KR100594027B1 - Apparatus and method for transmitting and receiving information of spreading code using in packet data channel of communication system - Google Patents

Abstract

The present invention relates to a method and apparatus for efficiently transmitting and receiving code information used for spreading a packet data transmission channel in a spread communication system supporting a packet data service. The base station determines a Walsh code used for spreading the packet data channel, and transmits a last index indicating the last Walsh code among the determined Walsh codes through the packet data control channel. If the last index alone does not fully represent the Walsh codes used for the packet data channel, the Walsh bitmap for indicating the Walsh codes used for the packet data channel may be changed to another packet data control channel or a Walsh activation indication channel (WAICH). Send it through. This invention transmits information about Walsh codes used in the packet data channel more efficiently and accurately.

Spread Code, Packet Data Control Channel

Description

Method and apparatus for transmitting / receiving spreading code information of packet data channel in communication system {APPARATUS AND METHOD FOR TRANSMITTING AND RECEIVING INFORMATION OF SPREADING CODE USING IN PACKET DATA CHANNEL OF COMMUNICATION SYSTEM}

1 is a diagram showing the configuration of a conventional packet data control channel transmitter;

2 is a diagram showing the configuration of a conventional packet data control channel receiver;
3 is a diagram illustrating an example of a list of Walsh codes promised in advance between a base station and a terminal;

4 illustrates Walsh codes used for a circuit channel and a packet data channel in a Walsh code list.

5 is a flowchart illustrating a Walsh code information transmission operation of a base station according to the first embodiment of the present invention;
6 illustrates an example of a Walsh bitmap transmitted on a second packet data control channel.

7 is a diagram showing the configuration of a second packet data control channel transmitter according to a first embodiment of the present invention;

8 is a flowchart illustrating an operation of receiving Walsh code information of a terminal according to the first embodiment of the present invention;

9 is a diagram showing the configuration of a second packet data control channel receiver according to the first embodiment of the present invention.

10 is a flowchart illustrating a Walsh code information transmission operation of a base station according to a second embodiment of the present invention;
FIG. 11 illustrates an example of a Walsh bitmap transmitted on a Walsh Activation Indication Channel (WAICH). FIG.

12 is a view showing the configuration of a WAICH transmitter according to a second embodiment of the present invention;

13 is a flowchart illustrating an operation of receiving Walsh code information of a terminal according to a second embodiment of the present invention;

14 is a diagram showing the configuration of a WAICH receiver according to a second embodiment of the present invention.

The present invention relates to a communication system supporting a packet data service, and more particularly, to a method and apparatus for transmitting and receiving information indicating a spreading code used for a packet data channel.

Typical mobile communication systems only support voice services. However, as technology advances along with user demand, it is also evolving to support data services.

A mobile communication system supporting multimedia services including voice and data services supports voice services to a plurality of users using the same frequency band, and also supports data services by a time division multiplexing (TDM) method. In particular, a code division multiple access (CDMA) mobile communication system uses a time division multiplexing (TDM) scheme in which only one user data is transmitted during a specific time interval.

A mobile communication system supporting a packet data service includes a packet data channel (PDCH) for transmitting actual packet data and a packet data control channel (PDCCH) for transmitting control information for efficient transmission of packet data. Channel). The packet data is transmitted in units of physical layer packets (PLPs), and the receiver efficiently receives the packet data using the control information.

The control information is transmitted to a plurality of users who want to receive data service through a packet data channel using which modulation scheme at which data rate the data being transmitted at a specific time point is for which user, for what length, and at what data rate. Transmission parameters for whether a connection is being made. Table 1 below shows fields of control information transmitted through a packet data control channel. In Table 1 below, some fields may be added or deleted, and the length of each field may be set in various ways according to the system.

Field Length in bits MAC_ID 8 ARQ Channel ID 2 Subpacket ID 2 Encoder Packet Size 3 Last Walsh Code Index 5 Sequence Bit One Total 21

Referring to <Table 1>, the control information includes an MAC (Media Access Control) ID of 8 bits indicating a specific user who receives a data service and an encoding packet size (EP_Size) 3 indicating a payload size. Bits, 2 bits of a SPID (Sub-packet ID) indicating the number of retransmissions of the same packet data, 2 bits of an ARQ (Automatic Repeat Request) channel indicating a channel on which data is transmitted, and Walsh codes used for spreading a packet data channel ( A total of 21 bits are included, including 5 bits of the last Walsh code index and 1 bit of sequence information to indicate Walsh Codes).

In general, in a high-speed packet transmission mobile communication system, a transmission unit of data transmitted through a packet data channel is called a sub-packet, and the length information of the subpacket is a time length of data transmitted by time division multiplexing into a packet data channel. In a system where the transmission length of data is variable, this must be known to the receiving side. Since the receiver repeatedly transmits control information appropriately according to the length of the subpacket, the receiver can know the length of the subpacket based on the control information.

The data rate and modulation scheme of the packet data channel are determined according to the combination of the length and payload size of the subpacket and the Walsh code information used for the packet data transmission channel. Here, the data rate refers to a transmission rate of data transmitted through a packet data channel, and the modulation scheme refers to quadrature phase shift keying (QPSK), 8-ary PSK (8PSK), and 16-ary quadrature amplitude amplitude (16QAM). Modulation) indicates which modulation scheme is modulated among 64 QAM (64-ary QAM).

The payload size refers to the number of information bits constituting one subpacket, and the SPID is an identifier for identifying a series of subpackets retransmitted by an automatic repeat request (ARQ). Automatic Repeat Request (ARQ) channel ID is an identifier for supporting continuous data transmission to a user and is used to distinguish parallel transmission channels.

The terminal that wants to receive the high speed packet data service determines whether its packet is received through the packet data channel based on the MAC ID obtained by assigning a unique MAC ID and demodulating the packet data control channel by system access. . If its own packet is received, the remaining information fields of the packet data control channel are used to obtain the payload size, the SPID, the ARQ channel ID, the Walsh code used for the packet data channel, and demodulate the packet data channel.

1 is a diagram illustrating a configuration of a transmitter 100 of a packet data control channel for transmitting control information.

