CN1323495C - Method and device used for transferring data speed control informaton - Google Patents

Abstract

A method and apparatus are provided for transmitting/receiving data rate control (DRC) information in a mobile telecommunication system transmitting packet data. In order to determine the data rate on the forward link in a mobile telecommunication system such as an HDR system, DRC information is sent on the reverse link only when user data is scheduled. The access network (AN) sends a DRC request indicator (DRI) bit or the access terminal (AT) detects the preamble of all users or its own preamble in order to control the transmission of the DRC information. Along with the DRC information transmission control, certain ATs are controlled to transmit pilot channels and reverse rate indicator (RRI) channels at different points in time from other ATs. Therefore, the interference load on the reverse link is reduced, and the system capacity of the reverse link is increased.

Description

Method and apparatus for sending data rate control information

This patent application is a branch of a patent application with an application date of June 23, 2001, an application number of 01801772.X, and a patent application titled "Method and device for transmitting data rate control information in a mobile telecommunication system for packet data transmission". case application.

technical field

The present invention relates generally to mobile telecommunications systems for packet data transmission, and in particular to methods and apparatus for transmitting data rate control (DRC) information.

Background technique

Research has been actively conducted on high data rate transmission (or packet data transmission) in a CDMA (Code Division Multiple Access) mobile communication system. The main mobile communication system having a channel structure suitable for high-rate transmission is the so-called HDR (High Data Rate) system standardized by 3GPP2 (Third Generation Partnership Project 2) to enhance data communication in the IS-2000 system .

The HDR system employs a link adaptation scheme in which the data rate is controlled by adapting to a code rate and modulating to the channel state. In an HDR system, the pilot channel, MAC (Media Access Control) channel, traffic channel and control channel on the forward link are time division multiplexed (TDM) before being transmitted. By combining three modulations QPSK (Quadrature Phase Shift Keying, Quadrature Phase Shift Keying), 8PSK (8 Phase Shift Keying, 8-ary Phase Shift Keying), 16QAM (16 Phase Shift Keying, 16-ary Quadrature Amplitude Modulation) , three kinds of code rates 1/4, 3/8, and 1/2, and the number of time slots for packet transmission, the forward traffic channel adapted to the link can be transmitted at 13 data rates.

The access terminal (access terminal, AT) measures the carrier-to-interference ratio (C/I) of the forward pilot channel received from the 8 active sectors (active group sectors), estimates the channel state, and then requests access to the DRC channel. The data rate of the forward traffic channel of the incoming network (AN) and the sector from which the access terminal will receive data. The DRC information includes data rate information of a 4-bit DRC symbol and cell selection information of a 3-bit index, and an 8-bit orthogonal (Walsh) code is determined through the 3-bit index.

Figure 1 shows the relationship between back channels in a typical HDR system. The puncturing patterns of the pilot channel, DRC channel and RRI (Reverse Rate Indicator, reverse rate indicator) channel on the reverse link are shown here.

In Fig. 1, the RRI channel indicates the data rate of the reverse traffic channel, and the DRC channel transmits the DRC information to the AN as before. Each bit of the DRC information sent on the DRC channel is retransmitted once and spread with an 8-bit Walsh code indicating a sector. The resulting result is then spread with a 4-bit Walsh code. Therefore, the DRC symbol has a total of 512 chips, and retransmits itself once, so that 1024 chips are filled on the DRC channel. After puncturing in the pattern shown in Figure 1, the DRC chips are divided into 16 64-chip TDM slots, and the TDM is transmitted with the pilot channel and the RRI channel. Once the data rate is received on the DRC channel from the ATs in the sector, the AN schedules the user data according to the packet data volume and each user's requested data rate, and selects the AT that will receive a data packet in the next time slot. The AN sends data packets at the requested data rate to the selected AT for one packet period starting from the next slot.

Figure 2 shows the length of data packets at data rates on the forward link in a typical HDR system.

Referring to Figure 2, the forward traffic channel sends packets of different lengths at the data rate requested by the AT. After sending a packet, the AN selects an AT to serve on the forward traffic channel in the next time slot and determines a data rate at which to send data to the AT based on the DRC information received from the AT in the sector . AN sends a preamble at the beginning of each packet, informing the target AT to receive the packet and the length of the packet. The preamble is multiplied by a Walsh code corresponding to the MAC index assigned to the AT, and the number of retransmissions of the preamble is determined according to the data rate of the packet. Table 1 shown below lists preamble retransmissions and preamble chip counts with respect to data rate.

