KR100389816B1 - Data rate control information transmission method and apparatus in high data rate communication system - Google Patents

Abstract

A method and apparatus for transmitting and receiving rate control (DRC) information in a communication system for high speed data transmission is disclosed. The present invention is to transmit the DRC information transmitted in the reverse direction only when necessary for scheduling in the HDR system to determine the data rate of the forward link. Transmission control of the DRC information is possible by using a DRC Request Indicator (DRI) bit, detecting preambles of all users, or detecting a user's own preamble. In addition to controlling the transmission of DRC information, it is controlled so that the timing of transmission of the pilot channel and the RRI channel is different between users. This invention reduces the interference load on the reverse link and increases the system capacity.

Description

Transmission rate control information transmission method and apparatus for communication system for high speed data transmission {DATA RATE CONTROL INFORMATION TRANSMISSION METHOD AND APPARATUS IN HIGH DATA RATE COMMUNICATION SYSTEM}

The present invention relates to a communication system for high-speed data transmission, and more particularly, to a method and apparatus for transmitting rate control (DRC) information.

Recently, many studies have been made to enable high-speed data transmission in a code division multiple access mobile communication system (hereinafter referred to as a "CDMA system"). A representative mobile communication system having a channel structure for high speed data transmission is a so-called "High Data Rate (HDR)" (or HDR system). The HDR system is a mobile communication system of the HDR standard proposed by the 3rd Generation Partnership Project 2 (3GPP2) to complement the data communication of the IS-2000 system.

The HDR system uses a link adaptation method that adjusts a data rate by changing a coding rate and a modulation method according to a channel state. In the forward link of the HDR system, a pilot channel, a forward media access control (MAC) channel, a forward traffic channel, and a forward control channel are time division multiplexed (TDM) and transmitted. The forward traffic channel using the link adaptation method has three modulation schemes: Quadrature Phase Shift Keying (QPSK), 8-ary Phase Shift Keying (8PSK), and 16-ary Quadrature Amplitude Modulation (16QAM), 1/4, 3 / A combination of three coding rates of 8 and 1/2 and the number of slots in which packets are repeatedly transmitted enables transmission at data rates according to 13 transmission schemes.

In order to select the forward data rate, the base station measures the received signal-to-interference ratio (hereinafter referred to as "C / I") of the forward pilot channel and predicts the change of the next channel to predict the data of the forward traffic channel. Require a bit rate. This request, i.e., the channel from which the terminal is fed back to the base station in the reverse link to request a data rate, is called a Data Rate Control (DRC) channel. The terminal requests a data transmission rate of a forward traffic channel and a sector to transmit data to a receiver among eight valid sectors through the DRC channel. That is, the terminal determines the data rate and the sector by measuring the pilot channel C / I of the effective sectors, the data rate information thus determined is a 4-bit DRC symbol, the cell selection information is 8-bit orthogonal ( Walsh) DRC information is configured with a 3-bit index that determines the spreading code and transmitted to the base station.

FIG. 1 is a diagram illustrating a relationship between channels transmitted through a reverse link in a general HDR system, and shows a puncturing pattern of a pilot channel, a DRC channel, and a reverse rate indicator (RRI) channel through the reverse link.

In FIG. 1, an RRI channel is a channel indicating a data rate of a reverse traffic channel. As described above, the DRC channel is a channel through which the terminal transmits DRC information to the base station. DRC symbols transmitted on the DRC channel correspond one-to-one with each code of the (8,4,4) bi-orthogonal code according to the data rate. Each bit of the 8-bit DRC symbol is repeated once and spread by an 8-bit Walsh code representing the sector. Again spread with a 4-bit Walsh code, the DRC symbols total 512 chips and are repeated once again, filling each slot with 1024 chips allocated to the DRC channel. The DRC chip is divided into 16 TDM slots of 64 chips each and is punctured as shown in FIG. 1, and then time-division multiplexed with the pilot channel and the RRI channel. When the base station receives the data rate required by the terminals in the sector through the DRC channel, the base station schedules the data data in the next slot according to the amount of packet data of each user and the required data rate. Select the terminal to receive. The base station transmits the data packet to the selected terminal at the data rate requested by the terminal for one packet period from the next slot.

2 is a view showing the length of a data packet according to the transmission rate of the forward link of a typical HDR system.

Referring to FIG. 2, the forward traffic channel may have a different packet length according to the data rate required by the terminal. After the transmission of one packet, the base station reschedules the DRC information received from the terminals in the sector and determines the terminal and the data rate of the terminal to be served in the forward traffic channel from the next slot. The base station transmits a preamble at the beginning of each packet to inform the terminal to receive the packet and the length of the packet. The preamble is multiplied by the Walsh code according to the MAC index assigned to each terminal, and the number of repetitions is determined according to the data rate of the packet. Table 1 below shows the number of repetitions and the number of chips according to the packet data rate. The terminal searches for the preamble with the Walsh code for the MAC index assigned to it and confirms the data rate.

