KR20050013038A - Method and apparatus for transmitting/receiving reverse data in wireless communication system supporting hybrid automatic repeat request - Google Patents

Abstract

PURPOSE: A method and a device for transceiving reverse data in a mobile communication system supporting an HARQ(Hybrid Automatic Retransmission reQuest) method are provided to enable a mobile terminal to include the maximum transmission frequency in an RRI(Reverse Rate Indicator), and to transmit the frequency to a base station, thereby effectively operating an outer loop power control and a data rate control. CONSTITUTION: A mobile terminal decides whether a sub packet refers to an initial transmission(402). If so, the mobile terminal determines the maximum transmission frequency of a corresponding EP(Encoder Packet)(404). The mobile terminal maps EP size, SPID(Sub Packet ID), and N_Max_Tx values with an RRI sequence(406). The terminal channel-encodes the RRI sequence, and transmits the encoded RRI sequence with traffic data(408). If the N_Max_Tx value is 1, the terminal does not receive an ACK/NAK for the initial transmission with regards to the EP, and does not perform an additional retransmission process(414).

Description

METHOD AND APPARATUS FOR TRANSMITTING / RECEIVING REVERSE DATA IN WIRELESS COMMUNICATION SYSTEM SUPPORTING HYBRID AUTOMATIC REPEAT REQUEST}

The present invention relates to a mobile communication system supporting a hybrid automatic retransmission reQuest (HARQ) scheme, in particular, the mobile station informs the base station of the maximum number of transmissions for a particular encoder packet and the base station receives A method and apparatus for adjusting an ACK / NAK and a power control target setpoint using a maximum number of transmissions.

In general, a mobile communication system may be classified into a form supporting only a voice service and a form supporting only a data service. A typical example of such a system is a code division multiple access (CDMA) mobile communication system. Currently, a system supporting only voice service in a CDMA system is a system according to the IS-95 standard. As communication technology develops along with user demands, mobile communication systems are also being developed to support high-speed data services. For example, CDMA 2000 is proposed to support voice service and high speed data service at the same time.

In the mobile communication system, since data is transmitted / received on a radio link, loss or loss of transmitted data may occur. Typical real-time services such as voice services do not need to retransmit data loss or loss. However, in the case of packet data service, when data loss or loss occurs, the message having meaningful meaning can be completely transmitted only by retransmitting the lost or lost data. Therefore, in a communication system in which data transmission is performed, data retransmission is performed in various ways.

Referring to the retransmission scheme of the radio link protocol, which is one of known retransmission schemes, when a reception error occurs, the RLP layer of the base station notifies the mobile station of an error using a signaling channel and receives the notification. The mobile terminal retransmits the same packet data. However, the retransmission by the RLP layer as described above has a problem in that it takes a long time from the initial transmission time of the traffic data where an error occurs to the retransmission time. This is because the base station receiver does not process the packet data in the physical layer, and can process only the RLP layer or higher layer, which is an upper layer thereof. In addition, when the retransmission method of the radio link protocol is used, an error occurs and the received data cannot be recycled. Therefore, it is generally advantageous to minimize the retransmission of radio link protocols in communication systems.

Hybrid automatic repeat reQuest (HARQ) scheme can compensate for the problems caused by the retransmission scheme of the radio link protocol described above. In the case of using the complex automatic retransmission method, when an error occurs in the transmission, the transmitter performs retransmission at the physical layer, and the receiver corrects the error in the data by combining the retransmitted data with the previously transmitted signal. In other words, the complex automatic retransmission scheme determines whether to retransmit in the physical layer, and thus can compensate for the disadvantage of longer error processing time. In addition, it is possible to reuse error packet data.

Even in the case of using the complex automatic retransmission scheme, it is necessary to use retransmission of the radio link protocol for some packets due to the limit of the number of retransmissions. The complex automatic retransmission method retransmits by Radio Link Protocol (RLP) ARQ by setting the residual error rate, which is the rate of error of the finally combined data, to a very small value such as 0.01 or less. Reduces the number of times. However, when using the hybrid automatic retransmission scheme, the proportion of the radio link protocol retransmission becomes very small compared with the case where the hybrid automatic retransmission scheme is not used.

1 is a diagram illustrating an operation of transmitting and receiving traffic data when a reverse automatic compound retransmission is applied in a typical mobile communication system.

