KR101298580B1 - Method and apparatus for transmitting/receiving for packet decoding information of packet service in mobile telecommunication system - Google Patents

Abstract

The present invention relates to a method and apparatus for efficiently signaling packet decoding information to a terminal when providing a packet service in a mobile communication system. According to the present invention, a method of transmitting packet decoding information includes determining packet decoding information of a packet to be transmitted and comparing the determined packet decoding information with a set basic packet decoding information, wherein the determined packet decoding information is decoded from the basic packet. If the information is the same, the process of transmitting the packet to be transmitted through the common channel using the set basic transmission resource without transmitting the determined packet decoding information, and if the determined packet decoding information is different from the basic packet decoding information And transmitting the packet to be transmitted and the determined packet decoding information together through the shared channel using a transmission resource allocated for the packet to be transmitted. This invention reduces the signaling overhead due to the transmission of packet decoded information.

Packet Decoding Information, Grant Channel, VoIP

Description

METHOD AND APPARATUS FOR TRANSMITTING / RECEIVING FOR PACKET DECODING INFORMATION OF PACKET SERVICE IN MOBILE TELECOMMUNICATION SYSTEM}

1 is a diagram illustrating an example of a structure of a next generation mobile communication system.

2 illustrates the characteristics of VoIP traffic.

3 is a flowchart illustrating signaling between a base station and a terminal according to a preferred embodiment of the present invention.

4 is a diagram illustrating the transmission of packet decoding information according to a preferred embodiment of the present invention.

5 is a flowchart illustrating the operation of a terminal according to a preferred embodiment of the present invention.

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

7 is a block diagram illustrating a receiving device of a terminal according to an exemplary embodiment of the present invention.

8 is a block diagram showing an apparatus for transmitting a base station according to a preferred embodiment of the present invention.

The present invention relates to a mobile communication system, and more particularly, to a method and apparatus for efficiently signaling packet decoding information to a terminal when providing a packet service.

The Universal Mobile Telecommunication Service (UMTS) system is based on a Global System for Mobile Communications (GSM) and a General Packet Radio Services (GPRS), which are European mobile communication systems, and includes a Wideband Code Division Multiple Access Quot; CDMA ") as a third generation asynchronous mobile communication system.

The 3rd Generation Partnership Project (3GPP), which is in charge of UMTS standardization, is discussing the Long Term Evolution (LTE) system as the next generation mobile communication system of the UMTS system. The LTE system aims to commercialize about 2010, and is a technology for implementing high-speed packet-based communication having a transmission rate of up to about 100 Mbps. Various schemes are being discussed for this purpose. For example, there are discussions to reduce the number of nodes located on the communication path by simplifying the structure of the network, and to approach the wireless protocols as much as possible to the wireless channel.

1 illustrates an example of a structure of a next generation (Evolved) UMTS mobile communication system.

Referring to FIG. 1, as illustrated, an Evolved UMTS Radio Access Network (hereinafter referred to as an “E-UTRAN”) 110 is an Evolved Node B (hereinafter referred to as “ENB” or “Node B”). It is simplified to a two node structure of 120, 122, 124, 126, and 128 and an anchor node 130, 132. A User Equipment (UE) 101 is connected to an Internet Protocol (IP) network by an E-UTRAN 110.

The ENBs 120 to 128 correspond to existing Node Bs of the UMTS system and are connected to the UE 101 by a radio channel. Unlike the existing Node B, the ENBs 120 to 128 play a more complex role. In LTE, all user traffic, including real-time services such as Voice over IP (VoIP) over the Internet protocol, is serviced through a shared channel, which requires a device that collects and schedules UE information. 120 to 128 are in charge.

Similar to High Speed Downlink Packet Access (HSDPA) or Enhanced Uplink Dedicated Channel (E-DCH), LTE AR (Hybrid ARQ) is performed between ENBs 120 to 128 and UE 101, but HARQ alone provides various quality of service ( Since the requirements of QoS (Quality of Service) cannot be satisfied, an outer ARQ may be performed at a higher layer, and the separate ARQ (hereinafter, referred to as 'outer-ARQ') may also be used as a terminal. 101) and ENBs 120-128.

In order to realize a transmission rate of up to 100 Mbps, LTE has been discussed to use Orthogonal Frequency Division Multiplexing (OFDM) as a radio access technology in a 20 MHz bandwidth. In addition, an adaptive modulation & coding (AMC) scheme that determines a modulation scheme and a channel coding rate according to the channel state of the terminal is applied.