Data rate Preamble Repetitions Chip count 38.4 kbps 32 1024 76.8 kbps 16 512 102.4 kbps 12 384 153.6 kbps 8 256 204.8 kbps 6 192 307.2 kbps 4 128 614.4 kbps 2 64 921.6 kbps 2 64 1228.8 kbps 2 64 1843.2 kbps 2 64 2457.6 kbps 2 64

As such, when transmission of one packet is terminated and a new packet is transmitted in the forward link of the HDR system, the base station performs scheduling of packet data of several users. To this end, the base station refers to the DRC information of each terminal immediately before the end of packet transmission. In this case, note that the DRC information is transmitted in every slot on the reverse link. In fact, DRC information is not needed when scheduling is not performed, but the transmission of DRC information over the DRC channel continues. Continuous transmission of DRC information over this DRC channel is to continue to occupy the resources of the reverse link, and as a result, there is a problem that reduces the system capacity of the reverse link. In particular, this problem becomes large when data is transmitted at a low data rate (for example, 38.4 kbps and 76.8 kbps in FIG. 2) on the forward link. This is because the DRC information of the reverse link is used at the scheduling point that is executed just before the packet is terminated while any packet is transmitted on the forward link, and thus no previous DRC information is required. Therefore, the case of transmitting data at a low data rate corresponds to the case of transmitting a long packet (increasing the number of slots), thereby increasing the number of slots that do not require DRC information. Continuous transmission of the DRC channel greatly increases the interference load by the DRC channel on the reverse link, so if DRC information is not needed, the interference on the reverse link can be reduced if the DRC channel is not transmitted. Will be able to increase.

Accordingly, an object of the present invention is to provide a method and apparatus for transmitting DRC information transmitted backward in order to determine a data rate of a forward link in an HDR system only at a time required for scheduling.

Another object of the present invention is to provide a method and apparatus for reducing an interference load of a reverse link in an HDR system.

It is still another object of the present invention to provide a method and apparatus for increasing the system capacity of a reverse link in an HDR system.

It is still another object of the present invention to provide a method and apparatus for reducing an interference load generated when a DRC information is not transmitted in a reverse link of an HDR system.

The present invention to achieve these objects is to ensure that the DRC information transmitted in the reverse direction to be transmitted only when the scheduling is necessary to determine the data rate of the forward link in the HDR system. Transmission control of the DRC information is possible by using a DRC Request Indicator (DRI) bit, detecting preambles of all users, or detecting a user's own preamble. In addition to controlling the transmission of DRC information, it is controlled so that the timing of transmission of the pilot channel and the RRI channel is different between users. This invention has the advantage of reducing the interference load of the reverse link and increasing the system capacity.

1 is a diagram illustrating a puncturing pattern for pilot channels, DRC channels, and RRI channels transmitted through a reverse link in a typical HDR system.

2 is a diagram illustrating the length of a data packet according to a transmission rate of a forward link of a typical HDR system.

3 is a diagram illustrating a slot transmission / reception relationship between a forward link and a reverse link in a DRC channel transmission control operation according to a first embodiment of the present invention.

4 is a flowchart illustrating a DRC channel transmission control operation according to a first embodiment of the present invention.

5 is a diagram illustrating a transmitter structure of a base station according to the first embodiment of the present invention.

6 is a diagram illustrating a transmitter structure of a terminal according to the first embodiment of the present invention.

FIG. 7 illustrates slot transmission / reception relations between a forward link and a reverse link in a DRC channel transmission control operation according to a second embodiment of the present invention; FIG.

8 is a flowchart illustrating a DRC channel transmission control operation according to a second embodiment of the present invention.

9 illustrates a structure of a transmitter of a terminal according to a second embodiment of the present invention.

FIG. 10 is a diagram illustrating slot transmission / reception relations between a forward link and a reverse link in a DRC channel transmission control operation according to a third embodiment of the present invention; FIG.

11 is a flowchart illustrating a DRC channel transmission control operation according to a third embodiment of the present invention.

12 is a diagram illustrating a structure of a transmitter of a terminal according to a third embodiment of the present invention.

FIG. 13 is a view illustrating a transmission time of pilot and RRI channels in a section in which a DRC channel is not transmitted according to the fourth embodiment of the present invention. FIG.

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.

First of all, the present invention intends to transmit DRC information transmitted backward in order to determine the data rate of the forward link in the HDR system only when scheduling is required. That is, in the present invention, when the base station needs to transmit a new packet in the HDR system, the terminal transmits DRC information only at a time point immediately before the transmission of the previous packet is terminated. According to the present invention, a determination is made as to whether or not it is time to transmit the DRC information, and selectively transmits the DRC information only when it is necessary to transmit the DRC information according to the determination result. In addition, according to the present invention, even when the DRC information is not transmitted, the transmission time of the pilot channel and the RRI channel between users is changed to reduce the interference load on the reverse link. This operation according to the present invention will be described divided into the following embodiments. In the following <Embodiment 1> to <Embodiment 3>, an operation of selectively transmitting DRC information according to a determination as to whether it is time to transmit DRC information and a result of the determination will be described. In the following <Example 4>, in addition to the <Example 1> and <Example 2>, the operation of reducing the interference load on the reverse link by changing the transmission time of the pilot channel and the RRI channel between users will be described.

