KR20060089956A - Method for uplink packet data service in asynchronous wcdma system - Google Patents

Abstract

The present invention relates to a method for transmitting packet data in a mobile communication system. The method of the present invention comprises the steps of determining a physical channel data bit size in consideration of a packet data bit size and a punctuation limit among a set of usable physical channel data bit sizes, and using the determined physical channel data bit size. And transmitting the packet data using the maximum physical channel data bit size in the set of physical channel data bit sizes when there is no physical channel data bit size satisfying the puncturing limit. Here, the physical channel data bit size corresponding to the combination of the spreading index and the number of channel codes is such that maximum transmission efficiency and minimum number of bits are punctured without requiring an additional physical channel in transmitting the packet data. Is determined. The present invention has the effect of maximizing transmission efficiency, saving transmission resources, and reducing signaling overhead incurred in transmitting control information required for transmission and reception of the packet data.

WCDMA, E-DCH, uplink packet transmission, TFRI, MF, SF, TBS, PL

Description

Method of transmitting packet data in mobile communication system {METHOD FOR UPLINK PACKET DATA SERVICE IN ASYNCHRONOUS WCDMA SYSTEM}             

1 is a conceptual diagram illustrating transmission of typical uplink data.

2 is a message flow diagram illustrating a procedure for transmission of uplink data.

3 is a diagram showing transport block sizes (TBSs) of data that can be transmitted for combinations of a modulation scheme (MF) and a spreading index (SF).

4 illustrates a one-to-one mapping relationship of transport block sizes for combinations of modulation schemes and spreading indexes in accordance with a preferred embodiment of the present invention.

5 is a block diagram of a determiner for determining a modulation scheme and a spreading index using a transport block size according to a preferred embodiment of the present invention.

6 is a flowchart illustrating a procedure for determining a modulation scheme and a spreading index using a transport block size according to a preferred embodiment of the present invention.

7 is a block diagram of a terminal transmitter according to a preferred embodiment of the present invention.

8 is a block diagram of a base station receiver according to a preferred embodiment of the present invention.

9 is a flowchart illustrating a procedure of determining a spreading index and the number of code channels using a transport block size according to a preferred embodiment of the present invention.

The present invention relates to asynchronous wideband code division multiple access (WCDMA) communication, in particular data of an enhanced uplink dedicated channel (hereinafter referred to as EUDCH or E-DCH). The present invention relates to a method for efficiently determining and transmitting control information necessary for transmitting a signal.

The UMTS (Universal Mobile Telecommunication Service) system, a third generation mobile communication system based on the Global System for Mobile Communications (GSM), which uses a wideband code division multiple access (WCDMA) technology, is a mobile phone or computer. It provides a consistent service that enables users to transmit packet-based text, digitized voice or video and multimedia data at speeds of more than 2 Mbps wherever they are in the world. UMTS uses the concept of virtual access, which is a packet-switched connection that uses a packet protocol such as Internet Protocol (IP), and can always be connected to any other end in the network.

In particular, in the UMTS system, an uplink dedicated channel (E-) is improved to further improve the performance of packet transmission in uplink (UL) communication from a user equipment (UE) to a base station (BS). DCH). E-DCH is an improvement from a typical dedicated channel (DCH) to support more stable high-speed data transmission. ) And a transmission channel supporting techniques such as base station control scheduling.

AMC is a technology that increases the use efficiency of the data channel by variably determining the modulation method and coding method of the data channel according to the channel state between the base station and the terminal. The AMC uses Modulation and Coding Scheme (MCS) levels representing various combinations of modulation and coding schemes. AMC adaptively determines the MCS level according to the channel state between the terminal and the base station to increase the overall use efficiency.

HARQ refers to a technique for retransmitting a packet for compensating for the error packet when an error occurs in an initially transmitted data packet. The receiver soft-combines and decodes the packet retransmitted to the initially received data packet. The complex retransmission technique includes a chase combining technique (hereinafter referred to as CC) that retransmits the same bits as an initial transmission when an error occurs, and an incremental redundancy technique that retransmits different bits than the initial transmission when an error occurs. IR).

The base station control scheduling method refers to a method in which a base station determines and transmits uplink data and an upper limit of a possible data rate by the base station when the data is transmitted using the E-DCH. . The terminal determines the data rate of possible uplink E-DCH data based on the informed information. In this case, the MCS level is adaptively determined according to the channel state between the terminal and the base station in order to increase the use efficiency.

1 is a conceptual diagram illustrating transmission of data through an E-DCH in a radio link.

Referring to FIG. 1, reference numeral 110 denotes a Node B supporting the E-DCH, and reference numerals 101, 102, 103, and 104 are terminals transmitting the E-DCH. The Node B 110 determines the channel status of the terminals 101 to 104 using the E-DCH and schedules data transmission of each terminal. Scheduling provides a low data rate to the terminal 104 far from the Node B 110 while ensuring that the Rise Over Thermal (RoT) value of the Node B 110 does not exceed the target value in order to improve system-wide performance. And a high data rate is assigned to the terminal 101 near.