Many next generation mobile communication systems including LTE use HARQ as an error correction technique. HARQ is a technique of increasing reception success rate by soft combining with retransmitted data without discarding previously received data. In more detail, the HARQ receiver determines whether there is an error in a received packet, and according to whether the error exists, a HARQ positive acknowledgment signal (hereinafter, referred to as a HARQ ACK) signal or a HARQ negative acknowledgment. Acknowledgement: hereinafter referred to as 'HARQ NACK' signal is transmitted to the transmitting side. Therefore, the transmitting side performs retransmission of a HARQ packet or transmission of a new HARQ packet according to the HARQ ACK / NACK signal. The HARQ receiver side soft combines the retransmitted packet with the previously received packet to reduce the error occurrence probability.

In a communication system to which base station scheduling is applied, forward packet transmission and reception proceed as follows.

The base station collects information necessary for scheduling, such as channel conditions, from the terminals, and if there is data to be transmitted to the terminal, the base station determines the transmission resource to be used for data transmission by referring to the collected information. The base station signals transmission resource information indicating the transmission resource to the terminal and transmits data to the terminal by using the signaled transmission resource. In OFDM, a specific frequency band for a specific period is used as a transmission resource, and the base station notifies the terminal of transmission resource information through a predetermined channel. For convenience of description, a channel through which a control message containing transmission resource information is transmitted is called a grant channel.

When the terminal receives the transmission resource information signaling, the terminal receives and processes the packet transmitted through the transmission resource. In order to process the packet, information on the size of the packet, a channel coding scheme applied to the packet, a channel coding rate, and a modulation scheme should be known to the terminal. In addition, for HARQ operation, the UE must recognize HARQ-related information such as an incremental redundancy (IR) version, HARQ processor identifier, and the like. For convenience of description, the information that should be recognized by the receiver in order to process a packet as described above is referred to as packet decoding information.

Packet decoding information is transmitted with the packet and is usually signaled using a portion of the transmission resource over which the packet is transmitted. The terminal processes the packet with reference to the packet decoding information and performs a cyclic redundancy check (CRC) operation to check whether there is an error in the packet. If an error exists, a HARQ NACK is sent, requiring retransmission of the packet. The packet decoding information and the packet are repeatedly transmitted until the terminal detects that there is no error in the packet.

As described above, in the system to which the base station scheduling is applied, the following control information is required to transmit one packet in the forward direction, and the size thereof is about several tens of bits.

Transmission resource information: information about a transmission resource to which a packet is to be transmitted. The packet is transmitted in a channel different from the channel in which the packet is transmitted, and is also referred to as Category 1 (CAT 1) information.

Information necessary for packet decoding: information that the terminal needs to recognize in order to decode the packet. The packet is transmitted through a channel through which the packet is transmitted, and is also referred to as category 2/3 (CAT 2/3) information.

In LTE, scheduling is also applied to services such as Voice over Internet Protocol (VoIP), where relatively small packets continuously occur at regular intervals. However, since the size of VoIP packets is about 300 bits, it is inefficient to transmit the control information together every time a VoIP packet is transmitted.

Since the size of the VoIP packets is generally constant and the timing of the occurrence of the packets can be predicted, a method of distributing semi-permanent transmission resources for the VoIP service so as not to transmit the transmission resource information for every packet transmission is under consideration.

In more detail, during the call setup process for the VoIP service, the base station and the terminal share information on the packet generation period, and the base station transmits the first VoIP packet to the terminal, after which the transmission is semi-permanently assigned to the VoIP service. Notifies the terminal of the resource. Thereafter, the base station transmits packets using the semi-permanently allocated transmission resources at every packet generation period, and does not transmit the transmission resource information. The terminal regards the VoIP packets to be transmitted through the semi-permanently allocated transmission resources at every packet generation period, and receives the VoIP packets through the allocated transmission resources at the corresponding time points.

The packet decoding information for the VoIP packets is transmitted together with the VoIP packets in the channel through which the VoIP packets are transmitted, and the terminal processes the VoIP packets with reference to the packet decoding information and performs an HARQ operation.

As described above, in the conventional VoIP service, transmission resource information is not transmitted, thereby preventing waste of transmission resources due to transmission of resource information. However, packet decoding information is transmitted every time. However, considering the size of the VoIP packet, it is also desirable to reduce the overhead incurred due to the transmission of the packet decoding information. Therefore, there is a need for a method and apparatus for transmitting packet decoding information only when necessary, so as to efficiently use transmission resources.

Accordingly, the present invention, which was devised to solve the problems of the prior art operating as described above, provides a method for minimizing signaling overhead due to transmission of packet decoding information for a packet service in which packets of relatively similar sizes occur at regular intervals; Provide a device.

The present invention provides a method and apparatus for efficiently using transmission resources by transmitting packet decoding information only when necessary in a packet service.