Example 1

3 is a diagram illustrating slot transmission / reception relations between a forward link and a reverse link in a DRC channel transmission control operation according to a first embodiment of the present invention. This embodiment is characterized by controlling the DRC channel by introducing a DRI (DRC Request Indicator) bit. Although the data rate is limited to 76.8 kbps, it should be noted that generalization is possible for all data rates.

Referring to FIG. 3, an access network (AN) of the present invention informs all users (access terminals) of whether a reverse DRC channel needs to be transmitted, thereby transmitting the DRC channel of all users. To control. To inform of such information, the base station transmits a DRI bit through a MAC channel. The DRI bit is information indicating whether DRC information is required for scheduling after a preset slot interval. The DRC information is needed when the current forward packet ends in the set slot period and needs to determine a transmission rate and a terminal to receive a packet from the next slot. The DRI bit transmits a value of "1" when the forward packet ends in the set slot period, and transmits a value of "0" when the packet is continuously transmitted without ending. When the base station requests DRC information within the set slot period and the requested information arrives at the base station, the base station determines the data rate for the next packet to be transmitted. In other words, assuming that the base station intends to transmit a new packet in a second transmission section after the first transmission section while transmitting a packet in a first transmission section including a plurality of slots to the terminal, the base station In the second slot of the last slot of the first transmission interval, and performs the scheduling to determine the terminal to transmit the packet in the second transmission interval and the data transmission rate at this time. To this end, the base station transmits a DRI bit for requesting DRC information to the terminal in a preset slot of the first transmission interval. Herein, the set slot may be determined as a slot at least one slot before the last slot of the first transmission interval. Preferably, the set slot may be defined as a second previous slot from the last slot. In addition, the set slot may be determined as slots from the last slot to the second before, which is also considered in the case where a packet consisting of one slot is transmitted in the second transmission interval. For example, assuming that the last slot is 16 slots, the set slot is 14 slots, or 14 slots, 15 slots and 16 slots. Of course, if necessary, the set slot may be set to another slot before the second slot.

FIG. 4 is a flowchart illustrating a DRC channel transmission control operation according to the first embodiment of the present invention, and illustrates an algorithm for controlling the transmission of a DRC channel by a terminal by receiving a DRI bit.

Referring to FIG. 4, the terminal reads the DRI bit transmitted through the forward MAC channel in step 401, and determines whether the read DRI bit is “1” in step 402. If it is determined that the read DRI bit has a value of "1", the terminal measures pilot C / I of valid sectors (active set sectors) in step 403, and in step 404 according to the measurement result, A large C / I and a sector corresponding to the C / I are determined. In step 405, the largest C / I is converted into a corresponding DRC symbol, and in step 406, the DRC symbol is transmitted to the base station. After performing step 406, the next slot is received in step 407, and the operation returns to step 401 to repeat the above operation. Here, the process of generating a DRC symbol is performed by mapping a corresponding DRC symbol among the DRC symbols corresponding to a series of C / I, as is well known.

If it is determined in step 402 that the DRI bit value is "0", the terminal does not perform the operations of steps 403 to 406 and immediately proceeds to step 407, thereby omitting the aforementioned C / I measurement and DRC symbol transmission operation. , Receives the next slot.

Referring back to FIG. 3, the DRI bit of the n th forward slot controls the DRC channel of the n + 1 th reverse slot, and the DRC channel arrives in the n + 2 th slot period and the data rate of the n + 3 th forward slot Determine. That is, in order to determine the data rate of a new packet to be transmitted in the second transmission interval, three slots before the end of the packet transmitted in the first transmission interval before the second transmission interval (the second from the last slot of the first transmission interval). In the previous slot) DRC information may be requested to receive the DRC information at the scheduling time to determine the data rate. Therefore, the base station transmits a value of "1" in the DRI bit before the end of 3 slots of the packet and transmits a value of "0" in the other slots. Therefore, assuming that the packet length is N slots, the number of slots for which no DRC channel needs to be transmitted is N-3. The ratio of slots that do not require a DRC channel is (N-3) / N, and Table 2 below shows the ratio of slots that do not require a DRC channel to a data rate. If the length of the packet is 3 slots or less, the DRC channel is transmitted in all slots. In the case of a transmission rate of 153.6 kbps or less and a long packet 307.2 kbps, the interference load due to DRC channel transmission in the slot period can be reduced.

Data rate Slots per packet Percentage of slots that do not require a DRC channel 38.4 kbps 16 81.25 76.8 kbps 8 62.5 102.4 kbps 6 50 153.6 kbps Short 4 25 153.6 kbps Long 16 81.25 204.8 kbps 3 0 307.2 kbps Short 2 0 307.2 kbps Long 8 62.5 614.4 kbps One 0 921.6 kbps 2 0 1228.8 kbps One 0 1843.2 kbps One 0 2457.6 kbps One 0

FIG. 5 is a diagram illustrating a transmitter structure of a base station according to a first embodiment of the present invention, wherein the transmitter introduces a DRI request (DRC Request Indicator) bit. The traffic channel of FIG. 5 is encoded by the encoder 501, modulated by QPSK, 8PSK, 16QAM, etc. according to the transmission rate by the modulator 502, and interleaved by the interleaver 503. The interleaved traffic channel signal is punctured and repeated at the puncturing and repeater 504 according to the data rate to transmit 16 consecutive bits in the demultiplexer 505 to 16 parallel channels. Each of the 16 channels is multiplied by the Walsh cover processor 506 and 16 orthogonal Walsh codes and summed at the chip level at the Walsh Chip Level Summer 507. The preamble is repeated according to the data rate in the preamble repeater 511 and spread by a Walsh code such as the Walsh code assigned to the reverse power control channel in the Walsh spreader 512. The traffic channel and the preamble are delivered to the second multiplexer 562 by concatenating the preamble in the first section of the traffic channel in the first multiplexer.

