KR20070101889A - Apparatus and method for efficient node b scheduling in mobile telecommunication system - Google Patents

Abstract

An effective base station scheduling method and apparatus in a mobile communication system are provided to allow UE(User Equipment) to add an indicator indicating final packet re-transmission in control information and transmit it so that it is prevented that a base station allocates resources in advance. A UE(505) sets a final re-transmission indicator of packet decoding information as No and transmits it(515), and transmits a packet(520). A Node B(510) demodulates and decodes the packet, and performs CRC calculation(525). The UE(505) transmits packet decoding control information with respect to a packet re-transmitted according to a NACK(Non-ACKnowledged) signal received from the Node B(510)(530). The UE(505) packets a packet and the Node B(510) demodulates the packet, soft-combines it with a packet stored in an HARQ(Hybrid Automatic Retransmission reQuest) processor, and performs CRC(Cyclic Redundancy Check) calculation again(535). The Node B(510) determines that the packet has an error and transmits NACK to the UE(505)(540). The UE(505) prepares re-transmission of a packet, compares the set maximum re-transmission number of packets and the current transmission number, and sets a final re-transmission indicator(545). The UE sets the final re-transmission indicator of the packet decoding control information as Yes and transmits it(550). The UE(505) executes the final re-transmission of the packet(555). Upon receiving the packet decoding control information, the Node B(510) recognizes that the packet is finally re-transmitted and does not allocate resources(560).

Description

Apparatus and method for efficient Node B scheduling in mobile telecommunication system

1 is a diagram illustrating an example of wireless communication using a common channel to which the present invention is applied.

2 is a diagram illustrating a structure of a transmitting side and a receiving side performing HARQ.

3 illustrates a problem of the prior art when asynchronous HARQ operation.

4 illustrates a problem of the prior art when synchronous HARQ operation.

5 is a signal flow diagram of an overall system for transmitting an indicator indicating whether or not a last retransmission is in accordance with the present invention.

6A and 6B illustrate an example implementation of a last retransmission indicator in accordance with the present invention.

7 is a diagram illustrating a process of transmitting a last retransmission indicator of a transmitter according to the present invention.

8 shows the structure of a transmitter according to the invention. FIG. 9 shows the structure of a receiver according to the invention.

The present invention relates to a mobile communication system, and more particularly, to an efficient base station scheduling method and apparatus.

UMTS (Universal Mobile Telecommunication Service) system is based on the European mobile communication system Global System for Mobile Communications (GSM) and General Packet Radio Services (GPRS), and Wideband Code Division Multiple Access: Third generation asynchronous mobile communication system using " CDMA. &Quot;

The 3rd Generation Partnership Project (3GPP), which is in charge of UMTS standardization, is discussing Long Term Evolution (LTE) as the next generation mobile communication system for UMTS systems. LTE is a technology that implements high-speed packet-based communication of about 100 Mbps, aiming for commercialization in 2010. To this end, various methods are discussed. For example, the network structure can be simplified to reduce the number of nodes located on the communication path, or the wireless protocols can be as close to the wireless channel as possible. As a result, the structure of LTE is expected to change from the existing four-node structure to a two-node or three-node structure. For example, it can be simplified to a two-node structure of a next-generation base station (hereinafter referred to as 'Node B' or 'base station') and a gateway node.

In an LTE system, Node B is connected to a user equipment (hereinafter referred to as UE or UE) via a wireless channel, and collects situation information of the UE to perform scheduling. In addition, Node B performs a hybrid automatic retransmission request (Hybrid ARQ (hereinafter referred to as "HARQ")) with the terminal to prevent the loss of data transmitted. LTE to implement a transmission rate of up to 100 Mbps Orthogonal Frequency Division Multiplexing (hereinafter referred to as 'OFDM') in a 20 MHz bandwidth is used as a wireless access technology, and a modulation scheme and a channel coding rate according to the channel state of the terminal. Adaptive Modulation & Coding (hereinafter, referred to as 'AMC') is applied.

In LTE, all traffic is served through a common channel. The shared channel means a channel shared by several terminals, and the shared channel is dynamically allocated according to the channel condition or the buffer condition of the terminal. Transmitting / receiving data through a common channel involves three stages: buffer status reporting, channel allocation, and data transmission over the assigned channel. If this is described in more detail as shown in FIG.