According to a first aspect of the present invention, there is provided a method of transmitting packet decoding information for a packet service in a mobile communication system.

Determining packet decoding information of a packet to be transmitted and comparing the determined packet decoding information with a set basic packet decoding information;

If the determined packet decoding information is the same as the basic packet decoding information, transmitting the packet to be transmitted through a common channel using a set basic transmission resource without transmitting the determined packet decoding information;

When the determined packet decoding information is different from the basic packet decoding information, the packet to be transmitted and the determined packet decoding information are transmitted together through the common channel using the transmission resource allocated for the packet to be transmitted. It characterized in that it comprises a process.

Another embodiment according to the first aspect of the present invention is an apparatus for transmitting packet decoding information for packet service in a mobile communication system,

A packet encoding control unit for comparing the packet decoding information of the packet to be transmitted with the set basic packet decoding information;

When the packet decoding information of the packet to be transmitted is the same as the basic packet decoding information, the packet to be transmitted is transmitted through the common channel using the set basic transmission resource without transmitting the packet decoding information of the packet to be transmitted. If the packet decoding information of the packet to be transmitted is different from the basic packet decoding information, using the transmission resource allocated for the packet to be transmitted together with the packet to be transmitted and the packet decoding information of the packet to be transmitted It characterized in that it comprises a transceiver for transmitting through the common channel.

According to a second aspect of the present invention, in a method for receiving packet decoding information for packet service in a mobile communication system,

Monitoring a grant channel to determine whether new transmission resource information is received until an allocation time of a basic transmission resource set for the packet service is reached;

If the new transmission resource information is not received until the allocation time is reached, receiving a first packet through the basic transmission resource of a common channel, and processing the first packet using the set basic packet decoding information; ,

When the new transmission resource information is received before reaching the allocation time point, the second packet and the packet decoding information about the second packet are received through the transmission resource of the shared channel indicated by the new transmission resource information, and And processing a second packet according to the received packet decoding information.

Another embodiment according to the second aspect of the present invention is an apparatus for receiving packet decoding information for packet service in a mobile communication system,

A grant channel processing unit for monitoring a grant channel to receive transmission resource information;

A packet decoding control unit which determines whether new transmission resource information is received until an allocation time of the basic transmission resource set for the packet service is reached;

If the new transmission resource information is not received until the allocation time, the first packet is received through the basic transmission resource of the common channel and the first packet is processed according to the set basic packet decoding information. When the new transmission resource information is received before reaching, the second packet and the packet decoding information about the second packet are received through the transmission resource of the shared channel indicated by the new transmission resource information, and the packet decoding information is received according to the packet decoding information. And a transceiver for processing the second packet.

The operation principle of the preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings. In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. The following terms are defined in consideration of the functions of the present invention, and may be changed according to the intentions or customs of the user, the operator, and the like. Therefore, the definition should be based on the contents throughout this specification.

The main point of the present invention is to predetermine packet decoding information which is basically used for a service in which packets of substantially similar sizes, such as VoIP, occur at regular intervals, and only when the current packet decoding information is different from the basic packet decoding information. By transmitting the current packet decoding information, the transmission resource required for transmitting the packet decoding information is efficiently used. In the following description, the LTE system will be used as an example. However, the present invention can be applied to other mobile communication systems using similar technical backgrounds and communication schemes without any subtraction, which is possible by the judgment of those skilled in the art of the present invention. .

Before describing the preferred embodiment of the present invention will be described the concepts necessary to understand the present invention.

A vocoder generates a VoIP frame by sampling and encoding a human voice signal (ie, a source) for a set period of time. The generation period of the VoIP frame is determined according to the source coding scheme, and the generation period of the adaptive multi-rate (AMR) codec mainly used in UMTS is 20 msec. In addition, the size of the VoIP frame is constant at 244 bits. Internet Protocol (IP) / User Datagram Protocol (UDP) / Real-time Transfer Protocol (RTP) headers are added to the VoIP frame to create a VoIP packet, and the VoIP packet is subjected to a header compression process before being transmitted over a wireless channel. Rough

There are dozens of fields in the IP / UDP / RTP header. Among them, the RTP Sequence Number (RT) Sequence and the RTP Timestamp (TS) field change every packet, but the remaining fields are usually constant. Robust Header Header Compression (ROHC) protocol, which is most used in the mobile communication system, changes only the RTP SN and the RTP TS when only the RTP SN and the RTP TS change using the properties of the IP / UDP / RTP header. Transmit only small amounts of information (3 bytes in most cases depending on the configuration of the ROHC protocol, but usually 3 bytes) to derive the value, and more information (types and variations of fields with varying values) when other fields change It depends on the size of the value, but usually between 4 and 18 bytes).

