KR100753500B1 - Method for Link Adaptation using Hybrid Automatic Repeat Request in Reverse Link, System for the same - Google Patents

Abstract

The present invention efficiently supports the hybrid automatic repeat reQuest (abbreviated as HARQ) scheme of the reverse channel, and also combines the HARQ scheme with the dedicated rate control scheme of the reverse channel. The present invention relates to a link adaptation method using a hybrid automatic retransmission request scheme in a reverse link of 1xEV -DV and a system therefor. According to the present invention, the transmitting end multiplexes the initially transmitted frame and at least one retransmitted frame including different information previously transmitted, and transmits the multiplexed frame to the receiving end, and the receiving end multiplexes the receiving end. Decoding the initial transmission frame of the retransmitted frame using the received frame.

AMC, dedicated rate control, transmit energy, reverse link

Description

Method for link adaptation using hybrid automatic retransmission method on reverse link and system for same {Method for Link Adaptation using Hybrid Automatic Repeat Request in Reverse Link, System for the same}

1 is a functional block diagram for generating a transmission signal by applying the TDM scheme according to the present invention.

FIG. 2 is a diagram showing an output result of the serial connection block shown in FIG. 1. FIG.

3 is a functional block diagram for generating a transmission signal by applying the CDM scheme according to the present invention.

4 is a device block diagram illustrating a process of generating a transmission signal according to the CDM scheme of the present invention.

* Description of the symbols for the main parts of the drawings *

10,14 CRC and tailbit additional block

11,15: Turbo Encoder

12,16,19: Interleaver

13,17: symbol pruning block

18: serial connection block

20: modulator                 

21: diffuser

The present invention efficiently supports the hybrid automatic repeat reQuest (abbreviated as HARQ) scheme of the reverse channel, and also combines the HARQ scheme with the dedicated rate control scheme of the reverse channel. The present invention relates to a link adaptation method using a hybrid automatic retransmission request scheme in a reverse link of 1xEV -DV and a system therefor.

As is known, 1x DO (Data Only) is a mobile communication technology that only increases the data rate to 2Mbps or more in cdma2000-1x, which is called 2.5G mobile communication, and is representative of HDR (High Data Rate) developed by Qualcomm. On the contrary, 1x-EV DV is a service method that supports voice while realizing a data rate of 2 to 3Mbps even in a mobile section.

In other words, 1x-EV DV is a general term for standardization to support not only a voice service but also a high-speed packet data service based on the 1x technology of a conventional synchronous cdma2000 RTT.

Unlike the existing 1x RTT technology on the air interface, the 1x-EV DV adopts the adaptive modulation and coding (abbreviated as AMC) technique and the HARQ scheme in the forward direction. However, in the reverse direction, it is basically just adding channels to support the AMC technology and HARQ scheme adopted in this forward direction.

In general, link adaptation techniques include power control and rate control.

The rate control is for the receiver to adjust the rate of the transmitter by changing the power of the signal being received. To this end, the power level of the signal received at the receiving end should not be a constant level.

However, the purpose of power control is to adjust the level of power received by the receiver so that the modulation and coding techniques currently used in the wireless can be brought to a level that can operate at a desired level. Therefore, power control and AMC techniques are difficult to use together.

In addition, the power control is to solve the near-far problem occurring in the reverse link, by controlling the transmit power differently for the near terminal and the far terminal from the base station to a certain level of power level of all the terminals received by the base station It has a purpose to match.

In general, however, the reverse link has a near-far problem unlike the forward link, and power control is essential. Therefore, it is difficult to apply AMC techniques such as forward links.

Meanwhile, the HARQ scheme refers to a scheme combining a conventional forward error recovery coding scheme and an automatic repeat request (ARQ) through error detection.

In general, the HARQ method is divided into three types according to the method. Type I HARQ scheme refers to a scheme in which a chase combining form is used at the receiver side by transmitting the same information even when retransmission occurs when an error occurs in the first transmission.

The type II HARQ scheme and the type III HARQ scheme increase redundancy in each transmission, and the receiver code-combines the first transmission signal or the retransmission signal, resulting in a lower code rate. That is, the type II HARQ scheme and the type III HARQ scheme mean a scheme of obtaining coding gain as compared to chase combining.

