed using the limited gain factor values is shown in Table 2. Table 2 below is a value obtained by squaring a gain factor in Table 1, and upper indexes 37-30 are obtained as values close to 1 dB at each step difference when two or more code channels are used.

Table 2 above uses the gain factors determined by Table 1 as serving grants. Of course, since the power ratio is not the same as the gain factor representing the amplitude of the signal, square is applied in Table 2 above. Table 2 is used to define scheduling grants such as absolute grants and relative grants, as well as serving grants, and therefore, will be referred to as a scheduling grant table. Additional included indexes 30 to 37 take into account the case where two or more code channels are used, for example up to six code channels. That is, since the gain factor represents only a value for one code channel of the E-DPDCH, the serving grant represented regardless of the number of code channels has been enlarged to represent the values of all six code channels.

In the above description, a scheduling grant table representing a value of a serving grant that a terminal may have has been described. Hereinafter, the values indicated by the absolute grants presented by the preferred embodiments of the present invention will be described.

7 illustrates a transmission structure of an absolute grant according to a preferred embodiment of the present invention.

Referring to FIG. 7, an absolute grant is composed of an absolute grant value of 5 bits 701 and an absolute grant scope of 1 bit 702, and the absolute grant value of 5 bits 701. The absolute grant range 1 bit 702 is multiplexed by the multiplexer 703 and transmitted from the base station to the terminal by the E-AGCH transmitter 704.

Then, the reverse resource represented by the absolute grant is limited to only 32 values that can be represented by the 5-bit absolute grant value. Therefore, the values of the absolute grant should be defined in consideration of the 32 limitation. The absolute grant preferably uses all the possible values of the serving grants presented in the scheduling grant table of Table 2 as it directly indicates the serving grant of the terminal. However, the possible grants of the serving grant are 38 and the absolute grants are 38 Given that the grant value is 5 bits, it is desirable to select 32 appropriate values from the possible values of the serving grant and define them as possible values that the absolute grant can indicate.

Meanwhile, the absolute grant additionally indicates a zero grant and an inactive value. The zero grant means a state in which the serving grant is 0, and the inactive value means that the serving grant value is not valid. In the case of a zero grant, a zero serving grant can be changed to a non-zero serving grant using a relative grant. On the other hand, in the case of the inactive value, the UE sets the serving grant to 0 and cannot use the E-DPDCH, and can not change the serving grant of 0 even when using the relative grant, and only deactivates the E-DCH with the subsequent absolute grant. Can be changed to active.

That is, the two additional values (zero grant, inactive) must be included in the absolute grant. Accordingly, 30 values are selected from the 38 possible values in the scheduling grant table to limit the absolute grant to a value that can be expressed. Table 3 below shows an example of absolute grant values represented by 5 bits and corresponding serving grants.

index Serving Grant (E-DPDCH Power Ratio to DPCCH) 31 (168/15) ² x 6 30 (150/15) ² x 6 29 (168/15) ² x 4 28 (150/15) ² x 4 27 (134/15) ² x 4 26 (119/15) ² x 4 25 (150/15) ² x ² 24 (95/15) ² x 4 23 (168/15) ² 22 (150/15) ² 21 (134/15) ² 20 (119/15) ² 19 (106/15) ² 18 (95/15) ² 17 (84/15) ² 16 (75/15) ² 15 (67/15) ² 14 (60/15) ² 13 (53/15) ² 12 (47/15) ² 11 (42/15) ² 10 (38/15) ² 9 (34/15) ² 8 (30/15) ² 7 (27/15) ² 6 (24/15) ² 5 (19/15) ² 4 (15/15) ² 3 (11/15) ² 2 (7/15) ² One ZERO GRANT 0 INACTIVE

The absolute grant values shown in Table 3 exclude values of indices 0, 1, 3, 4, 6, 7, 9, and 11 from values of serving grants that a terminal may have shown in <Table 2>. The eight excluded serving grants can never be directed to a grant, so they are indicated using a relative grant. That is, if the reverse resource previously used in the E-DCH means the serving grant of index 5, the base station indicates the serving grant of index 6 by using the relative grant of UP, and uses the relative grant of DOWN, and indicates the serving grant of index 4 by using the relative grant of DOWN. Indicate the serving grant. As such, the base station may instruct all of the values of the serving grant as set forth in Table 2 in the combination of the absolute grant and the relative grant.