1 is a diagram illustrating an example of wireless communication using a common channel in a next generation mobile communication system to which the present invention is applied.

Referring to FIG. 1, in order to transmit a packet, in step 111, the terminal 105 transmits a buffer status or a channel state (UE) of the UE to the base station 110 through a shared channel (SCH). Channel Quality Information, hereinafter referred to as 'CQI'). In step 112, the base station 110 allocates radio resources (hereinafter, referred to as "resource") to the terminals based on the buffer state reported from the plurality of terminals and the channel state. The allocated resource is notified to the terminal through a downlink shared control channel (hereinafter, referred to as 'DL-SCCH'). In the DL-SCCH, which resource is allocated to which UE.

In step 115, the terminal 105 allocated the resource transmits data in the reverse direction using the resource. At this time, prior to transmitting data, packet decoding control information is transmitted first. The packet decoding control information includes packet size, modulation and channel coding information, HARQ related information, and the like. In step 120, the terminal 105 transmits user data through a reverse common channel, and the user data is transferred between the terminal 105 and the base station 110 through a HARQ process.

Here, HARQ is a technique for temporarily storing the previously received data in a buffer without discarding it, and requesting retransmission from the base station 110 to soft combine the retransmitted data and the temporarily stored data. This is a technique for the base station 110 to increase the success rate of receiving reverse data.

Therefore, in step 120, when the base station (receiving side, 110) receives the HARQ packet, the base station (receiving side, 110) refers to the packet decoding control information received in the previous step 115, and after decoding the HARQ packet, checks whether the packet has an error do. In step 125, an acknowledgment (NACK) signal / negative acknowledgment (NACK) signal is transmitted to the transmitter according to the presence of the error.

Thereafter, the terminal 105 retransmits the HARQ packet or transmits a new HARQ packet according to the ACK / NACK signal.

2 is a diagram illustrating a structure for performing HARQ between a transmitting side and a receiving side. In the reverse packet service to which the present invention is applied, the terminal is the transmitting side and the base station plays the role of the receiving side. On the other hand, in a general forward packet service, a terminal serves as a receiving side and a base station serves as a transmitting side.

Referring to FIG. 2, since various types of services may be provided to one terminal, the transmitting side includes a plurality of higher layer entities 280 and a multiplexing block 275, and the receiving side includes a plurality of higher layer entities. 205 and demultiplexing block 210. The upper layers 205 and 280 may be regarded as, for example, a set of services requiring the same quality of service. For convenience of description, the flows generated in one higher layer are referred to as' QoS flows. Name it '.

The multiplexing block 275 inserts multiplexing information into data generated from various upper layers 275 and delivers the multiplexing information to the HARQ block 272. On the other hand, the demultiplexing block 210 transmits to the appropriate upper layer by using the multiplexing information of the data received from the HARQ block 212.

Here, the HARQ blocks 212 and 272 are apparatuses for performing an HARQ operation, and are composed of a plurality of HARQ processors. The HARQ processor is a basic unit that is responsible for transmitting and receiving user packets, the transmitting HARQ processor is responsible for transmitting and retransmitting user packets, and the receiving HARQ processor is responsible for receiving and soft combining user packets.

The HARQ processors exist in pairs on the transmitting side and the receiving side, and one HARQ block 212 and 272 includes a plurality of HARQ processors, thereby allowing continuous transmission and reception. The operation of the HARQ processor is composed of operations of transmitting a user packet, receiving ACK / NACK information, and performing retransmission. Therefore, as an example, when only one HARQ processor exists, other packets cannot be transmitted until user data is transmitted and ACK / NACK information thereof is received. However, when a plurality of HARQ processors are provided, since one processor may transmit data while another processor waits for ACK / NACK reception, a plurality of HARQ processors may be provided, thereby allowing continuous transmission and reception.

The basic operation of the HARQ processor is as follows.

First, the transmitting HARQ processor (any one of HARQ P1 255, HARQ P2 260, HARQ P3 265, and HARQ P4 270) transmits by channel coding data received by the multiplexing block 275. And store the channel coded data in a buffer (not shown) for later retransmission. Upon receipt of the ACK information for the data, the data stored in the buffer is flushed. If the NACK information for the data is received, the data is retransmitted.

