KR100772129B1 - Serving scheduling cell selection method for mobile station during soft handoff for uplink packet transmission system and therefor apparatus - Google Patents

Abstract

The present invention relates to a method and apparatus for selecting an optimal scheduling base station for efficient reverse traffic rate control and scheduling of terminals located in a soft handover region. UEs located in the soft handover region select an optimal scheduling cell among cells included in the active set appropriately and notify the base station through reverse signaling. The optimal scheduling cell and the non-optimal scheduling cells are reversed of the terminal through independent scheduling. Control traffic efficiently. The present invention increases the overall system performance and increases the stability of the system through the efficient use of reverse resources.

WCDMA, UPLINK ENHANCEMENTS, NODE B CONTROLLED SCHEDULLING, SOFT HANDOVER, DYNAMIC NODE B SELECTION

Description

TECHNICAL FIELD OF THE INVENTION A cell selection method and apparatus for the scheduling of soft handover terminals in a reverse packet transmission system TECHNICAL FIELD

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

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

3 is a conceptual diagram illustrating transmission of data over an E-DCH in a typical radio link.

4 is a message flow diagram illustrating a transmission and reception procedure through an E-DCH.

5 is a diagram illustrating a rate scheduling method.

6 illustrates a time-rate scheduling method.

7 is a diagram illustrating an E-DCH operation of a terminal located in a soft handover region.

8 is a diagram illustrating a relationship between an E-DCH transmitting terminal, a cell, and a base station;

9 is a signaling diagram for transmitting reverse burden situation information through a broadcast channel according to an embodiment of the present invention.

10 is a signaling diagram for transmitting reverse burden situation information through a dedicated channel according to an embodiment of the present invention.

11 is a flowchart illustrating an operation of determining an optimal scheduling cell according to an embodiment of the present invention.

12 illustrates an apparatus for determining an optimal scheduling cell according to a preferred embodiment of the present invention.

13 is a diagram illustrating a process of setting a cell ID.

14 is a diagram illustrating an apparatus for optimal scheduling cell delivery using DPCCH according to an embodiment of the present invention.

FIG. 15 illustrates an apparatus for optimal scheduling cell delivery using E-DPCCH according to an embodiment of the present invention. FIG.

16 is a diagram illustrating a structure of a MAC-e PDU for transmitting optimal scheduling cell information according to an embodiment of the present invention.

The present invention relates to asynchronous wideband code division multiple access (WCDMA) communication. In particular, the terminal located in the soft handoff area provides an enhanced uplink dedicated channel for reverse packet transmission. The present invention relates to a method and an apparatus for enabling efficient scheduling of the enhanced uplink transport channel.

UMTS (Universal Mobile), a third-generation mobile communication system based on the Global System for Mobile Communications (GSM), which uses a European-style mobile communication system, and uses Wideband Code Division Multiple Access (CDMA). Telecommunication Service (Telecommunication Service) systems provide a consistent service that enables mobile phone or computer users to transmit packet-based text, digitized voice or video and multimedia data at speeds of more than 2 Mbps, anywhere in the world. 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 diagram illustrating a UMTS Terrestrial Radio Access Network (hereinafter referred to as UTRAN) of a UMTS system.

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

The RNC allocates or manages radio resources of Node Bs that it controls, and Node B plays a role of providing actual radio resources. The radio resource is configured for each cell, and the radio resource provided by the node B means radio resources of cells managed by the node B. The terminal may configure a radio channel and perform communication by using a radio resource provided by a specific cell of a specific Node B. From the point of view of the terminal, the distinction between the Node B and the cell is meaningless, and since only the physical layer configured for each cell is recognized, the Node B and the cell will be referred to as the same meaning.

The interface between the terminal and the Node B is called a Uu interface, and its detailed hierarchical structure is shown in FIG. The Uu interface is divided into a control plane used to exchange control signals between the terminal and the Node B and a user plane used to transmit actual data.

Referring to FIG. 2, the signaling 30 of the control terminal may include a radio resource control (RRC) layer 34, a radio link control (RLC) layer 40, a media access control (MAC) layer 42, and a physical ( It is processed through the Physical (44) layer 44, the information 32 of the user end includes the PDCP (Packet Data Control Protocol) layer 36, BMC (Broadcast / Multicast Control) layer 38, RLC layer 40, MAC Processing is carried out via the layer 42 and 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 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, the MAC layer 42 inserts additional information into data received through a logical channel or a transmission channel or interprets the additional information inserted into the data to take an appropriate operation. It also controls the random access operation. In this MAC layer 42, the part related to the user terminal 32 is referred to as MAC-d, and the part related to the control terminal 30 is referred to as MAC-c.

The RLC layer 40 is responsible for establishing and releasing logical channels. The RLC layer 40 may operate in one of three operation modes, that is, 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 terminal 32, and functions to compress and restore headers of data transmitted in the form of IP packets, and to provide services to specific terminals with mobility. It is responsible for the lossless transfer of data, etc. under the situation that is changed.

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 transport format (TF) specified.

In particular, in the UMTS system, an enhanced uplink dedicated channel (hereinafter referred to as Enhanced Uplink Dedicated Channel) may be further improved to further improve packet transmission performance in uplink (UL) communication from a user equipment (UE) to a base station (Node B). EUDCH or E-DCH). In order to support more stable and high-speed data transmission, the E-DCH uses techniques such as Adaptive Modulation and Coding (AMC), Hybrid Automatic Retransmission Request (HARQ), and base station control scheduling. Support. The processing of the E-DCH is performed by the MAC-e layer which exists below the MAC-d layer, and the E-DCH data output from the MAC-e layer is MAC-enhanced Protocol Data Unit (MAC-e PDU). It is called.

3 is a conceptual diagram illustrating transmission of data through an E-DCH for reverse packet transmission in a radio link.

Referring to FIG. 3, reference numeral 100 denotes a Node B supporting the E-DCH, and terminals represented by 101, 102, 103, and 104 become terminals receiving the E-DCH. The node B 100 determines the channel status of the terminals 101 to 104 using the E-DCH and schedules data transmission of each terminal. Scheduling assigns a low data rate to a terminal far from Node B and high data to a near terminal while ensuring that Node B's measured rise over thermal (RoT) value does not exceed the target noise increase to improve system-wide performance. This is done by assigning a transmission rate.

4 is a message flow diagram illustrating a transmission and reception procedure through an E-DCH.

Referring to FIG. 4, in step 202, the Node B and the UE configure an E-DCH. The configuration process 202 includes the delivery of messages over a dedicated transport channel. If the E-DCH is configured, the UE informs the Node B of the scheduling information in step 204. The scheduling information may be terminal transmission power information indicating reverse channel information, extra power information that can be transmitted by the terminal, and an amount of data to be transmitted in a buffer of the terminal.

Receiving scheduling information from a plurality of terminals in communication, the Node B monitors scheduling information received from the plurality of terminals in step 206 to schedule data transmission of each terminal. Specifically, in step 208, the Node B determines to allow reverse packet transmission to the terminal and transmits scheduling assignment information to the terminal. The scheduling allocation information includes an allowed data rate and an allowable timing.