(Table 1)

data rate Preamble retransmission number of chips 38.4kbps 32 1024 76.8kbps 16 512 102.4kbps 12 384 153.6kbps 8 256 204.8kbps 6 192 307.2kbps 4 128 614.4kbps 2 64 921.6kbps 2 64 1228.8kbps 2 64

1834.2kbps 2 64 2457.6kbps 2 64

As described above, after transmitting a packet on the forward link in the HDR system, the AN schedules user packet data with reference to the DRC information received from the AT just before packet transmission. Note here that DRC information is sent in every time slot on the reverse link. Although the DRC information is not needed when no scheduling is in progress, the DRC information is sent continuously on the DRC channel. This means that reverse link resources are continuously occupied, thereby reducing the system capacity of the reverse link. The problem gets worse when data is sent on the forward link at low data rates (eg, 38.4kbps and 76.8kbps in Figure 2). Since DRC information is only used when scheduling before a packet is fully transmitted, other untimely DRC information for scheduling is useless. Therefore, when data is sent at a low data rate, it means that long packets are sent, that is, more slots are used, and the number of slots used for sending unnecessary DRC information increases. Continuous transmission of the DRC channel severely increases the interference load on the reverse link. Accordingly, if the transmission of the DRC channel is turned off when DRC information is not needed, interference is reduced and system capacity on the reverse link is increased.

Contents of the invention

It is therefore an object of the present invention to provide a method and arrangement for sending DRC information on the reverse link for determining the data rate of the forward link only when scheduling is required in a mobile telecommunication system like an HDR system .

Another object of the present invention is to provide a method and arrangement for reducing the interference load on the reverse link in a mobile telecommunication system like an HDR system.

Another object of the present invention is to provide a method and apparatus for increasing the system capacity of a reverse link in a mobile telecommunication system like an HDR system.

Another object of the present invention is to provide a method and apparatus for reducing interference load on a reverse link during a non-transmission period of DRC information in a mobile telecommunication system like an HDR system.

The foregoing and other objects of the present invention are achieved by providing a method and apparatus for transmitting/receiving DRC information in a mobile telecommunication system transmitting packet data. In order to determine the data rate on the forward link in a mobile telecommunication system such as an HDR system, DRC information is sent on the reverse link only when user data is scheduled. The AN sends the DRI bit, or the AT detects the preamble of all users or its own preamble, so as to control the sending of the DRC information. Along with the DRC information transmission control, some ATs are controlled to transmit the pilot channel and the RRI channel at different time points from other ATs. Therefore, the interference load on the reverse link is reduced and the system capacity of the reverse link is increased.

In order to achieve the above objects of the present invention, there is provided a method of sending data rate control information to an access network in a mobile telecommunication system having an access network, the method being used for sending data in a second group of access terminals rate control information to the access network for transmitting packet data at the requested data rate in a first transmission time period having a plurality of time slots, and the plurality of access terminals are divided into first interface an incoming terminal group and a second access terminal group, the first access terminal group including at least one access terminal receiving packet data during the first transmission time period, the second access terminal group during the first transmission time period not receiving packet data, and receiving packet data during a second time period subsequent to the first transmission time period, the method comprising the steps of: Multiplying, detecting the access terminals of the first group; detecting the length of the packet data sent to the first group of access terminals in the first transmission time period from the preamble, and checking the last time of the first transmission time period and generating data rate control information within a predetermined time slot before the end of the last time slot, and sending said data rate control information to the access network.

In order to achieve the above objects of the present invention, an access terminal as a member of a second group of access terminals among a plurality of access terminals divided into a first group and a second group in a mobile telecommunication system having an access network terminals, the access network is configured to transmit packet data at a requested data rate during a first transmission time period having a plurality of time slots, and the plurality of access terminals are divided into a first access terminal group and a second two access terminal groups, the first access terminal group comprising at least one access terminal receiving packet data during the first transmission time period, the second access terminal group not receiving packet data during the first transmission time period, and receiving packet data during a second transmission time period subsequent to the first transmission time period, the access terminal that is a member of the second access terminal group includes: a multiplier configured by combining the received preamble with the Multiple predetermined orthogonal codes of the incoming terminal are multiplied to detect the first group of access terminals; the packet length detector detects from the preamble the packets sent to the first group of access terminals in the first transmission time period the length of the data; the controller, checking the last time slot of the first transmission time period; and the transmitter, under the control of the controller, selectively sends the data rate control information to the receiver in the predetermined time slot before the end of the last time slot into the network.

In order to achieve the above objects of the present invention, there is provided a method of transmitting data rate control information to an access network in a mobile telecommunication system having an access network, said method being used for transmitting in a first group of access terminals data rate control information to an access network for transmitting packet data at a requested data rate in a first transmission time period having a plurality of time slots, and the plurality of access terminals are divided into first a group of access terminals and a second group of access terminals, the first group of access terminals comprising at least one access terminal receiving packet data during the first transmission time period, the second group of access terminals during the first transmission period The time period does not receive packet data, and the second time period after the first transmission time period receives packet data, the method includes the steps of: checking the last time slot of the first transmission time period; at a predetermined time before the end of the last time slot generating data rate control information in the slot, and sending the data rate control information to the access network.