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

Referring to FIG. 2, in step 203, the Node B 201 and the terminal 202 configure an E-DCH. The setup process 203 includes a process of delivering messages through a dedicated transport channel. If the E-DCH is configured, the terminal 202 informs the node B 201 of the status information as in step 204. The state information may include terminal transmission power information indicating uplink channel information, extra power information that can be transmitted by the terminal, and an amount of data to be transmitted in a buffer of the terminal.

Upon receiving the status information, the Node B 201 monitors the status information of the terminal 202 in step 211. In step 211, the Node B 201 determines that the uplink packet transmission is allowed to the terminal 202, and transmits scheduling assignment information to the terminal 202 in step 205. The scheduling allocation information includes an allowed data rate and an allowed timing.

The terminal 202 determines the transport format (TF) of the E-DCH to be transmitted in the uplink using the scheduling assignment information in step 212, and the E-DCH in steps 206 and 207. The UL data is transmitted through the TF information to the Node B. Here, the TF information includes a transport format resource indicator (hereinafter referred to as TFRI) indicating information necessary for demodulating the E-DCH. In step 207, the terminal 202 transmits the uplink data using the corresponding MCS level selected in consideration of the data rate and channel state allocated by the Node B 201.

In step 213, the Node B 201 determines whether there is an error in the TFRI and the data. In step 208, the Node B 201 receives a non-acknowledge (NACK) when an error appears in any one of the determination results, and acknowledges an acknowledgment (ACK) when all errors are found. To). When the ACK information is transmitted, the data is completed and the terminal 202 transmits new user data through the E-DCH. However, when the NACK information is transmitted, the terminal 202 transmits the same data through the E-DCH. Resend again.

In the transmission through the E-DCH, the UE uses a different MCS level at each transmission time and uses a different Spreading Factor (SF) hereinafter according to the size of data to be transmitted. In order to demodulate normally, control information about the packet, that is, TFRI information, must be obtained normally.

TFRI information necessary for demodulating uplink data includes a modulation format (MF), a spreading factor (SF), and a transport block size (TBS). Reducing the peak-to-average power ratio (hereinafter referred to as PAR) in the E-DCH is a very important issue, so modulation methods include binary phase shift keying (BPSK), quadrature PSK (QPSK), and 8-PSK. (8-ary PSK) and the like. In the case of SF, various Orthogonal Variable Spreading Factor (OVSF) codes may be used because uplink is not limited to code resource usage. In the case of TBS, E-DCH considers the peak data rate as about 2Mbps and supports various TBSs to satisfy various services.

The number of physical layer bits required for transmitting all the above control information through physical layer signaling becomes a total of 11 bits as follows.

MF [2], transport block size [6], SF [3]

These control information is transmitted using uplink resources, causing direct interference on the uplink. Therefore, the technology for more efficiently transmitting control information for demodulation of E-DCH data to the base station with only a small amount of bits in transmitting related information such as modulation method, transport block size and spreading index required for demodulation of E-DCH. Needed.

 Accordingly, the present invention, which is designed to solve the problems of the prior art operating as described above, in a demodulating data received by a base station from an MS through an uplink enhanced dedicated channel (E-DCH) in an asynchronous WCDMA communication system. A method for efficiently determining and transmitting necessary control information is provided.

The present invention provides a method for efficiently determining and transmitting control information necessary for demodulating data while reducing overhead of uplink in uplink enhancement dedicated channel which improves performance of uplink packet transmission system by base station control scheduling and AMC. To provide.

The present invention provides a method for efficiently delivering TFRI information for uplink enhancement dedicated channel.

In accordance with another aspect of the present invention, there is provided a method of transmitting packet data in a mobile communication system.

Determining a physical channel data bit size from the set of available physical channel data bit sizes in consideration of the packet data bit size and the puncturing limit;

Transmitting packet data using the determined physical channel data bit size;

If there is no physical channel data bit size that satisfies the puncturing limit, the packet data is transmitted using the maximum physical channel data bit size in the set of physical channel data bit sizes.

Another embodiment of the present invention for achieving the above object, in the method for transmitting packet data in a mobile communication system,

A first process of selecting a physical channel data bit size capable of transmitting the packet data without puncturing, in consideration of the packet data bit size from among a set of usable physical channel data bit sizes;

If there is no physical channel data bit size for transmitting the packet data without puncturing in the first process, the physical channel data capable of transmitting the packet data within a predetermined puncturing limit in consideration of the packet data bit size A third process of selecting a bit size,

Selecting a maximum physical channel data bit size from the set of physical channel data bit sizes when there is no physical channel data bit size capable of transmitting the packet data within the puncturing limit in the third process;

And transmitting the packet data using the selected physical channel data bit size.

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

In the present invention described below, in transmitting data through an uplink enhancement dedicated channel in an asynchronous WCDMA system, only the transport block size (TBS) information indicating the transport channel data bit size is informed to the base station so that the base station can spread the modulation scheme (MF) and spread. It is possible to reduce the signaling overhead of the uplink by obtaining an index (SF). To this end, the present invention will be described in detail the operation of the terminal determines the corresponding modulation scheme and spreading index according to the transport block size. The above operation is equally applicable to the case where the base station controls the modulation scheme and spreading index of the E-DCH according to the transport block size notified from the terminal.