The UE determines a transport format (TF) of the E-DCH to be transmitted in the reverse direction using the scheduling assignment information in step 210, and transmits reverse (UL) packet data through the E-DCH in step 212. At the same time, the TF information is transmitted to the Node B in step 214. In step 216, the Node B determines whether there is an error in the TF information and the packet data. In step 218, the node B receives a non-acknowledge (NACK) when an error occurs in any one of the determination results, and receives an acknowledgment (ACK) when all errors are found through the ACK / NACK channel. Send to the terminal.

When the ACK is transmitted, the packet data is completed and the terminal transmits new data through the E-DCH. When the NACK is transmitted, the terminal retransmits the packet data having the same contents through the E-DCH.

Various methods may be used as the scheduling method for reverse packet transmission described above. Representative scheduling methods include rate scheduling and time and rate scheduling. The rate scheduling method is a method in which the base station controls the transmission rate of each terminal step by step, and the time-rate scheduling is a method in which the base station simultaneously controls the time and transmission rate of the reverse packet transmission of the terminal.

5 is a diagram illustrating a rate scheduling between a UE and a base station.
Referring to FIG. 5, the terminal 502 transmits a rate request information 505 and E-DCH data 506, and the base station 501 transmits a transmission rate allocated to the terminal 502 through scheduling. Rate Grant (503) information indicating information is being transmitted.

That is, the terminal 502 determines how much data is in the buffer to be sent in the reverse direction, and also checks the power surplus value that the terminal 502 can transmit to set a transmission rate to be transmitted next. The information 505 is requested to increase or decrease the transmission rate. The base station 501 receiving the request information 505 increases the transmission rate to the terminal 502 by combining the transmission rate request information transmitted by the terminal 502 and other terminals managed by the base station 501. The rate grant information 503 is used to determine whether to reduce, decrease, or maintain the data.

5, the terminal 502 requests a rate increase using the rate request information 508 in order to increase the rate in step 508. The base station 501 receiving the request information 508 transmits information to increase the transmission rate to the terminal 502 by using the transmission rate information 509 in step 510 through scheduling. The terminal 502 is allowed to increase the transmission rate, so that the reverse packet can be transmitted at the transmission rate 11 (512) which is increased by one step compared to the previous transmission rate 10 (511).

In the rate scheduling described above, the rate information may represent various stages of a table that the base station and the terminal have in common. In other cases, the rate information may be represented by a transport block combination (hereinafter referred to as TBC) indicating a transport block size (hereinafter referred to as TBS).

FIG. 6 is a diagram illustrating transmission of control information in a reverse direction and a forward direction in time-rate scheduling, and a state in which a terminal transmits a reverse packet based on the control information.

Referring to FIG. 6, the terminal 603 transmits the terminal state information 604 to the base station 601 in a predetermined manner such as a periodic or event-triggered scheme or an event triggered scheme based on the periodic scheme. do. The base station 601 receiving the terminal state information selects a terminal 603 to allow transmission during the next frame period through internal scheduling, and determines scheduling rate by determining an allowed transmission rate of the selected terminal 603. It transmits to the terminal 603 using the assignment) information 602. Accordingly, the terminal 603 transmits the E-DCH data 605 in the reverse direction for a predetermined time interval by using the transmission rate indicated by the scheduling assignment information 602.

For example, initially, the terminal 603 uses the rate 1 610 for transmission of the E-DCH data 605. When the terminal 603 transmits the terminal state information 611 to the base station 601 in step 621, the base station 601 performs scheduling to allow the terminal 603 to transmit the E-DCH during the next frame time interval. In the case of allowing the transmission, the transmission rate to be allowed to the terminal 603 and the time information to which the transmission is allowed are determined. In step 641, the base station 601 transmits allocation time information and allocation rate information to the terminal using the scheduling allocation information 631. The terminal 603 transmits the E-DCH data according to the allocated transmission rate 10 651 during the time interval based on the scheduling allocation information 631. Since the scheduling allocation information 631 includes information for allowing transmission using the transmission rate 10, the terminal 603 transmits the E-DCH data 605 at the transmission rate 10 654.
On the other hand, when the base station 601 does not set scheduling assignment information for the terminal 603 as shown by reference numeral 630, the terminal 603 uses E-DCH data using a rate 1 (650), which is a minimum set. 605 is transmitted. Thereafter, when the base station 601 transmits scheduling allocation information 632 indicating a transmission rate 15 in step 642, the UE 603 transmits the E-DCH data 605 at the transmission rate 15 652 according to the scheduling allocation information 632. ) Will be sent.

The scheduling scheme that can be generally used has been described above. Since E-DCH is an enhanced channel for packet transmission of an uplink transport channel, it follows the basic characteristics of a dedicated channel. One of them is to support soft handover, which is a terminal in the soft handover area can receive forward information from all of the base stations in the active set (Active set). Accordingly, the terminal located in the soft handover area receives scheduling allocation information from all base stations belonging to the activity set in order to transmit the E-DCH.

In this case, when the base station schedules the terminal in the soft handover region, all the base stations belonging to the activity set transmit signaling allocation information to the terminal, thereby causing signaling overhead, and receiving the plurality of scheduling allocation information. May cause a problem in determining the TF for transmitting the E-DCH.

Accordingly, the present invention, which is designed to solve the problems of the prior art operating as described above, provides an improved reverse dedicated channel scheduling method and apparatus for terminals located in a soft handover area in a WCDMA communication system.

The present invention also provides a method and apparatus for selecting a serving scheduling base station for a terminal located in a soft handover area.

Finally, the present invention provides a signaling method and apparatus for enabling the optimal scheduling base station information selected in a terminal located in a soft handover region to be shared between the terminal and the base station.

According to a preferred embodiment of the present invention, a method for transmitting reverse packet data by a terminal communicating with a plurality of cells by soft handover in a mobile communication system supporting enhanced reverse packet data service,
Selecting an optimal scheduling cell for scheduling the reverse packet data service of the terminal according to at least one of forward path loss information, backward burden situation information, and ratio information of a positive response signal (ACK);
Notifying the plurality of cells of information indicating the selected optimal scheduling cell;
Receiving rate grant information for transmission of reverse packet data from the selected optimal scheduling cell and the unselected non-optimal scheduling cells of the plurality of cells;
And transmitting the reverse packet data to the plurality of cells according to the rate grant information.

Another preferred embodiment according to the present invention is a terminal device for communicating with a plurality of cells by soft handover and transmitting reverse packet data in a mobile communication system supporting enhanced reverse packet data service.
An optimal scheduling cell selector for selecting an optimal scheduling cell for scheduling the reverse packet data service of the terminal according to at least one of forward path loss information, backward burden situation information, and ratio information of a positive response signal;
A control information transmitter for transmitting identification information indicating the selected optimal scheduling cell to the plurality of cells;
Receiving rate grant information for transmission of reverse packet data from the selected optimal scheduling cell and non-selected non-optimal scheduling cells of the plurality of cells, and transmitting the reverse packet data to the plurality of cells according to the rate grant information It characterized in that it comprises a data transmission unit.
According to another preferred embodiment of the present invention, in a mobile communication system supporting an enhanced reverse packet data service, a base station communicating with a terminal in soft handover receives a reverse packet data from the terminal.
Receiving, from the terminal, information indicating a selected optimal scheduling cell among a plurality of cells with which the terminal communicates, wherein the optimal scheduling cell includes forward path loss information, backward burden situation information, and a positive response signal (ACK); Selected by the terminal according to at least one of ratio information of
Transmitting rate grant information indicating a transmission rate allocated for transmission of reverse packet data to the terminal through the selected optimal scheduling cell or the unselected non-optimal scheduling cells according to the optimal scheduling cell information;
And receiving the reverse packet data according to the rate grant information from the terminal.

