KR20030035043A - Apparatus for transmitting multi-media data in mobile communication system - Google Patents

Abstract

PURPOSE: An apparatus for multimedia data transfer in mobile communication system is provided to performe packet retransfer efficiently and stably by generating a rule for transfer unit retransfer of HARQ using MQC. CONSTITUTION: A radio link protocol layer(210) receives data information having plural different service qualities and divides the data information in size according to each service quality. A multiplexing layer multiplexes the divided data information from the radio link protocol layer and outputs the multiplexed data information by a transfer unit. A quality control channel receives the multiplexed data information and outputs transfer unit blocks determined by the service qualities by punching and repeating information added according to the service qualities with respect to the multiplexed data information.

Description

Device for transmitting multimedia data in mobile communication system {APPARATUS FOR TRANSMITTING MULTI-MEDIA DATA IN MOBILE COMMUNICATION SYSTEM}

The present invention relates to a mobile communication system applying a multimedia data transmission method, and to generate a rule for TU unit retransmission of HARQ using MQC in an asynchronous / rate adaptive transmission method, it is possible to efficiently and reliably perform packet retransmission. To be.

In general, a mobile communication system is typically a code division multiple access (Code Division Multiple Access) method. Many studies are being actively conducted to enable high-speed data transmission in such mobile communication systems. Recently, new researches have been conducted to service multimedia data in 3GPP2 to supplement the shortcomings of the 1XEV-DO system, a packet data transmission system. Such a system for servicing multimedia data is called a 1X EV-DV (1X EVolution Data and Voice) system.

The 1XEV-DV system can be used not only for data transmission such as 1XEV-DO, but also for services requiring real time such as voice. That is, it is a multimedia service providing system that supports not only packet data transmission but also real time service. In order to support the multimedia service, various new technologies must be combined. That is, the 1XEV-DV system, which is a system for providing a multimedia service, should be optimized for general packet data transmission in which data transmission delay is not a problem. In recent years, the general tendency of separating and processing packets that require different transmission importance and real time even in general Internet protocol becomes clear. However, currently implemented mobile communication systems do not consider much of the above trends, and are not configured to provide multimedia services, and have the same transmission superiority and quality of service (QoS) requirements for all packets. Processing.

Meanwhile, in the 1xEV-DV system, various attempts have been made to efficiently implement a hybrid ARQ (HARQ) technique applied in 1xEV-DO. 1 is a timing diagram of an asynchronous and adaptive rate adaptation Incremental Redundancy (hereinafter, AAIR) of HARQ. This method uses a synchronous transmission scheme as a transmission technique for applying HARQ and has a scheme of having multiple users together in a transmission target. In the synchronous transmission method, when a response (ACK / NACK) is received to a transmission packet and a retransmission is required, a time point for sending a retransmission packet is always constant.

In addition, in the 1xEV-DV system, methods for maximizing the effects of multi-user diversity applied in 1xEV-DO have been sought, and as one of them, an asynchronous transmission method has been proposed. In the asynchronous transmission method, the retransmission packet is not transmitted at regular intervals as in the synchronous transmission method, and when the channel characteristic is superior to other users in order to ensure the transmission superiority to the user having excellent channel characteristics, The concept of transmitting the retransmission packet. This will be described with reference to FIG. 1. After sending a packet, a response is transmitted to the transmitter after a predetermined time. In this case, a method of attempting retransmission at a predetermined time is called a synchronous transmission method. In this case, the retransmitted packet is transmitted at the same transmission rate.

An object of the present invention is to retransmit HARTU TU unit in the asynchronous / rate adaptive transmission scheme applying the MQC concept capable of inter-service transmission quality control to the newly proposed asynchronous transmission scheme to increase the efficiency of the conventional HARQ synchronous transmission scheme. By providing a scheme, it supports stable packet transmission.

1 is a timing diagram of an asynchronous and adaptive rate adaptation Incremental Redundancy (hereinafter AAIR) of HARQ.