Referring to FIG. 1, the mobile station transmits a first subpacket for an encoder packet (EP), which is new traffic, in the reverse time interval 102. This is called initial transmission. The reverse rate indicator (RRI) transmitted by the mobile station together with the traffic data notifies the base station of an EP size indicating the number of bits of the encoding transmitted in the same time interval and a subpacket ID (SPID) indicating the number of retransmissions. It is to. The base station performs decoding using the EP size and the SPID obtained from the RRI.

If the initially transmitted subpacket fails to be received by the base station without error, the base station transmits a 'NAK' to the mobile terminal, which means that a decoding error occurs in the corresponding forward time interval 116. The mobile station receiving the 'NAK' signal transmits a second subpacket for the same encoded packet in the time interval 104. This is called the first retransmission. If the first retransmitted subpacket also fails to be received by the base station without error, the base station also transmits 'NAK' to the mobile station in the time interval 118, which means that a decoding error occurs. The mobile station receiving the 'NAK' signal transmits a third subpacket 106 for the same encoded packet. This is called the second retransmission.

In FIG. 1, the maximum number of subpackets that a mobile station can transmit to the same encoded packet is limited to three times. That is, after performing initial transmission, first retransmission, and second retransmission, the mobile station no longer performs transmission on the corresponding encoded packet. This is to prevent the mobile station from overloading the mobile station and the base station by performing unlimited retransmission for one encoded packet in a very poor wireless environment. Therefore, the base station does not transmit the ACK / NAK signal after receiving the subpacket according to the second retransmission.

The subpackets of the time intervals 102, 104 and 106 are to be sent for the first encoded packet. After the transmission of the first coded packet is terminated, the mobile station transmits the first subpacket for the next coded packet in the time interval 108. (Initial transmission) The base station decodes the initially transmitted subpacket without error. If successful, the time interval 120 transmits an 'ACK' signal to the mobile station, indicating the successful decoding. Upon receipt of the 'ACK' signal, the mobile station no longer performs transmission of the corresponding encoded packet and starts transmission of the next encoded packet.

In FIG. 1, the mobile station performs three transmissions for the first coded packet. In addition, one transmission is performed on the second coded packet. Finally, two transmissions 110 and 112 are performed on the third encoded packet, and responses 122 and 124 to the transmissions are performed.

As such, when HARQ is operated, the maximum number of transmissions is promised between the mobile station and the base station. If the base station succeeds in decoding without error before receiving the maximum number of transmissions, the transmission is terminated early by transmitting an 'ACK' to the mobile station. Termination.

As described above, when the maximum number of transmissions is promised between the mobile station and the base station, the mobile station always performs automatic retransmission according to the promised maximum number of transmissions, but the mobile station does not reserve the maximum number of transmissions on its own without prior appointment with the base station. I can regulate it. For example, the mobile station may set the maximum number of transmissions to a smaller value in the case of a data packet requiring a low time delay.

Meanwhile, in a mobile communication system such as CDMA 2000 1x, power control is performed on a reverse pilot signal so that a traffic channel for reverse data transmission maintains a constant reception performance. Power control for the reverse signal can be classified into two types. First, the base station transmits a power control command to the mobile station every time slot (for example, 1.25ms) so that the Ep / Nt (noise ratio of received pilot energy to noise) of the signal transmitted by the mobile station is set by the base station. (inner loop power control) that controls the transmit power of the mobile terminal to approach the power control target setpoint, and the second is an outer loop power control that adjusts the reference point every frame period. to be. External cyclic power control is to adjust the reference point of the power control so that the reception performance of the received traffic channel is kept constant.

However, when the mobile station adjusts the maximum number of transmissions on its own in performing the hybrid automatic retransmission, that is, the base station cannot know this when the mobile station adjusts the maximum number of transmissions according to its own judgment. As an example, a case in which the mobile terminal adjusts the maximum number of transmissions from three times to two times at its own discretion. The base station transmits a NAK requesting retransmission to the mobile station if the base station fails to perform decoding for the second transmission. Since the mobile station has set the maximum number of transmissions to two times, it ignores the 'NAK' from the base station and transmits the next coded packet.

Here, the base station cannot know why the mobile station performs transmission for the next coded packet. That is, the base station can discriminate whether the mobile station transmits the coded packet only twice because of its own configuration or because the 'NAK' signal transmitted by the base station is incorrectly determined to be 'ACK' by the mobile station. Can not. If it is due to the mobile terminal's own configuration, if the error-free decoding fails after two transmissions, the power control reference point may be adjusted upward. On the other hand, if it is due to an ACK / NAK decision error, adjusting the power control reference point may adversely affect external circulation power control to maintain a constant reception performance of the traffic channel. Since the base station cannot know whether the mobile station has adjusted the maximum number of transmissions by its own setting, should the power control reference point be adjusted if the mobile station transmits less than the predetermined number of transmission times for the coded packet that transmitted 'NAK'? Can't make a judgment about whether or not.