Hereinafter, the operating principle of the present invention will be described in detail with reference to the accompanying drawings. 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.

In the present invention, an increase in forward signaling information generated when a UE is located in a soft handover region and a method of determining a transmission format for an E-DCH by a UE receiving scheduling assignment information are unclear in a system supporting an E-DCH. Losing security. In addition, an optimal scheduling base station is selected for efficient scheduling and information accompanying is signaled.

The present invention aims at E-DCH scheduling of a UE located in a soft handover region.

Hereinafter, the soft handover operation will be described with reference to FIG. 7.

In FIG. 7, base station 1 701 and base station 2 702 may receive E-DCH data, and terminals 1, 2 and 3 703, 706, and 710 may transmit E-DCH data. Terminal 1 703 and terminal 2 706 do not belong to the soft handover region, and are only E-DCH scheduled by base station 1 701 and base station 2 702, respectively. Accordingly, the terminal 1 703 may receive the scheduling allocation information 704 from the base station 1 701 and transmit the E-DCH data 705 using the scheduling allocation information 704. On the contrary, the terminal 2 706 can receive the scheduling assignment information 707 from the base station 2 702 and transmit the E-DCH data 708.
However, the terminal 3 710 belonging to the soft handover has both the base station 1 701 and the base station 2 702 as an active set. Accordingly, the terminal 3 710 may receive the signals transmitted from the base station 1 701 and the base station 2 702, and the base station 1 701 and the base station 2 702 also receive signals transmitted from the terminal 3 710. All can be received. Accordingly, the base stations 1, 2 (701, 702) performs E-DCH scheduling for the terminal 3 (710) for transmission of the E-DCH data of the terminal 3 (710) and provides scheduling allocation information as shown in 711 and 713, respectively. Terminal 3 (710) will be transmitted. Terminal 3 (701) receives one or more scheduling assignment information from the base station 1, 2 (701, 702), it is difficult to determine the transmission format of the E-DCH data (712,714). Accordingly, the terminal 3 710 located in the soft handover area performs E-DCH transmission in a different manner from the terminals 1, 2 (703, 706) located in the soft handover area.
In the present invention, among the base stations belonging to the active combination of the terminals located in the soft handover area, the base station that can improve the system performance and stability when scheduling is selected as the "optimized scheduling base station" to inform the selected optimal scheduling base station, The optimal scheduling base station and the other base stations (ie, non-serving scheduling base station) may use different E-DCH scheduling methods. The easiest way to select the optimal scheduling base station is to select the base station that is most affected by the reception noise in terms of the E-DCH transmitted by the terminal as the optimal scheduling base station.

Different scheduling methods of the optimal scheduling base station and the non-optimal scheduling base station may be described as follows.

First, for systems that only use rate scheduling:

The terminal located in the soft handover area selects an optimal scheduling base station, and only the selected optimal scheduling base station performs E-DCH scheduling for the terminal. That is, only the selected optimal scheduling base station transmits the rate grant information to the terminal. Base stations that belong to the activity combination of the terminal and are not optimal scheduling base stations do not perform E-DCH scheduling for the terminal, that is, do not transmit rate grant information to the terminal. The terminal also receives only rate grant information from the optimal scheduling base station and uses the same to determine the transmission format of the E-DCH.

Second, for systems using only time-rate scheduling:

The terminal located in the soft handover area selects an optimal scheduling base station, and only the selected optimal scheduling base station transmits scheduling assignment information to the terminal, and base stations belonging to the activity combination of the terminal and not the optimal scheduling base station are scheduled for the terminal. Do not do it. In other words, the scheduling allocation information is not transmitted. The scheduling assignment information includes an assigned transmission rate and timing information that allows transmission. The terminal also receives only scheduling information from the optimal scheduling base station and uses the same to determine the format of the E-DCH.

Third, for a system using rate scheduling and time-rate scheduling at the same time:

The UE located in the soft handover region selects an optimal scheduling base station, and only the selected optimal scheduling base station performs rate scheduling and time-rate scheduling to transmit rate grant information or scheduling assignment information. Base stations that belong to the activity combination of the terminal and are not optimal scheduling base stations perform only rate scheduling. That is, only rate grant information can be transmitted. The terminal receives rate grant information and scheduling assignment information from the optimal scheduling base station and only rate grant information from the non-optimal scheduling base station. The terminal uses the scheduling allocation information of the optimal scheduling base station and information of rate grant information transmitted from the non-optimal scheduling base station to determine the transmission format of the E-DCH.
1, determination of optimal scheduling cell / base station

In order to implement the scheduling method of the terminals located in the soft handoff region, a technique necessary first of all is a method of determining an optimal scheduling base station. The terminal determines the optimal scheduling base station for E-DCH scheduling of the terminal using various information received from the base station and state information inside the terminal.

Hereinafter, a method of determining an optimal scheduling base station by a terminal located in a soft handoff region will be described. In the following description of the present invention, it is assumed that each base station includes a plurality of cells, and the cells are distinguished according to a frequency (FA) and a scrambling code. In this case, the UE may select a specific cell as an optimal scheduling cell or select a base station to which the specific cell belongs as an optimal scheduling base station.

According to an embodiment of the present invention, the terminal located in the soft handover area selects a cell having the smallest path loss among the cells belonging to the activity combination and selects the base station to which the cell belongs as an optimal scheduling base station. The specific selection method is as follows.

First, how to consider the forward path loss for each cell / base station:

Each of the cells with which the terminal communicates has one common control pilot channel (CPICH). The terminal measures the received signal code power (RSCP) of the CPICH, and since the terminal receives the transmission power of the CPICH from the system through higher-level signaling, the terminal is expressed by Equation 1 below. Calculate the downlink path loss of each cell.

Here, Primary CPICH Tx power is the transmission power of the CPICH received through higher signaling, and CPICH_RSCP means the received signal code power (RSCP) measured for the CPICH.
As shown in Equation 1, the terminal calculates forward path loss values of cells belonging to an activity combination and then selects an optimal scheduling base station by comparing the calculated forward path loss values with each other. The forward path loss value is a variable representing the channel condition between the base station and the terminal best, and the base station with the smallest path loss value is most affected in the reverse transmission of the terminal. Of course, there may be some difference between the backward path loss value and the forward path loss value, but it may be considered that the forward path loss value is the same as the backward path loss value for a long time period.

8 illustrates a conceptual diagram of communication between a terminal located in a soft handoff area and a plurality of base stations.
Referring to FIG. 8, base station 1 801 manages cell A 803, and base station 2 802 manages cell B 804 and cell C 805. In this case, the terminal 810 located in the region 806 where the cell A 803, the cell B 804, and the cell C 805 overlaps has the cells 803, 804, and 805 as an active combination, and the base stations 801 and 802 are included in the activity combination. The cells 803, 804 and 805 transmit CPICHs 811, 812 and 813 respectively, and the terminal 810 receives each CPICH 811, 812 and 813 all from the cells 803, 804 and 805, and also through respective upper layer signaling. CPICH transmit power is already known. Accordingly, the terminal 810 calculates forward path loss values based on a difference in transmission power of CPICH RSCP and CPICH of the cells 803, 804, and 805, and compares the path loss values with a minimum path loss value. Select the cell. Then, the terminal selects the selected cell as an optimal scheduling cell or selects a base station including the selected cell as an optimal scheduling base station.