2 is a protocol of a multiple quality channel (MQC) applying the AAIR transmission method,

3 is a diagram summarizing various combinations for determining an input packet in a structure using an MQC channel according to size;

4 is a diagram illustrating an example of a TU configuration of a subpacket generated when retransmission is performed in a transport block (TU) unit during retransmission;

5A to 5B are flowcharts illustrating a TU repetition rule occurring when retransmission of a TU unit of HARQ using the MQC proposed in the present invention;

6 is a timing diagram for packet transmission using the scheme of FIG. 5;

7 is a flowchart illustrating a method for controlling an error that may occur when retransmission of a TU unit of HARQ using the MQC proposed in the present invention;

8 is a timing diagram illustrating an example of error recovery to which the solution of FIG. 7 is applied.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. First of all, in adding reference numerals to the components of each drawing, it should be noted that the same reference numerals have the same reference numerals as much as possible even if displayed on different drawings. Also, in the following description, many specific details such as components of specific circuits are shown, which are provided to help a more general understanding of the present invention, and the present invention may be practiced without these specific details. It is self-evident to those of ordinary knowledge in Esau. In the following description of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

Detailed operation and structure of the present invention will be described with reference to the accompanying drawings.

FIG. 2 is a block diagram illustrating a protocol structure in which the MQC scheme is applied to an asynchronous / rate adaptive scheme. Hereinafter, a detailed description will be given with reference to FIG. 2.

The protocol configuration illustrates interfaces and functional blocks of an RLP layer, a multiplexing layer, and a physical layer, which are upper layers. 2 is a protocol structure for providing different QoS using a physical layer subchannel, and illustrates a structure in which pure user information is transmitted instead of user plane, that is, control information. In the case of indicating a control plane, logical channels are mapped to specific control channels, and physical layer subchannels are mapped 1: 1 to specific logical channels. Hereinafter, the operation will be described as an example in the case of a user plane. However, the respective functional blocks can be applied to the control plane as it is.

The RLP layer 200 is a structure of a logical channel determined according to the class of the application service stream. Accordingly, the RLP layer 200 may be configured with a plurality of logical channels according to the class of the application service. That is, each logical channel may be provided with an independent RLP or one RLP. When each independent RLP is provided, RLP instances may be generated by the number of classified logical channels. At this time, the RLP performs a sequence number management and segmentation function of data transmitted to each logical channel. However, when one RLP manages a plurality of logical channels, management of comprehensive logical channels is required rather than management of independent logical channels, so that functions of different RLPs may be required. Hereinafter, an example in which an independent RLP is provided for each logical channel will be described. The transmission unit of the data transmitted through the logical channel may be determined according to the source data rate generated in the application service, and the transmission unit of the configured data is a transmission unit provided by the physical layer sub-channel. It may be smaller or the same size.

The MUX & QoS layer 210 performs mapping between logical channels and physical layer subchannels. The logical channel input to the MUX & QoS layer 210 is mapped to a physical layer subchannel through three functions as follows.

(1) Multiplexing functionality: fixed-length data when the length of data transmitted on the logical channel is smaller than the transport unit (hereinafter referred to as "TU"), which is a data unit transmitted on the physical layer subchannel. It is assembled with data transmitted through other logical channels to form a unit.

(2) Switching functionality: If the length of data transmitted on the logical channel is the same as the length of the TU transmitted on the physical layer subchannel, switching to a specific physical layer subchannel without assembly with data transmitted on other logical channels. Can be mapped. In addition, it is possible to map data generated from logical channels having the same or similar QoS to physical layer subchannels that provide a specific QoS, or to appropriately distribute data transmitted from logical channels to always activate the physical layer subchannels. to provide.

(3) QoS control functionality: Data transmitted on a logical channel may be transmitted on a physical layer subchannel according to transmission priority. At this time, the priority assigned can be determined according to the characteristics of the logical channel. In addition, the control information may be applied together with the user data information, or signaling information for transmitting the system information is transmitted along with other data information.

The physical layer subchannel 220 may be composed of a plurality of channels generated in the RLP layer and corresponding to the number of TUs output by the three controls in the MUX & QoS layer 210. Each physical layer subchannel may have different QoS settings according to functional blocks provided in the physical layer. The length of the TU transmitted to the physical layer subchannel may be set differently according to the case of forward and reverse directions. The forward / reverse direction may consist of a fixed length TU or a variable length TU, the forward direction being a fixed length TU, the reverse direction a variable length TU or the reverse direction a variable length TU or the reverse direction a fixed length TU. It may be. The physical layer subchannels 220, in which QoS may be set differently by functional blocks provided in the physical layer, may be mapped to TUs generated through the MUX & QoS layer 210. QoS of the physical layer subchannel may be determined according to an assigned value of QM (QoS Matching), which is a function of the physical layer that actually provides the QoS of the transmitted TU.