Accordingly, an object of the present invention, which was devised to solve the problems of the prior art operating as described above, includes the maximum number of transmissions determined by the mobile station in an automatic complex retransmission scheme and transmits the maximum number of transmissions to the base station to the base station for external cyclic power control. To provide an effective method and apparatus for operating.

In addition, the present invention provides a method and apparatus for effectively operating the data rate control by including the maximum number of transmissions determined by the mobile station in the RRI to the base station in the automatic complex retransmission method.

According to a first aspect of the present invention, a method for transmitting reverse data in a mobile communication system supporting complex automatic retransmission,

Determining a maximum number of transmissions for the encoded packet when an initial transmission subpacket occurs for the encoded packet to be transmitted;

And encoding the information sequence indicating the size of the encoded packet, the number of retransmissions, and the determined maximum number of transmissions, and transmitting the same sequence in the same time interval as the initial transmission subpacket.

According to a second aspect of the present invention, a method for receiving reverse data in a mobile communication system supporting complex automatic retransmission,

Receiving an information sequence indicating the size, the number of retransmissions and the maximum number of transmissions of the encoded packet in the reverse direction, and the subpackets corresponding to the encoded packet;

Stopping the retransmission procedure for the encoded packet without transmitting a response to the subpacket when the number of subpackets received corresponding to the encoded packet reaches the maximum number of transmissions;

And if the number of subpackets received corresponding to the encoded packet does not reach the maximum number of transmissions, transmitting a response to the subpackets.

1 is a diagram illustrating an operation of transmitting and receiving traffic data according to automatic hybrid retransmission in a reverse direction in a typical mobile communication system.

2 is a diagram illustrating a reverse automatic hybrid retransmission operation of a mobile station according to an embodiment of the present invention.

3 is a diagram illustrating a reverse automatic hybrid retransmission operation of a mobile station according to another preferred embodiment of the present invention.

4 is a flowchart illustrating an operation of a mobile station for transmitting an RRI and receiving an ACK / NAK according to an embodiment of the present invention.

5 is a diagram illustrating a mapping rule for mapping an EP size, an SPID, and a maximum number of transmissions to an RRI sequence according to an embodiment of the present invention.

6 is a flowchart illustrating the operation of a base station receiving an RRI and transmitting an ACK / NAK according to an embodiment of the present invention.

7 is a block diagram of a mobile station transmitter for transmitting an RRI sequence in the reverse direction according to an embodiment of the present invention.

8 is a block diagram of a base station receiver for receiving an RRI sequence in the reverse direction according to an embodiment of the present invention.

9 is a diagram illustrating a device for transmitting and receiving reverse data in a mobile communication system supporting complex automatic retransmission according to another embodiment of the present invention.

10 is a flowchart illustrating a method of transmitting reverse data in a mobile communication system supporting a hybrid automatic retransmission scheme according to another embodiment of the present invention.

11 is a flowchart illustrating a method of receiving reverse data in a mobile communication system supporting a hybrid automatic retransmission scheme according to another preferred embodiment of the present invention.

DETAILED DESCRIPTION A detailed description of preferred embodiments of the present invention will now be described with reference to the accompanying 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.

The present invention described below is to inform the base station of information corresponding to the case where the mobile terminal down-regulates the maximum number of transmissions for the complex automatic retransmission. The mobile terminal transmits a reverse rate indicator (RRI) including an EP size indicating the number of bits of encoding to be transmitted in the same time interval and a subpacket ID (SPID) indicating the number of retransmissions for each transmission of traffic data. send. In the present invention, the RRI further includes information on the maximum number of transmissions.

2 illustrates an automatic compound retransmission operation of a mobile terminal according to an embodiment of the present invention. Here, the maximum number of transmissions is promised three times between the base station and the mobile station, but the mobile station itself adjusts the number of transmissions to two times.

In FIG. 2, the RRI transmitted by the mobile terminal includes an EP size and an SPID which is an identifier indicating the order of subpackets for the encoded packet transmitted in the corresponding time interval.

Referring to FIG. 2, the mobile station initially transmits and retransmits subpackets corresponding to the first encoded packet in reverse time intervals 202 and 204 in order, and then receives 'NAK' from the base station in the forward time interval 210. Even when receiving, only the RRI is transmitted in the time interval 206 without performing a second retransmission. The RRI carries information on the third transmission and information on the EP size of the encoded packet corresponding to the subpackets. The base station then adjusts the reference point of the external cyclic power control from after receiving the RRI.