In the above, we proposed a method to find the cell with the minimum career loss in comparing the career loss. In another embodiment, the terminal may select a base station having a minimum path loss value and select the optimal scheduling base station. That is, since the uplink signals received in the multiple cells managed by one base station are soft-combined at the base station, the terminal may calculate path loss values in units of base stations. At this time, all procedures for calculating the path loss value for each base station are the same as the procedures for calculating the path loss value for each cell. That is, the terminal adds the path loss values of all the cells belonging to one base station to obtain the path loss value of the base station. The base station with the smallest path loss value is then selected as the optimal scheduling base station.

Second, how to use RoT:

In selecting an optimal scheduling base station, the UE considers a UL Load Condition as an additional variable other than the path loss value of the CPICH described above. The reverse burden situation information is an extra resource, i.e., RoT, of a reverse resource that the base station uses in scheduling terminals. In other words, the base station that does not have a large amount of uplink resources is greatly affected by the uplink transmission of the terminal. Therefore, the terminal selects the base station having the largest RoT as the optimal scheduling base station.

In order for the terminal to use the reverse burden situation in determining the optimal scheduling base station, the base station provides the reverse burden situation information to the terminal. When the terminal is located in the soft handover area, the terminal receives the reverse burden situation information from all the cells in the activity combination. Therefore, a new procedure for delivering reverse burden situation information should be added and the following methods can be used.

The reverse burden situation information may be defined in units of cells, and the base station that manages the cell has reverse burden situation information of the cell. Here, RoT may be calculated as the ratio of the thermal noise power spectral density No of the base station to the total received wideband power spectral density lo of the base station. Accordingly, the RoT becomes a radio resource that can be allocated by the base station for the reverse packet data service on the uplink. Since the reverse burden situation information is all the same information to the terminals belonging to the cell, it is advantageous in resource utilization to select a method that can be transmitted to all the terminals in one transmission rather than separately sent to each of the terminals. Can be seen.

A broadcast channel (BCH) is used as a method of transmitting uplink burden situation information to all terminals belonging to one cell. The BCH is a channel determined for each cell and uses a predetermined encoding and a predetermined transmission format so that all the terminals included in the cell can receive information limited to each cell. Therefore, not only a terminal that does not have a dedicated channel, but also a terminal in a CELL-DCH (Cell Dedicated Channel) state having a dedicated channel, receives and decodes the BCH for E-DCH service to provide the reverse burden status information. Acquire.

9 shows a signaling flow diagram for transmitting the reverse burden situation information to the UE through the BCH.
Referring to FIG. 9, the terminal 901 belongs to a cell managed by the base station 902, and in step 904, the base station 902 controls the terminal 901 to receive uplink burden situation information of the cell. It transmits through a Node B Application Part Protocol (NBAP) signaling to a network controller 903 (Serving RNC (SRNC)). In step 905, the SRNC 903 transmits the backward burden situation information to the terminal 901 through RRC signaling using BCH.
In another embodiment, since the reverse burden situation information is required only for a terminal included in a soft handover region, the reverse burden situation information may be transmitted only to each terminal in the soft handover region, not all terminals in a cell. have. For example, the SRNC may transmit reverse burden situation information using a dedicated channel (DCH) to each UE located in the soft handover area.
10 shows a process of transmitting reverse burden situation information through the RRC signaling.
Referring to FIG. 10, the terminal 1001 belongs to a cell managed by the base station 1002 and is located in a soft handover area. In step 1004, the base station 1002 transmits the reverse burden situation information of the cell to the radio network controller 1003 (SRNC) controlling the terminal 1001 through NBAP signaling. In step 1005, the SRNC 1003 transmits the backward burden situation information to the terminal 1001 through RRC signaling using DCH.

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In the above, a method of using a BCH or a DCH for transmitting reverse burden situation information is proposed. However, another channel or method for transmitting reverse burden information to a terminal performing reverse packet data service in a cell, a terminal belonging to a handover region, or terminals requiring reverse burden situation information may be applied to the present invention. Self-explanatory

Third, how to use compound automatic retransmission (HARQ):

Since the E-DCH supports HARQ, the terminal receives ACK or NACK as feedback information on the E-DCH data from the base station after transmission of the E-DCH data. At this time, the UE located in the soft handover area receives ACK / NACK from a plurality of base stations. Accordingly, the terminal located in the soft handover region may determine that the base station having a high ACK ratio for the base stations belonging to the active combination is the base station having a better reverse channel situation, that is, the base station most affected by the reverse transmission of the terminal. have. Accordingly, the terminal selects a base station having a high transmission rate of ACK as the lowest scheduling base station.

Fourth, the method using the forward career loss information, the reverse burden situation information ACK ratio information:

Hereinafter, the fourth method will be described in detail with reference to FIG. 11.

FIG. 11 illustrates a method in which a terminal located in a soft handover region finally selects an optimal scheduling cell or an optimal scheduling base station using the above-listed information.
Referring to FIG. 11, in step 1101, the terminal compares path loss values of forward path loss values of all cells included in the activity combination and selects at least one cell having the smallest path loss value among the cells. In performing the step 1101, cells having the same path loss value may exist according to the quantization method of the path loss values. Therefore, in step 1102, the terminal determines whether the number of cells having the minimum path loss value is one. When the number of cells having the minimum path loss value is one, the terminal manages the cell having the minimum path loss value as in step 1103. The base station is selected as the optimal scheduling base station.

When the number of cells with the minimum career loss value is one or more in step 1102, the UE has at least one of the highest reverse burden conditions, that is, the maximum RoT value Max RoT, among the cells having the minimum career loss value in step 1104. Select the cell of. Similarly, since there may be cells having a maximum RoT value, the UE determines whether the number of cells having the maximum RoT value is one in step 1105. When there is only one cell having the maximum RoT value in the comparison of step 1105, the UE selects a base station that manages the cell having the maximum RoT value as an optimal scheduling base station as in step 1106. On the contrary, when there is more than one cell having the maximum RoT value in step 1105, the UE compares the ratios of ACKs for the cells having the maximum RoT value in step 1107 and selects the base station of the cell having the largest ACK rate. Select as the scheduling base station.
In the above, a case in which a base station managing a specific cell is selected as an optimal scheduling base station has been described. As another embodiment, the terminal may select the specific cell as an optimal scheduling cell. In the above, the process of selecting an optimal scheduling cell on a cell basis has been described. However, unlike the above method, it is possible to find an optimal scheduling base station from the viewpoint of the base station. A detailed method thereof will be described with reference to FIG. 11.

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Since the uplink signals received from several cells managed by one base station are soft-combined at the base station, the terminal can enumerate the path loss value in each base station unit. That is, the terminal calculates the path loss value of the base station by using the sum of the path loss values for all the cells belonging to the base station. Then, in step 1101, the base station having the lowest total path loss value is found, and in step 1102, it is determined whether the number of base stations having the lowest sum path loss value is 1.