In the uplink, when the AMC technology is used, the available SF for each MF is described as follows. Basically, among the number of OVSF codes that can be supported and the transmission combinations with the MF, the physical transmission combinations that can be actually used by each UE are set by the capability and higher layer signaling of the UE. In the asynchronous method, the data rate is divided into a spread index (SF). As the data rate increases, SF becomes lower. Since the data rate represents the data size that can be transmitted for a unit time, SF is related to the data size. If the terminal supports BPSK, QPSK, 8-PSK and can use all OVSF codes, the following combinations are possible.

{(MF, SF)} = {(BPSK, 256), (BPSK, 128), (BPSK, 64), (BPSK, 32), (BPSK, 16), (BPSK, 8), (BPSK, 4) , (QPSK, 4), (8-PSK, 4)}

In the case of QPSK and 8-PSK, the PAR is larger than BPSK, so it is used only when a large amount of data is transmitted, that is, when the data is larger than the size of data that can be transmitted by (BPSK, 4). Is suitable.

3 shows transport channel data bit sizes that can be transmitted according to respective MF / SF combinations. Herein, the transport channel data bit size means an encoded transport block size.

In FIG. 3, reference numeral 302 denotes a transport block size (TBS) that can be transmitted without puncturing when a code rate of 1/3 is used in each MF / SF combination, and reference numeral 304 denotes 1/3 in each MF / SF combination. When the code rate of is used, it shows the range of transport block size (TBS) that can be supported through puncturing. In this case, the indexes of the MF / SF combinations are in order: 1 for BPSK and SF = 256, 2 for BPSK and SF = 128, 3 for BPSK and SF = 64, 4 for BPSK and SF = 32, 5 for BPSK and SF = 16, 6 means BPSK and SF = 8, 7 means BPSK and SF = 4, 8 means QPSK and SF = 4, and 9 means 8-PSK and SF = 4.

Since the actual code rate can be adjusted according to the rate (i.e., puncturing rate) of puncturing the encoded information data at the time of encoding, the MF possible for a specific data bit size (here 500 bits) without limiting the puncturing rate. / SF combinations vary as indicated by X in FIG. 3. That is, when the TBS N _info to be transmitted is 500 bits, there are four MF / SF combinations that can be used as follows.

{(MF, SF)} = {(BPSK, 16), (BPSK, 8), (BPSK, 4), (QPSK, 4)}

When several MF / SF combinations are possible as described above when the 500-bit information is to be transmitted, the terminal selects an appropriate combination. In terms of transmission efficiency, if the information data to be transmitted using the same modulation scheme is the same size, transmission without puncturing is most efficient. Therefore, the terminal selects a combination of MF / SF that can transmit the data of the corresponding TBS as much as possible without puncturing among the possible MF / SF combinations for the size of one information data.

In the above example, combinations that satisfy these conditions include (BPSK, 4) and (QPSK, 4). In both combinations, the transport block size 302 that can be transmitted without puncturing is greater than 500 bits. Both combinations do not require puncturing to transmit 500 bits of data, but a low-order modulation scheme that uses relatively little energy in consideration of efficiency should select (BPSK, 4). More preferred. If the code resources are insufficient, even if the transmission efficiency is low, even if the same transport block size may use a different MF / SF combination may occur, but in the case of the uplink compared to the downlink OVSF code that can be used by one terminal Since there is almost no limit, one-to-one selection of the best transmission efficiency for each TBS is possible.

4 is a diagram illustrating a one-to-one mapping relationship between a combination of a modulation scheme (MF), a spreading index (SF), and a transport block size (TBS) according to a preferred embodiment of the present invention. Here, reference numeral 402 denotes a TBS that can be transmitted without puncturing when a 1/3 code rate is used in each MF / SF combination, and reference numeral 404 denotes a perforation when 1/3 code rate is used in each MF / SF combination. It shows the TBS that can be transmitted by.

As shown in FIG. 4, the TBS and the MF / SF combination are mapped one-to-one, and this mapping information is previously promised between the UE and the Node B before communication starts. After determining the combination of the modulation scheme and spreading index for transmitting the E-DCH data according to the TBS, the terminal transmits only the TBS of the modulation parameters used in the E-DCH in the TFRI information. Node B then recognizes the MF / SF combination of E-DCH data via the TBS.

5 shows a configuration of an apparatus for determining a modulation scheme (MF) and a spreading index (SF) using TBS according to a preferred embodiment of the present invention. Referring to FIG. 5, the determiner 502 takes the TBS 501 as an input, and the MF 503 by the decision equation f () according to the pre-stored puncturing limit (PL) values 505. ) And SF 504. The MF 503 and the SF 504, as mentioned above, are determined to use a higher efficiency modulation scheme as far as possible without puncturing. The puncturing limit PL is a parameter that indicates a limit ratio at which puncturing can be performed.

The operation of obtaining the MF / SF is performed immediately before the rate matching process of the uplink transmission path. The rate matching refers to a process of repeating or puncturing transport channel data bits, which are input of the rate matching after encoding, in accordance with a physical channel bit size in each transport channel. In the uplink, the physical channel bit size that can be transmitted without puncturing the data bits of the transport channel at every TTI (Transport Transmission Interval) is determined. When the physical channel bit size is determined, MF and SF are determined according to the physical channel bit size. The transport channel transmitter modulates and spreads the rate matched transport block according to the determined MF and SF to generate a physical channel frame having the determined physical channel bit size.