In this case, the type II HARQ scheme and the type III HARQ scheme are distinguished from each other by type II when each transmission information is not self-decodable and type when self-decodable. It is divided into III.

As described above, there are differences between the forward channel and the reverse channel, and because of these differences, it is difficult to apply techniques for increasing data throughput in the existing forward link even in the reverse direction.

In general, the HARQ scheme currently considered in the reverse link considers the following.

First, when the turbo code rate is 1/4, the receiver uses type I HARQ and applies chase combining.

Secondly, when the turbo code rate is 1/2, the receiver uses incremental redundancy, which is increased by using type II and type III HARQ.                         

The reason for using such a scheme is that the lowest code rate of the turbo code, which is the coding scheme currently used in 1x-RTT, is 1/5.

The first approach is that the use of increased redundancy is not so great when using turbo code at 1/4 code rate, since we have already gained sufficient coding gain.

The second approach is that large coding gains can be obtained by using increased redundancy when the code rate is 1/2.

However, some problems arise when using the above scheme.

First, as described above, in the reverse link, power control is performed to maintain a constant quality by appropriately adjusting the reception power level.

However, if Chase Combining is used as in the first method, the result is that the retransmission will use as much energy as the first transmission.

That is, most of cases where a frame error occurs in the reverse direction may be solved when only a small amount of energy is added to the energy of the first transmission, but the signal having the same energy as the first transmitted signal is transmitted again. , Waste of energy occurs.

In addition, when chase combining is performed at the receiving end, a problem arises in that a dedicated data rate control for reverse link traffic under consideration cannot be applied to a frame for retransmission.

Therefore, there is a need to come up with a new link adaptation method to secure the problems arising in the first scheme and to increase the coding gain which is an advantage of the second scheme.

Accordingly, an object of the present invention is to provide a link adaptation using a hybrid automatic retransmission request scheme in a reverse link to effectively perform power control and data rate control in a reverse link. It is to provide a method and a system therefor.

Another object of the present invention is to provide a link adaptation method using a hybrid automatic retransmission request scheme in a reverse link and a system for controlling the power of a retransmitted signal to prevent waste of transmission energy.