The following describes the transmitter structure for the DRI bit in accordance with the present invention in detail. In the forward MAC channel, the pilot, FA, and RA bits are multiplied by the Walsh 0, 1, and 2 codes, respectively, and the remaining 29 Walsh codes are multiplied by the reverse power control bits for each user. One of the 29 Walsh codes used for the RPC bit may be allocated and used for the transmission of the DRI bit. For example, Walsh 3 may be allocated to transmit the DRI bit. Accordingly, according to the structure of the base station transmitter of the present invention, the FA bit is repeated 16 times in the repeater 521, and the Walsh 1 code is multiplied by the multiplier 522, and the RA bit is repeated by the RABLength index in the repeater 531, and the RA bit by the multiplier 532. The Walsh No. 2 sign is multiplied, and the DRI bit is multiplied by the Walsh No. 3 sign by the multiplier 541. The RPC bit is controlled by the RPC channel gain controller 551 by the RPC channel gain, and the multiplier 552 multiplies the remaining Walsh codes by the channel gain controlled RPC bit. The outputs of the multipliers 522, 532, 541, 552 are summed to chip level by summer 553, and the summation result by summer 553 is repeated four times by MAC channel repetition block 554 to perform the second pilot of each slot of the forward channel. It is punched halfway before and after the burst. The second multiplexer connects the output of the first multiplexer 513 and the output of the MAC channel repeater 554 as shown in FIG. 3. The second multiplexer output is complex-spread at the complex spreader 503 and filtered at the baseband filter 504 for output.

6 is a diagram illustrating a structure of a transmitter of a terminal according to a first embodiment of the present invention, wherein the transmitter introduces a DRI bit. In the following description, a transmitter structure for determining whether to transmit a DRC symbol using DRI bits according to the present invention will be described in detail.

The pilot channel is multiplied by the Walsh 0 sign by a multiplier 601. The RRI channel is modulated into an 8-bit Walsh symbol by an 8 orthogonal modulator, repeated 64 times in Walsh symbol repeater 612, and then Walsh 0 is multiplied by multiplier 613. The multiplexer 631 controls whether the DRC channel is transmitted by the DRI bit. The multiplexer 631 passes DRC symbols when the DRI bit is "1", and blocks transmission of the DRC symbol when the DRI bit is "0". The DRC symbol is block coded by a block encoder 632, and a code word that is an output of the block encoder 632 is repeated by a code word repetition block 633. The output of the iterator 633 is multiplied with Walsh codes in a series of multipliers 634, 635, and 636 and then TDM and piloted by a multiplexer (MUX) 637.

The traffic channel is encoded at encoder 641 and interleaved by interleaver 642 and then multiplied by the data channel power gain at gain multiplier 643. The output of gain multiplier 643 is multiplied by Walsh number 2 by multiplier 644. The multiplexer 637 output is transmitted on the in-phase axis and the output of the multiplier 644 is transmitted on the quadrature axis, respectively, spread on the complex spreader 646, filtered by the baseband filter 647, and then output for transmission. do.

Example 2

FIG. 7 is a diagram illustrating slot transmission / reception relations between a forward link and a reverse link in a DRC channel transmission control operation according to a second embodiment of the present invention. According to this embodiment, the terminal controls the DRC channel by detecting the preambles of all terminals belonging to the base station. That is, according to the second embodiment, the terminal detects preambles for all terminals to determine the terminal that is currently transmitting and receiving packet data with the base station, and DRC transmission is performed in a preset slot period before the transmission of the packet data ends. To lose.

According to the second embodiment of the present invention shown in FIG. 7, when the entire user detects the preambles of other users at the same time, the length of the packet transmitted in the forward direction is known so that the DRC channel is not transmitted until the scheduling is required. Each user checks whether DRC channel transmission is required and controls the DRC channel so that the DRC channel is not transmitted except at the scheduling time. As mentioned above, the preamble is multiplied by the Walsh code according to the MAC index assigned to each user, and the packet length varies according to the data rate of the packet. Accordingly, each terminal decodes Walsh codes of all MAC indexes assigned to each user, detects energy, and compares it with the preamble repetition lengths of Table 1, and the length of the currently transmitted packet and the positions of start and end slots. It can be seen. Since the DRC channel transmits DRC information for the n + 2th slot after receiving the first pilot burst of the nth slot, the DRC channel transmits the DRC channel from two slots before the end slot of the packet. In addition, since one slot is required to receive the start slot and determine the length of the packet, the DRC channel is transmitted during the start slot. Therefore, as in the first embodiment, in the second embodiment, the ratio of slots for which no DRC channel is required for packets of length N slots is (N-3) / N.