2 is for explaining the characteristics of VoIP traffic applied to the present invention.

Referring to FIG. 2, since header compression is performed at an upper node of the base station in the LTE system, VoIP packets 210, 215, and 220 compressed with headers arrive at the base station. Since the size of the VoIP frame is 32 bytes in the case of the 12.2 kbps AMR codec, the VoIP packet 210 having the size of 35 bytes arrives most frequently at the base station, and sometimes 35 when the field values other than the RTP SN and the RTP TS change. VoIP packets 215 and 220 with sizes other than bytes arrive. All packets have an interval of a predetermined packetization interval 205.

Each VoIP packet is transmitted to the terminal through a wireless channel along with packet decoding information. The packet decoding information is information related to AMC and HARQ, and the following information is included in the packet decoding information.

Packet size: Information indicating the size of a packet transmitted over a wireless channel.

Modulation method: Modulation method applied to packets such as Quadrature Phase Shifting Keying (QPSK), 16-ary Quadrature Amplitude Modulation (16QAM), and 64-QAM (64-ary QAM).

HARQ Identifier: Information indicating which packet should be combined with the currently transmitted packet, and is not used in the synchronous HARQ scheme.

Information capable of deriving a redundancy version (RV) or an RV: In an IR scheme of increasing a coding rate through retransmission, an RV of a currently transmitted packet should be informed to a receiver. The RV is information representing a structure in which system bits and parity bits are multiplexed in the packet. The base station may directly signal the RV, or send some kind of serial number to cause the receiving side to derive the RV from the serial number.

Applying different packet decoding information to every packet has the advantage of increasing the transmission efficiency, but also has the disadvantage of using extra transmission resources for the transmission of the packet decoding information. Since the overhead of transmitting the packet decoding information increases as the packet size is smaller, it is not necessary to transmit the packet decoding information without changing the packet decoding information for every packet in a service having a small packet size, such as a VoIP service. Rather, it can be efficient.

For example, even if the modulation scheme is fixed to one regardless of the channel state of the terminal, the performance degradation is not large in the transmission of small packets such as VoIP packets. In addition, it is more efficient to apply the synchronous HARQ scheme to the VoIP packet transmission to avoid the overhead caused by the HARQ identifier transmission.

For reference, HARQ may be classified into a synchronous HARQ scheme and an asynchronous HARQ scheme according to retransmission timing. In the synchronous HARQ, the retransmission time point is spaced apart from the previous transmission time by a predetermined time interval. As a result, the receiving side determines which packet among the previously received packets is soft-combined based on the transmission time point of the received packet. On the other hand, in asynchronous HARQ, there is no restriction on the time of retransmission, and a separate control signal called HARQ identifier is required to help the soft combining decision of the receiver. The asynchronous HARQ scheme has the advantage of scheduling that a packet can be retransmitted flexibly, but has a disadvantage of transmitting an HARQ identifier. Since the scheduling flexibility for small packets, such as VoIP packets, has a minimal effect on overall scheduling efficiency, the preferred embodiment of the present invention does not use asynchronous HARQ techniques for VoIP packets.

The base station may determine the RV of the current packet in consideration of the transmission resources available at the present time and the amount of transmission resources used for a particular packet up to the present time. In this case, the base station does not transmit the RV by associating the RV with the retransmission order in advance.

As described above, in the preferred embodiment of the present invention, a predefined modulation scheme and a synchronous HARQ scheme are used for the VoIP packet, and the RV and the retransmission order are previously associated with each other, thereby, among the packet decoding information, the modulation method and the HARQ identifier. Eliminate information that may lead to RV or RV.

On the other hand, since the packet size may change at any time, at least when the packet size is changed, the terminal should be informed of the changed packet size. Accordingly, the terminal and the base station recognize the default packet size in advance, and the base station does not transmit packet decoding information when the size of the current packet to be transmitted is the same as the default packet size, and the size of the current packet is the default packet size. If different from the packet transmission information is transmitted. The presence of packet decoding information is related to the presence or absence of transmission resource information. When the base station needs to transmit the packet decoding information, the base station transmits the transmission resource information through the grant channel, and notifies the terminal that the packet decoding information is also transmitted to the downlink shared channel (DL-SCH). If there is no need to transmit the packet decoding information, the base station transmits only the packet on the shared channel. At this time, the packet decoding information is not transmitted. Of course, if a transmission resource needs to be newly allocated, the transmission resource information is transmitted regardless of the necessity of transmitting the packet decoding information.