When the number of base stations having the lowest total path loss value is 1 in step 1102, the terminal determines the base station having the lowest sum path loss value as the optimal scheduling base station in step 1103. If the number of base stations having the lowest total path loss value is greater than 1 in step 1102, the process after step 1104 is performed as described above.
In performing the procedure shown in FIG. 11, the UE needs information on which base station each cell belonging to the activity combination belongs to. That is, the path loss values of a plurality of cells belonging to the same base station can be summed as described above only when the base stations to which the cells belong are known. To this end, the SRNC for controlling the terminal delivers information on the base station to which each cell belonging to the activity combination to the terminal using an RRC message.

In the above-described embodiments of the present invention, the optimal scheduling base station / cell is selected in order of forward path loss information, backward burden situation information, and ACK rate information. However, the present invention is applied to the above information according to a system designer's selection. It does not exclude that the order may vary. In another embodiment, an optimal scheduling base station / cell may be selected based on only a part of the information presented above. That is, the terminal may select an optimal scheduling base station / cell by using at least one of the forward path loss information, the backward burden situation information, and the ACK rate information.

Fifth, a weighted combination of forward career loss information, backward burden situation information, and ACK rate information is used:

Hereinafter, the fifth method will be described in detail using the apparatus shown in FIG. 12.

In FIG. 12, the UE determines a forward path loss value 1201, a reverse burden situation information (ie, a RoT value) 1202, an ACK ratio value 1203 among ACK / NACK signals, and other criteria for each cell belonging to an activity combination. The sum of the values 1204 is obtained. In this case, as shown in FIG. 12, the career loss value 1201 is multiplied by the weight W1 1205 in the multiplier 1206, and the reverse burden situation information (RoT value) 1202 is the weight W2 1207 in the multiplier 1208. Getting multiplied. The ratio value 1203 of the ACK is multiplied by the weight W3 1209 in the multiplier 1210, and the other reference value 1204 is multiplied by the weight W4 1211 in the multiplier 1212. At this time, the RoT value 1202 and the ratio value 1203 of the ACK are proportional to the scheduling priority, but since the forward path loss value is inversely proportional to the scheduling priority, the weight W1 1205 is different from the other weights 1207 and 1209. May have a negative value otherwise. In other cases, the inverse of the forward path loss value may be input to the multiplier 1206.

The priority calculator 1213 obtains a weighted sum by summing values multiplied by the weights, and inputs the priority 1214 of the corresponding cell according to the weighted sum to an optimal scheduling cell selector 1217 that selects an optimal scheduling base station. . The optimal scheduling cell selector 1217 receives a priority 1214, 1215, 1216 for all cells belonging to the activity combination of the terminal, and compares the weighted sums 1214, 1215, 1216 with the highest priority. A base station that manages a cell having a is selected as an optimal scheduling base station. Alternatively, the cell having the highest weighted sum is selected as an optimal scheduling cell.
In another embodiment, the terminal obtains a weighted sum of the career loss value summed for the cells of each base station, the summed RoT value and the summed ACK rate value, and compares the weighted sums obtained for the plurality of base stations to obtain a maximum. A base station having a weighted sum of is selected as an optimal scheduling cell.
The optimal scheduling cell selector 1217 transfers information indicating the optimal scheduling cell selected according to the method illustrated in FIG. 12 or one of the other methods described above to the E-DCH transmitter 1219 and the control information transmitter 1221. The control information transmitter 1221 notifies the optimal scheduling cell information to a plurality of cells communicating with the terminal, and the E-DCH transmitter 1219 recognizes the optimal scheduling cell and the non-optimal scheduling cells according to the optimal scheduling cell information. The E-DCH transmission rate is determined according to scheduling allocation information or rate grant information received from the optimal scheduling cell and the non-optimal scheduling cells, and the E-DCH data is transmitted.
2. Notification of the optimal scheduling cell / base station ID

In the above, the elements and methods for selecting the optimal scheduling base station proposed by the present invention have been described. Hereinafter, a method of notifying an optimal scheduling base station determined by a terminal located in the soft handover region will be described.

First, in selecting the optimal scheduling base station, an optimal scheduling cell is first selected. The terminal informs the system of the cell ID of the optimal scheduling cell using the cell ID, and the system selects a cell that matches the cell ID of the optimal scheduling cell. The base station may be determined as an optimal scheduling base station. For this purpose, signaling for configuring cell IDs is first required. That is, when the terminal and the base stations have the same cell ID, the terminal can inform the system of the optimal scheduling cell or the optimal scheduling base station using the cell ID.

A signaling process for setting the cell ID will be described with reference to FIG. 13.

Referring to FIG. 13, the terminal 1301 is in a transceiving relationship with a cell belonging to the base station 1302, and the base station 1302 is connected to the DRNC 1303 through an Iub connection and controls the terminal 1301. 1304 makes an Iur connection with the DRNC 1303. In order to configure the E-DCH, the SRNC 1304 sends a RADIO LINK SETUP REQUEST message 1310 for RNSAP (Radio Network Subsystem Application Part protocol) signaling to the DRNC 1303, and the DRNC 1303 sends the RADIO LINK SETUP REQUEST message. Information included in 1310 is transmitted to the base station 1302 through the RADIO LINK SETUP 1311 for NBAP signaling. The RADIO LINK SETUP messages 1310 and 1311 include cell information about cells with which the terminal 1301 can communicate. The cell information includes cell IDs of the cells.

The base station receiving the RADIO LINK SETUP message 1311 sends a response to the DRNC 1303 through a RADIO LINK SETUP RESPONSE message 1312, which is an NBAP message, and the DRNC 1303 sends a RADIO for RNSAP signaling to the SRNC 1304. Reply with a LINK SETUP RESPONSE message 1313. The process is the same for all cells included in the activity combination that the terminal 1301 has.
Subsequently, the SRNC 1304 uses the RADIO BEARER SETUP message 1314 for RRC signaling to inform the terminal 1301 of a cell ID of each cell included in the activity combination of the terminal 1301. Informs the cell IDs assigned to the cells. The terminal 1301 transmits a RADIO BEARER SETUP COMPLETE message 1315 for the RRC signaling to the SRNC 1304, thereby completing the setup of the cell ID.
Subsequently, the SRNC 1304 controlling the terminal 1301 uses an RRC message such as the RADIO BEARER SETUP 1314 of FIG. 13 to obtain information about a base station to which each cell included in the activity combination of the terminal 1301 belongs. To deliver to the terminal.

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The process of selecting an optimal scheduling cell or an optimal scheduling base station has been described above. After the selection of the optimal scheduling cell or the optimal scheduling base station, when the terminal selects the cell ID of the optimal scheduling cell or the base station ID of the optimal scheduling base station using various methods described below, the base station with which the terminal is communicating Tell them.

In a first method, the UE transmits an optimal scheduling cell ID or an optimal scheduling base station ID to base stations using an existing dedicated physical control channel (DPCCH). A terminal device for delivering an optimal scheduling cell ID or an optimal scheduling base station ID determined by a terminal to a base station using a DPCCH will be described with reference to FIG. 14.
Referring to Fig. 14, an optimal scheduling cell / base station ID selector 1401 selects an optimal scheduling cell ID or an optimal scheduling base station ID, and the cell ID / base station ID is selected by the encoder 1402 to give robustness in a channel. Channel coding. The encoded signal is multiplexed with the pilot signal 1403, the power control signal 1404, the other signals 1405, etc. in the multiplexer 1406 to form the DPCCH 1407. The DPCCH data 1407 together with Dedicated Physical Data Channel (DPDCH) data 1408, Enhanced DPCCH (E-DPCCH) 1409, and Enhanced Dedicated Physical Channel (E-DPDCH) 1410 in the multiplexer 1411. Multiplexed and modulated via modulator 1412 and then transmitted back to the base station by transmitter 1413. Here, the E-DPDCH is a physical channel to which the E-DCH is mapped, and the E-DPCCH is control information for the E-DCH, for example, a physical channel carrying a transmission parameter for the E-DPDCH.