FIG. 8 is a flowchart illustrating a DRC channel transmission control operation according to a second embodiment of the present invention, and illustrates an algorithm for controlling a DRC channel by detecting preambles of all terminals.

Referring to FIG. 8, in step 801, the terminal AT detects preambles for all terminals in a sector and determines a length of a current packet. That is, each of the plurality of terminals belonging to the base station determines a terminal that is currently receiving a packet from the base station by multiplying a reception preamble and a plurality of predetermined orthogonal codes, typically Walsh codes, for the plurality of terminals. The length of the transport packet is detected from the information included in the preamble. Next, in step 802, the terminal checks whether the current packet ends in two slots. In case of terminating in two slots, the terminal measures pilot C / I of valid sectors (active set sectors) in step 803. The largest C / I and the sector corresponding to the C / I are determined. In step 805, the terminal converts the determined C / I value into a corresponding DRC symbol, and in step 806, the terminal transmits the converted DRC symbol to the base station AN. If it is determined in step 802 that the current packet does not end in two slots, C / I measurement and DRC transmission operation are omitted. That is, the operations of steps 803 to 807 are not performed.

If it is determined in step 807 that the packet has ended, the terminal returns to step 801 again to detect the preamble of all terminals to read the length of the next packet. If it is determined in step 807 that the packet has not been terminated, the process proceeds to step 808 to receive the next slot, and then to step 802, it is checked whether the current packet ends in two slots for the newly received slot. The operation of steps 806 to 806 determines whether to transmit the DRC.

9 is a diagram illustrating a structure of a transmitter of a terminal according to the second embodiment of the present invention, wherein the transmitter detects preambles of all terminals to control a DRC channel. The transmitter structure of the pilot channel, the reverse rate indicator (RRI) channel, and the traffic channel among the components shown in FIG. 9 is the same as the configuration of FIG. 6 described above. Only the transmitter structure for determining whether to transmit a DRC symbol using the reception preamble from all relevant users will be described in detail.

Referring to FIG. 9, when a preamble is received, a preamble buffer 901 of the terminal stores the reception preamble. The Walsh generator 902 generates Walsh codes of all terminals in the sector. Multiplier 903 multiplies the Walsh codes of all the terminals in the sector generated by the Walsh code generator 902 with the receive preamble stored in the buffer 901. An accumulator 904 accumulates the multiplication result of the multiplier 903, and an energy detector 905 detects energy from the accumulation result of the accumulator 904. A packet length detector 906 finds packet length information from the output of the energy detector 905. If the length of the packet is found, the required interval of DRC symbol transmission can be known as shown in FIG. 7, and thus, the DRC controller 907 controls the multiplexer (MUX) 921 which inputs and selectively outputs the DRC symbol and then DRC as shown in FIG. 7. Allow the symbol to be sent selectively. The DRC controller 907 controls the multiplexer 921 to pass the DRC symbol only two slots before the packet ends, and to block the transmission of the DRC symbol in other sections. In other words, when a packet is less than 3 slots in length, the DRC symbol is always passed. According to the above-described operation, any one of a plurality of terminals receives packet data from a base station in a first transmission interval including a plurality of slots. When receiving, the terminal transmits a DRC symbol to a preset slot (2 from the last slot) before the first transmission interval ends in order to request a transmission rate of packet data to be transmitted in the second transmission interval after the first transmission interval. First previous slot). This operation may be performed not only in the terminal receiving the packet data transmitted from the base station in the first transmission interval but also in the terminal not receiving the packet data. That is, assuming that a terminal receiving packet data from a base station in the first transmission interval among a plurality of terminals is a terminal of a first group, and that a terminal not being transmitted is a terminal of a second group, The terminal transmits a DRC symbol to the base station in a preset slot before the packet data transmission between the terminal of the first group and the base station ends. Similarly, the terminal of the first group transmits the DRC symbol to the base station in a preset slot before the packet data transmission between the terminal of the first group and the base station ends.

Example 3

FIG. 10 is a diagram illustrating slot transmission / reception relations between a forward link and a reverse link in a DRC channel transmission control operation according to a third embodiment of the present invention. According to this embodiment, the DRC channel of the forward channel user is controlled.

Referring to FIG. 10, since the third embodiment of the present invention controls only the DRC channel of the terminal AT0 receiving a packet from the base station AN, a detector for a different user preamble is different from the second embodiment. It is not necessary. The terminal AT0 currently assigned the forward traffic channel may know the length of the packet and the positions of the start slot and the end slot when it detects its preamble. In addition, it is possible to know a time interval in which DRC information is not required until a scheduling point before packet termination. Like the second embodiment, the third embodiment also transmits a DRC channel in the start slot period and the last two slots.

FIG. 11 is a flowchart illustrating a DRC channel transmission control operation according to a third embodiment of the present invention, and illustrates an algorithm for controlling a DRC channel of a terminal receiving a forward traffic channel.