First, in order to obtain a physical channel bit size capable of transmitting transport channel data, the determiner 502 estimates the data bit size to be obtained after the late match. This is called the predicted total transmit data bit size. Here, the total means the sum of data bits of a plurality of transport channels multiplexed into one physical channel.

When using a combination of j th TFs (TF Combination: hereinafter referred to as TFC) in the x th transport channel, the transport channel data bit sizes as inputs of the late matching are N _{x, 1} , N _{x, 2} ,... N _{x, j} Although the rate matching is performed separately for each transport channel, since a plurality of transport channels are multiplexed into one physical channel, the transmittable physical channel data bits are determined according to the total size of the transmitted data bits to be obtained after the rate matching.

The predicted total transmission data bit size is the sum of the data bits after each transport channel data has passed the rate matching. In the absence of puncturing or repetition, the rate matching does not change each transport channel data bit size, so the estimated total transport data bit size is the sum of the data bits of all transport channels. However, the transport channel data bits of each transport channel are not collectively multiplexed, but are summed through the rate matching according to the importance of each transport channel. The rate matching rate is determined by the rate matching attribute value RM known through higher layer signaling. That is, the ratio of the x th transport channel data bit to all the transport channels is given as the ratio of the rate matching attribute value RMx of the x th transport channel to the minimum RM (minRM). Therefore, the total transmission data bit size predicted in the absence of puncturing or repetition is expressed by Equation 1 below.

If there is no physical channel bit size that can be transmitted without puncturing the size of the transmission channel data to be transmitted, the rate matching punctures the transmission channel data. When the maximum number of bits are punctured according to the preset puncturing limit PL, the total transmission data bit size is as shown in Equation 2 below.

The PL is a value for limiting the maximum possible puncturing rate that can guarantee the quality of the transmission channel data. The PL is given in common for the transport channels.

The determiner 502 selects a physical channel data size that satisfies the data size of Equation 1 or Equation 2, and selects a modulation scheme and a spreading index corresponding to the physical channel data size. Decide

Hereinafter, embodiments of the present invention for obtaining MF and SF according to the transport channel data bit size will be described.

The first embodiment sets corresponding puncturing limits PL for each of the plurality of modulation schemes for the E-DCH. The reason why the PL value is set differently according to the modulation method is that the transmission efficiency is different according to the modulation method. As mentioned above, in the uplink, it is preferable to select a modulation scheme having the highest transmission efficiency among BPSK, QPSK, and 8-PSK available in order to apply AMC when the same transport block size is used. However, each modulation scheme has better transmission efficiency than the higher modulation scheme even if it is punctured to some extent. Therefore, a puncturing limit (PL) indicating a maximum puncturing degree for each modulation scheme may be set. The puncturing limit corresponding to the specific modulation scheme is determined as the maximum puncturing rate such that the specific modulation scheme has a higher transmission efficiency than at least the immediately higher modulation scheme. PL values for each modulation scheme are determined by experiments, or adaptive PL values are notified to the UE by higher signaling.

For example, when a code rate of 3/4 using the QPSK method and puncturing is used and a code rate of 8-PSK and 1/2 is used, data having the same TBS can be transmitted. However, the transmission efficiency is better when transmitting using the QPSK method, so it is more appropriate to set MF as QPSK. Here, even when the data is punctured as much as possible and transmitted to the BPSK, a puncturing limit PL _bpsk is used for the transmission of the BPSK in order to determine whether the transmission efficiency is better than that of the QPSK. In addition, in order to determine whether the transmission efficiency is better when the data is punctured as much as possible through the QPSK and the 8-PSK transmission, the predetermined puncturing limit PL _qpsk is used for the transmission of the QPSK. That is, puncturing limits are set for each modulation scheme that can maintain higher performance than the higher modulation scheme.

The puncturing is accomplished by rate matching, which matches the transport channel bit size, that is, the transport block size to the desired physical channel bit size. Rate matching is performed by puncturing (or repeating) a transport block by a Rate Matching Attribute value RM known by higher layer signaling. Therefore, the size of the rate matched transport block is represented by the product of N _info and RM. In addition, when BPSK is used, the transmittable physical channel bit size is N _{max, bpsk,} and when the PL _bpsk is applied, the maximum transport channel bit size is multiplied by 1 / PL _bpsk and N _{max, bpsk} .

을 만족하는 N_info에 해당하는 TBS의 변조방식은 BPSK로 결정되고,

을 만족하는 N_info에 해당하는 TBS의 변조방식은 QPSK로 결정되며, 나머지 TBS의 변조방식은 8-PSK로 결정되는 것이 E-DCH의 전송 효율을 가장 최적화할 수 있다.then

The modulation scheme of the TBS corresponding to N _info satisfying is determined by BPSK.

The modulation scheme of the TBS corresponding to N _info satisfying is determined by QPSK, and the modulation scheme of the remaining TBS is determined by 8-PSK, thereby optimizing the transmission efficiency of the E-DCH.