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In a second method, the UE transmits an optimal scheduling cell ID or an optimal scheduling base station ID using an enhanced dedicated physical control channel (E-DPCCH). The E-DPCCH is a reverse channel for transmitting control information for the E-DCH, and information included in the E-DPCCH may include HARQ information and transport block size (TBS) information.

A terminal device that delivers an optimal scheduling cell ID or an optimal scheduling base station ID determined by a terminal to an eNB using E-DPCCH will be described with reference to FIG. 15.
Referring to Fig. 15, an optimal scheduling cell / base station ID selector 1501 selects an optimal scheduling cell ID, or an optimal scheduling base station ID, and the cell ID / base station ID is an encoder 1502 to give robustness in a channel. In channel encoding. The coded signal is multiplexed in the multiplexer 1506 together with HARQ related information 1503, TBS information 1504, other control information 1505, and the like to form E-DPCCH data 1507. The E-DPCCH data 1507 is multiplexed in the multiplexer 1511 together with the DPCCH data 1508, the DPDCH data 1509, and the E-DPDCH data 1510 and modulated via the modulator 1512, and then the transmitter ( Backward transmission to the base station.

In a third method, the optimal scheduling cell ID or the optimal scheduling base station ID is included in the E-DCH MAC-e Protocol Data Unit (PDU) and transmitted. The MAC structure of the E-DCH is shown in FIG.

Referring to FIG. 16, the MAC-e SDU 1602, which is a user data portion, is combined with a MAC-e header 1601 including HARQ or scheduling related information to form a MAC-e PDU 1604. That is, the MAC-e header 1601 should be understood as a part including all the information except for user data, rather than information located in the header of the MAC-e PDU 1604. The MAC-e PDU 1604 is combined with the CRC 1603 to become a code block (code block (s)) 1605 used in the physical layer. In this case, the terminal includes the optimal scheduling cell ID or the optimal scheduling base station ID in the MAC-e header 1601 and transmits it. The base station receives the MAC-e header 1601 and decodes the base station to include the optimal scheduling cell. Or to become an optimal scheduling base station. In this way, when the MAC-e PDU is used, the control information transmitter for transmitting the optimal scheduling base station ID coincides with the E-DCH transmitter.
3. Perform Scheduling

Hereinafter, after a UE located in a soft handover region selects and signals an optimal scheduling cell or an optimal scheduling base station, specific scheduling operations of the optimal scheduling base station and the non-optimal scheduling base station will be described. As described above, the optimal scheduling base station has the greatest authority in scheduling of the terminal located in the soft handover area. That is, the optimal scheduling base station may use scheduling allocation information for time rate scheduling or rate grant for rate scheduling, and may also use scheduling allocation information for time rate scheduling and rate grant for rate scheduling.

On the other hand, a non-optimal scheduling base station that is included in the activity combination of the terminal but is not an optimal scheduling base station does not have great authority in scheduling of the terminal. That is, the non-optimal scheduling base station performs passive scheduling to minimize the influence of the terminal rather than actively allocating its uplink resources to the terminal. A scheduling method for a soft handover terminal of a non-optimal scheduling base station will be described below. In the following description, an optimal scheduling base station transmits scheduling allocation information for convenience of description.

The non-optimal scheduling base station receives the reverse signal from the terminal located in the soft handover area, but is not significantly affected by the reverse reception compared to the optimal scheduling base station. Therefore, the scheduling that takes into account such resource situation of the non-optimal scheduling base station will be described.

The first method uses a method in which a non-optimal scheduling base station schedules using a 1-bit signal that can represent two pieces of information. In more detail, the non-optimal scheduling base station transmits one bit of scheduling grant information that may indicate Don't Care information and DOWN information to terminals located in the soft handover area.

If the scheduling grant received from the non-optimal scheduling base station means disregard information, the terminal determines the data rate of the E-DCH using only scheduling allocation information of the optimal scheduling base station. On the contrary, if the scheduling grant received from the non-optimal scheduling base station means down information, the terminal ignores the scheduling allocation information of the optimal scheduling base station and reduces the transmission rate of the E-DCH by one step.
The scheduling grant is transmitted using one bit. At this time, a non-transmitting (DTX) method is used for information having the highest probability of occurrence. That is, if the disregarding information is more likely to occur than the lowering information, the non-optimal scheduling base station does not transmit the scheduling grant through the physical channel, thereby indicating the disregarding information as' 0 'value, and the down information is'+1' or '- Transmit to physical channel using 1 'value. If the probability of occurrence of the falling information is greater, the above method may be applied in reverse.

When two or more non-optimal scheduling base stations exist, the terminal receives two or more scheduling grants. The terminal combines the two or more scheduling grants received in the following manner to determine the final scheduling grant.
In the case of using the OR of "DOWN" method, if any one of the received scheduling grants is DOWN information, the terminal determines that the last scheduling grant is DOWN. In another method, when the weighted sum method is used, the terminal multiplies and sums scheduling grant values received from non-optimal scheduling base stations by weights set for the respective base stations, and then a weighted combined scheduled grant of the scheduling grant is added. The final scheduling grant is determined based on whether it is ignored or decremented. In this case, the scheduling grant value multiplied by the weight set for each base station is a soft decision value representing a real number or a hard decision value representing an integer.

The second method uses a scheduling method using a 1-bit signal that the non-optimal scheduling base station can represent three pieces of information. In more detail, the non-optimal scheduling base station transmits 1-bit scheduling grant information indicating don't care information, down information, and boundary information to terminals located in the soft handover area. .

If the scheduling grant received from the non-optimal scheduling base station means disregard information, the terminal determines the data rate of the E-DCH using only scheduling allocation information of the optimal scheduling base station. On the contrary, if the scheduling grant received from the non-optimal base station means down information, the terminal ignores the scheduling of the optimal scheduling base station and reduces the transmission rate of the E-DCH by one step. In addition, if the scheduling grant received from the non-optimal scheduling base station means boundary information, the terminal determines whether to reduce the transmission rate of the E-DCH by one step through a probabilistic method. That is, the terminal generates a random value and, when the random value is larger than the first preset reference value, follows the scheduling of the optimal scheduling base station. When the terminal is smaller than the preset second reference value, the UE reduces the transmission rate of the E-DCH by one step. If the random value is between the first reference value and the second reference value, the transmission rate of the E-DCH is maintained.
The scheduling grant is transmitted using one bit. In this case, information with the highest probability of occurrence is represented as DTX. That is, if the ignore signal is more likely to occur than the other information, the non-optimal scheduling base station does not transmit the scheduling grant through the physical channel to indicate the ignore information as a value of '0', the down information is '+1', The economic information is transmitted to the physical channel using a value of '-1'. If the probability of occurrence of half name falling information or boundary information is large, the information of the largest probability is indicated as untransmitted.

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When two or more non-optimal scheduling base stations exist, the terminal receives two or more scheduling grants. The terminal combines the two or more scheduling grants in the following manner to determine the final scheduling grant.