In FIG. 2 as described above, the base station can solve the problem that may occur due to the mobile station not performing retransmission after transmitting the 'NAK' 212, but the new encoding packet is transmitted while the RRI 206 is transmitted. Cannot perform the transfer. In addition, since the base station does not know whether the mobile station has adjusted its own transmission frequency, the base station must transmit an unnecessary NAK 212 signal corresponding to the third subpacket.

3 is a diagram illustrating an automatic compound retransmission operation of a mobile terminal according to another preferred embodiment of the present invention. Similarly, here, the maximum number of transmissions is promised three times between the base station and the mobile terminal, but the mobile terminal itself adjusts the number of transmissions to two times.

Referring to FIG. 3, the mobile station sequentially transmits subpackets for the first coded packet in reverse time intervals 302 and 304 by initial transmission and retransmission, and then, for the new coded packet in time interval 306. Send the first subpacket immediately. In this case, the RRI transmitted in the time intervals 302, 304, and 306 includes the maximum transmission frequency information set by the mobile terminal in addition to the EP size for the encoded packet transmitted in the corresponding time interval and the SPID which is an identifier indicating the order of the subpackets. .

That is, the mobile station notifies the base station of the EP size, the SPID, and the maximum number of times of transmission of the coded packet at every subpacket transmission. The base station can use the information transmitted by the mobile station to the RRI to know how many times the mobile station transmits the coded packet. Therefore, the base station knows that the mobile station no longer transmits the subpacket for the same coded packet after the subpacket of the time interval 304. Therefore, after receiving the subpacket of the time interval 304, the base station performs external cyclic power control by using the result of decoding the subpackets of the time intervals 302 and 304 without waiting for further retransmission.

In FIG. 3, the base station does not transmit an acknowledgment (ACK) / negative response (NAK) as a response after the mobile station receives the subpacket of the time interval 304. This is to increase forward system capacity by not transmitting unnecessary ACK / NAK signals.

4 is a flowchart illustrating an operation of determining, by a mobile terminal, information to be mapped to an RRI and receiving an ACK / NAK from a base station according to an embodiment of the present invention.

Referring to FIG. 4, the mobile station determines whether the current subpacket is initially transmitted in step 402. If it is determined that the initial transmission is determined in step 404, the mobile station determines how many times to transmit the encoded packet. In this case, the variable indicating the maximum number of times the mobile station transmits is indicated by 'N_Max_Tx'. The value of N_Max_Tx is equal to or less than the maximum number of transmissions previously promised between the mobile station and the base station. N_Max_Tx is a value determined by the mobile station in consideration of how sensitive the traffic data to be transmitted by the mobile station is to time delay and the memory situation of the mobile station. In addition, in step 404, N_Tx corresponds to the number of times a mobile station transmits a subpacket for one encoded packet. Since the process 404 corresponds to the case of initial transmission, N_Tx representing the number of transmissions for the corresponding encoded packet is set to '1'.

The mobile station having determined the value of N_Max_Tx maps the EP size, SPID, and N_Max_Tx of the encoded packet to the RRI sequence as in step 406. One way of mapping the R size of the EP size, SPID, N_Max_Tx is to use FIG.

FIG. 5 lists mapping rules for mapping possible combinations of EP size, SPID and N_Max_Tx of a coded packet to a unique RRI sequence, so that the mobile station can deliver the above three pieces of information to the base station with only a 4-bit RRI sequence. To be able. When a separate number of bits is allocated to each piece of information without using the mapping method as shown in FIG. 5, a 6-bit RRI sequence is required.

5 corresponds to the case where three EP sizes of 0, 192, and 384 are possible, and the mobile station can perform a maximum of three transmissions. In this case, the number of bits required for the required RRI sequence is determined by the number of possible combinations, and the number of possible combinations is shown in Equation 1 below.

here Is the sum of the applicable N_MAX_TXs. In the case of FIG. 3, N_MAX_TX may have values of 3, 2, and 1; The value of 6 is 6.

When the maximum number of transmissions that a mobile station can transmit is 3, and there are three possible EP sizes of an encoded packet, 0, 192, and 384, when the above Equation 1 is applied, (3-1) x (3 + 2) It can be seen that +1) + 1 = 13 RRIs are required. Therefore, by using an RRI sequence of at least 4 bits, possible combinations of EP size, SPID, and N_Max_Tx of the encoded packet can be mapped to the RRI sequence.