On the other hand, the receiving HARQ processor (any one of HARQ P1 215, HARQ P2 220, HARQ P3 225, HARQ P4 230) channel decodes the data received through the physical channel, The presence of an error is checked through a cyclic redundancy check (hereinafter referred to as a 'CRC') operation for checking whether the data has an error detected. If an error exists, the data is stored in a buffer and a NACK signal is sent. When the retransmission data for the data is received later, the data stored in the buffer and the retransmitted data are soft-combined and the error is again checked. If it is confirmed that an error still exists, the NACK signal is transmitted and the above process is repeated. If it is confirmed that the error has been resolved, an ACK signal is transmitted and the user data is transmitted to the demultiplexing block 210.

The HARQ block may set the maximum number of retransmissions differently according to the required transmission quality (QoS) of the packet to be transmitted. If a packet should be sent quickly but the required block error rate (hereinafter referred to as 'BLER') is relatively high, the maximum number of retransmissions for the packet is set small. If the request transmission delay for a packet is long while the request BLER is low, the maximum number of retransmissions is set for the packet.

As described above, the maximum number of retransmissions of the HARQ packet varies depending on which QoS packet is accommodated in any HARQ packet.

In this regard, a problem of the related art is that the scheduler of Node B does not know the maximum number of transmissions of HARQ packets transmitted by the UE, and thus, transmission resources may be wasted when the last retransmission fails.

HARQ includes an asynchronous HARQ technique and a synchronous HARQ technique.

Asynchronous HARQ is a HARQ scheme where retransmission time is free because retransmission for a specific HARQ packet is notified with explicit control information. On the other hand, synchronous HARQ is a technique in which retransmission for a specific HARQ packet is always performed after a certain time has passed from a previous transmission, and there is an advantage that no explicit control information for the retransmission time point is required, It has the disadvantage of being fixed.

In forward transmission, asynchronous HARQ is suitable because the scheduler and the transmission apparatus are located in the same node, and in reverse transmission, synchronous HARQ is suitable because the scheduler and the transmission apparatus are located in different nodes.

Since the problem to be solved by the present invention relates to a reverse packet, it is highly likely that synchronous HARQ operation is applied, but there is a problem to be solved by the present invention even in asynchronous HARQ operation. 4) The problem of the prior art on HARQ, and FIG. 4 describes the problem of the prior art on synchronous HARQ.

3 is a diagram illustrating a problem of the prior art on asynchronous HARQ.

Referring to FIG. 3, the terminal transmits a HARQ packet through an uplink shared channel (305) (320). Accordingly, after processing the packet, the base station is found to be in error and transmits a negative acknowledgment signal through the down-link feedback channel 310 (325). The scheduler of the base station allocates resources to the terminal and transmits scheduling information so that the terminal can retransmit the HARQ packet (330). The terminal retransmits the HARQ packet through the allocated resource (335), and the base station soft combines the packet with the packet stored in the HARQ processor. If the error still remains, the base station transmits a negative acknowledgment signal again on the forward feedback channel (340).

In this case, it is assumed that the number of retransmissions of the HARQ packet reaches a set maximum number of retransmissions. Since the base station is not aware of the fact, it allocates resources by transmitting scheduling information to the terminal so that retransmission can be performed for the HARQ packet (345). At this time, if there is no data to be transmitted to the terminal, the resource is wasted 350.

Or, if it is assumed that there is data to be transmitted to the terminal, there is a possibility that the base station may result in scheduling based on incorrect scheduling information. This is because a retransmission packet typically has a higher priority than the original transmission packet.

4 is a diagram illustrating a problem of the prior art when driving synchronous HARQ.

Referring to FIG. 4, the UE transmits a HARQ packet on the reverse common channel 405 (425), and the base station processes the packet and then turns out to be in error, thereby recognizing it negatively through the forward feedback channel 410. The signal is transmitted (425).

The scheduler of the base station executes retransmission at a predetermined fixed timing according to a synchronous HARQ scheme, that is, reserves a predetermined resource for the terminal without allocating a predetermined resource to another terminal (445).

The terminal retransmits an HARQ packet through the predetermined resource (435). The base station soft combines the packet with the packet stored in the HARQ processor. If the error still remains, the base station transmits a negative acknowledgment signal again on the forward feedback channel (440). In this case, assume that the number of retransmissions of the HARQ packet reaches the maximum number of retransmissions. Since the base station is not aware of this fact, it reserves a predetermined resource without allocating it to another terminal so as to execute retransmission of the HARQ packet. At this time, the terminal can no longer retransmit the packet, the resource is wasted (450).