Referring to FIG. 11, the terminal AT0 searches for a preamble of a packet transmitted by the base station AN in step 1101, and whether the preamble has been received by the base station AN in step 1102, that is, whether a packet transmitted from the base station has been received. Judge. If there is a packet received by the terminal AT0, it is checked in step 1103 whether the received packet ends in two slots. If it is determined in step 1103 that the received packet ends in two slots, each pilot C / I of valid sectors is measured in step 1104, and the largest C / I and the C / I in step 1105 according to the measurement result. In step 1106, the corresponding sector is determined, and the C / I value according to the determination result is a DRC symbol, and in step 1107, the generated DRC symbol is transmitted to the base station. If it is determined in step 1103 that the current packet does not end in two slots, C / I measurement and DRC transmission operations, that is, operations 1104 through 1107 are omitted. After performing step 1107, it is determined whether the packet is terminated in step 1108. If it is determined in step 1108 that the packet has ended, the terminal AT0 returns to step 1101 to search for the preamble and checks whether there is a packet received in step 1102. If it is determined in step 1108 that the packet has not ended, in step 1109 a next slot is received. After performing step 1109, the process returns to step 1103 to check whether the current packet ends in the two slots for the newly received slot and determines whether to transmit the DRC according to the check result.

12 is a diagram illustrating a structure of a transmitter of a terminal according to a third embodiment of the present invention, wherein the transmitter controls a DRC channel of the terminal receiving a forward traffic channel. The transmitter structure of the pilot channel, the reverse rate indicator (RRI) channel, and the traffic channel among the components shown in FIG. 12 is the same as the configuration of FIG. 6 described above. Only the transmitter structure for determining whether to transmit a DRC symbol using the reception preamble from all relevant users will be described in detail.

Referring to FIG. 12, the preamble detector 1201 of the terminal detects a preamble transmitted to the terminal. The packet length detector 1202 finds packet length information by using the preamble detected by the preamble detector 1201. If the length of the packet is known, the required interval of the DRC symbol transmission can be known as shown in FIG. 10. Thus, the DRC controller 1203 controls the multiplexer 1221 that inputs and selectively outputs the DRC symbol, thereby selectively selecting the DRC symbol. To be transmitted. The DRC controller 1203 controls the multiplexer 1221 to pass the DRC symbol only two slots before the packet ends, and to block the transmission of the DRC symbol in other sections. That is, the DRC symbol is always passed when the packet length is less than 3 slots.

Example 4

In the above-described first and second embodiments, the interference load is reduced by controlling the DRC channels of all users. However, as shown in FIG. 1, the DRC channel is transmitted by being time-divided with the pilot channel and the RRI channel in a 64 chip TDM slot, so that the pilot channel and the RRI channel of each user are transmitted at the same time without transmitting the DRC channel of the entire user. The interference load is not reduced at the time the pilot and RRI channels are transmitted. Therefore, if the interference load is equalized by varying the transmission time of the pilot channel and the RRI channel between users in the section in which the DRC channel is not transmitted for equalizing the interference load, the effect of not transmitting the DRC channel can be enhanced. Considering this is the fourth embodiment of the present invention.

FIG. 13 is a diagram illustrating a transmission time of pilot and RRI channels in a section in which a DRC channel is not transmitted according to the fourth embodiment of the present invention.

Referring to FIG. 13, the pilot and RRI channels are transmitted differently by dividing all users into a user group assigned an even MAC index and a user group assigned an odd MAC index. Criteria for dividing the user group may be different from the present embodiment. As shown in FIG. 13B, the odd MAC index group transmits pilot and RRI channels in odd TDM slots. As shown in (C) of FIG. 13, the even-numbered MAC index group transmits pilot and RRI channels in even-numbered TDM slots. As such, the interference load is equalized by changing the timing of pilot and RRI channel transmission between user groups, thereby contributing to the increase of reverse system capacity. That is, assuming that a plurality of terminals are composed of terminals of a first group and terminals of a second group such as odd and even numbers, when a DRC symbol is not transmitted, a pilot signal and an RRI are assigned to the terminals of the first group. Transmits in a first group of slots (eg, odd-numbered slots) among a plurality of multiplexed slots, and the terminals of the second group are slots of a second group (eg, even-numbered slots) among the multiplexed slots S).

Operations according to the fourth embodiment of the present invention may be performed independently or may be performed in connection with the above-described first, second and third embodiments of the present invention. That is, the combination of the first embodiment and the fourth embodiment is possible, the combination of the second embodiment and the fourth embodiment is possible, and the combination of the third embodiment and the fourth embodiment is possible.

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. For example, although specific embodiments of the present invention have been described as being representatively applied to an HDR system, the present invention may be applied to any communication system that transmits packet data and DRC information in addition to the HDR system. In addition, in the specific embodiment of the present invention, specific limitations such as Walsh codes are used, but the Walsh codes are used as representative examples of orthogonal codes, and need not be limited to Walsh codes. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined not only by the scope of the following claims, but also by the equivalents of the claims.