In the above, the values of the serving grant and the absolute grant which the terminal may have have been defined, and the operation of the relative grant is described in part. Here, the operation of the relative grant will be described in more detail.

The relative grant informs the serving grant of the terminal as a relative change relative to a predetermined reference value. In this case, when the relative grant indicates UP or DOWN, the reference value becomes the E-DPDCH power ratio to the DPCCH used in the previous transmission time interval (TTI) of the same HARQ process, and when the relative grant indicates HOLD, The reference value becomes a serving grant that the terminal was based on in the previous TTI (even if the previous TTI is not the same HARQ process). If the relative grant indicates HOLD, the serving grant is the same without change and can be simply defined. That is, the reference value of the relative grant and the values of the serving grant determined by the relative grant are as shown in the scheduling grant table shown in Table 2. That is, UP / DOWN indicated by the relative grant indicates an operation of moving the index by +1 or -1 in the scheduling grant table.

When the relative grant indicates UP or DOWN, since the reference value of the relative grant is the ratio of the E-DPDCH power to the DPCCH previously used in the same HARQ process, this may be different from the serving grant. This means that the serving grant is the maximum allowable reverse resource allocated to the terminal, and also because one or more code channels can be used. An example in which the E-DPDCH power ratio to the used DPCCH cannot be represented as a scheduling grant table will be described below.

For example, the serving grant in the terminal is (47/15) _² , which is index 18 of the scheduling grant table, and one code channel having an E-DPDCH power ratio of (47/15) _² to DPCCH is used. The data to be transmitted is rate matched to a value slightly exceeding PL_non_max, which is a value representing puncturing limit (PL) during rate matching. When the terminal receives the UP as a relative grant, the serving grant is updated to (53/15) ² , which is index 19 of the scheduling grant table, and the E-DCH data of the data size according to the updated serving grant is converted into one code channel. If so, the puncturing limit of the E-DCH data is smaller than PL_non_max, so that the terminal uses an additional code channel. Therefore, the UE should set the sum of the E-DPDCH power ratios for the two code channels to the DPCCH to be equal to or smaller than the serving grant (53/15) ² .

The E-DPDCH power ratio to the DPCCH possible for each code channel is determined in consideration of the possible gain factors of the E-DPDCH. Considering 34 and 30, among the possible values of the gain factor, (34/15) ² x2 (where x2 means two code channels) is slightly larger than (53/15) ² , and (30/15) ^{Since 2} x ² becomes smaller than (53/15) ² , the gain factor for the two code channels is set to 30, and the ratio of the E-DPDCH power to the used DPCCH of the current TTI is (30/15) ² x ² Becomes

In the above, an example of the operation of the relative grant when one or more code channels are used has been described. Then, if the E-DPDCH power ratio to the used DPCCH is set as (30/15) ² x ² as described above, if UP or DOWN is received again as a relative grant, the E-DPDCH power ratio to the used DPCCH of the terminal is Since the serving grant does not match a value that can be indicated, the serving grant updated by the terminal by the relative grant is different from the serving grant expected by the base station.

Therefore, even in the case described above through the following examples to provide a method of operation of the terminal operating by clearly interpreting the relative grant.

<< first embodiment >>

According to the first embodiment of the present invention, when the UE receives the UP or DOWN as the relative grant, the terminal first applies a rounding method to the E-DPDCH power ratio to the used DPCCH to schedule the reference value for the relative grant. Set to one possible value in the grant table. That is, in the scheduling grant table of Table 2, the minimum value not smaller than the E-DPDCH power ratio to the previously used DPCCH of the same HARQ process is set as the reference value of the relative grant.

Thereafter, the terminal sets the serving grant by increasing or decreasing the set reference value according to the relative grant. That is, if the relative grant means UP, a value one step larger than the reference value is set as a serving grant in the scheduling grant table of Table 2; on the contrary, if the relative grant means DOWN, a value one step smaller than the reference value The value is set to the serving grant. By using the method proposed by the first embodiment, the setting of the serving grant according to the relative grant becomes clear.