Referring to FIG. 1, an error detection bit adder 110 may include an 8-bit error detection bit for detecting a transmission error for an input sequence of 21 bits including control information. Error Detection Bit) is added to the input sequence. For example, the error detection bit adding unit 110 adds 8 bits of a cyclic redundancy code (CRC) to an input sequence and outputs 29 bits of information.

The tail bits adder 120 adds tail bits for convergence to a specific state to the 29 bits of information output from the error detection bit adder 110, thereby convolutional. Encoder 130). The tail bit adding unit 120 adds 8-bit tail bits composed of all zeros for the convolutional encoding. The convolutional encoder 130 encodes 37 bits of information output from the tail bit adding unit 120 according to a predetermined coding rate and outputs the encoded symbols. In this case, the convolutional encoder 130 uses two symbols per input of one bit using a coding rate of 1/2 when the slot is N (N = 1) according to the number of slots N used to transmit control information. In the case of 2 slots or 4 slots (N = 2 or N = 4), 3 symbols are output for each 1-bit input using a coding rate of 1/3.
The symbol repeater 140 repeats the convolutional coded symbol once when the number of slots is four. As a result, the symbol repeater 140 outputs 74, 111, and 222 symbols for the case where N = 1, 2 or 4, respectively. The symbols thus obtained are output to the puncturer 150.

The perforator 150 minimizes performance degradation and according to a perforation pattern for matching to an appropriate data rate, 26, 15, and 26 for the case where N = 1, 2 or 4, respectively, among the output symbols of the symbol repeater 140. 30 symbols are puncturing. Interleaver 160 interleaves the punctured symbols according to certain interleaving rules to reduce the effects of burst errors that degrade coding performance. As the interleaver 160, a bit reverse interleaver (hereinafter referred to as a BRI), which is a kind of block interleaver, may be used. The BRI places even-numbered symbols in the first half of the entire output symbol string after interleaving and odd-numbered symbols in the second half of the BRI, so as to minimize the distance between adjacent symbols.
A modulator 170 modulates the interleaved symbols in a predetermined modulation scheme such as Quadrature Phase Shift Keying (QPSK) to generate modulation symbols. The modulated symbols are spread by the spreaders 180 for the in-phase channel and quadrature channel with the spreading code W ⁶⁴ _i allocated for the packet data control channel and transmitted to the terminal.

2 is a block diagram showing the configuration of a typical packet data control channel receiver. FIG. 2 illustrates a configuration of a receiver 200 corresponding to the transmitter 100 of FIG. 1. As mentioned above, the control information is received through one, two or four slots depending on N and the length is the same as the length of the packet data. Therefore, the receiver 200 detects the length of the control information, that is, the length of the packet data, with the received signal of the packet data control channel.

Referring to FIG. 2, the receiver 200 is composed of four reception blocks 210 to 240. The reception blocks 210 to 240 receive 48 received symbols per slot including demodulated soft decision values and detect the presence of an error using a CRC to detect the length of packet data. .
The first receiving block 210 is for receiving control information of one slot length corresponding to the packet data of one slot length, and the second receiving block 220 is of two slot lengths corresponding to the packet data of two slot lengths. In order to receive control information, the third receiving block 230 is for receiving 4-slot length control information corresponding to 4-slot packet data, and the fourth receiving block 240 is an 8-slot packet. It is for receiving the control information of the 4-slot length corresponding to the data.

Referring to the operation of the reception blocks 210 to 240, first, the 48,96,192,192 symbols received during the 1,2,4 slot length are respectively deinterleavers 212,222,232,242. Deinterleaving and depuncturing by 10, 20, 40, 40 symbols by depuncturers 214, 224, 234, 244. In the reception blocks 230 and 240 corresponding to 4-slot length control information, symbol combiners 235 and 245 are reverse processes of the symbol repeater 140 shown in FIG. 1. Two adjacent symbols (Consecutive 2 symbols) among the symbols output from 234 and 244 are symbol combined.

The symbols punctured by the depuncturers 214, 224 and the symbols symbolized by the symbol combiners 235, 245 are convolutional decoders 216, 226, 236, 246, respectively. Is decoded with the corresponding coding rate. Here, the convolutional decoder 216 corresponding to the control information of one slot length uses a coding rate 1/2, and the convolutional decoders 226, 236, and 246 corresponding to the control information of two slots and four slot lengths use a coding rate of 1/3. use.

CRC checkers 218, 228, 238, and 248 perform CRC checks on the data decrypted by the corresponding convolutional decoders 216, 226, 236, and 246, respectively, to detect the presence or absence of errors. In the CRC test operation, a predetermined initial value 1 (for the inspectors 218,228,238) or 0 (for the inspector 248) is used.
Then, the controller 250 receives the test result by the CRC checkers 218, 228, 238 and 248 to detect the length of the control information, that is, the length of the packet data, and obtain the corresponding control information. That is, the slot length corresponding to the reception block for which no error is detected as a result of the CRC check is detected as the length of the control information. If the MAC ID included in the obtained control information matches that of its own, the packet data channel is received using the transmission parameters included in the control information.
Here, the four receiving blocks 210 to 240 may be composed of four physically different receiving blocks or shared with different receiving parameters (interleaving rule, puncturing pattern, coding rate, initial value, etc.). Consists of one receiving block.

Typically, Walsh codes of length 32 are used to spread the packet data channel, in which case all the available codes are used in the packet data channel. Here, all available codes refer to the remaining coded codes except for the code allocated for the circuit channel including the voice service and the code assigned for the common channel, among all code spaces. Therefore, the codes used for spreading the packet data channel are not fixed.

As mentioned above, information about the code used for spreading the packet data channel is transmitted through the packet data control channel. At this time, the base station transmits the last index indicating the last Walsh code used for the packet data channel in the list of pre-appointed Walsh codes between the terminal and the base station through the packet data control channel, and the terminal receives the received packet data channel. We use for. 3 shows an example of a list of Walsh codes promised in advance between the base station and the terminal.

3 illustrates an example where 28 Walsh codes are available for the packet data channel. In the illustrated Walsh code list, the base station informs of the last index corresponding to the last Walsh code among the Walsh codes used for the packet data channel as 5 bits of information.