For example, in the case of 10 EP sizes of 0, 192, 384, 768, 1536, 3072, 4608, 6144, 9216, and 12288, applying the above Equation 1, (10-1) x (3 + 2) +1) + 1 = 55 RRIs are required so the number of bits of the RRI sequence is 6 bits. Therefore, by using an RRI sequence of at least 6 bits, a combination of EP size, SPID, and N_Max_Tx of an encoded packet can be mapped to an RRI sequence.

After mapping possible combinations between EP size, SPID, and N_Max_Tx of the encoded packet to the corresponding RRI sequence according to the mapping rule as shown in FIG. 5 in step 406, the mobile terminal maps the corresponding RRI sequence as shown in step 408. After channel coding, it is transmitted along with traffic data (ie, initial transmission subpacket).

The mobile terminal that transmits the RRI sequence and traffic data decides whether or not to receive an ACK / NAK. If the initial transmission is performed in step 410 and the value of N_Max_Tx is determined to be '1', the mobile station does not receive ACK / NAK for the initial transmission of the corresponding encoded packet as in step 414 and does not perform additional retransmission. In this case, not performing additional retransmission means that transmission of the corresponding encoded packet is terminated and initial transmission of the next encoded packet is performed.

On the other hand, if the initial transmission is performed in step 410 and the N_Max_Tx value is determined to be greater than '1', the mobile station receives the ACK / NAK for the corresponding initial transmission and receives the 'NAK' signal as shown in step 412. Perform retransmission. In this case, performing retransmission means transmitting the next subpacket for the corresponding encoded packet.

On the other hand, if it is determined in step 402 that the retransmission, the mobile station increases the N_Tx value by '1' as in step 416. The mobile terminal then maps possible combinations of EP size, SPID, N_Max_Tx of the encoded packet to the corresponding RRI sequence according to the mapping rule as shown in FIG. The RRI sequence is channel coded in step 420 and then transmitted along with the traffic channel.

The mobile station that has transmitted the RRI sequence and traffic data (ie, retransmission subpacket) determines whether to receive an ACK / NAK for the corresponding subpacket as follows. If N_Tx is equal to N_Tx_Max as in step 422, the mobile station does not receive ACK / NAK for retransmission of the corresponding coded packet as in step 424 and does not perform additional retransmission and starts transmission for the next coded packet. On the other hand, if it is determined in step 422 that the value of N_Max_Tx is greater than N_Tx, the mobile station receives ACK / NAK for the corresponding subpacket and transmits the next subpacket for the corresponding encoded packet when receiving the 'NAK' signal.

6 is a flowchart illustrating an operation of a base station receiving information carried on an RRI channel and transmitting an ACK / NAK according to an embodiment of the present invention.

Referring to FIG. 6, in step 502, the base station receives a signal of the RRI channel from the mobile station, and demaps the RRI sequence obtained by decoding the RRI channel as a combination of EP size, SPID, and N_Max_Tx in step 504. By obtaining these information.

In step 506, the base station decodes the traffic channel using the obtained EP size and SPID. After decoding, the base station determines whether to transmit the ACK / NAK signal for the corresponding subpacket as follows.

In step 508, the base station compares the number of received subpackets with respect to the corresponding encoded packet and N_Max_Tx transmitted by the mobile station to the RRI. N_Rx in step 508 refers to the number of subpackets received by the base station for one specific encoded packet. If N_Rx and N_Max_Tx are the same in step 508, the base station determines that there is no additional retransmission for the encoded packet without transmitting ACK / NAK to the received subpacket as in step 510. In step 510, the base station determines that there is no additional retransmission and adjusts the reference point of the external cyclic power control using step 512 by using the success or failure of receiving the corresponding encoded packet.

On the other hand, if N_Rx is less than N_Max_Tx in step 508, the process proceeds to step 514, and it is determined whether the corresponding encoding packet has been successfully received or not. If it is determined that the ACK, the base station transmits the ACK in step 516 and adjusts the reference point of the external cyclic power control. On the other hand, if the encoded packet is not successfully received, the base station transmits a NAK in step 518.

7 is a block diagram of a mobile station transmitter for transmitting an RRI sequence in the reverse direction according to an embodiment of the present invention. Here, the configuration of the controller for determining the N_Max_Tx in the mobile terminal is not shown, only the configuration of the transmitter for transmitting the determined information.