As an example, when the E-DPDCH power ratio to the used DPCCH is (30/15) ² × ² , the reference value determined according to the first embodiment is (53/15) ² . In this case, when the relative grant is UP, the serving grant becomes (60/15) ^{2, which} is one step up from the scheduling grant table, and when the relative grant is DOWN, the serving grant is one step down from the scheduling grant table ( 47/15) ² .

8 is a flowchart illustrating the operation of a terminal according to an exemplary embodiment of the present invention.

Referring to FIG. 8, in step 802, a UE receives a scheduling grant from a base station, and in step 803, the terminal determines whether the scheduling grant is an absolute grant. If the scheduling grant is an absolute grant according to the determination process, in step 804, the UE sets a serving grant representing the maximum allowable reverse resource of the E-DCH as an absolute grant value of the absolute grant. On the other hand, if it is determined in step 803 that the scheduling grant is not an absolute grant, in step 805, the UE determines whether the scheduling grant is a relative grant indicating UP or DOWN.

If the scheduling grant is determined to be a relative grant indicating UP or DOWN, in step 506, the UE determines the E-DPDCH power ratio (ie, LUPR) to the DPCCH used immediately before in the same HARQ process. Rounding to set the raised value as a reference value, and sets a value one level higher or lower than the reference value according to the relative grant as a serving grant. Here, the serving grant is determined by changing the index of the reference value shown in the scheduling grant table of Table 2 by + 1 / -1. Therefore, the serving grant is determined between (168/15) ² x6, the maximum value of the scheduling grant table, and (5/15) ² , the minimum value.

In contrast, if it is determined in step 805 that the scheduling grant is a relative grant indicating HOLD instead of UP or DOWN, in step 807, the UE sets a serving grant to be the same as the previous serving grant. When the steps 804, 806, and 807 are completed, in step 808, the UE selects an appropriate E-TFC for the E-DCH based on the serving grant, and in step 809, E-DCH data using the selected E-TFC. Send it. Herein, the selected E-TFC is determined in a range that does not exceed the power of the E-DPDCH allowed by the serving grant.

9 is a block diagram showing the structure of a terminal according to an embodiment of the present invention.

Referring to FIG. 9, the terminal has a receiver 901 and a transmitter 902. The receiving unit 901 includes a scheduling grant receiving unit 903, and the scheduling grant received by the scheduling grant receiving unit 903 is transferred to the serving grant generating unit 904 included in the transmitting unit 902. The serving grant generator 904 refers to the scheduling grant related memory 906 in order to generate the serving grant 908 according to the scheduling grant. The scheduling grant table as shown in Table 2 is stored in the scheduling grant-related memory 906, and also the E-DPDCH power ratio and the serving grant of the previous TTI are stored.

The serving grant generator 904 generates a serving grant 908 through an operation as shown in FIG. 8, and the E-TFC selector 905 selects an appropriate E-TFC according to the serving grant 908. Done. The E-TFC is defined in a range that does not exceed the power of the E-DPDCH allowed by the serving grant 908. When the E-TFC is selected, the E-DCH generator 907 generates E-DCH data having a data size corresponding to the E-TFC, and the E-DCH data is an E-DPDCH generator 910. Is composed of an E-DPDCH frame through encoding, rate matching, and the like.

Meanwhile, the serving grant generator 904 provides a power control signal 909 indicating a gain factor corresponding to the serving grant 908 to the power controller 911. Then, the power control unit 911 applies the gain factor corresponding to the power control signal 909 to the E-DPDCH frame, and the multiplexing and transmitting unit 912 performs power control by the power control unit 911. The DPDCH frame is multiplexed with the frames of other channels and transmitted to the base station.

10 is a flowchart illustrating the operation of a base station according to an embodiment of the present invention.

Referring to FIG. 10, in step 1002, the base station receives E-DCH data transmitted through the E-DPDCH from the terminal. The E-DCH data may include scheduling information such as buffer information or reverse channel information, and the base station receives a happy bit indicating the state of the terminal from the terminal through the E-DPCCH. In step 1003, the base station schedules reverse data transmission of the terminal by using the scheduling information and the happy bit. The maximum allowable reverse resource is allocated to the terminal through the scheduling. In step 1004, the base station determines a scheduling grant for indicating the allocated maximum allowed uplink resource.