3 is a flowchart illustrating signaling between a base station and a terminal according to a preferred embodiment of the present invention, and FIG. 4 shows transmission of packet decoding information according to a preferred embodiment of the present invention. 3 and 4, the operation according to the preferred embodiment of the present invention is briefly described below.

The base station 310 determines default packet decoding information during the VoIP call setup process, and notifies the terminal 305 of this (315). The basic packet decoding information includes a modulation scheme to be used for transmission of the VoIP packet, a HARQ identifier, a relationship between retransmission sequence number and RV, and basic packet size.

The default packet size is appropriately set in consideration of the size of the VoIP packet to be used most frequently. The base station 310 may set the basic packet size to a value equal to the size of the VoIP packet to be used most frequently, or to a slightly larger value.

Since a method of predetermining a relationship between the retransmission sequence number and the RV is already used in a conventional synchronous HARQ such as an enhanced dedicated channel (EDCH), a detailed description thereof will be omitted. As an example, RV may be set to 0 during initial transmission of a packet, and RV may be set to a value indicating the number of retransmissions when retransmitting the packet.

The HARQ identifier is an identifier for the HARQ buffer in which the VoIP packet is to be stored. In general, considering that the terminal 305 does not simultaneously perform multiple VoIP services, it may not be necessary to explicitly signal an HARQ identifier for the VoIP service. That is, a specific HARQ buffer of the terminal 305 is set in advance as a buffer to be used for the VoIP service, and the VoIP packet is always stored in the HARQ buffer, thereby not using the HARQ identifier.

After notifying the terminal 305 of the basic packet decoding information, the base station 310 waits until the first VoIP packet arrives.

When the first VoIP packet arrives from an upper node (317), the base station 310 transmits transmission resource information indicating a permanent resource (320) through the grant channel for transmission of the VoIP packet (320), The VoIP packet is transmitted through the semi-persistent transmission resource (325). Since the base station 310 and the terminal 305 determine whether packet decoding information is present based on the presence of transmission resource information, the VoIP packet and the packet decoding information are transmitted together through the common channel (325). When the terminal 305 is allocated a semi-persistent transmission resource through the grant channel, it is assumed that the VoIP packet is transmitted through the semi-persistent transmission resource until a new semi-persistent transmission resource is allocated, and is received through the semi-persistent transmission resource. Process the signal to VoIP service. At this time, if transmission resource information is received through the grant channel, the terminal 305 determines that the VoIP packet and the packet decoding information are received together through the common channel, and processes the VoIP packet according to the packet decoding information.

When the base station receives subsequent VoIP packets from the higher node (327, 333; 405), it checks whether the size of the VoIP packet matches the basic packet size. If the size of the VoIP packet matches the basic packet size obtained through the basic packet decoding information, the base station transmits the VoIP packet at a predetermined time point through a common channel composed of pre-allocated semi-persistent transmission resources. Decoding information is not transmitted (330, 335; 415). In addition, since the base station transmits the packet using the semi-persistent transmission resources, the base station does not signal transmission resource allocation information again through the grant channel (410). The VoIP packet undergoes a synchronous HARQ process and is retransmitted until the terminal transmits an ACK (420, 425).

If the transmission resource information is not signaled through the grant channel (410), the UE considers that a VoIP packet having a basic packet size is transmitted through the semi-persistent transmission resource that is already allocated, and uses the basic packet decoding information to determine the VoIP packet. Receive and process That is, the packet is demodulated by a demodulation method of basic packet decoding information, and the channel size of the packet is decoded considering that the size of the packet is the same as the basic packet size, and then an RV corresponding to the number of (re) transmissions of the packet is applied. The packet is soft-combined with a packet stored in a predetermined HARQ buffer or stored in a predetermined HARQ buffer.

If the size of the VoIP packet received from the upper node does not match the basic packet size (337; 430), the base station transmits transmission resource information indicating a newly allocated transmission resource that may be the same as or different from the semi-persistent transmission resource through the grant channel. Signal (340; 435). The packet decoding information for the VoIP packet is transmitted together with the VoIP packet through the shared channel configured with the allocated transmission resource (345; 440). The VoIP packet may go through a synchronous HARQ process or an asynchronous HARQ process, and is retransmitted along with the packet decoding information until the UE transmits an ACK (445, 450, 455).

As described above, if the size of the VoIP packet matches the basic packet size, the base station processes and transmits the VoIP packet by applying basic packet decoding information. The packet decoding information is not transmitted. On the other hand, if the size of the VoIP packet does not match the basic packet size, in order to inform the UE that the packet decoding information is transmitted, the transmission resource information is transmitted through the grant channel, and then the packet decoding information and the VoIP packet are transmitted together. The base station transmits transmission resource information containing the semi-persistent transmission resource information, even if the VoIP packet of the different size is transmitted using a conventional semi-persistent transmission resource.