As described above, the present invention has the advantage of reducing the interference load of the reverse link by controlling the transmission of the DRC channel to transmit only when the DRC information is required in the reverse link of the HDR system, thereby increasing the reverse system capacity. In addition, in the period in which the DRC channel is not transmitted, by adjusting the transmission time of the pilot and the RRI channel differently between users, the interference load is equalized, thereby increasing the effect of reducing the interference load generated when the DRC channel is not transmitted.

Claims (67)

In the mobile communication system comprising a terminal and a base station for transmitting packet data to the terminal in a first transmission interval consisting of a plurality of slots in accordance with the data rate required by the terminal, the second after the first transmission interval In the method for transmitting data rate control (DRC) information from the terminal to the base station to request the transmission rate of the packet data to be transmitted in the transmission interval, Receiving, from the base station, an indicator requesting a data rate in a preset slot before a last one of the plurality of slots; And generating the DRC information in response to reception of the indicator and transmitting the generated DRC information to the base station. delete delete A mobile communication system comprising a base station for transmitting packet data and a terminal for requesting a transmission rate of the transmitted packet data to the base station, the base station for controlling data rate control (DRC) information transmission from the terminal. , A controller for determining a last slot of the plurality of slots when packet data is transmitted to the terminal in a first transmission interval including a plurality of slots; And a transmitter for transmitting an indicator requesting a data rate to the terminal so that the terminal requests DRC information to be used in a second transmission interval after the first transmission interval in a preset slot before the last slot. The base station. delete delete The base station for transmitting packet data in a first transmission interval consisting of a plurality of slots according to the required data transmission rate, and the data transmission rate for requesting a transmission rate of packet data to be transmitted in a second transmission interval after the first transmission interval. In the terminal of the mobile communication system comprising a terminal for transmitting control (DRC) information to the base station, A receiver for receiving an indicator from the base station for requesting a data rate in a preset slot before a last one of the plurality of slots; And a transmitter for selectively transmitting the DRC information to the base station according to the indicator. A base station which transmits packet data in a first transmission interval consisting of a plurality of slots according to a required data transmission rate, and transmits an indicator for requesting a data transmission rate in a preset slot before a last slot among the plurality of slots; And a terminal for selectively transmitting data rate control (DRC) information to the base station according to the indicator in order to request a transmission rate of packet data to be transmitted in a second transmission interval after the first transmission interval. delete delete A base station for transmitting packet data in a first transmission interval consisting of a plurality of slots according to a data rate required in advance, and a plurality of terminals, the plurality of terminals receiving the packet data in the first transmission interval A first group of terminals including at least one terminal and a second group of terminals for receiving packet data in a second transmission section after the first transmission section without receiving packet data in the first transmission section In the mobile communication system, a method for transmitting data rate control (DRC) information from the terminal of the second group to the base station, Determining a terminal of the first group by multiplying a plurality of orthogonal codes predetermined for a reception preamble and each of the plurality of terminals; Detecting a length of packet data transmitted to the first group of terminals from the preamble and determining a last slot of the plurality of slots in the first transmission interval; And generating the DRC information in a preset slot before the last slot among the plurality of slots and transmitting the generated DRC information to the base station. delete A first group of terminals including a base station for transmitting packet data in a first transmission interval consisting of a plurality of slots according to a data rate required in advance, and at least one terminal for receiving packet data in the first transmission interval. And a plurality of terminals including a second group of terminals that do not receive packet data in the first transmission interval, wherein the second group transmits data rate control (DRC) information to the base station. In the terminal, A multiplier for determining the first group of terminals by multiplying a reception preamble and a plurality of orthogonal codes corresponding to each of the plurality of terminals; A packet length detector for detecting a length of packet data transmitted from the preamble to the terminals of the first group in the first transmission interval; A controller for determining a last slot of the plurality of slots from the detection result; And a transmitter for selectively transmitting the DRC information to the base station in a preset slot before a last one of the plurality of slots under the control of the controller. delete delete delete A base station for transmitting packet data in a first transmission interval consisting of a plurality of slots according to a data rate required in advance, and a plurality of terminals, the plurality of terminals receiving the packet data in the first transmission interval A first group of terminals including at least one terminal and a second group of terminals for receiving packet data in a second transmission section after the first transmission section without receiving packet data in the first transmission section In the mobile communication system, a method for transmitting data rate control (DRC) information from the terminal of the first group to the base station, Detecting a preamble and determining a last slot of the plurality of slots; And generating the DRC information in a preset slot before the last slot among the plurality of slots and transmitting the generated DRC information to the base station. delete delete delete delete delete In a mobile communication system comprising a base station, a terminal of the first group and a terminal of the second group and a plurality of terminals for selectively transmitting data rate control (DRC) information to the base station, from the terminals to the base station In the method of transmitting a signal, Determining whether the DRC information is transmitted from each of the terminals; When the DRC information is not transmitted, transmitting an indicator and a pilot signal indicating a data rate in a terminal of the first group to the base station in a first group of slots among a plurality of multiplexing