Referring to FIG. 7, the RRI sequence mapper 610 receives an EP size, SPID, and N_Max_Tx of a transmitted packet, and outputs a result of mapping it to a corresponding RRI sequence. For example, the sequence mapper 610 performs mapping according to the mapping rule shown in FIG. 5. The RRI sequence output from the sequence mapper 610 is channel-coded by the channel encoder 620 and then Walsh code spread by the spreader 630 and then transmitted.

8 is a block diagram of a base station receiver for receiving an RRI sequence in the reverse direction according to an embodiment of the present invention. Here, the configuration of the controller for transmitting the ACK / NAK and performing power control using N_Max_Tx and the encoded packet received from the base station is not shown, only the configuration of the receiver for receiving the determined information.

Referring to FIG. 8, the despreader 710 performs Walsh code despreading on a received signal of an RRI channel. The despread signal is input to the channel decoder 720 and decoded into an RRI sequence. The decoded RRI sequence is recovered by the RRI sequence demapper 730 through the RRI sequence demapping to the EP size, SPID, and N_Max_Tx information of the encoded packet.

Meanwhile, an apparatus for transmitting and receiving reverse data in a mobile communication system supporting complex automatic retransmission according to another embodiment of the present invention will be described with reference to FIG. 9.

In FIG. 3, the base station determines whether to transmit or receive ACK / NACK by using the maximum number of transmission information transmitted by the mobile station. In addition to efficiently operating the transmission and reception of ACK / NACK by using the maximum number of transmission information, EP size, and SPID included in the RRI, the base station transmits a forward rate control channel (F-RCCH). It can also be used. Here, the F-RCCH is a forward channel transmitted by the base station to the mobile station and has information on whether to increase or decrease the data transmission rate for each mobile station. The base station individually controls the reverse data rate of each mobile station by transmitting a rate control bit (RCB) unique to the mobile station on the F-RCCH.

That is, the RCB generally has a 1-bit information amount, and the base station controls whether the data transmission rate is increased or decreased by one step to the mobile terminal by using the 1-bit information amount.

FIG. 9 illustrates a case in which the maximum number of transmissions is promised three times between the base station and the mobile station as in FIG. 3, but the mobile station adjusts the number of transmissions twice.

The mobile station sequentially transmits the subpackets for the first coded packet in the reverse time intervals 901 and 902 by initial transmission and retransmission, and then immediately transmits the first subpacket for the new coded packet in the time interval 903. send. In this case, the RRI transmitted in the time intervals 901, 902 and 903 includes the maximum transmission frequency information set by the mobile terminal in addition to the EPID and the SPID indicating the subpacket sequence number for the encoded packet transmitted in the corresponding time interval. .

Transmission of the ACK / NACK in the base station is performed using the same method as in FIG. On the other hand, the RCB controlling the reverse data rate of the mobile station is transmitted to the mobile station only when the mobile station transmits the last subpacket or ACK for one encoded packet. That is, the base station transmits the RCB to the mobile terminal only after receiving the last subpacket 902 for the first coded packet and performing error-free decoding on the received coded packet (909). The reason why the base station transmits the RCB only after receiving the last subpacket from the mobile station or when the base station performs error-free decoding on the received encoded packet is otherwise the data transmission rate is independent of the RCB transmitted. Because it is maintained. In other words, except for the last subpacket of one encoded packet or the encoded packet which has been subjected to error-free decoding, the case corresponds to a case in which retransmission is to be performed, and the data transmission speed of retransmission is always kept the same. For example, the base station does not transmit the RCB to the mobile terminal after receiving the subpacket transmitted by the mobile station in the time interval 901. This is because the mobile terminal fails to perform error-free decoding using the subpackets of the time interval 901, and the subpackets of the time interval 901 are not the last transmission of the corresponding encoded packet. For this reason, the subpackets of the time interval 902 following the time interval 901 correspond to retransmission of the encoded packet transmitted in the time interval 901 and the retransmission has the same data transmission rate as the initial transmission.

A method of transmitting reverse data in a mobile communication system supporting a hybrid automatic retransmission scheme according to another embodiment of the present invention will be described with reference to the flowchart shown in FIG. 10. In other words, the base station receives the information carried on the RRI channel and transmits the RCB.

First, the base station receives the information carried in the RRI channel from the mobile station in step 1001, and determines whether the corresponding subpacket is the last transmission using the information of the EP size, SPID, N_Max_Tx in the RRI channel received from the mobile station. If it is determined in step 1001 that the corresponding sub packet is the last transmission from the information on the RRI channel, the base station transmits the RCB to the mobile station using the F-RCCH without transmitting the ACK / NACK as in step 1004. . The reason why the RCB is transmitted without transmitting the ACK / NACK in step 1004 is that there is no additional retransmission for the corresponding encoded packet and a new initial transmission must be performed.