5 is a flowchart illustrating a terminal operation according to a preferred embodiment of the present invention.

While performing the VoIP call setup process with the base station, the terminal is informed of semi-permanent transmission resource information and basic packet decoding information to be used for transmission of the VoIP packet (505).

As described above, the semi-persistent transmission resource is a basic transmission resource that is automatically allocated without transmitting and receiving separate transmission resource information every predetermined period, and the transmission resource related information means a period in which the semi-persistent transmission resource is allocated. In VoIP, packets are generated every 20 msec. Therefore, the allocation period of the semi-persistent transmission resource is preferably 20 msec.

The UE monitors the grant channel until the semi-persistent transmission resource is allocated (510), and receives the transmission resource information indicating the semi-persistent transmission resource through the grant channel (515), and transmits the packet and the packet decoding information through the semi-persistent transmission resource. Receives and decodes the packet with reference to the packet decoding information (525).

After the reception of the packet is completed, the terminal monitors the grant channel until reaching the semi-persistent transmission resource allocation time (530) and determines whether new transmission resource information is received (535). Herein, the semi-persistent transmission resource allocation time point means a time at which the semi-persistent transmission resource is available, and exists at every allocation period of the semi-permanent transmission resource starting from the time when the semi-persistent transmission resource is first allocated.

If the new transmission resource information is not received until the next semi-persistent transmission resource allocation time, the process proceeds to step 540, and if the transmission resource information is received, step 545.

The fact that new transmission resource information has not been received until the next semi-persistent transmission resource allocation time means that the base station transmits the packet by applying a basic packet decoding scheme through the semi-persistent transmission resource. Accordingly, the terminal receives the packet through the semi-persistent transmission resource, and decodes the received packet by using the basic packet decoding information (540). That is, the terminal considers that packet decoding information is not transmitted through the semi-persistent transmission resource and processes the packet.

On the other hand, since the new transmission resource information is received, the packet decoding information and the packet are transmitted together, so that the terminal receives the packet and the packet decoding information through the transmission resource indicated by the new transmission resource information, and the received packet decoding information. The packet is processed using 545.

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

Referring to FIG. 6, the base station determines a semi-persistent transmission resource and basic packet decoding information to be used for transmitting a VoIP packet while performing a VoIP call setup process for the terminal (605).

When the base station receives the first VoIP packet from the upper node (610), it notifies the terminal of the semi-persistent transmission resources allocated to the terminal through the grant channel (615), and transmits the VoIP packet through the semi-persistent transmission resources (620). Since the transmission resource information is transmitted through the grant channel, the VoIP packet is transmitted with packet decoding information.

If the VoIP packet arrives from the higher node after the semi-persistent transmission resource is allocated (625), the base station checks whether the basic packet decoding information can be applied to the VoIP packet (630). If the size of the VoIP packet is smaller than or equal to the size of the basic packet indicated by the basic packet decoding information, the basic packet decoding information may be applied. Then, the base station transmits only the VoIP packet through the common channel (645) and returns to step 625.

On the other hand, if the packet size is larger than the basic packet size, the basic packet decoding information cannot be applied, and the flow proceeds to step 635. The base station transmits transmission resource information through the grant channel to inform the terminal that the packet decoding information and the packet are transmitted together (635). Then, the base station transmits the VoIP packet and the packet decoding information together through the common channel (640), and returns to step 625.

 7 is a block diagram showing a terminal receiving apparatus according to a preferred embodiment of the present invention. As illustrated, the terminal receiver includes a demultiplexer 705, a HARQ processor 715, a transceiver 730, a grant channel processor 720, and a packet decoding controller 725.

The grant channel processor 720 receives the transmission resource information through the grant channel, and informs the packet decoding controller 725 of the allocated transmission resource when the transmission resource is allocated to the terminal.

The packet decoding controller 725 controls the transceiver 730 to receive a radio signal through a specific transmission resource at a specific time point with reference to the transmission resource information. When the semi-persistent transmission resource is allocated, it is determined whether the packet decoding information is included in the radio signal received through the specific transmission resource at the specific time according to the presence or absence of the transmission resource information. If the packet decoding information is not included in the received radio signal, the transceiver 730 is controlled to process (demodulate and decode) the received packet by applying basic packet decoding information received from an upper control layer. When the received radio signal includes packet decoding information, the transceiver 730 notifies that the packet decoding information is included.