The following MQC channels provide different QoS over the physical layer subchannel 220. Each of the MQC channels performs the same operation. However, the QoS value of each transmission TU or the size of the transmission data may be configured differently, but the internal processing is the same. Therefore, hereinafter, only one MQC channel is described as a representative.

CRC combiner 240 is added to the CRC added for each TU. This may be used as a retransmission unit according to a transmission scheme provided by a lower layer, that is, ARQ. As described above, the data combined with the CRC by the CRC combiner 240 is input to the encoder. The encoder 250 is illustrated as a turbo encoder. However, it can also be configured using other encoders. The turbo encoder 250 encodes the input TU. In this case, the coding rate may be differently applied to each TU transmitted to each physical layer subchannel. Alternatively, the same coding rate may be applied to each TU transmitted from each physical layer subchannel. In addition, in the case of retransmission using HARQ, when retransmission due to an error of initially transmitted data, a coding rate may be determined to be different from the initial transmission.

Redundancy Selection (Redundancy Selection) 260 is a block that can be useful in the case of using HARQ Type II / III (Hybrid ARQ) as a link transmission method when retransmission after the initial transmission failed (in the present invention between TUs) Retransmission is possible.) It is used to improve the combining performance of the receiver by transmitting a redundancy matrix different from the initial transmission, that is, supplementary code. In addition, in the present invention, the same TU may be configured to perform different repetition and puncturing to generate transmission symbols of various sizes. The additional code used in the above should also consider the retransmission order, but since it must go through different repetition and puncturing processes, it is necessary to specify a complex additional code that can have complementarity in each repetition and puncture.

QoS Matching (QM) 270 substantially provides different QoS to each TU. Punching and repetition are used to appropriately adjust the value of QM. The value of QM is a value that can be assigned a fixed value or provided dynamically when the channel is set to static. When statically provided, it is determined when the channel is set up between the base station and the mobile station for data transmission. When the QM value is dynamically changed, the QM value is transmitted to the receiver through the control channel when each TU is transmitted. The QM value that is assigned to a fixed value or that can change dynamically during initial transmission or retransmission is a relative value between physical layer subchannels and is used as an important parameter for differently setting the quality of the physical layer subchannels according to the characteristics of the application service. do.

The MQC structure can generate multiple transmission symbols to support various subpacket transmission rates. However, the ratio of weights applied to each MQC channel is always processed equally for one input packet. Therefore, for each subpacket transmission rate, one transmission symbol that supports the same transmission rate among various types of transmission symbols for each MQC channel is selected and sent to the serial combiner.

The physical channel serial concatenation unit 280 combines the processed TUs and outputs the combined TUs to the channel interleaver 290. In addition, the serial combiner 280 according to the present invention receives a transmission symbol supporting the same data rate and combines in series. The TUs combined in series in the serial combiner 280 are input to the channel interleaver 290. The channel interfiber 290 performs channel interleaving and outputs TUs which are input in series. The data output as described above is mapped to a transmission slot of a physical channel and transmitted to a receiver. The number of TUs mapped to the slots of the physical channel may be determined differently according to the transmission rate of the physical channel provided at any moment.

When the asynchronous retransmission method is used using the structure of FIG. 2, the retransmission packet is a value obtained by encoding the same input packet, but the retransmission packet is punctured and repeated in various forms through repetition and puncturing to support different transmission rates. It will generate a symbol for the proper data rate. Therefore, in the present invention, the number of TUs constituting the transmission symbol is determined according to the size of the input packet. In the present invention, a method of supporting various data rates among asynchronous retransmission schemes is considered. That is, in the present invention, when the size of the input packet entering the encoder is determined, the number of TUs is determined accordingly. When the number of TUs is determined, the QMI set to be applied is also determined accordingly.

The principle of constructing a QMI set is to ensure that values delivered from information sources with the same class have the same weight. The remaining area in the packet determined according to the transmission rate should be filled with the TU delivered from the higher level information source. However, if the data generation of the lower level information source is fast, fill it first. The weight is adjusted so that the sum of processed symbols in the QM block of each TU is equal to the interleaver size based on the interleaver size possible at each transmission rate.

When retransmitting HARQ, the same QMI (Quality Matching Index) may be transmitted in the forward and reverse directions, respectively, or may be transmitted by applying different QMI. It can work as determined which option to use when setting up the initial service environment. In case of retransmission, since retransmission is possible for each TU, one of the appropriate initial negotiated QM sets may be indexed or the same weight may be used for each TU location.