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For example, if the number (index) of the Walsh codes used in the packet data channel is 31 (0), 15 (1), 23 (2), 7 (3), 27 (4), 11 (5), then the base station The index "00101 (5)" of the Walsh code is transmitted through the packet data control channel, and the terminal obtains the number 11 of the Walsh code corresponding to the index 5 from the Walsh code list as shown in FIG. Accordingly, the terminal determines that Walsh codes of numbers 31, 15, 23, 7, 27, and 11 are used for the packet data channel.

On the other hand, when a relatively short Walsh code having a length of 4 or 8 is used in a circuit channel for a high speed circuit data service, the last index of the last available Walsh code is reported using the Walsh code list as shown in FIG. Occurs when all Walsh codes specified by are not available for the packet data channel. An example of such a problem is shown in FIG. 4.

4 illustrates the Walsh code assigned to the voice and circuit data channels and the Walsh code available for the packet data channel at a specific time point. Referring to FIG. 4, the first column represents a Walsh code list of length 32 shown in FIG. 3, and the second, third, and fourth columns represent Walsh code lists of corresponding lengths of 16, 8, and 4, respectively. Here, the part indicated by the down-right hatch indicates Walsh codes of length 4 assigned to the circuit data channel, that is, the Forward Supplemental Channel (F-SCH), and the part indicated by the horizontal hatch is assigned to the voice service and circuit data channel. The Walsh codes indicate the Walsh codes, and the portion indicated by the upward upward hatch indicates the Walsh codes available for the packet data channel at that time.

Referring to FIG. 4, Walsh codes available for the packet data channel do not start from the beginning of the Walsh code list but start from the middle. This is due to the fact that the Walsh code of number 3 among the Walsh codes of length 4 is used in the circuit data channel. In this case, although there are eleven Walsh codes available for the packet data channel, numbers 29 to 26, the last index of 5 bits which is notified through the packet data control channel cannot express this. The problem arises that it is not possible to inform the receiver of the Walsh codes used.

Accordingly, an object of the present invention is to provide a method and apparatus for efficiently using the Walsh code available for the packet data channel by efficiently transmitting information on the Walsh code used for the packet data channel to solve the above problem. .

Another object of the present invention is to provide a method and apparatus for efficiently receiving information on Walsh codes used in a packet data channel.

The present invention for achieving the above object can be used when the Walsh code available for the packet data channel starts from the middle instead of the beginning of the pre-appointed Walsh code list between the terminal and the base station, or can be used for the pre-appointed Walsh code list. When the Walsh code and the Walsh code are discontinuously distributed, a method for informing the information about the Walsh code through the new physical channel is provided. As a result, the terminal obtains Walsh code information allocated to the packet data channel using information obtained through the new physical channel in addition to 5-bit information obtained through the packet data control channel. In addition, the present invention transmits a flag bit indicating the presence or absence of the new physical channel in the packet data control channel, the terminal determines whether the new physical channel is transmitted from the flag bit.

DETAILED DESCRIPTION A detailed description of preferred embodiments of the present invention will now be described with reference to the accompanying drawings. It should be noted that reference numerals and like elements among the drawings are denoted by the same reference numerals and symbols as much as possible even though they are shown in different drawings. 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.

Hereinafter, a packet data control channel transmitter and receiver and an operation flowchart thereof according to an embodiment of the present invention for transmitting and receiving control information of the packet data in a mobile communication system for transmitting packet data will be described. Note that the transmitter and receiver according to the embodiment of the present invention and the flowchart thereof are equally applicable to not only a mobile communication system but also a communication system that transmits packet data and also transmits control information for efficient transmission of such packet data. shall.

The present invention proposes two preferred embodiments in transmitting information on a spread code of a packet data channel. Hereinafter, embodiments of the present invention will be described in detail.

<< first embodiment >>

In the first embodiment of the present invention, the last data indicating the last Walsh code among the Walsh codes used in the packet data channel is notified through the packet data control channel (hereinafter referred to as the first packet data control channel). If all the Walsh codes used for are not represented, other packet data control channels (hereinafter, referred to as second packet data control channels) having the same structure are used for the remaining Walsh codes except for the Walsh codes used for the common channel. It is to send a Walsh Space Bitmap indicating whether or not to use. The Walsh bitmap may also be referred to as a Walsh Mask Bitmap.
Here, the control information transmitted through the first packet data control channel is referred to as first control information, and the control information transmitted through the second packet data control channel is referred to as second control information. The first control information includes a last index of a Walsh code available for a packet data channel in a pre-appointed Walsh code list, and the second control information individually indicates whether to use Walsh codes specified by the last index. Contains a bitmap.

The receiver derives from the first control information transmitted on the first packet data control channel the last Walsh code index indicating the Walsh codes used for the packet data channel from a list of Walsh codes previously promised with the transmitter. The receiver then determines whether a second packet data control channel has been received, and if the second packet data channel has been received, the Walsh indicated by the last index from the Walsh bitmap in the second control information received over the second packet data channel. Determine whether each code is used. Herein, the case where Walsh codes used for the packet data channel do not start from the beginning of the Walsh code list or are discontinuously positioned is referred to as "the Walsh hole exists".

5 is a flowchart illustrating an operation of a base station for transmitting information of Walsh codes used for spreading a packet data channel through packet data control channels according to the first embodiment of the present invention.

Referring to FIG. 5, in step 410, the base station determines Walsh codes usable for spreading the packet data channel. At this time, the remaining Walsh codes are the Walsh codes available in the packet data channel except the Walsh codes allocated to the voice and other circuit data channels in the whole Walsh space. In step 420, it is determined whether Walsh codes determined to be usable in the packet data channel can be expressed using only the last index. In other words, it is determined whether Walsh holes exist in the list of Walsh codes previously promised with the receiver. As described above, the presence of Walsh holes means that Walsh codes available for the packet data channel start in the middle of the Walsh code list or are discontinuously located in the middle of the Walsh code list.

If it is determined in step 420 that there is no Walsh hole, that is, if it is determined that all Walsh codes starting from the first index to the last index of the Walsh code list are available in the packet data channel, the base station proceeds to step 430. The first control information including the last index of 5 bits is transmitted through the first packet data control channel. Here, the second packet data control channel is not transmitted.

On the other hand, if it is determined in step 420 that the Walsh hole exists, the Walsh codes available for the packet data channel cannot be represented only by the last index. Thus, a need arises to transmit a Walsh bitmap over the second packet data control channel indicating which of the consecutive Walsh codes indicated by the last index are used.