As described above, the conventional base station scheduling has a problem in that a limited resource is allocated to the terminal regardless of retransmission of the terminal. That is, in the case of synchronous HARQ, there is a problem in that a predetermined resource is allocated to the terminal for a terminal transmitting a packet with a fixed timing. In addition, in the case of asynchronous HARQ, there is a problem of allocating resources to the terminal unconditionally in response to the priority of the retransmission packet.

There is a need for an optimization method of base station scheduling to efficiently use limited resources in a mobile communication system.

Accordingly, the present invention, which was devised to solve the problems of the prior art operating as described above, provides a base station scheduling method and apparatus for efficiently performing packet transmission in a mobile communication system.

In addition, the present invention provides a base station apparatus and scheduling method for efficiently performing HARQ to variably allocate radio resources defined in a mobile communication system.

In addition, the present invention provides a method and apparatus for notifying a receiving end of packet retransmission to a receiving end in a mobile communication system.

The present invention provides an efficient base station scheduling method in a mobile communication system, the terminal transmitting packet decoding control information including an indicator indicating the last packet retransmission to the base station, the terminal retransmitting the packet, and the base station is the packet And decoding the packet using decoding control information and allocating a radio resource for retransmission of the next packet in response to the indicator.

The present invention relates to a transmission apparatus for efficiently supporting base station scheduling in a mobile communication system. And an indicator setting unit and a packet decoding control information generation unit for setting a last packet retransmission indicator according to the set value using packet control information related to the packet.

The present invention is a receiving apparatus for efficiently supporting base station scheduling in a mobile communication system, comprising: a packet decoding control information analyzing unit for analyzing control information including an indicator for notifying the last retransmission of a packet, and the packet decoding control information analyzing unit A plurality of retransmission processors for retransmitting the packet using the control information provided by the controller, and a scheduler for allocating a resource for retransmission of the packet to a transmitter according to a set value of an indicator indicating the last retransmission. It features.

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

The present invention, which will be described later, proposes an efficient base station scheduling of a mobile communication system. The present invention provides an apparatus and a method for notifying a receiving side of a last retransmission.

In addition, the present invention proposes a method for transmitting by including the last retransmission in the packet decoding control information. In addition, the present invention proposes a method for confirming whether the retransmission packet received from the transmission side is the last packet.

According to the present invention, the terminal informs the base station of the receiving side whether the terminal retransmits whether the terminal retransmits as the reverse packet is transmitted.

In addition, although the present invention has been described with reference to LTE system application, retransmission can be applied to all mobile communication systems using the operation without any significant modification.

5 is a diagram illustrating a process of transmitting control information including an indicator indicating whether a transmission side is retransmitted according to the present invention.

As an example, the present invention will be described by taking an arbitrary terminal 505 and a Node B 510 as an example. The process of allocating a resource from the Node B to the UE is not illustrated in FIG. 5 to clearly illustrate the configuration of the present invention. This is the same as steps 111 and 112 shown in FIG. 1, that is, any terminal reports its buffer status information or CQI to the base station 110 via the SCH. The base station allocates resources through the DL-SCCH based on the buffer state information and the channel state reported from a plurality of terminals.

Referring to FIG. 5, in step 515, the terminal 505 that has been allocated resources transmits packet decoding control information to the Node B 510 before transmitting any packet through a common channel. The packet decoding control information is information necessary for the receiver to decode the packet, and includes, for example, the size of the packet, the modulation scheme of the packet, the coding rate of the packet, and the retransmission number of the packet.

In the present invention, the last retransmission indicator is added to the packet decoding information. The last retransmission indicator is an identifier indicating whether the corresponding packet is the last retransmission. If set to Yes according to the present invention, the last retransmission indicator indicates that the packet is the last retransmission packet. Means resend continuously in.

In step 515, since the terminal does not transmit the last retransmission, the terminal transmits the last retransmission indicator of the packet decoding control information by setting it to No. In step 520, the terminal transmits a packet. The packet is an initial transmission.

In step 525, the base station 510 demodulates and decodes the packet and then performs CRC operation. At this time, if it is determined that there is an error in the packet according to the CRC operation result, the terminal 505 transmits a NACK.