First, we use the OR of Worst method. That is, if any one of the received scheduling grants is DOWN, the terminal determines the last scheduling grant as DOWN. If any of the scheduling grants is border information, the terminal determines the final scheduling grant as 'boundary'. The final scheduling grant is determined to be 'ignored'.

Secondly, we use the weighted sum method. The terminal multiplies and adds the scheduling grant values received from the non-optimal scheduling base stations by multiplying the weights set for the respective base stations and then final scheduling grant depending on whether the weighted combined scheduling grant value is ignored, lowered, or bounded. Judge. At this time, the scheduling grant value multiplied by the weight set for each base station is a soft decision value representing a real number or a hard decision value representing an integer.
The method of the present invention described above may be somewhat specific, but is not limited to the above description, and 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 method described above, but should be defined not only by the scope of the following claims, but also by those equivalent to the scope of the claims.

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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 provides a method for efficiently scheduling a terminal located in a soft handoff area in performing a rate scheduling for reverse packet transmission in an asynchronous WCDMA communication system using an E-DCH. A method of selecting an optimal scheduling base station using a loss delay, a reverse burden situation, HARQ information, and the like among base stations belonging to an activity combination of a terminal is provided. In addition, the present invention provides a method for the UE to transmit the selected optimal scheduling base station.

Claims (45)