In order to transmit the Walsh bitmap, in step 440, the MAC ID field (bits 1 to 8) of the second control information transmitted through the second packet data control channel is set to a predetermined value, for example, "0000 0000". do. This is for indicating that subsequent bits indicate Walsh hole information, and may be set to the same value as the MAC ID of the first control information or to another value not used by another terminal. In step 450, the base station transmits a Walsh bit map of the remaining 13 bits (bits 9 to 21) of the second control information to a value indicating whether each of the Walsh codes having a length of 16 is used. The Walsh codes of length 16 correspond to two Walsh codes of length 32, respectively.

For example, in the case of FIG. 4, the order of Walsh codes having a length of 16 is 15,7,11,3,13,5,9,14,6,10,2,12,4,8, and the last Walsh code is (No. 8) is not available. Therefore, bits 9 to 21 of the second control information bit are used for Walsh codes 15,7,11,3,13,5,9,14,6,10,2,12,4 of length 16, respectively. It is represented by the values '0' and '1'.

In step 460, the base station transmits the first control information including the last index determined as described above and the second control information including the MAC ID and the Walsh bitmap through the first and second packet data control channels, respectively.

Table 2 below shows second control information transmitted through a second packet data control channel according to the first embodiment of the present invention.

Field Length in bits MAC ID 8 16-ary Walsh Bit Map 13 Total 21

As shown in Table 2, the second control information is 21 bits in total and is equal to the number of bits of the first control information transmitted through the first packet data control channel.

As mentioned above, in Table 2, the MAC ID 8 bit does not refer to a specific user of the packet data channel, unlike the first packet data control channel, and the second packet data control channel transmits Walsh hole information. It has a value of "0000 0000" to indicate that it is present. At this time, the base station does not allocate "0000 0000" when allocating 8 bits of MAC ID for identifying a user.

As another example, the MAC ID of the second packet data control channel may be set equal to the MAC ID of the first packet data control channel to identify a user instead of indicating whether subsequent information is transmitting Walsh Hall information. . However, hereinafter, the rest of the information will be described as transmitting Walsh hole information when the MAC ID of the second packet data channel has a value of "0000 0000".

That is, when the Walsh hole is present, the MAC ID bit of the second packet data control channel means that the remaining 13 bits indicate whether each of Walsh codes having a length of 16 is used.

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6 shows an example of a 13-bit Walsh bit map transmitted through a second packet data control channel. In FIG. 6, a first column shows a Walsh bit map of second control information transmitted through a second packet data control channel. As shown, the Walsh bitmap occupies bits 9 through 21 of the second control information. The second and third columns show Walsh coding of length 16 corresponding to two Walsh codes of length 32. The order of the Walsh codes of length 32 shown in the third column is the same as the order of the pre-appointed Walsh code list (ie, FIG. 3).
As such, the second control information transmitted through the second packet data control channel may be used for each of Walsh codes having a length of 16 corresponding to two Walsh codes having a length of 32, respectively. Inform via Accordingly, the receiver determines that two Walsh codes having a length of 32 corresponding to Walsh codes having a length of 16 set to '1' can be used for the packet data channel.

7 is a diagram illustrating a configuration of a second packet data control channel transmitter 500 according to the first embodiment of the present invention.

Referring to FIG. 7, an error detection bit adder 510 may detect a transmission error for an input sequence of 21 bits representing second control information including a user identifier and a Walsh bitmap. To add an error detection bit (Error Detection Bit) to the input sequence. For example, the error detection bit adding unit 510 adds 8 bits of cyclic redundancy code (CRC) to a 21 bit input sequence and outputs 29 bits of information.

The tail bits adder 520 is a convolutional coder by adding tail bits for convergence to a specific state to the 29 bits of information output from the error detection bit adder 510. Encoder) (530). The tail bit adding unit 520 adds 8 bits of tail bits composed of all zeros for convolutional encoding. The convolutional encoder 530 encodes the output from the tail bit adding unit 520 according to a predetermined coding rate and outputs the encoded symbols. In this case, the convolutional encoder 530 is 2 per input of 1 bit using a coding rate of 1/2 in the case of 1 slot (N = 1) according to the slot length N used to transmit the second control information. Two symbols are outputted, and in the case of 2 slots or 4 slots (N = 2 or 4), 3 symbols are output for each 1-bit input using a coding rate of 1/3.
A symbol repeater 540 repeats the convolutional coded symbols once when the number of slots is four. (Repetition Factor = 2) As a result, the symbol repeater 540 performs N = 1,2, For 4, 74, 111, and 222 symbols are output, respectively. The symbols thus obtained are output to the puncturer 550.

The puncturer 550 is 26, 15, and 30 for N = 1, 2, and 4 among the output symbols of the symbol repeater 540 according to a puncturing pattern for minimizing performance degradation and matching to an appropriate data rate. Puncturing and outputting the symbols. The interleaver 560 interleaves the output symbols of the puncturer 550 according to a predetermined interleaving rule for reducing the influence of burst error, which degrades encoding performance. The interleaver 560 may be a bit reverse interleaver (BRI), which is a type of block interleaver. The BRI interleaves the space between adjacent symbols as much as possible, and then places even-numbered symbols in the first half of the entire output symbol string and odd-numbered symbols in the second half.
A modulator 570 modulates the interleaved symbols in a predetermined modulation scheme such as Quadrature Phase Shift Keying (QPSK) to generate modulation symbols for transmission. The modulated symbols are spread by the spreaders 580 for the in phase channel and the quadrature phase channel with a spread code W ⁶⁴ _i assigned to the packet data control channel and transmitted to the terminal.
The configuration shown in FIG. 7 is the same as that of the first packet data control channel transmitter described in FIG. That is, the base station transmits the second packet data control channel with the same structure and the same transmission power as the first packet data control channel.

8 is a flowchart illustrating an operation of a terminal that receives information of Walsh codes used for spreading a packet data channel through a packet data control channel according to the first embodiment of the present invention.