According to a first embodiment, the decision formula f () of FIG. 5 is expressed as Equation 3 below. Here, the uplink packet data service is serviced by I transport channels, and the transport format (TF) of each transport channel is transport format combination set for each transmission time interval (TTI). It is determined by selecting one transport block combination (hereinafter referred to as TFC) from TFCS).

Here, RM _x is a rate matching attribute value of the x th transport channel given by higher layer signaling, and PL _bpsk and PL _qpsk represent a ratio of maximum punctured bits for BPSK and QPSK, that is, a predetermined puncturing limit. SET0 represents a set of all physical channel data bit sizes that can be transmitted in a combination of SFs and a physical channel number N _phy . The minimum SF (minSF) and the number of physical channels (N _phy ) for configuring the aggregation are given by higher layer signaling. When the number of SFs or physical channels that can be used for the E-DCH varies for every TTI, the UE arbitrarily determines SET0. An example of SET0 is as follows.

SET0 = {N ₂₅₆ , N ₁₂₈ , ... N _minSF , 2 × N _minSF , ... N _phy × N _minSF }

In addition, N _{x, j} represents the coded transport channel data bit size before rate matching (ie puncturing) in the x th transport channel using the j th transport format combination (TFC), and N _{data, j} is the j th transport format The transmittable physical channel data bit size in a combination (TFC) is shown. N _{max, bpsk} is the data bit size in the physical channel that can be transmitted with the minimum SF when using BPSK _{, which} is equal to N _minSF here. N _{max, qpsk} is the data bit size on the physical channel that can be transmitted with minimum SF when using QPSK. SF (N _{data, j} ) means SF used to transmit N _{data, j} .

FIG. 6 is a flowchart illustrating a procedure of determining a modulation scheme 503 and a spreading index 504 using the transport block size 501 in the determiner 502 according to the first embodiment of the present invention. Here, the terminal will be described as an operation of determining parameters (MF and SF) for use in the transmission of the E-DCH, but the same description will be given for the parameters (MF and SF) for the base station to use for reception of the E-DCH data. This also applies to control.

Referring to FIG. 6, in step 601, the UE has a maximum physical channel data bit size (N _{max, bpsk} ) when the BPSK is used, the puncturing limit of the BPSK as shown in Equation 2 above (PL). _bpsk ) to determine whether or not the maximum punctured transmission channel data bit size is equal to or greater than. If greater than or equal to, in step 602, the modulation scheme (MF) of the E-DCH is determined to be BPSK. Then, in step 606, SET1 is set to a combination of physical channel data bits having a value greater than the unperforated transport channel data bit size in the combination SET0 of all physical channel data bit sizes. Herein, the unperforated transport channel data bit size is as shown in Equation 1 mentioned above.

In step 609, the terminal determines whether the SET1 is not empty, that is, whether there is a physical channel data bit having a value larger than the size of the unperforated transport channel data bit. If the SET1 is not empty, in step 610, the UE determines SF corresponding to the minimum physical channel data bit size in the SET1 as SF for E-DCH data, and if the SET1 is empty, in step 611 In the SET0, the smallest SF (minSF) is determined as SF for E-DCH data.

On the other hand, if the maximum physical channel data bit size (N _{max, bpsk} ) when using the BPSK in step 601 is smaller than the maximum punctured transmission channel data bit size as shown in Equation 2 above, the terminal Proceeding to step 603, if the maximum physical channel data bit size (N _{max, qpsk} ) when using QPSK is greater than or equal to the maximum punctured transmission channel data bit size by applying the puncturing limit (PL _qpsk ) of QPSK. To judge. If greater or equal, in step 604 the modulation scheme MF of the E-DCH is determined to be QPSK and in step 607 the SF of the E-DCH is determined to be the minimum SF of SET0. On the other hand, if the maximum physical channel data bit size (N _{max, qpsk} ) when using QPSK is smaller than the maximum punctured transmission channel data bit size by applying the puncturing limit (PL _qpsk ) of QPSK _{, in step} 605 The modulation scheme (MF) of the -DCH is determined to be 8-PSK, and in step 608, the SF of the E-DCH is determined as the minimum SF (minSF) of SET0.

As described above, the UE first determines SF and MF using the PL value given for each modulation scheme. In the case of QPSK and 8-PSK, the SF for the E-DCH is determined as the minimum SF possible, but in the case of BPSK, various SFs may be used. Accordingly, when the MF is determined to be BPSK, the UE determines that the SF that can be transmitted without puncturing the TBS is SF for the E-DCH.

For example, when one E-DCH service is provided using one transport channel, at least SF is 4, PL _bpsk is 0.5, PL _qpsk is 0.75, and RM is 1, Equation 3 is represented by the following < It is simplified as shown in Equation 4>.

Referring to Equation 2, first, a case where the transport channel data bit size N _j is 500 bits will be described. Since N _{max, bpsk} is 640, N _{max, bpsk} -PL _bpsk x N _j is 390. Therefore, the MF of the transport channel data is determined as BPSK. When rescue SET1 to save the SF for BPSK SET1 should contain only N _4. Since the minimum component of SET1 becomes N _{data, j that} can be transmitted, N _{data, j} becomes N ₄ , and SF of the transport channel data is determined to be 4. That is, when N _j is 500 bits, MF is BPSK and SF is 4.