In step 1004, the base station refers to a previously used transmission rate and a previous serving grant of the terminal. Specifically, the base station finds an appropriate value corresponding to the scheduling result in the scheduling grant table stored in advance and indicates the determined value. To determine an absolute grant or a relative grant. If it is desired to generate an absolute grant, the base station finds an appropriate value corresponding to the scheduling result among the possible values of the absolute grant shown in Table 3 and generates an absolute grant including the absolute grant value. On the other hand, if a relative grant is to be generated, in Table 3, a relative grant representing a change corresponding to the scheduling result is generated by using a minimum scheduling grant value larger than a previously used transmission rate as a reference value.

In step 1005, the generated absolute grant or relative grant is transmitted to the terminal through a corresponding channel, that is, E-AGCH or E-RGCH.

11 is a block diagram showing the structure of a base station according to a preferred embodiment of the present invention.

Referring to FIG. 11, the base station includes a receiver 1101 and a transmitter 1102. The E-DCH reception unit 1103 included in the base station reception unit 1101 receives the E-DCH data and the E-DCH control information transmitted by the UE through the reverse link, and the buffer state or the reverse direction included in the E-DCH data. The scheduling information such as channel information, the happy bit included in the E-DCH control information, the E-TFC, and the like are detected and transmitted to the scheduler 1104 included in the transmitter 1102.

The scheduler 1104 stores the information transmitted from the E-DCH receiver 1103 in the memory 1105, and uses the information and a scheduling grant table previously stored in the memory 1105 for the terminal. Scheduling is performed. The maximum allowable reverse resource is allocated to the terminal through the scheduling. Then, the scheduling grant generation unit 1106 generates an absolute grant or a relative grant for the terminal by performing an operation as shown in FIG. 10 according to the scheduling result. The generated absolute grant or relative grant is multiplexed with signals of other channels by the multiplexing and transmitting unit 1107 and transmitted to the terminal.

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.

The present invention, in the use of the absolute grant and the relative grant as a scheduling grant for the reverse packet transmission in the WCDMA communication system using the E-DCH, by presenting the correct transmission and reception of the scheduling grant, the terminal according to the scheduling grant It is possible to efficiently perform reverse packet data transmission.

Claims (2)

A method of receiving a scheduling grant for controlling reverse data transmission in a mobile communication system, Receiving a scheduling grant indicating a maximum power ratio of the enhanced dedicated physical data channel (E-DPDCH) to the power controlled dedicated physical control channel (DPDCH) allocated for reverse data transmission from the base station; If the scheduling grant is an absolute grant representing a value in a scheduling grant table having predetermined values of the maximum power ratio, determining a value indicated by the absolute grant as a serving grant; If the scheduling grant is a relative grant that indicates an increase or decrease in the maximum power rate, then the minimum value in the scheduling grant table that is not less than the power rate just previously used in the complex automatic retransmission request (HARQ) process to be transmitted currently is determined. Setting a reference value and determining, by the serving grant, a value that is increased or decreased by one step in the scheduling grant table according to the relative grant; Transmitting enhanced dedicated channel (E-DCH) data using a power ratio that does not exceed the determined serving grant. A method of receiving a scheduling grant for controlling reverse data transmission in a mobile communication system, Allocating a maximum power ratio of the enhanced dedicated physical data channel (E-DPDCH) to the terminal, the power-controlled dedicated physical control channel (DPDCH); Determining whether a value indicating the allocated maximum power ratio can be directly instructed by the terminal from a scheduling grant table having predetermined values of the maximum power ratio; Generating a value representing the allocated maximum power ratio as an absolute grant if directly indicating a value representing the allocated maximum power ratio; If the value indicating the allocated maximum power ratio cannot be directly indicated, the minimum value in the scheduling grant table, which is not smaller than the previously used power ratio of the terminal, is set as a reference value, and the allocated maximum power for the reference value is set. Generating a relative grant indicating a change in ratio, Transmitting the absolute grant or the relative grant to the terminal.

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