Referring to FIG. 8, in step 610, the terminal receives first control information through a first packet data control channel. Here, the first control information includes a last Walsh code index of Walsh codes usable in the packet data channel in a pre-appointed Walsh code list with the base station. In step 620, the UE checks the MAC ID included in the first control information in order to know whether its own packet is transmitted through the packet data channel. If the received MAC ID does not match the MAC ID assigned thereto, the flow returns to step 610. On the contrary, if it matches its own MAC ID, the second control information is received through the second packet data control channel in step 630.

In step 640, the terminal checks whether the MAC ID included in the second control information is a value indicating that Walsh Hall exists, for example, "0000 0000". If the MAC ID is not "0000 0000", it is determined that there is no hole in the Walsh codes indicated by the first control information, and in step 650, the Walsh codes indicated by the first control information are used. Receive a packet data channel.
On the other hand, if the MAC ID is "0000 0000", it is determined that the remaining 13 bits are Walsh bitmaps indicating whether Walsh codes are used. In step 660, whether Walsh codes of length 16 are used by the Walsh bitmap is determined. Find out. Thereafter, in step 670, the UE receives the packet data channel with the Walsh codes found by the last index included in the first control information and the Walsh bit map included in the second control information.

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For example, referring to FIG. 4, if the last index obtained from the first control information indicates the Walsh code 26 having a length of 32, the terminal has 31, 15, 23, 7, 27, 11, 19, It is determined that 3,29,13,21,5,25,9,30,14,22,6,26 are used for the packet data channel. In addition, if the Walsh bitmap obtained from the second control information is 0000 1111 1111 1, 0 indicates that it is unavailable and 1 indicates that it is available, 31,15,23,7,27,11,19 among the Walsh codes. , 3 cannot be used, and only the remaining 29, 13, 21, 5, 25, 9, 30, 14, 22, 6, 26 can be used.

9 is a diagram illustrating a configuration of a second packet data control channel receiver according to a first embodiment of the present invention. 9 illustrates a configuration of a receiver 700 corresponding to the transmitter 500 of FIG. 7.

Referring to FIG. 9, the receiver 700 is composed of four reception blocks 710 to 740. The switch controller 701 controls the switch 702 by the length information found from the first control information received through the first packet data control channel. The switch 702 receives reception blocks 710, 720, 730, and 740 for 48 received symbols per slot consisting of soft decision values demodulated according to the determined length information (N = 1, 2, 4, 8). ) To the appropriate one. The corresponding receiving block then processes the received symbols and outputs second control information.
Here, the first receiving block 710 is for processing one slot length control information corresponding to one slot length packet data, and the second receiving block 720 is two slots corresponding to two slot length packet data. The third receiving block 730 is for processing 4-slot control information corresponding to 4-slot packet data, and the fourth receiving block 740 is for 8 slots long. This is for processing control information having a length of 4 slots corresponding to the packet data.

Referring to the operation of each of the reception processing blocks 710 to 740, 48, 96, 192, and 192 received symbols are deinterleaved by deinterleavers 712, 722, 732, and 742, respectively. Depuncturing by depuncturers 714, 724, 734, 744 by 10, 20, 40, 40 symbols. As a reverse process of the symbol repeater 540 shown in FIG. 7 in the reception blocks 730 and 740 corresponding to 4-slot length control information, symbol combiners 735 and 745 are two adjacent symbols (consecutive 2). symbols are combined.

The symbols punctured by the reverse puncturers 714 and 724 and the symbol combined symbols are respectively decoded by convolutional decoders 716, 726, 736 and 746 according to the corresponding coding rates. . Here, the convolutional decoder 716 corresponding to the control information of one slot length uses a code rate 1/2, and the convolutional decoder 726 corresponding to the control information of a two slot length uses a code rate 1/3. The convolutional decoders 736 and 746 corresponding to the slot length control information use a coding rate 1/3.

The CRC checkers 718, 728, 738, and 748 detect a presence of an error by performing a CRC check operation on the symbols decoded by the corresponding convolutional decoders 716, 726, 736, and 746, respectively. In the CRC test operation, a predetermined initial value 1 (inspector 718,728,738) or 0 (inspector 748) is used.
If the second control information determined that no error exists from the corresponding one of the receiving blocks 710 to 740 is output through the operation as described above, the controller 750 is connected to the second control information. The first control information previously received through the first packet data control channel is analyzed to determine Walsh codes used in the packet data channel.
Here, the four receiving blocks 710 to 740 are physically different receiving processing blocks or a shared one having different receiving parameters (interleaving rule, puncturing pattern, coding rate, initial value, etc.). Consists of the receiving block.

<< 2nd Example >>

In the second embodiment of the present invention, if the last index indicating the last Walsh code available for the packet data channel cannot be represented by all the Walsh codes available for the packet data channel only by informing the packet data control channel, it is selectively transmitted. The other physical channel is used to transmit a Walsh bitmap indicating whether the remaining Walsh codes are used except for the Walsh codes used for the common channel. Herein, the other physical channel will be referred to as WAICH (Walsh Availability Indication Channel) in that it transmits information indicating whether a Walsh code is used.

The WAICH is only activated when it is determined that it is necessary to transmit the Walsh bitmap. The transmitter further transmits a 1-bit flag (hereinafter referred to as a "hole flag") to inform the receiver that the WAICH is activated through a packet data control channel. Table 3 below shows control information including the hole flag.

Field Length in bits MAC_ID 8 ARQ Channel ID 2 Subpacket ID 2 Encoder Packet Size 3 Last Walsh Code Index 5 Sequence Bit One Hole flag One Total 22

In comparison with Table 1, the Table 3 includes a 1-bit hole flag. The hole flag is set to '1' when the WAICH is activated, and set to '0' otherwise.
In the second embodiment, 22 bits of control information including the MAC ID, the last index, and the hole flag are transmitted and received through the packet data control channel transmitter (FIG. 1) and the receiver (FIG. 2) having the same structure as before. Detailed description will be omitted. However, as shown in Table 3, by adding a 1-bit hole flag, the number of symbols to be punctured and counter-punched should be increased by 2, 3, 3, respectively, when the slot length N = 1, 2, 4 .

10 is a flowchart illustrating an operation of a base station for transmitting information of Walsh codes used for spreading a packet data channel according to a second embodiment of the present invention.