In order to achieve the above objects of the present invention, an access terminal as a member of a first group of access terminals among a plurality of access terminals divided into a first group and a second group in a mobile telecommunication system having an access network terminals, the access network is configured to transmit packet data at a requested data rate during a first transmission time period having a plurality of time slots, and the plurality of access terminals are divided into a first access terminal group and a second two access terminal groups, the first access terminal group comprising at least one access terminal receiving packet data during the first transmission time period, the second access terminal group not receiving packet data during the first transmission time period, and receiving packet data during a second transmission time period after the first transmission time period, the access terminals that are members of the first access terminal group include: a preamble detector for detecting a preamble; a packet length detector for Detecting the length of the packet data received in the first transmission time period from the preamble; the controller, checking the last time slot of the first transmission time period based on the packet length; and the transmitter, under the control of the controller, in Data rate control information is selectively sent to the access network during a predetermined time slot before the end of the last time slot.

In order to achieve the above-mentioned objectives of the present invention, an access terminal in a mobile telecommunication system is provided, including: a multiplier for sequentially combining the received preamble with a plurality of predetermined orthogonal codes assigned to a plurality of access terminals multiplication; a detector for detecting an access terminal receiving the packet data and a length of the packet data from a result of the multiplication; a controller for determining an end time period of a packet data transmission time period based on the packet length; The data rate control information is selectively transmitted to the access network for a predetermined time period before an end time period of the data transmission time period.

In order to achieve the above objects of the present invention, there is provided a method of signaling to an access network among a plurality of access terminals divided into a first group and a second group for selectively Sending data rate control information to the access network includes the steps of: detecting whether the access terminal sends the data rate control information; if the data rate control information is not sent, the first group of access terminals in multiple sending a reverse rate indicator and a pilot signal to the access network in a predetermined first set of time slots in the multiplexing slots; and if the data rate control information is not sent, by a second set of access terminals at The reverse rate indicator and the pilot signal are sent to the access network in two groups of time slots, the second group of time slots being the remaining time slots after subtracting the first group of time slots from the plurality of multiplexing time slots.

Description of drawings

The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description with reference to the accompanying drawings.

Figure 1 shows the puncturing patterns of the pilot channel, DRC channel and RRI channel on the reverse link in a typical HDR system;

Fig. 2 shows in a typical HDR system, the data packet length with respect to the data rate on the forward link;

FIG. 3 shows a time slot transmission/reception relationship between a forward link and a reverse link in a DRC channel transmission control operation according to an embodiment of the present invention;

Fig. 4 is a flow chart of the DRC channel transmission control operation according to an embodiment of the present invention;

Figure 5 is a block diagram of an AN transmitter according to an embodiment of the present invention;

Figure 6 is a block diagram of an AT transmitter according to an embodiment of the present invention;

7 shows a time slot transmission/reception relationship between a forward link and a reverse link in a DRC channel transmission control operation according to another embodiment of the present invention;

FIG. 8 is a flow chart of the DRC channel transmission control operation according to the second embodiment of the present invention;

9 is a block diagram of an AT transmitter according to a second embodiment of the present invention;

10 is a time slot transmission/reception relationship between the forward link and the reverse link in the DRC channel transmission control operation according to the third embodiment of the present invention;

Fig. 11 is a flow chart of the DRC channel transmission control operation according to the third embodiment of the present invention;

12 is a block diagram of an AT transmitter according to a third embodiment of the present invention;

13A, 13B and 13C show the transmission of the pilot channel and the RRI channel in the non-transmission period of the DRC channel according to the fourth embodiment of the present invention.

Detailed ways

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. In the following description, well-known functions or constructions are not described in detail since they would easily obscure the invention in unnecessary detail.

It will be explained that the present invention provides an apparatus and method for determining the data rate of the forward link in a mobile telecommunication system like an HDR system for sending a DRC on the reverse link only when scheduling is required. That is, when the AN intends to send another packet in an HDR system, the AT sends the DRC information just before the previous packet is completely sent. According to the present invention, when to send the DRC information is first decided, and the DRC information is sent only at the decided time. The pilot channel and the RRI channel are sent at different time points according to users, so as to reduce the interference load on the reverse link when the DRC information is not sent. The decision whether to transmit the DRC information at the current point of time and the selective transmission of the DRC information based on the result of the decision will be described in Embodiment 1 to Embodiment 3. Embodiment 4 includes Embodiment 1 to Embodiment 3, and provides a method for reducing the interference load on the reverse link by sending the pilot channel and the RRI channel at different time points according to users.

Example 1

FIG. 3 shows the time slot transmission/reception relationship between the forward link and the reverse link in the DRC channel transmission control operation according to the first embodiment of the present invention. This embodiment is characterized in that a DRI (DRC Request Indicator) bit is introduced to control the DRC channel. Although the following embodiment is described for a data rate of 76.8 kbps, it is only one example application. Obviously, the first embodiment can be used for any data rate.