On the other hand, if it is determined in step 1001 that the corresponding subpacket is not the last transmission from the information on the RRI channel, the base station receives the corresponding subpacket in step 1002 and determines whether or not error-free decoding is successful. If it is determined that the decoding of the subpacket received in step 1002 was successful, the base station transmits an ACK signal to the mobile station in step 1005 and transmits the RCB using the F-RCCH. However, if it is determined that the decoding of the subpacket received in step 1002 was not successful, the base station transmits a NACK to the mobile station in step 1003 and does not transmit the RCB.

A method of receiving reverse data in a mobile communication system supporting a hybrid automatic retransmission scheme according to another embodiment of the present invention is described below with reference to the flowchart shown in FIG. That is, a flowchart illustrating an operation of receiving a RCB by the mobile terminal.

First, the mobile station determines whether the subpacket transmitted to the base station in step 1101 is the last transmission. If it is determined that the subpacket transmitted to the base station is the last transmission, the mobile station does not receive the ACK / NACK signal transmitted from the base station in step 1104 and determines that it will receive the RCB. Used to determine the decoding packet size of the packet.

On the other hand, if it is determined that the subpacket transmitted in step 1101 is not the last transmission, the mobile station determines whether the base station transmits an ACK in step 1102. If it is determined that the base station has transmitted the ACK, the mobile station determines that the base station has transmitted the RCB with the ACK in step 1103. Therefore, when receiving the RCB from the base station, the mobile station determines the size of the decoded packet transmitted to the new coded packet using the RCB.

On the other hand, if it is determined in step 1102 that the base station has not transmitted the ACK, the mobile station determines in step 1105 that the base station fails to decode the corresponding encoded packet without error. In this case, the mobile station does not need to receive the RCB because it needs to retransmit the same coded packet. Therefore, the mobile station retransmits to the existing EP size.

9, 10, and 11 illustrate an operation of a base station and a mobile terminal when the base station transmits an RCB to the mobile terminal. In the case of using a forward grant channel (F-GCH) indicating a multi-step increase or decrease instead of RCB, which means one step increase or decrease of the reverse data transmission rate, the contents of FIGS. 9, 10, and 11 will be described. The same may apply. In general, the F-GCH has a plurality of bits of information amount. The F-GCH is a forward control channel transmitted by the base station to the mobile station. The base station uses the F-GCH to inform the mobile station of how much data transmission rate the mobile station can transmit in the reverse direction.

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

In the present invention, a mobile communication system supporting a complex automatic retransmission scheme informs the base station of each subpacket transmission of information on the maximum number of transmissions controlled by the mobile station itself. Make control more efficient.

In addition, the present invention in the mobile communication system that supports the complex automatic retransmission scheme to inform the base station of each subpacket transmission information on the maximum number of transmissions that the mobile station adjusts itself by the base station to control the ACK / NCAK transmission and rate control Make it more efficient.

Claims (22)