Referring to FIG. 10, in step 810, the base station determines Walsh codes available for the packet data channel. The remaining Walsh codes are the Walsh codes available in the packet data control channel except the Walsh codes assigned to the voice and other circuit data service channels in the entire Walsh space. In step 820, it is determined whether Walsh codes determined to be usable in the packet data channel can be expressed using only the last index. In other words, it is determined whether Walsh holes exist in the list of Walsh codes previously promised with the receiver. As described above, the presence of Walsh holes means that Walsh codes available for the packet data channel start in the middle of the Walsh code list or are discontinuously located in the middle of the Walsh code list.

If it is determined in step 820 that there is no Walsh hole, that is, if all Walsh codes starting from the first index to the last index of the Walsh code list are determined to be available in the packet data channel, WAICH needs to be transmitted. There is no. Accordingly, the base station proceeds to step 830 and sets the hall flag value of the control information to '0', and transmits control information including the hole flag through the packet data control channel in step 840. The control information includes a last index of 5 bits representing the last Walsh code in the pre-appointed Walsh code list among the Walsh codes available in the packet data channel together with the hole flag.

On the other hand, if it is determined in step 820 that the Walsh hole exists, the Walsh codes available for the packet data channel cannot be represented by the last index of 5 bits. Thus, there is a need to transmit a Walsh bitmap on the WAICH indicating which of the consecutive Walsh codes indicated by the last index are available and which are not available. In order to transmit the Walsh bitmap through the WAICH, the base station sets the hole flag of the control information to '1' in step 850 and, in step 860, the 13-bit Walsh bitmap to be transmitted through the WAICH in each of the 13 Walsh codes. Set to a value indicating whether or not to use.

For example, in the case of FIG. 4, the order of Walsh codes having a length of 16 is 15,7,11,3,13,5,9,14,6,10,2,12,4,8, and the last Walsh code is (No. 8) is not always available. Therefore, the Walsh bitmap is a bit value '0', 'indicating whether or not to use Walsh codes 15,7,11,3,13,5,9,14,6,10,2,12,4 of length 16, respectively. It is set to 1 '.

In step 870, the base station transmits the control information and the Walsh bitmap including the last index determined as described above through the packet data control channel and the WAICH, respectively. At this time, the length of the Walsh bitmap transmitted through the WAICH is the same as the length of the control information transmitted through the packet data control channel.

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As described above, WAICH is a Walsh bitmap indicating whether or not Walsh codes, which are length 16 corresponding to two Walsh codes each having a length of 32, can be used for the remaining Walsh codes except for Walsh codes used in a common channel. Send it. The 13-bit Walsh bit map indicates whether or not each of the 13 Walsh codes can be used in the packet data channel.
11 illustrates an example of a 13-bit Walsh bit map transmitted through a WAICH.

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In FIG. 11, the first column shows a Walsh bit map transmitted to WAICH. As shown, the Walsh bitmap occupies bits 0 through 12 transmitted on the WAICH. The second and third columns represent Walsh codes of length 16 and corresponding two Walsh codes of length 32. The order of the Walsh codes of length 32 shown in the third column is the same as the order of the pre-appointed Walsh code list (ie, FIG. 3).
As such, the Walsh bitmap transmitted to the WAICH indicates whether each Walsh code having a length of 16 is used. Accordingly, the receiver determines that two Walsh codes having a length of 32 corresponding to Walsh codes having a length of 16 set to '1' can be used for the packet data channel.
12 is a diagram showing the configuration of a WAICH transmitter 900 according to a second embodiment of the present invention.

Referring to FIG. 12, the error detection bit attaching unit 910 detects a transmission error for an input sequence of 13 bits representing a Walsh bitmap to be transmitted through a WAICH. Add Detection Bit. For example, the error detection bit adding unit 901 adds 8 bits of a cyclic redundancy code (CRC) to a 13-bit input sequence and outputs 21 bits of information.

The tail bit adding unit 920 adds tail bits for convergence to a specific state to the 21 bits of information output from the error detection bit adding unit 910 and outputs the tail bits to a convolutional encoder 930. The tail bit adding unit 920 adds 8-bit tail bits composed of all zeros for the convolutional encoding. The convolutional encoder 930 convolutionally encodes the information output from the tail bit adding unit 902 according to a predetermined coding rate to output encoded symbols. In this case, the convolutional encoder 930 is 2 for every 1-bit input using a coding rate of 1/2 when the slot length is 1 (N = 1) according to the transmission slot length (N = 1, 2 or 4) of the WAICH. Two symbols are output, and four symbols are output for each 1-bit input using a coding rate of 1/4 when the length is 2 or 4 slots (N = 2 or 4).
A symbol repeater 940 repeats the convolutional coded symbols once when the slot length is 4. (Repetition Factor = 2) As a result, the symbol repeater 940 outputs 58N symbols. . The symbols thus obtained are output to the puncturer 950.

The puncturer 950 punctures 10N symbols among the output symbols of the symbol repeater 940 according to a puncturing pattern for minimizing performance degradation and matching to an appropriate data rate. The interleaver 960 interleaves the punctured symbols according to a predetermined interleaving rule for reducing the influence of aggregation error that degrades coding performance, and outputs 48N symbols for every N slots. As the interleaver 960, a bit reverse interleaver (BRI), which is a kind of block interleaver, may be used.
A modulator 970 modulates the interleaved symbols according to a predetermined modulation scheme such as Quadrature Phase Shift Keying (QPSK) to generate modulation symbols for transmission. The modulated symbols are spread by the spreaders 980 for in-phase (I) channel and quadrature (Q) channel with active code W ⁶⁴ _i assigned to WAICH and transmitted to the terminal.

FIG. 13 is a flowchart illustrating an operation of a terminal obtaining information on Walsh codes used in a packet data channel using information received through a packet data control channel and a WAICH according to the second embodiment of the present invention.

Referring to FIG. 13, in step 1010, the terminal receives control information through a packet data control channel. Here, the control information includes a last index indicating the last Walsh code among the Walsh codes available for the packet data channel in a list of Walsh codes previously promised with the base station. In step 1020, the terminal checks the MAC ID included in the received control information. If the received MAC ID does not match the MAC ID assigned thereto, the flow returns to step 1010.