Referring to FIG. 3, the AN controls the transmission of the DRC channel from all ATs by informing all ATs whether it needs to receive the reverse DRC channel. AN sends information in DRI bits on the MAC channel. The DRI bit indicates whether DRC information is required for scheduling after a predetermined slot time period. When the transmission of forward packets is terminated at a predetermined slot time period, the DRC information is required and the AN has to select the next AT and data rate. The DRI bit is set to 1 if the transmission of the forward packet is terminated at the predetermined time slot, and is set to 0 if the transmission of the current forward packet is continued. If the AN requests DRC information within a predetermined time slot period, and receives the requested information, it determines the data rate of the next packet to be sent. Assuming that AN transmits a packet to AT in the first transmission time period with multiple time slots and at the same time transmits a new packet in the second transmission time period, AN performs a schedule to determine to receive the new packet in the second transmission time period AT and data rate used for packets in the second half of the last slot of the first transmission period. To this end, the AN sends a DRI bit requesting DRC information to the AT in a predetermined time slot in the first sending time period. The predetermined time slot is located at least two time slots before the last time slot. Preferably, the predetermined time slot is the second time slot from the last time slot. In consideration of the case where one packet is completely transmitted in one slot of the second transmission period, the predetermined slot may mean the first two slots from the last slot and the last slot. For example, if the last time slot is the 16th time slot, the scheduled time slot is the 14th time slot or the 14th, 15th and 16th time slots. The predetermined time slot can be set to a different value when necessary.

FIG. 4 is a flowchart of the DRC channel transmission control operation according to the first embodiment of the present invention. This is an algorithm that controls the transmission of the DRC channel from the AT through the DRI bit.

Referring to FIG. 4, in step 401, the AT reads the DRI bit from the forward MAC channel signal, and in step 402 checks whether the DRI bit is 1 or 0. If the DRI bit is 1, in step 403, the AT measures the pilot C/I of each active sector (active group sector), in step 404, determines a sector corresponding to the highest C/I, in step In 405, the highest C/I is converted into a corresponding DRC symbol, and in step 406, the DRC symbol is sent to the AN. In step 407, the AT receives the next time slot, and returns to step 401, DRC symbol conversion is performed by mapping C/I to corresponding DRC symbols, as is well known.

On the other hand, if the DRI bit is 0 in step 402, the AT jumps to step 407.

Returning to FIG. 3, the DRI bit in the nth forward slot controls the DRC channel in the (n+1)th reverse slot. The DRC channel arrives in the (n+2)th time slot, and a data rate is determined for the (n+3)th forward time slot. The DRC information must be requested three slots before the current packet is fully transmitted in the first transmission period, i.e., in the second slot from the last slot of the first transmission period, so that the DRC information can be received in time with The scheduling is used to determine the data rate of new packets to be sent in the second sending time period. Thus, three slots before packet transmission is terminated, the AN sends the DRI bit set to 1, and in the other slots, sends the DRI bit set to 0. If a packet is N slots long, the DRC channel need not be sent in (N-3) slots. The ratio of the number of slots transmitted by the non-DRC channel to the total number of slots in the packet is (N-3)/N. Table 2 shows the ratio of the number of slots transmitted by a non-DRC channel to the total number of slots with respect to the data rate. If the packet length is three slots or less, the DRC channel is sent in all slots. The interference load caused by the transmission of the DRC channel during the slot period can be reduced at data rates of 153.6 kbps or lower and at 307.2 kbps (long packets).

(Table 2)

data rate time slot for each packet Time slots sent by non-DRC channels (%) 38.4kbps 16 81.25 76.8kbps 8 62.5 102.4kbps 6 50 153.6kbps short 4 25 153.6kbps long 16 81.25 204.8kbps 3 0 307.2kbps short 2 0 307.2kbps long 8 62.5 614.4kbps 1 0

921.6kbps 2 0 1228.8kbps 1 0 1843.2kps 1 0 2457.6kps 1 0

Fig. 5 is a block diagram of an AN transmitter according to a first embodiment of the present invention. The transmitter is characterized by the introduction of the DRI bit.

Referring to FIG. 5 , a traffic channel is encoded in an encoder 501 , modulated in QPSK, 8PSK or 16QAM in a modulator 502 according to a data rate, and interleaved in an interleaver 503 . In the puncturer and retransmitter 504, the interleaved traffic channel signal is punctured and retransmitted according to the data rate. Demultiplexer (DEMUX) 505 outputs 16 consecutively retransmitted signal bits on 16 parallel channels. The Walsh covering unit 506 performs Walsh covering on 16 channels with 16 Walsh codes, and the Walsh chip level adder 507 will correlate the channel data covered by Walsh at the chip level add. The preamble is retransmitted at the data rate in the preamble retransmitter 511 and spread in the Walsh spreader 512 with the Walsh code assigned to the reverse power control channel. Multiplexer (MUX) 513 multiplexes the output of Walsh chip level adder 507 and the extended preamble received from Walsh spreader 512 in such a way that the preamble is at the beginning of the traffic channel. Multiplexing.