A method for transmitting reverse packet data by a terminal communicating with a plurality of cells by soft handover in a mobile communication system supporting enhanced reverse packet data service, Selecting an optimal scheduling cell for scheduling the reverse packet data service of the terminal according to at least one of forward path loss information, backward burden situation information, and ratio information of a positive response signal (ACK); Notifying the plurality of cells of information indicating the selected optimal scheduling cell; Receiving rate grant information for transmission of reverse packet data from the selected optimal scheduling cell and the unselected non-optimal scheduling cells of the plurality of cells; And transmitting the reverse packet data to the plurality of cells according to the rate grant information. Claim 2 was abandoned when the setup registration fee was paid. The method of claim 1, wherein the reverse packet data service, The method of claim 1, wherein the method is performed through an enhanced uplink dedicated channel (E-DCH) of a wideband code division multiple access (WCDMA) system. The method of claim 1, wherein the forward path loss information, And calculating a difference value between a received signal code power (RSCP) measured for a common control pilot channel (CPICH) transmitted by the plurality of cells and a transmit power of the CPICH. According to claim 1, The reverse burden situation information, The method represents a Root Over Thermal (RoT) value of the plurality of cells and is received from the plurality of cells to the terminal through a broadcast channel (BCH) or a dedicated channel (DCH). The method of claim 1, wherein the ratio information of the ACK, And for each of the plurality of cells, is calculated as a ratio value of the ACK among the positive response signal (ACK) and the negative response signal (NACK) received for the reverse packet data service. The method of claim 1, wherein the selecting process comprises: Obtain weighted sums for the plurality of cells by applying a predetermined weight to at least two of the forward path loss information, the backward burden situation information and the ratio information of the ACK, and obtain the highest priority according to the weighted sums. And selecting the cell having the optimal scheduling cell. The method of claim 1, wherein the selecting process comprises: And selecting the optimum scheduling cell by sequentially applying the forward path loss information, the backward burden situation information, and the ratio information of the ACK. The method of claim 1, wherein the notifying process comprises: And transmitting a cell ID indicating the selected optimal scheduling cell to the plurality of cells through a dedicated physical control channel (DPCCH). Claim 9 was abandoned upon payment of a set-up fee. The method of claim 1, wherein the notifying process comprises: And transmitting a cell ID indicating the selected optimal scheduling cell to the plurality of cells over an enhanced dedicated physical control channel (E-DPCCH) for the reverse packet data service. The method of claim 1, wherein the notifying process comprises: And a cell ID indicating the selected optimal scheduling cell is transmitted to the plurality of cells in a medium access control protocol data unit (MAC-e PDU) for the reverse packet data service. The method of claim 1, wherein the transmitting step comprises: Determining a final scheduling grant by combining Rake grant values representing rate grant information received from the non-optimal scheduling cells; If the last scheduling grant indicates DOWN, reducing the reverse rate for the reverse packet data service by one step; Controlling the uplink rate according to rate grant information received from the optimal scheduling cell when the last scheduling grant does not indicate a fall or when the rate grant values are not received from the non-optimal scheduling cells; And transmitting the reverse packet data to the plurality of cells using the reverse rate. 12. The method of claim 11, wherein if any one of the rate grant values received from the non-optimal scheduling cells indicates a round, the final scheduling grant is determined to be round. 12. The method of claim 11, wherein when the weighted sum of the scheduling grants calculated by applying preset weights for cells corresponding to rate grant values received from the non-optimal scheduling cells indicates a decrease, the final scheduling grant is determined to be rounded down. Said method, characterized in that. The method of claim 1, wherein the transmitting of the Determining a final scheduling grant by combining rate grant values representing rate grant information received from the non-optimal scheduling cells; If the last scheduling grant indicates DOWN, reducing the reverse rate for the reverse packet data service by one step; If the last scheduling grant indicates Don't Care or fails to receive the rate grant values from the non-optimal scheduling cells, controlling an annoying reverse rate according to the rate grant information received from the optimal scheduling cell and, When the last scheduling grant indicates marginal, controlling the uplink rate or reducing the uplink rate by one step according to rate grant information received from the optimal scheduling cell probably according to predetermined reference values and, And transmitting the reverse packet data to the plurality of cells using the reverse rate. 15. The method of claim 14, wherein the final scheduling grant is determined to be down when any of the rate grant values received from the non-optimal scheduling cells indicate a round down, and the last scheduling when any of the rate grant values indicates a boundary. The grant is determined as a boundary, and the final scheduling grant is determined to be ignored if all of the rate grant values indicate ignore. 15. The method of claim 14, wherein the final scheduling grant is lowered, bounded, or ignored according to a weighted sum of the scheduling grants calculated by applying preset weights for cells corresponding to rate grant values received from the non-optimal scheduling cells. Determining said method. A terminal apparatus for communicating with a plurality of cells by soft handover and transmitting reverse packet data in a mobile communication system supporting enhanced reverse packet data service, An optimal scheduling cell selector for selecting an optimal scheduling cell for scheduling the reverse packet data service of the terminal according to at least one of forward path loss information, backward burden situation information, and ratio information of a positive response signal; A control information transmitter for transmitting identification information indicating the selected optimal scheduling cell to the plurality of cells; Receiving rate grant information for transmission of reverse packet data from the selected optimal scheduling cell and non-selected non-optimal scheduling cells of the plurality of cells, and transmitting the reverse packet data to the plurality of cells according to the rate grant information And the data transmitter. Claim 18 was abandoned upon payment of a set-up fee. The method of claim 17, wherein the reverse packet data service, The apparatus of claim 1, wherein the apparatus is performed through an enhanced uplink dedicated channel (E-DCH) of a wideband code division multiple access (WCDMA) system. The method of claim 17, wherein the forward path loss information, And calculating a difference value between a received signal code power (RSCP) measured for a common control pilot channel (CPICH) transmitted by the plurality of cells and a transmit power of the CPICH. The method of claim 17, wherein the reverse burden situation information, The apparatus represents a rise over thermal (RoT) value of the plurality of cells and is received from the plurality of cells to the terminal through a broadcast channel (BCH) or a dedicated channel (DCH). The method of claim 17, wherein the ratio information of the ACK, And for each of the plurality of cells, calculated as a ratio value of the ACK among the positive response signal (ACK) and the negative response signal (NACK) received for the reverse packet data service. The method of claim 17, wherein the optimal scheduling cell selector, Obtain weighted sums for the plurality of cells by applying a predetermined weight to at least two of the forward path loss information, the backward burden situation information and the ratio information of the ACK, and obtain the highest priority according to the weighted sums. And the cell having the optimal scheduling cell. The method of claim 17, wherein the optimal scheduling cell selector, And the optimal scheduling cell is selected by sequentially applying the forward path loss information, the backward burden situation information, and the ratio information of the ACK. The method of claim 17, wherein the control information transmitter, And transmitting a cell ID indicating the selected optimal scheduling cell to the plurality of cells through a dedicated physical control channel (DPCCH). Claim 25 was abandoned upon payment of a registration fee. The method of claim 17, wherein the control information transmitter, And transmitting a cell ID indicating the selected optimal scheduling cell to the plurality of cells over an enhanced dedicated physical control channel (E-DPCCH) for the reverse packet data service. The method of claim 17, wherein the control information transmitter, And a cell ID indicating the selected optimal scheduling cell is transmitted to the plurality of cells in a medium access control protocol data unit (MAC-e PDU) for the reverse packet data service. The method of claim 17, wherein the data transmission unit, Combining rate grant values indicative of rate grant information received from the non-optimal scheduling cells to determine a final scheduling grant, If the last scheduling grant indicates DOWN, reduce the reverse rate for the reverse packet data service by one step, If the last scheduling grant does not indicate a fall or if the rate grant values have not been received from the non-optimal scheduling cells, the reverse rate is controlled according to rate grant information received from the optimal scheduling cell, And the reverse packet data is transmitted to the plurality of cells using the reverse rate. The method of claim 27, wherein the data transmission unit, And if any one of the rate grant values received from the non-optimal scheduling cells indicates a round down, the final scheduling grant is determined to be round down. 28. The method of claim 27, wherein when the weighted sum of the scheduling grants calculated by applying preset weights for cells corresponding to rate grant values received from the non-optimal scheduling cells indicates a decrease, the final scheduling grant is determined to be rounded down. Said method, characterized in that. 18. The apparatus of claim 17, wherein the data transmission unit Combining rate grant values indicative of rate grant information received from the non-optimal scheduling cells to determine a final scheduling grant, If the last scheduling grant indicates DOWN, reduce the reverse rate for the reverse packet data service by one step, If the last scheduling grant indicates Don't Care or fails to receive the rate grant values from the non-optimal scheduling cells, control an annoying reverse rate according to the rate grant information received from the optimal scheduling cell, If the last scheduling grant indicates a margin, the reverse rate is controlled or the reverse rate is reduced by one step according to rate grant information received from the optimal scheduling cell probably according to predetermined reference values, And the reverse packet data is transmitted to the plurality of cells using the reverse rate. The method of claim 30, wherein the data transmission unit, If any one of the rate grant values received from the non-optimal scheduling cells indicates a round down, the final scheduling grant is determined to be rounded down, and if any of the rate grant values indicates a border, the last scheduling grant is determined as a border. And determining that the last scheduling grant is to be ignored if all of the rate grant values indicate to ignore. The method of claim 30, wherein the data transmission unit, According to a weighted sum of scheduling grants calculated by applying preset weights for cells corresponding to rate grant values received from the non-optimal scheduling cells, the final scheduling grant is determined to be lowered, bounded or ignored. The device. A method for receiving a reverse packet data from a terminal by a base station communicating with a terminal in soft handover in a mobile communication system supporting enhanced reverse packet data service, Receiving, from the terminal, information indicating a selected optimal scheduling cell among a plurality of cells with which the terminal communicates, wherein the optimal scheduling cell includes forward path loss information, backward burden situation information, and a positive response signal (ACK); Selected by the terminal according to at least one of ratio information of Transmitting rate grant information indicating a transmission rate allocated for transmission of reverse packet data to the terminal through the selected optimal scheduling cell or the unselected non-optimal scheduling cells according to the optimal scheduling cell information; And receiving the reverse packet data according to the rate grant information from the terminal. Claim 34 was abandoned upon payment of a registration fee. The method of claim 33, wherein the reverse packet data service, The method of claim 1, characterized in that it is performed through an enhanced uplink dedicated channel (E-DCH) of a wideband code division multiple access (WCDMA) system. The method of claim 33, wherein the forward path loss information, And calculating a difference value between a received signal code power (RSCP) measured for a common control pilot channel (CPICH) transmitted by the plurality of cells and a transmit power of the CPICH. The method of claim 33, wherein the reverse burden situation information, Representing a rise over thermal (RoT) value of the plurality of cells, characterized in that received from the plurality of cells to the terminal via a broadcast channel (BCH) or a dedicated channel (DCH). The method of claim 33, wherein the ratio information of the ACK, And for each of the plurality of cells, is calculated as a ratio value of the ACK among the positive acknowledgment signal (ACK) and the negative acknowledgment signal (NACK) received for the reverse packet data service. 34. The method of claim 33, wherein receiving the optimal scheduling cell information comprises: And receiving a cell ID indicating the selected optimal scheduling cell from the terminal through a dedicated physical control channel (DPCCH). Claim 39 was abandoned upon payment of a registration fee. 34. The method of claim 33, wherein receiving the optimal scheduling cell information comprises: And receiving a cell ID indicating the selected optimal scheduling cell from the terminal through an enhanced dedicated physical control channel (E-DPCCH) for the reverse packet data service. 34. The method of claim 33, wherein receiving the optimal scheduling cell information comprises: And receiving a cell ID indicating the selected optimal scheduling cell from the terminal through a medium access control protocol data unit (MAC-e PDU) for the reverse packet data service. The method of claim 33, wherein the transmitting step, And transmitting rate grant information indicative of the allocated transmission rate through the optimal scheduling cell. 42. The method of claim 41, wherein the transmitting step, And transmitting rate grant information indicating DOWN or Don't Care through the non-optimal scheduling cells, according to the assigned transmission rate. 42. The method of claim 41, wherein the transmitting step, And transmitting rate grant information indicating DOWN, Don't Care, or Marginal through the non-optimal scheduling cells according to the assigned transmission rate. An apparatus for receiving uplink packet data from a terminal in a node ratio communicating with a terminal performing soft handover in a mobile communication system supporting an enhanced reverse packet data service, Receiving, from the terminal, information indicating a corresponding optimal scheduling cell selected by the terminal according to at least one of forward path loss and reverse burden situation information and ratio information of an ACK among the plurality of cells communicating with the terminal. An optimum scheduling cell for transmitting rate grant information indicating a transmission rate allocated for transmission of the uplink packet data to the terminal; Receiving, from the terminal, information indicating a corresponding optimal scheduling cell selected by the terminal according to at least one of forward path loss and reverse burden situation information and ratio information of an ACK among the plurality of cells communicating with the terminal. And a non-optimal scheduling cell that transmits rate grant information indicating don't care or down to the terminal. The method of claim 44, wherein the disregarding information, The terminal instructing the terminal to follow the rate grant information of the optimal scheduling cell.

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