In the asynchronous transmission scheme of the HARQ, QMI for retransmission packets may be equally weighted as in the synchronous transmission scheme. Alternatively, different weights may be used for retransmission and initial transmission. At this time, the criteria for allocating the QMI depends on the size of the input packet.

In the present invention, it is assumed that the service negotiation process of the IS-2000 system is used in setting up a service to select a type of a QM set to be used in a corresponding application service or an operation of a QM to be used for retransmission of HARQ. In the case of a QM set, different QoS parameters may be required for each application service, and an appropriate value may be used according to a situation in the current cell area.

FIG. 3 is a diagram illustrating various combinations for determining an input packet according to a size in a structure using an MQC channel. A description with reference to FIG. 3 is as follows.

First, the smallest input packet size is shown as 384 bits. However, this can be changed to a smaller or larger size. The size of each TU can determine its size once within the limits of the input packet. For example, one of 384, 768, 1536, and 3072 bits is selected and combined. The combined packet size is one of the TU sizes mentioned above. However, it is a content that can always change when a transmission rate that supports these combinations is added. These combinations are each indexed with QMI. Each combination is assigned 0000, 768 bits to 0001,0010 for at least 384 bits, 1536 bits to 0011 to 1000, and finally 3072 bits to 1001 to 1110. These indices can be combined if the supported bit rate or the size of the input packet changes.

4 is a diagram illustrating examples of subpackets retransmitted. This results in the same result as in FIG. 4 according to the configuration of the response (ACK / NAK) bit returned in the case of an input packet including the same four TUs. The number on the left shows the configuration of multiple ACK / NAK bits and the right describes the NAKed TU configuration in the subpacket accordingly.

In the above, the NAKed TU configuration in the subpacket may be determined with the following factors. It will replace the position of the ACKed TU.

1) Iteratively repeats the service priority of each TU.

2) Next, in the case of TUs with the same value, the left side TU is repeated first.

3) If two or more TUs fail at the same time, they are not repeated more than three times for each TU.

5A is a control flowchart of determining whether to transmit a retransmission subpacket and transmitting a request signal according to the present invention. Hereinafter, the retransmission subpacket transmission process will be described in detail with reference to FIGS. 2 to 5.

In the packet generated by the configuration of FIG. 2, packet data is transmitted through an environment of a wireless channel in a format as shown in FIG. The receiver then receives the subpacket in step 500. The receiver then proceeds to step 510 to check for errors in the received packet. At this time, in the present invention, the error for each TU constituting the subpacket is checked. If there is no error as a result of the error test in step 510, an ACK signal is generated in step 511 and the test result is sent to the transmitter through a wireless environment. On the contrary, if an error occurs in the TU in step 510, the process proceeds to step 520 to check the configuration of the TU in which the error occurs. The receiver determines the configuration of the NAK in step 520, and generates the QMI promised to both sides when setting up the service according to the repetition rule of the TU as shown in FIG. 3 and FIG. The QMI is used to check the subpacket according to the error of the ACK channel of the retransmitted subpacket. The receiver proceeds to step 540 and transmits the value of QMI generated according to ACK / NAK to the transmitter in step 530.

FIG. 5B is a control flowchart when retransmission is performed on the transmitter side when the NAK transmitted to the transmitter in FIG. 5A is returned. Hereinafter, the present invention will be described in detail with reference to FIGS. 2 to 5A and 5B.

The transmitter receives an Ack / Nak signal when a predetermined time elapses after transmitting the packet data. That is, in step 550, the Ack / Nak signal is received. At this time, the transmitter checks the Nak signal. Upon receiving the Nak signal, the transmitter proceeds to step 560 to check service superiority of TUs requiring retransmission. This is to repeatedly transmit a higher number of data having a higher service superiority according to the inspection of the service superiority. In step 570, if the nak TU has the same superiority, it is determined that the superiority of the TU located on the left side is high. After filling the packet for retransmission in this manner, the process proceeds to step 575. In step 575, the transmitter checks whether the TUs to perform the retransmission match the size of the initially transmitted PLP. If the result of the check is not matched, the process proceeds to step 560 where the packet having a high service superiority is further repeated.