Now, a detailed description will be given of the transmitter structure associated with the DRI bits of the present invention. The pilot channel, FA (Forward Active) bit or FAB, and RA (Reverse Active) bit or RAB are multiplied with Walsh codes #0, #1, and #2, respectively, and sent on the forward MAC channel. The other 29 Walsh codes are multiplied with reverse power control (RPC) bits for the user before transmission. One of the 29 Walsh codes assigned to RPC bits can be assigned for transmission of DRI bits. For example, Walsh code #3 may be assigned to the DRI bits. According to the structure of the AN transmitter of the present invention, the FA bit is retransmitted 15 times in the retransmitter 521 (occurs 16 times), and is multiplied by the Walsh code #1 in the multiplier 522 . One RA bit occurs as many times as the RAB length factor in repeater 531 and is multiplied by Walsh code #2 in multiplier 532 . One DRI bit is multiplied with Walsh code #3 in multiplier 541 . The RPC Walsh channel gain controller 551 controls the gain of the RPC channel, and the multiplier 552 multiplies the gain-controlled RPC bits with other Walsh codes, respectively. Walsh chip level adder 553 will sum the signals received from multipliers 533, 532, 541 and 552 at the chip level. The addition occurs 4 times in the MAC channel repeater 554 and is sent before and after the second pilot burst that divides each slot in half. In multiplier 561 the pilot channel signal is multiplied by Walsh code #0. The second MUX562 is connected to the output of the first MUX513, the output of the MAC channel repeater 554 and the output of the multiplier 561, as shown in FIG. 5 . The output of the second MUX 562 is complex spread in complex spreader 563 and filtered in baseband filter 564 before transmission.

Fig. 6 is a block diagram of an AT transmitter according to a first embodiment of the present invention. This transmitter also features the introduction of the DRI bit. The description of the AT receiver for receiving the DRI bits related to the present invention from the AN will be omitted, and only the structure of the AT transmitter related to determining whether a DRC symbol will be transmitted according to the DRI bits related to the present invention will be described in detail below.

Referring to FIG. 6, the pilot channel is multiplied by Walsh code #0 in a multiplier 601. Referring to FIG. The RRI channel is modulated into 8-bit Walsh symbols in 8-quadrature modulator 611 , retransmitted 63 times in Walsh symbol retransmitter 612 , and multiplied by Walsh code #0 in multiplier 613 . If the DRI bit is 1, the MUX631 passes the DRC symbol, and if the DRI bit is 0, it blocks the DRC symbol. That is, MUX631 functions as a selector for selecting DRC symbols according to DRI bits. The DRC symbols are block encoded in a block encoder 632 and the encoded words are retransmitted in a repeater 633 . The output of repeater 633 is multiplied by the Walsh code in a series of multipliers 634,635 and 636. The MUX637 TDM-multiplexes the spread signal with the pilot signal and RRI.

The traffic channel is encoded in encoder 641 , interleaved in interleaver 642 , and multiplied with the data channel power gain in gain multiplier (gain controller) 643 . The output of the multiplier 643 is multiplied by the Walsh code #2 in the multiplier 644 . The outputs of MUX 637 and multiplier 644 are output to the in-phase (I) branch and the quadrature (Q) branch, respectively. The I and Q branches are spread in complex spreader 645 and filtered in baseband filter 646 before transmission.

Example 2

FIG. 7 shows the relationship in slot transmission/reception between the forward link and the reverse link according to the second embodiment of the present invention. In the second embodiment, the transmission of the DRC channel is controlled by allowing the AT to search for the preambles of all ATs within the service area of the AN. According to the second embodiment, the AT determines the AT that communicates the packet data with the AN by detecting the preambles of all the ATs, and transmits the DRC information at a predetermined slot time period before the packet data is completely transmitted.

If each AT also searches the preambles of other ATs, it can find the length of the current forward packet. Thus, the AT does not send its DRC channel until scheduling is required. That is, each AT checks whether its DRC channel is to be sent, and as a result, it sends a DRC channel only when scheduled. In this way the transmission of the DRC channel is controlled. As before, a preamble is multiplied by a Walsh code according to the MAX index assigned to the AT, and the length of the packet is variable depending on the data rate. Therefore, each AT measures the energy by decoding a preamble with a Walsh code corresponding to the MAX index assigned to all ATs, and compares the measured energy with the preamble retransmission times shown in Table 1, whereby , find out the length of the current packet, and locate the start and end slots of the packet. After receiving the first pilot burst in the nth time slot, the DRC channel transmits the DRC information of the corresponding (n+2)th time slot. Therefore, the AT sends the DRC channel two slots before the end slot of the packet. Because the length of the packet is known by taking a slot after the start slot is located, the AT also sends the DRC channel in the start slot. Therefore, the number of slots that do not need to be transmitted is (N-3), and the ratio of the number of slots transmitted by the non-DRC channel to N-slot packets is (N-3)/N as in the first embodiment.

FIG. 8 is a flow chart of the DRC channel transmission control operation according to the second embodiment of the present invention.