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According to a first aspect of the present invention for achieving the above object, the transmitting end multiplexes the multiplexed frame by multiplexing the initially transmitted frame and at least one retransmitted frame including different information previously transmitted. And transmitting to the receiving end, and the receiving end decoding the initial transmission frame of the retransmitted frame using the multiplexed frame.
The retransmitted frame is preferentially assigned a predetermined ratio of transmit energy allocated to the initial transmission frame of the retransmitted frame.
When the initial transmission frame and the retransmitted frame are time multiplexed, the remaining energy allocated to the retransmitted frame among the transmission energy allocated to the multiplexed frame is allocated to the initial transmission frame.
At this time, the initial transmission frame, the code symbols included in the frame is repeated or punctured, so that the data rate corresponding to the transmission energy allocated to the frame, the retransmitted frame corresponds to the allocated transmission energy Has a data rate.
However, when the initial transmission frame and the retransmitted frame are code multiplexed, the initial transmission frame includes a sum of the transmission energy allocated to the initial transmission frame and the transmission energy allocated to the retransmitted frame. The maximum transmission energy defined by the transmitting end is allocated within a range not exceeding the transmission energy which is larger by a predetermined amount than the transmission energy allocated to the frame.
In this case, the initial transmission frame or the retransmitted frame has a data rate corresponding to the transmission energy allocated to each.
The multiplexed frame further includes a redundancy code not transmitted in the initial transmission frame or the previously retransmitted frame of the retransmitted frame.
According to a second aspect of the present invention for achieving the above object, when the initial transmission frame and the retransmitted frame is time multiplexed, the initial transmitted frame and the retransmitted frame are respectively encoded by a turbo code. Reordering the order of each coded code symbol, truncating each reordered code symbol to a desired length, time multiplexing each truncated code symbol, and multiplexing A multiplexed frame is generated including interleaving the coded symbols, modulating the interleaved code symbols, and allocating and spreading one Walsh code to the modulated code symbols.
In the reordering, the order of code symbols included in these frames is adjusted to distinguish between the initial transmission frame and the redundancy code included or not included in the retransmitted frame, respectively.
In the time multiplexing step, the initial transmission frame and the frame to be retransmitted are multiplexed so that each constitutes a continuous field.
The code rate of the turbo code is 1/5.
The time multiplexed frame is transmitted to a receiver through one physical channel.
According to a third aspect of the present invention for achieving the above object, when the initial transmission frame and the retransmitted frame is code multiplexed, the initial transmitted frame and the retransmitted frame are respectively encoded by a turbo code. Interleaving an order of each coded code symbol, cutting each of the rearranged code symbols to a desired length, modulating each of the truncated code symbols, respectively, A multiplexed frame is generated including assigning and spreading at least two Walsh codes to the modulated code symbol.
The initial transmission frame and the retransmitted frame are code multiplexed and transmitted to the receiver through different reverse auxiliary channels.
Similarly, the code rate of the turbo code is 1/5.
In the interleaving, the order of the code symbols included in each of the frames is adjusted so that the initial transmission frame and the redundancy code not included in the retransmitted frame are distinguished from each other, and a burst error does not occur.
According to a fourth aspect of the present invention for achieving the above object, the retransmitted frame is a retransmission request received a different number of times from the receiving end.
According to a fifth aspect of the present invention for achieving the above object, the receiving end uses an independent channel of the forward link or informs the dedicated rate control to inform the transmitting end whether the initial transmitted frame or the retransmitted frame is received. Use a common channel for
In addition, the signal for receiving the receiving end is managed by either the base station or the base station controller.
According to a sixth aspect of the present invention for achieving the above object, a turbo coder for encoding an initially transmitted frame, a retransmitted frame into a turbo code, and a rearrangement order of the respective coded code symbols, respectively. A first interleaver, a symbol pruning block for truncating each of the rearranged code symbols to a desired length, a serial connection block for time multiplexing the respective truncated code symbols, a second interleaver for interleaving the multiplexed code symbols, and And a modulator for modulating the interleaved code symbol and a spreader for allocating and spreading one Walsh code to the modulated code symbol to generate a multiplexed frame.
According to a seventh aspect of the present invention for achieving the above object, a turbo coder for encoding an initially transmitted frame, a retransmitted frame into a turbo code, and an interleaver for interleaving the sequence of each coded code symbol, respectively. And a symbol pruning block for truncating each of the rearranged code symbols to a desired length, a modulator for modulating each of the truncated code symbols, and assigning and spreading at least two Walsh codes to each of the modulated code symbols. Configured to include a spreader to generate a multiplexed frame.
According to an eighth aspect of the present invention, a link adaptation method using an automatic retransmission request scheme according to the present invention is a mobile communication system that supports an automatic retransmission request scheme, in response to a packet initially transmitted or retransmitted from a receiver. Receiving a negative acknowledgment signal (NAK), and transmitting a retransmission packet to the receiver at a transmission energy corresponding to a predetermined ratio of transmission energy of the initially transmitted or retransmitted packet.
Hereinafter, a configuration and an operation according to an exemplary embodiment of the present invention will be described with reference to the accompanying drawings.

The present invention proposes a method for efficiently supporting HARQ in the reverse link and a combination method with a dedicated control scheme for the data rate of reverse traffic.

Therefore, in the present invention, the redundancy code that is increased in all cases regardless of the code rate is used. This is to prevent the use of excessive energy in retransmission.

For reference, a redundancy code represents a code in which an extra symbol sequence is added to a symbol sequence necessary to represent original information in order to detect or correct an error occurring in a data transmission process.

Next, in the present invention, only partial energy of initial transmission energy is used for retransmission. For example, only 1/4 or 1/8 of the transmission energy is allocated to the initial energy to be used for retransmission.

In addition, it can be seen that the energy available in the frame is determined according to the data rate determined by the dedicated rate control. In this case, the remaining portion except for the energy portion required for retransmission is used as energy for the initially transmitted frame.

And when the NAK is received from the receiver for the frame transmitted at the data rate determined by the dedicated rate control, the transmitter determines the retransmission data rate and the data rate for the initial transmission frame for transmitting new information, and then the data rates. Multiplex the generated frames and send them.