The transceiver 730 receives the radio signal through a radio channel, and then uses the packet decoding information included in the radio signal, or uses the basic packet decoding information transmitted from the packet decoding control unit 725 to transmit the radio signal. The signal is demodulated and channel decoded to obtain a packet. The packet is then forwarded to the appropriate HARQ processor 715.

The HARQ processor 715 soft-combines the packet transmitted by the transceiver 730 with the packet stored in the HARQ processor 715, and then performs CRC check on the combined packet. If the CRC check determines that there is no error, the combined packet is transferred to the demultiplexer 705, and when it is determined that there is an error, the combined packet is stored in the HARQ processor 715.

Demultiplexer 705 examines the header of the packet from HARQ processor 715 and forwards it to the appropriate upper layer.

8 is a block diagram showing a base station transmitting apparatus according to a preferred embodiment of the present invention. As illustrated, the base station transmitter includes a multiplexer 805, a HARQ processor 815, a grant channel processor 820, a packet encoding controller 825, a channel coding apparatus 807, and a transceiver 830.

Referring to FIG. 8, the grant channel processing unit 820 configures transmission resource information according to a scheduling decision of a scheduler (not shown) and transmits the transmission resource information to the transmission / reception unit 830. In addition, at the request of the packet encoding control unit 825, the transmission resource information indicating the transmission resource allocated to the specific terminal is configured and transmitted to the transmission / reception unit 830.

The packet encoding control unit 825 receives basic packet decoding information from an upper control layer, and if the size of a packet to be transmitted at a specific time point does not match the basic packet size indicated by the basic packet decoding information, the grant channel processing unit 820 Request the transmission resource information to be sent. The packet encoding control unit 825 also notifies the channel coding apparatus 807 of packet decoding information to be applied to the packet. When the packet encoding control unit 825 also applies basic packet decoding information to the packet, the packet encoding control unit 825 controls the transceiver unit 830 to transmit only the packet without the packet decoding information through the allocated transmission resource (ie, semi-permanent transmission resource), When the packet decoding information other than the basic packet decoding information is applied, the transceiver 830 is controlled to transmit the packet and the packet decoding information together through the allocated transmission resource.

The multiplexer 805 inserts the appropriate header (s) into the packets delivered from the upper layer, multiplexes them into one packet, and then delivers them to the channel coding apparatus 807. The channel coding apparatus 807 performs channel coding on the packet transmitted by the multiplexer 805 and transmits the packet to the HARQ processor 815 under the control of the packet encoding controller 825. The HARQ processor 815 stores the channel coded packet received from the channel coding apparatus 807 until the corresponding ACK is received. The transceiver 830 modulates the channel-coded packet received from the HARQ processor 815 under the control of the packet encoding controller 825 and transmits the channel-coded packet together with the packet decoding information alone or through a wireless channel.

While the present invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments, but is capable of various modifications within the scope of the invention. As a specific example, the example of the VoIP service has been described above, but the present invention is applicable to a similar kind of service in which packets occur relatively regularly, which is described in the detailed description of the present invention by those skilled in the art. It may be implemented by the description. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined by the scope of the appended claims, and equivalents thereof.

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

In the present invention, if the packet decoding information of the packet to be transmitted currently is the same as the predetermined basic packet decoding information, only the packet is transmitted and the packet decoding information is not transmitted, thereby providing an effect of efficiently using limited transmission resources. .

Claims (19)