Referring to FIG. 8, in step 801, the AT searches all AT's preambles and determines the length of the current packet. That is, each AT within the service area of the AN determines the AT that is receiving the packet from the AN by multiplying the received preamble with a plurality of predetermined orthogonal codes, mainly Walsh codes assigned to the AT, and from the preamble The length of the detection packet in the code. In step 802, the AT determines whether the current packet will terminate within two slots. If the current packet terminates within two slots, in step 803 the AT measures the pilot C/I of the active sector (active group sector), and in step 804, determines the highest C/I and the corresponding highest C/I I's sector. In step 805, the AT converts the determined C/I into corresponding DRC symbols, and in step 806 sends the DRC symbols to the AN. On the other hand, if the current packet does not terminate within two slots in step 802, steps 803 to 807 are omitted.

Once packet transmission is terminated in step 807, the AT returns to step 801, searches all AT's preambles, and reads the length of the next packet. If in step 807 the packet transmission is not complete, the AT receives the next time slot in step 808 and returns to step 802 . In step 802, the AT checks whether the current packet will terminate within two of the received slots.

Fig. 9 is a block diagram of an AT transmitter according to a second embodiment of the present invention. The AT transmitter is characterized by searching all AT preambles for control of the DRC channel. The structure of the AN transmitter related to the pilot channel, RRI channel and traffic channel is the same as that shown in FIG. 6 . Therefore, only the structure of the transmitter related to deciding whether to send the DRC symbol according to the preambles of all ATs will be described.

Referring to FIG. 9, when a preamble is received, a preamble buffer 901 stores it. Walsh code generator 902 generates Walsh codes for all ATs in the sector. The multiplier 903 multiplies the preamble stored in the buffer 901 by the Walsh code. The accumulator 904 accumulates the product received from the multiplier 903, and the energy detector 905 detects energy from the accumulated result. The packet length detector 906 detects the packet length from the output of the energy detector 905 . Since the cycle suitable for DRC symbol transmission can be known from the packet length, DRC controller 907 controls MUX 921 to selectively transmit DRC symbols as shown in FIG. 7 . The DRC controller 907 controls the MUX 921 to pass the DRC symbols in two time slots before the packet transmission is completed, and block the DRC symbols in other time slots. That is, if the length of the packet is shorter than three slots, DRC symbols are transmitted all the time.

In the case where one of the plurality of ATs receives packet data from the AN in the first transmission time period including a plurality of time slots, the AT receives packet data in the time slot starting from the predetermined time slot before the end of the first transmission time period (the last The DRC symbols are transmitted in two slots preceding the slot) to request a data rate for packet data transmitted in a second transmission period following the first transmission period. This operation can be performed in the AT that is not receiving packet data from the AN in the first transmission period, and in the AT that receives packet data in the first transmission period. That is, if a terminal receiving packet data from the AN in the first transmission period is the first group, and a terminal that is not receiving packet data from the AN in the first transmission period is the second group, after completing the transfer to the first group Within a predetermined time slot before packet data transmission, the second group sends DRC symbols to the AN. The first group also sends DRC symbols to the AN within a predetermined time slot before completing packet data transmission.

Example 3

FIG. 10 shows the relationship in slot transmission/reception between the forward link and the reverse link in the DRC channel transmission control operation according to the third embodiment of the present invention. In this embodiment, the DRC channel of the AT receiving the current forward channel is controlled.

Referring to FIG. 10, since only the DRC channel of the AT receiving the packet from the AN is controlled in the third embodiment of the present invention, compared with the second embodiment, a detector for detecting preambles of other ATs is not required. The AT assigned to the current forward traffic channel can detect the packet length and locate the start and end slots of the packet by searching the preamble of the incoming AT. The AT can also find a period of time where no DRC information is needed until the scheduled time before the packet is fully sent. As in the second embodiment, the DRC channel is sent in the first and last two slots of the packet.

FIG. 11 is a flow chart of the DRC channel transmission control operation according to the third embodiment of the present invention, wherein the DRC channel of the AT receiving the forward traffic channel is controlled.

Referring to FIG. 11, in step 1101, the AT searches for the preamble sent from the AN, and in step 1102, determines whether it has received a packet. Once a packet is received, in step 1103, the AT determines whether the packet will terminate within two slots. If so, in step 1104, the AT measures the pilot C/I of the valid sector; in step 1105, determines the highest C/I and the sector corresponding to the highest C/I, in step 1106, the I is mapped to a corresponding DRC symbol; and in step 1107, the DRC symbol is sent to AN. On the other hand, if in step 1103 the packet will not terminate within two slots, the AT jumps to step 1108 . If in step 1108 the packet transmission is complete, in step 1109 the AT receives the next time slot. Then, in step 1103, the AT determines whether the current packet will be terminated within two of the new time slots, and according to the result of the determination, determines whether the DRC channel will be sent.

Fig. 12 is a block diagram of an AT transmitter according to the third block diagram of the present invention. The AT transmitter is characterized in that the DRC channel of the AT receiving the current forward traffic channel is controlled. Since the transmitter structure related to the pilot channel, RRI channel and traffic channel is the same as that shown in FIG. 6, only the transmitter structure related to determining whether to transmit the DRC symbol will be described in detail.