At this time, the data rate for the initial transmission and the data rate for the retransmission are properly adjusted according to what percentage of the original transmission energy is allocated during retransmission as described above.

The multiplexing method of a frame for retransmission and a frame for initial transmission is largely divided into a code division multiplexing (hereinafter, referred to as CDM) method and a time division multiplexing (hereinafter, referred to as TDM) method.

First, in the TDM scheme, the transmitting end has a predetermined data rate according to a reverse dedicated rate control, and in order to generate a code symbol having a desired interleaver length according to the data rate, a code symbol for initial transmission and retransmission are used. The code symbols are divided and generated, and each generated symbol is multiplexed in time. After that, it adopts a transmission method through one modulation process and a spreading process. At this time, the retransmission frame and the frames for the initial transmission all use one Walsh code and are transmitted through one physical channel. This process will be described in detail with reference to FIG. 1 as an example.

1 is a functional block diagram for generating a transmission signal by applying the TDM scheme according to the present invention. Here, FIG. 1 illustrates an example in which the transmitter limits the number of times of retransmission of a frame in which an error occurs.

Referring to FIG. 1, generation of a transmission signal according to the TDM scheme of the present invention may include a newly transmitted data or previously transmitted data, that is, a cyclic redundancy code (CRC) and a tail bit for error checking on each information bit. The respective CRC and tail bit addition blocks 10 and 14 to be added, the respective turbo encoders 11 and 15 for encoding the outputs of the blocks 10 and 14 into turbo codes at a 1/5 code rate, Each of the first and second interleavers 12 and 16 to rearrange the order of the coded code symbols, and each of the rearranged code symbols to generate a sequence of code symbols of desired length by pruning some of the rearranged code symbols. A symbol pruning block 13 and 17, a serial connection block 18 for time multiplexing each of the pruned code symbols into a single code symbol string, and a third interleaver interleaving the multiplexed code symbol strings. (19) and interleaved code symbol strings It consists of the crude modulator 20 and the modulated code symbol sequence with a diffuser 21 to spread using a single Walsh code.

That is, the transmitting end may include an initial transmission frame for transmitting new information, a CRC and tail bit addition block 10 or 14, a turbo encoder 11 or 15, and an interleaver 12 or 16 to generate a retransmission frame. , Each generating block comprising a symbol pruning block 13 or 17. These building blocks increase in proportion to the number of retransmissions of any data.

Accordingly, the CRC and tail bit addition block 10 or 14 add a CRC for error checking and tail bits to the information bits to be transmitted to the receiver.

The turbo encoder 11 or 15 encodes the bit string to which the CRC and tail bits are added as a turbo code having a 1/5 code rate.

The first or second interleaver 12 or 16 rearranges the order of code symbols encoded with the turbo code. That is, the interleavers 12 and 16 rearrange the order of input code symbols to efficiently support increased redundancy rather than performing interleaving to convert burst errors, which are the role of the channel interleaver in the prior art, into random errors. It plays a role.

In other words, the order of the code symbols is properly adjusted so that the redundancy code to be transmitted in the initial transmission frame or the redundancy code to be transmitted in the retransmission frame (redundancy code not included in the previous transmission signal) among the transmission signals to be generated currently is distinguished. By the operation of the interleaver 12 or 16, the next pruning process can be easily performed.

The symbol pruning block 13 or 17 pruns the code symbols whose order is rearranged in order to match the number of coded symbols allocated for each initial transmission and retransmission.                     

The serial connection block 18 time multiplexes each symbol pruned by the symbol pruning blocks 13 and 17 into one column. The generated column is filled with code symbols indicating new information in the upper field of the transmission signal, and the code symbols consisting of redundancy codes that have not been transmitted in the previous transmission signal are filled in the generated column.

The third interleaver 19 interleaves the code symbols of each of the upper field or the lower field among the code symbols filled as described above.

These code symbols are then modulated by modulator 20 and spread using one Walsh code in spreader 21.

Table 1 shows the energy allocation for the reverse HARQ scheme configured using TDM under the assumption that the transmitting end allows only one retransmission. In this example, it is assumed that only 25% of the original transmission energy is transmitted during retransmission.