A method of transmitting packet decoding information for a packet service in a mobile communication system, Determining packet decoding information of a packet to be transmitted and comparing the determined packet decoding information with a set basic packet decoding information; If the determined packet decoding information is the same as the basic packet decoding information, transmitting the packet to be transmitted through a common channel using a set basic transmission resource without transmitting the determined packet decoding information; When the determined packet decoding information is different from the basic packet decoding information, the packet to be transmitted and the determined packet decoding information are transmitted together through the common channel using the transmission resource allocated for the packet to be transmitted. A transmission method comprising a process. The method of claim 1, wherein the comparing is performed. Comparing the packet size of the packet to be transmitted with a basic packet size indicated by the basic packet decoding information; Determining that the determined packet decoding information is the same as the basic packet decoding information when the packet size of the packet to be transmitted is smaller than or equal to the basic packet size; And if the packet size of the packet to be transmitted is larger than the basic packet size, determining that the determined packet decoding information is different from the basic packet decoding information. The transmission method of claim 1, further comprising acquiring transmission resource related information indicating an allocation time point of the basic transmission resource when establishing a call for the packet service. The method of claim 1, wherein if the determined packet decoding information is different from the basic packet decoding information, the radio resource information indicating a radio resource allocated for the packet to be transmitted is transmitted through a grant channel distinct from the public channel. The transmission method further comprises the step of. The method of claim 1, wherein the determined packet decoding information, At least one of a packet size of the packet to be transmitted, a modulation method applied to the packet to be transmitted, a hybrid automatic retransmission request (HARQ) identifier, and free version (RV) information indicating the number of transmissions of the packet to be transmitted. The transmission method characterized by the above-mentioned. An apparatus for transmitting packet decoding information for a packet service in a mobile communication system, A packet encoding control unit for comparing the packet decoding information of the packet to be transmitted with the set basic packet decoding information; When the packet decoding information of the packet to be transmitted is the same as the basic packet decoding information, the packet to be transmitted is transmitted through the common channel using the set basic transmission resource without transmitting the packet decoding information of the packet to be transmitted. If the packet decoding information of the packet to be transmitted is different from the basic packet decoding information, using the transmission resource allocated for the packet to be transmitted together with the packet to be transmitted and the packet decoding information of the packet to be transmitted And a transmitter / receiver transmitting through the shared channel. The method of claim 6, wherein the packet encoding control unit, Compare the packet size of the packet to be transmitted with the basic packet size indicated by the basic packet decoding information, and if the packet size of the packet to be transmitted is smaller than or equal to the basic packet size, the packet decoding information of the packet to be transmitted. Determines that the same as the basic packet decoding information, and if the packet size of the packet to be transmitted is larger than the basic packet size, it is determined that the packet decoding information of the packet to be transmitted is different from the basic packet decoding information. Transmitting device. The method of claim 6, wherein the packet encoding control unit, And transmission resource related information indicating an allocation time point of the basic transmission resource when establishing a call for the packet service. The grant of claim 6, wherein, if the packet decoding information of the packet to be transmitted is different from the basic packet decoding information, radio resource information indicating a radio resource allocated for the packet to be transmitted is distinguished from the shared channel. And a grant channel processing unit transmitting through a channel. The apparatus of claim 6, further comprising a channel coding apparatus for encoding and transmitting the packet according to the basic packet decoding information or the packet decoding information of the packet to be transmitted under the control of the packet encoding control unit. . The method of claim 6, wherein the packet decoding information of the packet to be transmitted, At least one of a packet size of the packet to be transmitted, a modulation method applied to the packet to be transmitted, a hybrid automatic retransmission request (HARQ) identifier, and free version (RV) information indicating the number of transmissions of the packet to be transmitted. A transmitting device, characterized in that. A method of receiving packet decoding information for a packet service in a mobile communication system, Monitoring a grant channel to determine whether new transmission resource information is received until an allocation time of a basic transmission resource set for the packet service is reached; If the new transmission resource information is not received until the allocation time is reached, receiving a first packet through the basic transmission resource of a common channel, and processing the first packet using the set basic packet decoding information; , If the new transmission resource information is received before reaching the allocation time point, a second packet and packet decoding information about the second packet are received through the transmission resource of the shared channel indicated by the new transmission resource information, and Receiving a second packet according to the received packet decoding information. 13. The method of claim 12, further comprising acquiring transmission resource related information indicating the allocation time of the basic transmission resource when establishing a call for the packet service. The method of claim 13, further comprising receiving basic transmission resource information indicating information about the basic transmission resource after acquiring the transmission resource related information. The method of claim 12, wherein the packet decoding information about the second packet, And at least one of a packet size of the second packet, a modulation method applied to the second packet, a complex automatic retransmission request (HARQ) identifier, and free version (RV) information indicating the number of transmissions of the second packet. How to receive. An apparatus for receiving packet decoding information for a packet service in a mobile communication system, A grant channel processing unit for monitoring a grant channel to receive transmission resource information; A packet decoding control unit which determines whether new transmission resource information is received until an allocation time of the basic transmission resource set for the packet service is reached; If the new transmission resource information is not received until the allocation time, the first packet is received through the basic transmission resource of the common channel and the first packet is processed according to the set basic packet decoding information. When the new transmission resource information is received before reaching, the second packet and the packet decoding information about the second packet are received through the transmission resource of the shared channel indicated by the new transmission resource information, and according to the packet decoding information. And a receiving unit which processes the second packet. The method of claim 16, wherein the packet decoding control unit, And receiving resource information related to the allocation time of the basic transmission resource when establishing a call for the packet service. The method of claim 17, wherein the packet decoding control unit, And after receiving the transmission resource related information, basic transmission resource information indicating the information on the basic transmission resource through the grant channel processing unit. 17. The method of claim 16, wherein the packet decoding information about the second packet, And at least one of a packet size of the second packet, a modulation method applied to the second packet, a complex automatic retransmission request (HARQ) identifier, and free version (RV) information indicating the number of transmissions of the second packet. Receiving device.

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