On the other hand, if the received MAC ID coincides with its own MAC ID, in step 1030, the terminal reads the hole flag included in the received control information. If the hole flag is set to '0', the terminal determines that there is no Walsh hole, so that information on Walsh codes used in the packet data channel can be obtained using only the control information. Therefore, the process proceeds to step 1040 to obtain information on the Walsh codes used in the packet data channel by using the last index included in the control information and receives the packet data channel. If the hole flag is set to '1', the terminal determines that a Walsh hole exists so that the Walsh bitmap should be received through the WAICH. Therefore, the flow proceeds to step 1050 to demodulate the WAICH with the same length as the control information and receive the Walsh bitmap.

In step 1060, the terminal reads each bit of the received Walsh bitmap and determines whether each of Walsh codes having a corresponding length of 16 is used. That is, the portion of the Walsh codes used in the packet data channel is found. In step 1070, the terminal combines the last index included in the control information and the Walsh bitmap to obtain information of Walsh codes used in the packet data channel, and receives the packet data channel using the same.

The information on the Walsh codes thus obtained is used to despread the received packet data channel.

For example, referring to FIG. 4, if the last index obtained from the control information represents the Walsh code 26 having a length of 32, the terminal may have 31, 15, 23, 7, 27, 11, 19, 3, It is determined that 29, 13, 21, 5, 25, 9, 30, 14, 22, 6, and 26 are available for the packet data channel. In addition, if the Walsh bitmap obtained through WAICH is "0000 1111 1111 1," the first eight 31,15,23,7,27,11,19,3 cannot be used according to the Walsh bitmap. The final judgment is that only 13, 21, 5, 25, 9, 30, 14, 22, 6, and 26 are available.

14 is a block diagram showing the configuration of a WAICH receiver according to a second embodiment of the present invention. 14 is a receiver 1100 corresponding to the transmitter 900 of FIG. 12. In this case, the length of the Walsh bitmap received through the WAICH is the same as the length of the control information already received through the packet data control channel.

Referring to FIG. 14, the QPSK demodulator 1110 demodulates an I, Q signal despread with a spread code allocated for WAICH and outputs 48N symbols. According to the slot length N of the control information received through the packet data control channel, 48N symbols output from the QPSK demodulator 1110 are deinterleaved by a deinterleaver 1120 and deinterleaved. It is depunctured by depuncturer 1130 by 10N symbols. In the case of 4-slot control information, the symbol combiner 1140 performs symbol combining on two adjacent symbols among the symbols output from the back puncher 1130.

The symbols punctured by the de puncturer 1130 and symbols combined by the symbol combiner 1140 are decoded at a corresponding coding rate by a convolutional decoder 1150. In this case, when the control information is 1 slot long, the coding rate 1/2 is used. When the control information is 2 slots or 4 slots long, the coding rate 1/4 is used.
The CRC checker 1160 performs a CRC check on the data decoded by the convolutional decoder 1150 to detect the presence of an error, and output a 13-bit Walsh bit map when no error exists. The controller 1170 then determines the control information already received through the packet data control channel and the Walsh codes used for the packet data channel using the Walsh bitmap.

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 appended claims, but also by the equivalents 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.

The present invention improves the performance of the packet data channel, i.e., the data throughput of the system, by accurately transmitting the information of the Walsh codes available to the packet data channel.

Claims (60)