Referring to FIG. 12, a preamble detector 1201 detects a preamble transmitted to an AT. Packet length detector 1202 detects the packet length from the preamble. Since the time period in which the DRC symbols must be sent can be known from the packet length, as shown in Figure 10, the DRC controller 1203 controls the MUX 1221 to pass the DRC symbols in two time slots before terminating the packet transmission, and to block in other time slots DRC symbols. That is, if the packet length is shorter than 3 slots, the DRC symbols are passed all the time.

Example 4

In the first and second embodiments, the interference load is reduced by controlling the DRC channels of all ATs. However, since the DRC channel is transmitted in time division with the pilot channel and the RRI channel, even if the DRC channel is not transmitted, the pilot channel and the RRI channel from the user are transmitted at the same time point. As a result, the interference load is not reduced when the pilot and RRI channels are transmitted from the user. Therefore, if the pilot channel and the RRI channel are transmitted at different time points according to users during the non-transmission period of the DRC, the interference load can be evenly distributed. This is the basic idea of Embodiment 4.

13A, 13B, and 13C show time points at which a pilot channel and an RRI channel are transmitted corresponding to a DRC non-transmission period.

Referring to FIGS. 13A, 13B and 13C, all ATs are grouped into groups allocated to even-numbered MAC indexes and odd-numbered MAC indexes to transmit their pilot and RRI channels at different time points. ATs can be grouped in different ways. The odd-numbered MAC index group transmits pilot and RRI channels in odd-numbered TDM slots, as shown in Figure 13B, while the even-numbered MAC index group transmits pilot and RRI channels in even-numbered TDM slots, as shown in Figure 13C . The resulting equal distribution of the interference load results in an increase in reverse link system capacity. That is, if multiple ATs are divided into a first group (e.g., an odd-numbered group) and a second group (e.g., an even-numbered group), the terminals of the first group The frequency signal and the RRI channel, and the second group of terminals transmit the pilot signal and the RRI channel in the second group of time slots (for example, even numbered time slots).

The operations described above can be performed independently, or in combination with the first to third embodiments, respectively.

According to the present invention as described above, the transmission of the DRC channel is controlled such that DRC information is transmitted on the reverse link only when required in an HDR system. Therefore, the interference load on the reverse link is reduced and the system capacity of the reverse link is increased. In addition, for the DRC non-transmission time period, the pilot channel and the RRI channel are transmitted according to users at different time points, thereby further reducing the interference load generated by the DRC non-transmission time period.

While there have been shown and described with reference to certain embodiments of the invention, these are exemplary applications only. Although these embodiments are described with reference to an HDR system, they are applicable to any telecommunication system that transmits packet data and DRC information. The embodiments are also not limited to Walsh codes. Accordingly, it will be understood by those skilled in the art that various changes in form and details may be made without departing from the spirit and scope of the present invention as defined by the appended claims.

Claims (21)

1, a kind of method of data rate control information that in having the mobile communication system of access network, send to access network, this method is used for sending data rate control information to access network second group access terminal, described access network is used for sending grouped data in the first transmitting time section with a plurality of time slots with requested data rate, and a plurality of accessing terminal is divided into first access terminal group and second group that accesses terminal, described first accesses terminal, and group is included in the first transmitting time section receiving block data that at least one accesses terminal, described second accesses terminal group at first transmitting time section receiving block data not, and the second time period receiving block data after the first transmitting time section, described method comprises step:

By the preamble that will receive with distribute to a plurality of a plurality of predetermined orthogonal codes that access terminal and multiply each other, detect first group access terminal;

Detect the described first transmitting time section from described preamble and send to first group of length that inserts the grouped data of terminal, and check the last time slot of the first transmitting time section; With

Produce data rate control information in the predetermined time slot before in the end time slot finishes, and send described data rate control information to access network.

2, the method for claim 1, wherein described predetermined time slot is at least two time slots before the last time slot.

3, the method for claim 1, wherein described predetermined time slot is represented preceding two time slots and the last time slot from last time slot.

4, in a kind of a plurality of accessing terminal that is divided into first group and second group in having the mobile communication system of access network as second access terminal the accessing terminal of group membership, described access network is used for sending grouped data in the first transmitting time section with a plurality of time slots with a requested data rate, and a plurality of accessing terminal is divided into first access terminal group and second group that accesses terminal, described first accesses terminal, and group is included in the first transmitting time section receiving block data that at least one accesses terminal, described second accesses terminal group at first transmitting time section receiving block data not, and the second transmitting time section receiving block data after the first transmitting time section describedly comprises as second the accessing terminal of group membership that access terminal:

Multiplier, by the preamble that will receive with distribute to a plurality of a plurality of predetermined orthogonal codes that access terminal and multiply each other, detect first group access terminal;

The block length detector detects the described first transmitting time section from described preamble and sends to first group of length that inserts the grouped data of terminal;

Controller is checked the last time slot of the first transmitting time section; With

Transmitter under the control of controller, optionally sends data rate control information to access network in the predetermined time slot before in the end time slot finishes.