The terminal retransmits the packet according to an instruction of the base station or at a predetermined time point. Therefore, in step 530, the terminal 505 transmits packet decoding control information for the retransmitted packet according to the NACK signal received from the base station 510. At this time, since the packet retransmission is not the last retransmission, the last retransmission indicator is set to No. In step 535, the terminal 505 transmits the packet, and the base station demodulates the packet, soft combines the packet stored in the HARQ processor, and then performs CRC operation again. In step 540, the base station 510 determines that there is an error in the packet and transmits a NACK to the terminal.

Upon receiving the NACK signal from the base station 510, the terminal prepares for retransmission of the packet in step 545, and sets the last retransmission indicator by comparing the maximum retransmission number of the packet with the current transmission count. For example, when the maximum number of retransmissions is set to two times, since the number of times of transmission is limited to the maximum number of retransmissions, in step 550, the last retransmission indicator of the packet decoding control information is set to Yes and transmitted.

In step 555, the terminal 505 executes the last retransmission of the packet.

In step 560, when the base station 510 receives the packet decoding control information in step 550, the base station 510 recognizes that the packet transmitted from the terminal 505 is the last retransmission, and thus does not allocate resources for retransmission of the packet. Prevent waste.

6A and 6B illustrate methods of setting a final retransmission indicator according to an embodiment of the present invention.

Adding 1 bit to the packet decoding control information for the last retransmission indicator increases the size of the packet decoding control information, which requires the consumption of limited transmission resources.

However, when any packet decoding control information has a plurality of code points, by using one of the code points as the last retransmission indicator, the size of the packet decoding control information may not be increased.

The number of code points means the number of logical meanings that control information can have and is determined by the number of bits allocated to the control information. For example, 4 code points of control information having a 2-bit size are 16 code points of control information having a 4-bit size.

Information having a plurality of code points among the packet decoding control information includes RSN (Retransmission Sequence Number) or RV (Redundancy Version) information.

Referring to FIG. 6A, as described above, RSN 605 is information indicating the number of transmissions of a specific HARQ packet. For example, RSN 0 610 is the first transmission, RSN 1 615 is the first retransmission, and RSN. 2 means second retransmission. When RSN has (n + 1) code points from 0 to n, RSN n 625, which is the last code point, is set to indicate the value of the last retransmission, not the nth retransmission.

That is, the maximum number of retransmissions may be greater than the code point of the RSN. For example, even if the maximum number of retransmissions of a particular flow is set to eight, only two bits may be allocated to the RSN. In this case, RSN is set as follows every time retransmission.

First transmission: RSN 0, first retransmission: RNS 1, second retransmission: RSN 2, third retransmission: RSN 3, fourth retransmission: RSN 3,... , Last retransmission: RSN 3.

From the fourth retransmission, RSN 3 continues to be used, and the receiver recognizes RSN 3 as the third or subsequent retransmissions. This is the conventional method using the RSN, and what is said in Fig. 6a means that the last code point of the RSN means the last retransmission, not the third or subsequent retransmissions. Thus, returning to the above example, the RSN is set as follows.

First transmission: RSN 0, first retransmission: RSN 1, second retransmission: RSN 2, third retransmission: RSN 2, fourth retransmission: RSN 2,... , Last retransmission: RSN 3.

As such, one code point does not indicate a specific number of retransmissions, but rather indicates that it is the last retransmission, thereby avoiding adding one bit to the last retransmission indicator. In the RSN scheme, when a code point indicating the last retransmission is transmitted, the last retransmission indicator is set to Yes, and in other cases, the last retransmission indicator is assumed to be set to No.

The same approach can be applied to RV information.

Referring to FIG. 6B, RV 630 is information indicating an IR version of a HARQ packet. For example, RV 0 635 may mean an IR version x, and RV 1 640 may mean an IR version y. . One code point is used to indicate that a particular version is the last retransmission.

For example, if the RV is n 640, this indicates that the IR version is z and that it is the last retransmission. A different value of RV indicates that this is a predetermined IR version and not the last retransmission.

There is a limitation in the above scheme that the last retransmission always uses a fixed IR version.

7 is a diagram illustrating an operation of a transmitting side according to the present invention.