slots; When the DRC information is not transmitted, the BS and the pilot signal are transmitted from the MSs in the second group of slots except the slots of the first group among the multiplexed slots. The method comprising the step of transmitting to. delete delete delete delete delete delete delete delete delete delete The method of claim 1, wherein the set slot is a slot at least one slot before the last slot. The method as claimed in claim 1, wherein the set slots are slots from the last slot to a second previous slot. The base station as claimed in claim 4, wherein the set slot is a slot at least one slot before the last slot. The base station as claimed in claim 4, wherein the set slots are slots from the last slot to a second previous slot. 5. The base station as claimed in claim 4, wherein the transmitter includes a spreader that spreads the indicator by a preset orthogonal code. The terminal of claim 7, wherein the set slot is a slot at least one slot before the last slot. The terminal as claimed in claim 7, wherein the set slots are slots from the last slot up to a second previous. The method of claim 7, wherein the transmitter, A selector for inputting the DRC information and selectively outputting the DRC information according to the indicator; And a spreader configured to spread the output of the selector by a preset orthogonal code and output the transmission for transmission. The method of claim 8, wherein the terminal, A receiver for receiving the indicator from the base station; And a transmitter for selectively transmitting the DRC information to the base station according to the indicator. The method of claim 42, wherein the transmitter, A selector for inputting the DRC information and selectively outputting the DRC information according to the indicator; And a spreader configured to spread the output of the selector by a preset orthogonal code and output the transmission for transmission. The method of claim 8, wherein the base station, A controller for determining a last slot of the plurality of slots when packet data is transmitted to the terminal in the first transmission interval; And a transmitter for transmitting the indicator to the terminal in a preset slot before the last slot. 45. The mobile communication system according to claim 44, wherein said transmitter comprises a spreader for spreading said indicator by a preset orthogonal code. The mobile communication system of claim 8, wherein the set slot is a slot at least one slot before the last slot. The mobile communication system according to claim 8, wherein the set slots are slots from the last slot up to a second before. 12. The method as claimed in claim 11, wherein the set slot is a slot at least one slot before the last slot. The method as claimed in claim 11, wherein the set slots are slots from the last slot up to a second previous. The terminal of claim 13, wherein the set slot is a slot at least one slot before the last slot. The terminal of claim 13, wherein the set slots are slots from the last slot to a second previous slot. The method of claim 13, An accumulator for accumulating the multiplication result by the multiplier; And an energy detector for detecting an energy value of the accumulation result by the accumulator and providing the detection result to the packet length detector. The method of claim 13, wherein the transmitter, A selector for inputting the DRC information and selectively outputting the DRC information under control of the controller; And a spreader configured to spread the output of the selector by a preset orthogonal code and output the transmission for transmission. 18. The method as claimed in claim 17, wherein the set slot is a slot at least one slot before the last slot. 18. The method of claim 17, wherein the set slots are slots from the last slot up to a second previous. 24. The method of claim 23, wherein the slots of the first group are odd slots of the multiplexed slots. 24. The method of claim 23, wherein the slots of the second group are even slots of the multiplexing slots. A first group of terminals including a base station for transmitting packet data in a first transmission interval consisting of a plurality of slots according to a data rate required in advance, and at least one terminal for receiving packet data in the first transmission interval. And a plurality of terminals including a second group of terminals that do not receive packet data in the first transmission interval, wherein the first group transmits data rate control (DRC) information to the base station. In the terminal, A preamble detector for detecting the preamble, A packet length detector for detecting a length of packet data transmitted in the first transmission interval from the preamble; A controller for determining a last slot of the plurality of slots from the detection result; And a transmitter for selectively transmitting the DRC information to the base station in a preset slot before a last one of the plurality of slots under the control of the controller. 59. The terminal of claim 58, wherein the set slot is a slot at least one slot before the last slot. 59. The terminal of claim 58, wherein the set slots are slots from the last slot up to a second previous. The method of claim 58, wherein the transmitter, A selector for inputting the DRC information and selectively outputting the DRC information under control of the controller; And a spreader configured to spread the output of the selector by a preset orthogonal code and output the transmission for transmission. A multiplier for sequentially multiplying a reception preamble and a plurality of orthogonal codes corresponding to each of the at least one or more terminals; A detector for detecting a terminal of the plurality of terminals from which the packet data is received and a length of the packet data from the multiplication result; A controller for determining a transmission end section of the packet data using the length of the packet data; And a transmitter for selectively transmitting data rate control (DRC) information to a base station in a preset section before the transmission end section. 63. The terminal of claim 62, wherein when the transmission section is composed of a plurality of slots, the set section is at least one slot before a last slot of the plurality of slots. 63. The terminal of claim 62, wherein, when the transmission section is composed of a plurality of slots, the set section is slots from a last slot of the plurality of slots to a second previous slot. A mobile communication system comprising a base station for transmitting packet data and a terminal for requesting a transmission rate of the transmitted packet data to the base station, wherein the base station controls the transmission of data rate control (DRC) information from the terminal. In Determining a last slot of the plurality of slots when packet data is transmitted to the terminal in a first transmission interval including a plurality of slots; Transmitting an indicator requesting a data rate to the terminal so that the terminal requests the DRC information to be used in the second transmission interval after the first transmission interval in the preset slot before the last slot. The method. 66. The method of claim 65, wherein the set slot is a slot at least one slot before the last slot. 66. The method of claim 65, wherein the set slots are slots from the last slot up to a second previous.