Next, when N _j is 1500 bits, N _{max, bpsk} − PL _bpsk × N _j is −360, so that N _{max, qpsk} − PL _qpsk × N _j is 155. The MF of the transport channel data is then determined to be QPSK, and since SF is fixed to the minimum value in QPSK, the SF of the transport channel data is determined to be 4. That is, when N _j is 1500 bits, MF is QPSK and SF is 4.

Next, a second embodiment of the present invention will be described.

The second embodiment uses the plurality of PL values when only one modulation scheme is used, and the first for some MCS levels when the physical channel data bit size that can be supported by the first PL value cannot be obtained. By applying a second PL value having a greater puncturing rate than the PL value, the supportable physical channel data bit size is obtained again. This is to puncture a larger amount of bits when the physical channel data bit size that can be supported as the first PL value cannot be obtained. The second PL value is determined according to the type of physical channel used, that is, the physical channel data bit size according to the MCS level. At least one physical channel data bit size to which the second PL value is applied is given by higher layer signaling or is determined as a physical channel data bit size corresponding to the maximum MCS level. In addition, the PLs are set by higher layer signaling in consideration of the maximum transmittable rate or set to predetermined values.

For example, when IR-based HARQ is used, since different bits are retransmitted at the time of an error when the error occurs, the rate matching may puncture more bits for the transport channel data bits. Therefore, in this case, PL in general transmission and PL_IR having a larger processability than the PL are used together.

When the modulation scheme applied to the E-DCH is only BPSK and supports a plurality of physical channels, a second embodiment of the present invention for determining MF and SF using a plurality of PL values is shown in Equation 5 below. Is represented.

Here, RM _x is a rate matching attribute value of the x-th transport channel given by higher layer signaling, and PL0 and PL1 represent different puncturing limit values predetermined. PL1 represents a process flow chart larger than PL0. N _{x, j} represents the encoded data bit size before rate matching (i.e., puncturing) in the xth transport channel using the jth transport format combination (TFC), and N _{data, j} represents the jth transport combination ( TFC) shows the transmittable physical channel data bit size. Also SET0 is SF and the physical channel number that shows the set of all physical channel data bit size, can be combined transmission in the (N _phy), minimum SF (minSF) and a physical channel number (N _phy) for constituting the set are Given by higher layer signaling. When the number of SFs or physical channels that can be used for the E-DCH varies for every TTI, the UE arbitrarily determines SET0. For example, SET0 is given as follows.

SET0 = {N ₂₅₆ , N ₁₂₈ , N ₆₄ , ..., N _minSF , 2 × N _minSF , 3 × N _minSF , ... N _phy × N _{min SF} }

In addition, SET4 means a set of physical channel data bit sizes that are predefined or determined by higher signaling such that PL1 is applied. For example, SET4 may include only the maximum physical channel data bit size related to the maximum MCS level. .

Referring to Equation 5, the operation performed in the terminal will be described.

The terminal sets the physical channel data bit sizes (N _data ) larger than the unperforated transport channel data bit sizes to SET1 in the SET0. If the SET1 is not empty and the minimum component of the SET1 needs only one physical channel, the physical channel data bit size of the E-DCH is determined as the minimum component min SET1 of the SET1. If the SET1 is empty or the minimum component of the SET1 needs an additional physical channel, the terminal may have a physical channel larger than the maximum puncturing transport channel data bit size according to PL0 in the SET0. The combination of data bit sizes (N _data ) is set to SET2.

If the SET2 is not empty, the physical channel data bit size of the E-DCH is determined as the minimum component min SET2 of the SET2. At this time, if the determined physical channel data bit size is not the maximum component of SET2, and a follower following the determined physical channel data bit size does not need an additional physical channel, The final decision is made on the channel data bit size. That is, if the SET2 has at least two components and there is at least one component requiring only one physical channel, the physical channel data bit size of the E-DCH is at least one requiring only one physical channel. It is determined as the minimum of one component.

For example, if SET2 is {N ₁₆ , N ₈ , N ₄ , 2 × N ₄ }, the minimum component is 2N ₁₆ but N ₄ is physical because the next element, N ₈ , N ₄ , uses only one physical channel. The final selection is made to the channel data bit size. SF is then determined to be 4.

On the other hand, if the SET2 is empty, the terminal is larger than the transmission channel data bit size maximum punctured according to PL1, which is larger than the PL0 in the SET4 including at least one physical channel data bit size as described above. The set of physical channel data bit sizes (N _data ) is set to SET3, and the physical channel data bit size of the E-DCH is determined as the minimum component of the SET3.

7 shows a configuration of a terminal transmitter for determining MF / SF according to a preferred embodiment of the present invention.

Referring to FIG. 7, the MAC (Medium Access Control) layer processor 701 determines a transmission type combination (TFC) for use in transmitting input data through the E-DCH, and the data according to the determined transmission type combination. Create blocks. The TFC is the size and number of data blocks determined to satisfy a possible power level and channel condition of the terminal within the maximum allowable data rate set by the base station. The transport channel data bit size, that is, the transport block size TBS, is determined as the product of the size and the number of the data blocks.