Referring to FIG. 7, a new packet transmission is scheduled in step 705. In other words, the terminal has already transmitted information indicating its buffer status and channel status information to the base station, and the base station allocates a predetermined resource to the terminal based on the information. Accordingly, the terminal intends to transmit a new packet through the resource allocated from the base station.

In step 710, the terminal stores the maximum number of retransmissions of the packet in a variable called Max_retrans. The maximum number of retransmissions of a packet Max_retrans is determined according to the QoS flow to which the packet belongs. That is, if a packet is to be sent quickly but the BLER is relatively high, the maximum number of retransmissions for the packet is set small. If the request transmission delay for a packet is long while the request BLER is low, the maximum number of retransmissions is set for the packet.

In step 715, the terminal sets the current transmission number (No_retrans) to 0 according to the initial transmission of the packet, and transmits the packet in step 720.

In step 730, the terminal determines whether retransmission of the packet is necessary based on the feedback information transmitted by the base station. If retransmission is not needed, i.e., if a positive acknowledgment signal (ACK) has been received from the base station, the process proceeds to step 735 and waits until the next new packet is transmitted. On the other hand, if retransmission is needed, the process proceeds to step 740 and it is checked whether the No_retrans is equal to the configured Max_retrans. This is to determine whether the last retransmission indicator is transmitted. If No_retrans is the same as Max_retrans, the next retransmission is the last retransmission regardless of whether the transmission is successful. do. Here, setting the last retransmission indicator to 'Yes' may be implemented by the method shown in FIGS. 6A and 6B.

After that, the process proceeds to step 755 to increase No_retrans by one, and the process proceeds to step 760 to finally retransmit the packet. That is, after step 730, the packet does not need to be retransmitted, so it proceeds to step 735 and waits for transmitting the next packet. On the other hand, if the No_retrans is not equal to the set Max_retrans in step 740, the flow proceeds to step 750 to check whether the No_retrans is greater than Max_retrans. If No_retrans is greater than Max_retrans, since no further retransmission can be performed, the process proceeds to step 735 and waits until the next new packet is transmitted.

In addition, if No_retrans is smaller than Max_retrans in step 750, it means that retransmission is possible. Therefore, the process proceeds to step 755 to increase No_retrans by 1 and then returns to step 720 to retransmit the packet. In addition, if No_retrans is smaller than Max_retrans in step 750, it means that retransmission is possible. Therefore, before the step 755, the last retransmission indicator may be set to No and transmitted to the base station.

8 is a diagram illustrating the structure of a transmitter according to the present invention. According to an embodiment of the present invention, the transmitter is a din term for transmitting a reverse packet.

Referring to FIG. 8, the transmitter includes a multiplexer 805, a HARQ processor 815, a controller 810, an ACK / NACK analyzer 825, a packet control information generator 820, a transceiver 830, and last. The retransmission indicator setting unit 835 is configured.

The controller 810 notifies the multiplexing block 805 of the amount of data to be transmitted in the next transmission period, and the multiplexing block 805 receives user data from an upper layer according to the amount of data to be transmitted in the next transmission period. The multiplexing block 805 multiplexes the user data into one HARQ packet, and then transfers the user data to the HARQ processor 815. The HARQ processor 815 r channel-codes the HARQ packet, stores it in a buffer (not shown), and transmits the received HARQ packet to the transceiver 830. The transceiver 830 transmits the HARQ packet.

The packet decoding control information generator 820 generates the packet control information under the control of the controller 810. The packet control information generation unit 820 receives information to be included in the packet control information determined in consideration of the usage situation, channel state, etc. of the HARQ processor 815 from the control unit 810. Also, the packet decoding control information generator 820 sets the last retransmission indicator to an appropriate value under the control of the last retransmission indicator setting unit 835.

The last retransmission indicator setting unit 835 checks whether the number of retransmissions of the HARQ packets being processed by the HARQ processor 815 is equal to the maximum retransmission number, and if the retransmission number is the same as the maximum retransmission number, the packet decoding control information generation unit ( Instruct 820 to set the last retransmission indicator to 'Yes'. On the other hand, if the number of retransmissions is not equal to the maximum number of retransmissions, that is, if it is small, it may be instructed to set the last retransmission indicator to 'No'. Or no information can be sent without setting the last indicator.

That is, the packet control information generation unit 820 configures the information transmitted from the control unit 810 as the packet control information, sets the last retransmission indicator to an appropriate value, and transmits the information to the transmission / reception unit 830.