delete delete delete delete delete delete delete delete delete delete delete delete delete delete What is claimed is: 1. A method for transmitting information on spread codes used in a packet data channel in a spread communication system supporting a packet data service, the method comprising: Determining spreading codes available for the packet data channel in a predetermined spreading code list; Transmitting first control information including a last index indicating a last spreading code among the determined spreading codes through a first control channel; Determining whether the determined spreading codes can be represented by only the last index; If the determined spreading codes cannot be represented by only the last index, transmitting second control information including a spreading code bitmap individually indicating spreading codes available for the packet data channel through a second control channel. Transmission method comprising a. 16. The transmission method of claim 15, wherein the spread code list includes spread codes arranged in a predetermined order. 16. The method of claim 15 wherein the spreading codes are Walsh codes. 16. The method of claim 15, further comprising determining that the determined spreading codes cannot be represented only by the last index when holes exist in the determined spreading codes. The method of claim 15, wherein the first control information, And a user identifier indicating a user to which the packet data channel is allocated, and transmission parameters required for receiving the packet data channel. The method of claim 15, wherein the second control information, And a user identifier set to a predetermined value. 21. The method of claim 20, wherein the user identifier is set to a value indicating whether the determined spreading codes can be represented by the last index only. 21. The method of claim 20, wherein the user identifier is set to a value indicating a user to which the packet data channel is assigned. An apparatus for transmitting information on spreading codes used in a packet data channel in a spreading communication system supporting a packet data service, the apparatus comprising: A first control channel for determining available spreading codes for a packet data channel in a spreading code list and transmitting first control information including a last index indicating a last spreading code among the determined spreading codes through a first control channel With transmitter, If the determined spreading codes cannot be represented by only the last index, a second control information is transmitted through the second control channel, the second control information including a spreading code bitmap that individually indicates spreading codes available for the packet data channel. And a control channel transmitter. 24. The apparatus of claim 23, wherein the spread code list comprises spread codes arranged in a predetermined order. 24. The apparatus of claim 23, wherein the spreading codes are Walsh codes. 24. The apparatus of claim 23, wherein the first control channel transmitter determines that the determined spreading codes cannot be represented only by the last index when holes exist in the determined spreading codes. The method of claim 23, wherein the first control information, And a user identifier indicating a user to which the packet data channel is allocated, and transmission parameters required for receiving the packet data channel. The method of claim 23, wherein the second control information, And a user identifier set to a predetermined value. 29. The apparatus of claim 28, wherein the user identifier is set to a value indicating whether the determined spreading codes can be represented by only the last index. 29. The apparatus of claim 28, wherein the user identifier is set to a value indicating a user to which the packet data channel is assigned. A method for receiving information on spreading codes used in a packet data channel in a spreading communication system supporting a packet data service, Receiving first control information through a first control channel to identify a user identifier included in the first control information; If the user identifier included in the first control information is identical to its own, obtaining, from the first control information, a last index indicating the last spreading code among spreading codes available for the packet data channel in the spreading code list; and, Receiving second control information through a second control channel to identify a user identifier included in the second control information; If the user identifier included in the second control information matches a predetermined value, obtaining, from the second control information, a spreading code bitmap that individually indicates spreading codes available for the packet data channel; Determining spreading codes usable for the packet data channel using the last index and the spreading code bit map. 32. The method of claim 31, wherein the spread code list comprises spread codes arranged in a predetermined order. 32. The method of claim 31 wherein the spreading codes are Walsh codes. 32. The method of claim 31, further comprising determining spreading codes available for the packet data channel using only the last index if the user identifier included in the second control information does not match a predetermined value. A reception method characterized by the above. The method of claim 34, wherein the predetermined value is, And a spreading code available for the packet data channel indicates whether or not spreading codes available for the packet data channel can be represented by only the last index. 35. The method of claim 34, wherein the user identifier is set to a value indicating a user to which the packet data channel is assigned. An apparatus for receiving information on spreading codes used in a packet data channel in a spreading communication system supporting a packet data service, the apparatus comprising: Receiving first control information through a first control channel to confirm a user identifier included in the first control information, and if the user identifier included in the first control information matches its own, from the first control information A first control channel receiver for obtaining a last index indicating a last spread code among spread codes available for a packet data channel in a spread code list, Receiving second control information through a second control channel to confirm a user identifier included in the second control information, and if the user identifier included in the second control information matches a predetermined value, the second control. A second control channel receiver for obtaining from said information a spreading code bitmap that individually indicates spreading codes available for said packet data channel; And a controller for determining spread codes available for the packet data channel using the last index and the spread code bit map. 38. The apparatus of claim 37, wherein the spread code list comprises spread codes arranged in a predetermined order. 38. The apparatus of claim 37, wherein the spreading codes are Walsh codes. The method of claim 37, wherein the controller, And if the user identifier included in the second control information does not match a predetermined value, spreading codes usable for the packet data channel are determined using only the last index. The method of claim 40, wherein the predetermined value is, And a spreading code available for the packet data channel indicates whether or not spreading codes can be represented by only the last index. 41. The reception device according to claim 40, wherein the user identifier is set to a value indicating a user to which the packet data channel is assigned. Claims [1] A method for transmitting information on spread codes used in a packet data channel in a communication system using spread codes, the method comprising: Determining spreading codes available for the packet data channel in a predetermined spreading code list; Determining whether the determined spreading codes can be represented by only a last index indicating a last spreading code among the determined spreading codes; Transmitting first control information including the last index and a flag indicating the determination result through a first control channel; If the determined spreading codes cannot be represented by only the last index as a result of the determination, the second control information including a Walsh bit map indicating individually spreading codes available for the packet data channel is transmitted through the second control channel. A transmission method comprising a process. 44. The transmission method according to claim 43, wherein the spread code list includes spread codes arranged in a predetermined order. 44. The method of claim 43 wherein the spreading codes are Walsh codes. 44. The method of claim 43, further comprising determining that the determined spreading codes cannot be represented only by the last index when holes exist in the determined spreading codes. The method of claim 43, wherein the first control information, And a user identifier indicating a user to which the packet data channel is allocated, and transmission parameters required for receiving the packet data channel. An apparatus for transmitting information on spreading codes used in a packet data channel in a spreading communication system supporting a packet data service, the apparatus comprising: A last index indicating a last spreading code among spreading codes available for a packet data channel in a predetermined spreading code list, and a flag indicating whether spreading codes available for the packet data channel can be represented by the last index only. A first control channel transmitter for transmitting first control information through a first control channel; If spread codes available for the packet data channel cannot be represented with only the last index, second control information including a Walsh bit map indicating individually spread codes available for the packet data channel is transmitted through the second control channel. And a second control channel transmitter for transmitting. 49. The apparatus of claim 48, wherein the spread code list comprises spread codes arranged in a predetermined order. 49. The apparatus of claim 48, wherein the spreading codes are Walsh codes. 49. The apparatus of claim 48, wherein the first control channel transmitter further comprises determining that the determined spreading codes cannot be represented only by the last index when holes exist in the determined spreading codes. . The method of claim 48, wherein the first control information, And a user identifier indicating a user to which the packet data channel is allocated, and transmission parameters required for receiving the packet data channel. A method for receiving information on spreading codes used in a packet data channel in a spreading communication system supporting a packet data service, Receiving first control information through a first control channel and confirming whether a user identifier included in the first control information matches that of the first control information; If the user identifier included in the first control information is identical to its own, obtaining the last index indicating the last spreading code among the spreading codes available for the packet data channel in the predetermined spreading code list from the first control information. Process, Checking a flag included in the first control information to determine whether spread codes available for the packet data channel indicate that they can be represented only by the last index; If the flag indicates that spreading codes available for the packet data channel are not representable by the last index alone, spreading available for the packet data channel from the second control information by receiving second control information through a second control channel Obtaining a spreading code bit map that individually indicates codes; Determining spreading codes usable for the packet data channel using the last index and the spreading code bit map. 54. The method of claim 53, wherein the spread code list comprises spread codes arranged in a predetermined order. 54. The method of claim 53 wherein the spreading codes are Walsh codes. 54. The method of claim 53, further comprising: determining spreading codes available for the packet data channel using the last index if the flag indicates that spreading codes available for the packet data channel can be represented by the last index only. Receiving method, characterized in that. An apparatus for receiving information on spreading codes used in a packet data channel in a spreading communication system supporting a packet data service, the apparatus comprising: From the first control information received through the first control channel, the last index indicating the last spreading code among the spreading codes available for the packet data channel in the predetermined spreading code list, and the spreading codes available for the packet data channel are A first control channel receiver for obtaining a flag indicating whether the last index can be represented only; If the flag indicates that spread codes available for the packet data channel cannot be represented by the last index only, separately indicating spread codes available for the packet data channel from the second control information received through the second control channel; A second control channel receiver for obtaining a spread code bit map; And a controller for determining spread codes available for the packet data channel using the last index and the spread code bit map. 59. The apparatus of claim 57, wherein the spread code list comprises spread codes arranged in a predetermined order. 59. The apparatus of claim 57, wherein the spreading codes are Walsh codes. 58. The apparatus of claim 57, wherein the controller is further configured to determine spreading codes available for the packet data channel using the last index if the flag indicates that spreading codes available for the packet data channel can be represented by only the last index. The receiving device further comprises a process.

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