The determined TBS is provided to the MF / SF determiner 705 of the physical layer 700 in the form of an internal primitive. The MF / SF determiner 705 determines the appropriate MF / SF and physical channel data bit sizes through the above-described embodiments using the TBS and the preset late match attribute value and PL values. The SF and the MF are provided to a spreader 703 and a modulator 704, respectively, and the physical channel data bit size is provided to the matchers 710.

The data blocks generated by the MAC layer processor 701 are encoded by the encoders 702 for each transport channel and then input to the multiplexer 711 through the line matchers 710. Here, the matchers 710 perform a late match (ie puncturing) the data blocks according to the physical channel data bit size. The multiplexer 711 multiplexes the late matched transport channel data. The multiplexed data has the physical channel data bit size and is spread using the spreading index SF determined by the MF / SF determiner 716 in the spreader 703. The spread data is modulated according to the modulation scheme MF determined by the MF / SF determiner 705 in the modulator 704. The modulated data is carried on the carrier wave through the RF unit 712 and transmitted through an antenna.

Meanwhile, the control information including the determined TBS is transmitted to the base station through the encoder 707, the spreader 708, and the modulator 709 of the control channel transmission path for the E-DCH. The RF unit 712 converts the data of the E-DCH provided from the modulator 704 and the control information of the control channel provided from the modulator 709 into an RF signal and transmits the RF signal to the base station through the antenna.

8 shows a configuration of a base station receiver for determining MF / SF according to a preferred embodiment of the present invention.

Referring to FIG. 8, received data of a terminal received by an antenna and converted into baseband by the RF unit 812 includes data of E-DCH and control information and is provided to demodulators 804 and 809, respectively. .

First, the processing of the control information is as follows. The demodulator 809 demodulates the received data including data and control information, and the despreader 808 despreads the demodulated data into a channel code of a control channel to extract a control signal. The control signal is input to the decoder 807. The decoder 807 transfers the control information obtained by decoding the control signal to the MAC layer processor 801. The control information includes a TBS of E-DCH data, and the decoder 807 transfers the TBS to the MF / SF controller 805. The MF / SF controller 805 determines the MF / SF according to the above-described embodiments using the TBS to provide a despreader 803 and a demodulator 804, respectively.

The demodulator 804 demodulates the received data including data and control information by the MF determined by the MF / SF controller 805, and the despreader 803 converts the demodulated data into the MF / SF controller. The physical channel data is extracted by despreading the channel code according to the SF determined at 805. The physical channel data is demultiplexed for each transmission channel in the demultiplexer 811 and then input to the decoders 802 through the line dematchers 810. The decoders 802 decode the data for each transport channel transmitted from the late dematchers 810 and deliver the decoded data to the MAC layer processor 801. The MAC layer processor 801 transfers the decoded data to the upper layer.

Next, a third embodiment of the present invention will be described.

The third embodiment relates to a method for determining an MCS level suitable for a transport format combination (E-TFC) when only one modulation scheme is used. The MCS level means a physical layer transmission environment. When one modulation scheme is applied, the MCS level means a combination of the SF and the number of channelization codes of the physical layer code. Since the supportable physical layer data bit size is different according to each combination, the following description will be made using the term physical channel data bit size instead of the MCS level.

In the present embodiment, when the physical channel data size for transmitting any transport format combination (TFS) is determined, the physical channel data bits supporting one physical channel (E-DPDCH) as mentioned in the related art. Determining the transmittable physical channel data bit size does not cause puncturing, and when supporting more physical channels, the transmission block size is punctured to a predetermined puncturing limit to select the physical channel data bit size that can be transmitted. If there is no physical channel data bit size that can be supported after the puncturing limit, the maximum physical channel data bit size is determined as the physical channel data size of the transport format combination. The reason for not limiting the puncturing limit on the maximum physical channel data bit size as described above is that the E-DCH is capable of recovering the received signal even if a lot of puncturing occurs because HARQ is applied. When the puncturing is excessive, it is better to increase the number of channel codes, that is, the number of physical channels, in consideration of the additional power required, so that the puncturing limit is applied to the maximum physical channel data size smaller than the maximum physical channel data size.

The following describes a channel environment for the preferred implementation of embodiment 4 of the present invention. In the following example, one E-DCH is set and up to SF64 to SF2 are used. If the set of physical layer data bit sizes that can be used in the channel environment as described above is SET0, an example of SET0 is as follows.

SET0 = {N ₆₄ , N ₃₂ , N ₁₆ , N ₈ , N ₄ , 2N ₄ , 2N ₂ , 2N ₂ + 2N ₄ }.

The number of channel codes and the minimum SF that a terminal can have can be changed by the capacity or signaling of the terminal. In this case, the modified SET0 is at least a subset of the above example.

An algorithm for obtaining a physical channel data bit size requiring each transport format combination is shown in Equation 6 below.

N _{e, j} in Equation 6 represents the coded data bit size before the j-th transport format combination undergoes rate matching and is called a transport channel data bit size. N _{data, j} represents the transmittable physical channel data bit size in the j-th transmission format combination (E-TFC) and is determined by Equation (6).