9 is a diagram showing the structure of a receiver according to the present invention. According to an embodiment of the present invention, the receiver is characterized in that the base station for receiving the reverse packet.

Referring to FIG. 9, the receiver includes a demultiplexer 905, a HARQ processor 915, a scheduler 910, a packet decoding control information interpreter 920, an ACK / NACK generator 925, and a transceiver 930. It consists of.

The packet decoding control information analyzer 920 interprets the packet decoding control information including the last retransmission indicator received through the DL-SCCH and transmits the packet decoding control information to the HARQ processor 915. In this case, if the last retransmission indicator of the packet decoding control information is set to 'Yes', the scheduler 910 is notified. Alternatively, the scheduler 910 may be notified of the result of the analysis regardless of the setting of 'Yes' or 'No' of the last retransmission indicator.

The HARQ processor 915 demodulates / decodes an HARQ packet, which is a signal received by the transceiver 930, using the packet decoding control information received from the packet decoding control information analyzer 920. Thereafter, the demodulated / decoded HARQ packet is controlled to be delivered to an HARQ buffer (not shown but obviously provided therein). This is to perform soft combining to ensure reception performance of HARQ packets.

The scheduler 910 allocates resources to terminals in consideration of buffer status information, channel status information transmitted by the terminals, and HARQ retransmission status of each terminal. In this case, the scheduler 910 determines whether it is necessary to schedule retransmission for a specific HARQ packet as the last retransmission indicator value received from the packet decoding control information analyzer 920. That is, since the last retransmission indicator is set to 'Yes', the terminal does not perform retransmission anymore, so that the terminal no longer allocates resources to the terminal.

The ACK / NACK generator 925 generates an ACK signal or a NACK signal and transmits the generated ACK signal or the NACK signal to the transceiver 930 according to a CRC operation of the user data packet. The demultiplexing block 905 operates to deliver the HARQ packet processed by the HARQ processor 915 to an appropriate upper layer.

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 above in detail, the effects obtained by the representative of the disclosed invention will be briefly described as follows.

The present invention has the effect of preventing the resource allocation by the base station in advance by transmitting the indicator indicating the last packet retransmission in the control information in the mobile communication system performing HARQ. Therefore, there is an effect of efficiently allocating limited radio resources to a plurality of terminals.

Claims (8)

An efficient base station scheduling method in a mobile communication system, Transmitting, by the terminal, packet decode control information including an indicator indicating the last packet retransmission to the base station; The terminal retransmitting the packet, And a base station decoding the packet using the packet decoding control information and allocating a radio resource for a next packet retransmission in response to the indicator. The method of claim 1, The terminal further comprises the step of setting the indicator according to the comparison result by comparing the number of times to retransmit the packet and the set maximum number of retransmissions. The method of claim 2, If the terminal is equal to the number of retransmissions and the set maximum number of retransmissions, the base station scheduling method comprising the step of setting the indicator to a value indicating that the last packet retransmission. The method of claim 3, And a base station allocates a radio resource for a next packet retransmission for another terminal instead of the terminal in response to the indicator set to the value indicating that the last packet retransmission. The method of claim 3, And the indicator can be set in code information indicating the number of retransmissions (RSN). A transmitting apparatus for efficiently supporting base station scheduling in a mobile communication system, A last retransmission indicator setting unit which compares the number of retransmissions of the packet with a set maximum retransmission number and provides a value for setting an indicator indicating the last retransmission of the packet to the packet decoding control information generation unit; And a packet decoding control information generation unit for generating a last packet retransmission indicator according to a setting value provided from the last retransmission indicator setting unit as packet control information with respect to the packet.  The apparatus of claim 6, wherein the transmitting device; A plurality of retransmission processors for performing retransmission in consideration of the packet; And a controller configured to control the packet decoding control information generation unit to generate the packet control information including the last retransmission indicator in consideration of a usage situation of the retransmission processors or a packet transmission channel state. A reception apparatus for efficiently supporting base station scheduling in a mobile communication system, A packet decoding control information analysis unit for analyzing control information including an indicator indicating a last retransmission of a packet; A plurality of retransmission processors for retransmitting the packet by using the control information provided from the packet decoding control information analysis unit; And a scheduler for allocating a resource for packet retransmission to a transmitter according to a set value of the indicator for notifying the last retransmission.

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