If the TUs match the initial transmission PLP size through the above processes, the process proceeds to step 580. When the transmitter proceeds to step 580, the transmitter generates input packets according to the PLP field of TUs requiring retransmission. Thereafter, the transmitter proceeds to step 590 to determine a corresponding QMI, and then transmits a retransmission subpacket.

6 is a control flowchart for checking transmission errors of retransmitted TUs according to the present invention and recovering them when an error occurs. Hereinafter, the inspection of a transmission error of signals and a process for recovering the same will be described in detail with reference to FIGS. 2 to 6.

The receiver stores information on an error TU among the initially transmitted TUs. That is, it stores the information of the TUs requesting retransmission. In this state, the receiver receives the subpacket retransmitted from the transmitter. That is, in step 600, the subpacket is received. In step 610, the receiver compares the QMI value received from the transmitter with the stored QMI. If the two values match, the process proceeds to step 611. If the two values do not match, the process proceeds to step 620.

First, the case where the two values do not match is explained.

In step 620, the receiver checks whether an error exists in the retransmitted TU. If there is a TU having an error as a result of the check, the process proceeds to step 630; otherwise, the process proceeds to step 625. That is, when the process proceeds to step 625, an error does not occur in the retransmitted TU. In this case, an ACK value for the TUs retransmitted in step 625 is transmitted to the transmitter. However, if the flow proceeds to step 630, that is, if an error exists in the retransmitted TUs, the QMI values of the TUs to request retransmission are generated. Thereafter, the receiver proceeds to step 640 to transmit the NAK value for the TU that needs to be retransmitted to the transmitter.

Next, the two values do not match. If the two values do not match, the process proceeds to step 611 to discard the subpacket transmitted from the transmitter. In step 640, the NAK is returned to the transmitter to request retransmission of the same subpacket. At this time, the returned NAK becomes the value of the initially examined NAK.

7 is a timing diagram illustrating a process of retransmission when an input packet of 1536 bits is transmitted according to an embodiment of the present invention. Hereinafter, a process of retransmission will be described in detail with reference to FIG. 7. FIG. 7 is a view illustrating the case of “0011” in case (c) Case III of FIG. 3 described above. Therefore, it will be described using the index assigned in FIG.

Each TU is 384 bits in size. In addition, the corresponding QMI is 1101 '0011'. The packet data is transmitted at the first transmission. However, it is assumed that the receiver receives an acknowledgment using 0 in the case of ACK and 1 in the case of NAK, and it is described that the response signal transmits '0110' (ACK / NAK / NAK / ACK). This is a result of transmission error of TU1 and TU2. At this time, according to the repetition rule presented above, the PLP is configured by repeating TU1 / TU2. At this time, the QMI becomes '0110'. Then, the QMI during retransmission is retransmitted according to the method of FIG. 4.

When retransmission is requested as described above, correction of an error due to retransmission will be described with reference to FIG. 8. 8 is a packet transmission and reception timing diagram for performing error correction upon retransmission according to the present invention. A packet is transmitted as shown in FIG. 7, and an error occurs in the transmitted packet.

In case of transmitting a subpacket of QMI '0010' '0011', the receiver sends a response ('0110') indicating that an error occurs to TU1 and TU2. And, it generates and stores the QMI expected value (0011'0110 '). However, if an error occurs during transmission of the response signal and '0100010' is transmitted, the QMI of the retransmission subpacket is retransmitted by repeating the TU with a rule corresponding to the value of 0100'0010 ', which is completely different from the expectation of the receiver. . Therefore, the receiving side can compare this value (QMI: '0010') with the stored value ('0110') to determine whether the transmission is correct. In this case, if an error occurs, the corresponding subpacket is discarded and retransmission is requested for the same retransmission packet. When a request for retransmission is received, the modified value is retransmitted based on the previously stored value.

As described above, in the present invention, by generating a rule for TU unit retransmission of HARQ using MQC in the asynchronous / rate adaptive transmission scheme, it is possible to efficiently and stably perform packet retransmission.

Claims (1)

A radio link protocol layer for inputting data information having a plurality of different quality of service and dividing the size of the data information according to each quality of service; A multiplexing layer for multiplexing the divided data information from the radio link protocol layer and outputting the multiplexed data information in a transmission unit; Inputting the multiplexed data informations and puncturing and repeating information added according to the quality of service for the multiplexed data information according to the quality of service to output transmission unit blocks determined by the quality of service Protocol device for use in a mobile communication system comprising a quality control channel.