In the method for transmitting reverse data in a mobile communication system that supports complex automatic retransmission, Determining a maximum number of transmissions for the encoded packet when an initial transmission subpacket occurs for the encoded packet to be transmitted; And encoding the information sequence indicating the size of the encoded packet, the number of retransmissions, and the determined maximum number of transmissions, and transmitting the same information interval in the same time interval as the initial transmission subpacket. The method of claim 1, wherein if the determined maximum number of transmissions is not 1, waiting for a response corresponding to the initial transmission subpacket from a base station, and if another negative packet is received, transmitting another subpacket for the encoded packet. The method characterized in that it further comprises. The method as claimed in claim 2, further comprising: when the determined maximum number of transmissions is 1, transmitting the next encoded packet without waiting for a response corresponding to the initial transmission subpacket from the base station. . In the method for receiving reverse data in a mobile communication system that supports complex automatic retransmission, Receiving an information sequence indicating the size, the number of retransmissions and the maximum number of transmissions of the encoded packet in the reverse direction, and the subpackets corresponding to the encoded packet; Stopping the retransmission procedure for the encoded packet without transmitting a response to the subpacket when the number of subpackets received corresponding to the encoded packet reaches the maximum number of transmissions; And if the number of subpackets received corresponding to the encoded packet does not reach the maximum number of transmissions, transmitting a response to the subpackets. 5. The method of claim 4, further comprising adjusting a power control reference point according to whether an error is detected in the encoded packet after stopping the retransmission procedure for the encoded packet. An apparatus for transmitting reverse data in a mobile communication system supporting complex automatic retransmission, A controller for determining a maximum number of transmissions for the encoded packet when an initial transmission subpacket is generated for the encoded packet to be transmitted; And a transmitter for encoding the information sequence indicating the size and the number of retransmissions of the encoded packet and the determined maximum number of transmissions, and transmitting the encoded information sequence in the same time interval as the initial transmission subpacket. The method of claim 6, wherein the controller, When the sub packet for the encoded packet transmitted by the mobile station is the last transmission, it is determined that the rate control bit will be received from the base station using the forward rate control channel, and the next time is determined using the rate control bit received from the base station. The apparatus for determining the size of the decoded packet to be transmitted in the interval. The method of claim 6, wherein the controller, If the subpacket for the encoded packet transmitted by the mobile station is not the last transmission and does not receive an ACK from the base station, it is determined that the base station has failed to decode the decoded packet without error and retransmits the existing decoded packet size. The device, characterized in that. The method of claim 6, wherein the controller, If the sub packet for the encoded packet transmitted by the mobile station is not the last transmission and receives an ACK from the base station, the base station determines that the base station transmits a rate control bit using a forward rate control channel, and receives the received packet from the base station. And determining a size of a decoded packet to be transmitted in a next time interval using a rate control bit. The method of claim 6, wherein the controller, If the determined maximum number of transmissions is not 1, the base station waits for a response corresponding to the initial transmission subpacket, and if a negative response is received, transmits another subpacket for the encoded packet. The method of claim 6, wherein the controller, And if the determined maximum number of transmissions is 1, transmitting the next coded packet without waiting for a response corresponding to the initial transmission subpacket from the base station. An apparatus for receiving reverse data in a mobile communication system supporting complex automatic retransmission, A receiver for receiving an information sequence indicating the size, the number of retransmissions, and the maximum number of transmissions of the encoded packet in the reverse direction, and the subpackets corresponding to the encoded packet; If the number of received subpackets corresponding to the encoded packet reaches the maximum number of transmissions, the retransmission procedure for the encoded packet is stopped without transmitting a response to the subpacket, and the received subpackets are received. And a controller for sending a response to the subpacket if the number of packets has not reached the maximum number of transmissions. The method of claim 12, wherein the controller, And transmitting a rate control bit using a forward rate control channel when the sub packet for the encoded packet transmitted by the mobile station is the last transmission. The method of claim 12, wherein the controller, If the subpacket for the encoded packet transmitted by the mobile station is not the last transmission and the decoding packet is successfully decoded without error, the mobile station transmits an ACK to the mobile station and transmits a rate control bit using a forward rate control channel. The device, characterized in that. The method of claim 12, wherein the controller, And transmitting the NACK to the mobile terminal when the sub packet for the encoded packet transmitted by the mobile terminal is not the last transmission and fails to decode the decoded packet without error. The method of claim 12, wherein the controller, And adjusting a power control reference point according to whether an error is detected in the encoded packet after stopping the retransmission procedure for the encoded packet. In the method for transmitting reverse data in a mobile communication system that supports complex automatic retransmission, Determining whether the subpacket is the last transmission when a subpacket for the encoded packet to be transmitted is generated; And if the subpacket is the last transmission, determining a size of a decoded packet to be transmitted at a next time interval using a rate control bit received from a base station. The method of claim 17, If the subpacket for the encoded packet transmitted by the mobile station is not the last transmission and does not receive an ACK from the base station, it is determined that the base station has failed to decode the decoded packet without error and retransmits the existing decoded packet size. Said method, characterized in that. The method of claim 17, When the sub packet for the encoded packet transmitted by the mobile station is not the last transmission and receives an ACK from the base station, it is determined that the rate control bit is to be transmitted from the base station using the forward rate control channel, and the rate control bit is used. And determining a size of a decoded packet to be transmitted in a next time interval. In the method for receiving reverse data in a mobile communication system that supports complex automatic retransmission, Determining whether the subpacket for the encoded packet received from the mobile station is the last transmission; And transmitting a rate control bit using a forward rate control channel when the sub packet is the last transmission. The method of claim 20, If the subpacket for the encoded packet transmitted by the mobile station is not the last transmission and the decoding packet is successfully decoded without error, the base station transmits an ACK to the mobile station and transmits a rate control bit using a forward rate control channel. The method of transmission. The method of claim 20, And if the subpacket for the encoded packet transmitted by the mobile terminal is not the last transmission and fails to decode the decoded packet without error, the method transmits a NACK to the mobile terminal.