  Energy at retransmission Energy at initial transmission One 2 4 8 16 32 64 107 re-send Early re-send Early re-send Early re-send Early re-send Early re-send Early re-send Early re-send Early One One 0 One One One 2 + R One 4 + R One 8 + R One 16-P One 32 + R One 64 + R 2 One 0 One One One 2 + R One 4 + R One 8 + R One 16-P One 32 + R One 64 + R 4 One 0 One One One 2 + R One 4 + R One 8 + R One 16-P One 32 + R One 64 + R 8 One 0 2 0 2 2 2 4 + R 2 8 + R 2 16-P 2 32 + R 2 64 + R 16 One 0 2 0 4 0 4 4 4 8 + R 4 16-P 4 32 + R 4 64 + R 32 One 0 2 0 4 0 8 0 8 8 8 8 8 32 + R 8 64 + R 64 One 0 2 0 4 0 8 0 16 0 16 16 16 32 + R 16 64 + R 107 One 0 2 0 4 0 8 0 16 0 32 0 32 32 32 64 + R

In the TDM method according to the present invention, the set of data rates that can be adjusted by dedicated rate control is considered to be eight of {9.6kbps, 19.2kbps, 38.4kbps, 76.8kbps, 153.6kbps, 307.2kbps, 614.4kbps, 1024kbps}. It was.

In this case, assuming that the total energy for transmitting a data rate of 9.6 kbps is 1, the energy for the remaining data rates is normalized and expressed as 2, 4, 8, 16, 32, 64, 107.

Therefore, in Table 1, when the energy allocated to the frame during the initial transmission or retransmission is 1, 2, 4, 8, 16, 32, 64, 107, the lower field of the transmission signal at the time when retransmission is determined is shown in FIG. As shown, code symbols including redundancy codes that have not been transmitted to the previous transmission signal are included, and the energy allocated to these code symbols is allocated by 1/4 of the transmission energy allocated during initial transmission as shown in Table 1 above. do. In addition, when retransmission is determined, energy for the increased redundancy code is preferentially allocated, and the remaining energy is allocated to the initially transmitted information.

Therefore, the sum of the initial transmission frame at the time of retransmission and the transmission energy allocated to the retransmission frame does not exceed the transmission energy determined by the data rate control.

 One problem that may occur when using such a TDM scheme is that it is impossible to fit using only the existing data rate set to match the number of code symbols after multiplexing the code symbols.

For example, upon initial transmission of a frame including arbitrary information, the frame is transmitted at a rate of 76.8 kbps, and at the time of retransmission of the frame, a predetermined frame is transmitted at a rate of 153.6 kbps by dedicated rate control. Assume that the decision was made. It is also assumed that 25% of the initial transmission energy is allocated as the energy for retransmission. The predetermined frame includes code symbols including an increased redundancy code and code symbols of newly transmitted data.

Accordingly, an energy corresponding to 19.2 kbps is allocated for a code symbol including an increased redundancy code among code symbols having a transmission rate of 153.6 kbps, and the rest is used as energy for initially transmitted code symbols.

At this time, the remaining energy portion corresponds to 134.4kbps. Since this data rate is a data rate that does not exist in the existing data rate set, to solve this problem, the transmission rate of initially transmitted code symbols is set to 76.8kbps. Repeat the symbols to match the transmission rate of 134.4kbps.

Thus, in Table 1, code symbols with energy as R are repeated to generate code symbols having a transmission rate corresponding to the energy allocated for new information (eg, original 76.8 kbps to 134.4 kbps) or Code symbols with energy as much as P are punctured. The R (repetition energy) or P (punching energy) means that the corresponding code symbols are symbol repeated or punctured to fill the transmission energy corresponding to the data rate determined by the data rate control.

Another method is to subdivide the set of existing data rates into 9.6kbps units. In this case, it is cumbersome to determine all data rates ranging from 1 to 107 in terms of energy. On the other hand, this method has the advantage of increasing the filling efficiency in frame generation, but increases the number of Reverse Rate Indicators (hereinafter, RRI) for specifying the reverse data rate. There is a drawback to this.