5, as claimed in claim 4 as second access terminal the accessing terminal of group membership, wherein, described predetermined time slot is at least two time slots before the last time slot.

6, as claimed in claim 4 as second access terminal the accessing terminal of group membership, wherein, described predetermined time slot is represented from preceding two time slots of last time slot and last time slot.

7, as claimed in claim 4 as second access terminal the accessing terminal of group membership, further comprise: accumulator is used to the multiplication result that adds up and receive from multiplier; And energy detector, detect energy value, and energy value is presented to the block length detector corresponding to accumulation result.

8, as claimed in claim 4 as second access terminal the accessing terminal of group membership, wherein, described transmitter comprises: selector is used for the rate of received data control information and optionally output data rate control information under the control of controller; And expander, be used for the output of predetermined orthogonal code expansion selector.

9, a kind of method of data rate control information that in having the mobile communication system of access network, send to access network, described method is used for sending data rate control information to access network first group access terminal, described access network is used for sending grouped data in the first transmitting time section with a plurality of time slots with a requested data rate, and a plurality of accessing terminal is divided into first access terminal group and second group that accesses terminal, described first accesses terminal, and group is included in the first transmitting time section receiving block data that at least one accesses terminal, described second accesses terminal group at first transmitting time section receiving block data not, and the second transmitting time section receiving block data after the first transmitting time section, described method comprises step:

Check the last time slot of the first transmitting time section;

Produce data rate control information in the predetermined time slot before in the end time slot finishes, and send described data rate control information to access network.

10, method as claimed in claim 9, wherein, described predetermined time slot is at least two time slots before the last time slot.

11, method as claimed in claim 9, wherein, described predetermined time slot is represented from preceding two time slots of last time slot and last time slot.

12, in a kind of a plurality of accessing terminal that is divided into first group and second group in having the mobile communication system of access network as first access terminal the accessing terminal of group membership, described access network is used for sending grouped data in the first transmitting time section with a plurality of time slots with a requested data rate, and a plurality of accessing terminal is divided into first access terminal group and second group that accesses terminal, described first accesses terminal, and group is included in the first transmitting time section receiving block data that at least one accesses terminal, described second accesses terminal group at first transmitting time section receiving block data not, and the second transmitting time section receiving block data after the first transmitting time section describedly comprises as first the accessing terminal of group membership that access terminal:

Precode detector detects preamble;

The block length detector detects the length of the grouped data that the described first transmitting time section receives from described preamble;

Controller is checked the last time slot of the first transmitting time section based on block length; With

Transmitter under the control of controller, optionally sends data rate control information to access network in the predetermined time slot before in the end time slot finishes.

13, as claimed in claim 12 as first access terminal the accessing terminal of group membership, wherein, described predetermined time slot is at least two time slots before the last time slot.

14, as claimed in claim 12 as first access terminal the accessing terminal of group membership, wherein, described predetermined time slot is represented from preceding two time slots of last time slot and last time slot.

15, as claimed in claim 12 as first access terminal the accessing terminal of group membership, wherein, described transmitter comprises: selector is used for the rate of received data control information and optionally output data rate control information under the control of controller; And expander, be used for the output of predetermined orthogonal code expansion selector.

16, a kind of accessing terminal in mobile communication system comprises:

Multiplier, with the preamble that receives with distribute to a plurality of a plurality of predetermined orthogonal codes that access terminal and multiply each other in proper order;

Detector detects the length of accessing terminal of receiving block data and grouped data from described multiplication result;

Controller is determined the termination time section of grouped data transmitting time section based on block length; With

Transmitter before the termination time section, in the predetermined amount of time of described grouped data transmitting time section, optionally sends data rate control information to access network.

17, as claimed in claim 16 accessing terminal, wherein, if described grouped data transmitting time section comprises a plurality of time slots, described predetermined amount of time is at least two time slots before the last time slot.

18, as claimed in claim 16 accessing terminal, wherein, if described grouped data transmitting time section comprises a plurality of time slots, described predetermined amount of time is represented from preceding two time slots of last time slot and last time slot.

19, a kind of method that transmits a signal to access network in being divided into a plurality of the accessing terminal of first group and second group is used for optionally sending data rate control information to access network at mobile communication system, comprises step:

Detect whether described accessing terminal and send described data rate control information;

If do not send described data rate control information, in the predetermined first group time slot of described first group of access terminal in a plurality of multiplexing time slots, send reverse rate and pilot signal to access network; With

If do not send described data rate control information, insert terminal by second group and in second group of time slot, send reverse rate and pilot signal to access network, described second group of time slot is to deduct first group of remaining time slot of time slot from a plurality of multiplexing time slots.

20, method as claimed in claim 19, wherein, described first group of time slot is the strange numbering time slot of described multiplexing time slot.

21, method as claimed in claim 19, wherein, described second group of time slot is the idol numbering time slot of described multiplexing time slot.

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