First, in the SET0, the terminal determines the physical channel data bit sizes (N _data ) larger than the unperforated transport channel data bit sizes as SET1. If the SET1 is not empty and the minimum component of the SET1 needs only one physical channel, the physical channel data bit size of the E-DCH is determined to be the minimum component min SET1 of the SET1.

If the SET1 is empty or the minimum component of the SET1 requires an additional physical channel, the terminal transmits the maximum punctured transmission channel data according to a predetermined puncturing limit PL0 in the SET0. SET2, which is a combination of physical channel data bit sizes (N _data ) larger than the bit size, is obtained.

If the SET2 is not empty, the physical channel data bit size N _{e, data} of the E-DCH is determined as the minimum component min SET2 of the SET2. At this time, if the determined physical channel data bit size is not the maximum component of SET2, and a next follower of the determined physical channel data bit size does not need an additional physical channel, the next component is physical channel. The data bit size N _{e, data} is finally determined. That is, when SET2 has at least two components and only needs one physical channel, the physical channel data bit size of the E-DCH is determined to be the minimum of one component. For example SET2 is _{{N 16, N 8, N} 4, 2N 4} If the minimum of the component is N _16, but the N _8, N ₄ is so using a single physical channel N ₄ physical channel following elements The data bit size is finally selected. SF is then determined to be 4.

If there is no element of SET2, it means that there is no physical layer data size that can be transmitted by applying the jth transport format combination to the punctuation limit. Therefore, in the above case, the maximum physical layer data bit size max SET0 of the SET0 is determined as the physical layer data bit size N _{e, data, j} of the j th transport format combination.

9 is a flowchart illustrating the operation of a terminal according to another embodiment of the present invention.

Referring to FIG. 9, in step 901, a UE sets SET1 including elements of physical channel data bit sizes that can be supported without puncturing among elements of the set SET0 of possible physical channel data bit sizes for the j-th transmission format combination to be transmitted. Configure. In step 902, the terminal checks whether SET1 is not an empty set and the minimum element is composed of only one E-DPDCH, and proceeds to step 903 when all of the above conditions are satisfied. In step 903, the smallest element of SET1 is determined as the physical channel data bit size for transmitting the j th transport format combination. If the SET1 is empty or the minimum element of the SET1 requires two or more E-DPDCHs, the process proceeds to step 904.

In step 904, the terminal punctures the transmission channel data bits to a predetermined puncturing limit to configure SET2 with elements of SET0 that can be supported. In step 905 it is determined whether SET2 is empty. If the element of SET2 is present, the process proceeds to step 906. In step 906, the UE determines the minimum element among the elements in which the next element of the SET2 requires an additional E-DPDCH as the physical channel data bit size for the j-th transmission format combination. On the other hand, if SET2 is empty, the process proceeds to step 907 where the terminal determines the maximum element of SET0 as the physical channel data bit size of the j th transport format combination.

Meanwhile, in the detailed description of the present invention, specific embodiments have been described, but various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined not only by the scope of the following claims, but also by those equivalent to the scope of the claims.

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

According to the present invention, when data is transmitted through an enhanced uplink-oriented channel, control information including only a transport block size is mapped to a base station by mapping one to one combinations of modulation block and spreading index corresponding to transport block sizes of data. To pass. The base station calculates the MF and SF values by referring to the transport block size included in the control information. This invention has the effect of reducing the signaling overhead required for the transmission of control information related to the E-DCH while saving transmission resources by maximizing uplink transmission efficiency.

Claims (6)

In the method for transmitting packet data in a mobile communication system, Determining a physical channel data bit size from the set of available physical channel data bit sizes in consideration of the packet data bit size and the puncturing limit; Transmitting packet data using the determined physical channel data bit size; Wherein if there is no physical channel data bit size that satisfies the puncturing limit, the packet data is transmitted using the maximum physical channel data bit size in the set of physical channel data bit sizes. The method as claimed in claim 1, wherein the packet data is transmitted through an enhanced uplink dedicated channel of an asynchronous wideband code division multiple access system. The method of claim 1, wherein the physical channel data bit size is, The method according to the combination of the spreading coefficient and the number of channel codes. In the method for transmitting packet data in a mobile communication system, A first process of selecting a physical channel data bit size capable of transmitting the packet data without puncturing, in consideration of the packet data bit size from among a set of usable physical channel data bit sizes; If there is no physical channel data bit size for transmitting the packet data without puncturing in the first process, the physical channel data capable of transmitting the packet data within a predetermined puncturing limit in consideration of the packet data bit size A second process of selecting a bit size, A third process of selecting a maximum physical channel data bit size among the physical channel data bit size sets when there is no physical channel data bit size capable of transmitting the packet data within the puncturing limit in the second process; And a fourth process of transmitting the packet data by using the selected physical channel data bit size. 5. The method of claim 4, wherein the packet data is transmitted through an enhanced uplink dedicated channel of an asynchronous wideband code division multiple access system. The method of claim 4, wherein the physical channel data bit size is, The method according to the combination of the spreading coefficient and the number of channel codes.

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