In other words, currently, only 8 data rates are considered in the reverse direction, the data rate can be represented by a 3-bit RRI. However, 7-bit RRI is required to specify 107 data rates from 1 to 107. Done.

One thing to note is that the minimum energy unit for retransmission always considers 1, 9.6 kbps, as the normalized energy.

Second, the CDM method is applied.

In the reverse direction of 1x-EV DV, it is currently considered to use two code channels, Reverse Supplemental Channel 1 and Reverse Supplemental Channel 2.

The data rate under consideration in the reverse auxiliary channel 2 is {9.6kbps, 19.2kbps, 38.4kbps, 76.8kbps}.

Accordingly, in the present invention, the reverse auxiliary channel 1 is always used as a physical channel for initial transmission, and the reverse auxiliary channel 2 is always used as a physical channel for retransmission.

3 is a functional block diagram for generating a transmission signal by applying the CDM scheme according to the present invention.

Referring to FIG. 3, generation of a transmission signal according to the CDM scheme of the present invention includes code symbols including new information and a redundancy code that was not transmitted in a frame in which a NAK was received from a receiver of previously transmitted signals. In order to generate the code symbols, the transmitting end adds each CRC and tail bit addition blocks 30 and 36 to add a cyclic redundancy code (CRC) and tail bits for error checking to information bits to be transmitted to the receiving end for each channel. And each of the turbo encoders 31 and 37 for encoding the outputs of the blocks 30 and 36 in turbo code at a 1/5 code rate, and each of the first and second reordering orders of the encoded code symbols. A second interleaver (32, 38), each of the symbol pruning blocks (33, 39) for pruning some of the rearranged code symbols to produce a length of a predetermined code symbol sequence; Code symbols Each modulator (34, 40) for modulating a, and spreaders (35, 41) for spreading the modulated code symbols with their respective Walsh codes.

Accordingly, the CRC and tail bit addition block 30 or 36 add a CRC for error checking and tail bits to information bits (data to be newly transmitted or data transmitted to a previous transmission signal) to be transmitted to the receiver.

The turbo encoder 31 or 37 encodes the bit string to which the CRC and tail bits are added as a turbo code having a 1/5 code rate.

The first or second interleaver 32 or 38 rearranges the order of code symbols encoded with the turbo code. In other words, the interleavers 32 and 38 convert a burst error, which is a role of a channel interleaver in the prior art, into a random error, and at the same time distinguish a redundancy code not included in new data or previously transmitted data. The order of the coded symbols is properly adjusted.                     

The symbol pruning block 33 or 39 pruns the rearranged code symbols by a predetermined number of symbols to match the number of coded code symbols allocated for each initial transmission and retransmission.

The code symbols are then modulated by each modulator 34 or 40 and spread by each spreader 35 or 41 into their respective Walsh codes and transmitted to the receiver via reverse auxiliary channel 1 and reverse auxiliary channel 2. do.

 In this case, the code symbols retransmitted through the reverse auxiliary channel 2 are transmitted except for the redundancy code used for the original transmission, so that the effective code rate can be lowered through the code combining at the receiving end.

That is, after assigning reverse auxiliary channel 2 as a physical channel for retransmission for a frame in which NAK has occurred, a Walsh code for the channel can be independently assigned, and a code multiplexing method using the assigned Walsh code can be considered.

Table 2 shows normalization energy allocated to a code symbol initially transmitted or a code symbol including an increased redundancy code in the reverse HARQ scheme using the CDM scheme when the number of retransmissions is limited to one. Channel 2 or channel 1 is an abbreviation for one of the reverse auxiliary channels.

As in the previous assumption, Table 2 assumes that only 25% of the initial transmission energy is used for retransmission.

In addition, the data rate set available in the reverse auxiliary channel 2 is {2.4kbps, 4.8kbps, 9.6kbps, 19.2kbps, 38.4kbps, 76.8kbps, 153.6kbps, 307.2kbps}.

In this case, when the energy corresponding to 9.6kbps is normalized to 1, the energy that can be used for retransmission is expressed as {0.25, 0.5, 1, 2, 4, 8, 16, 32}. The energy for initial transmission is {1, 2, 4, 8, 16, 32, 64, 107} as in the case of the conventional reverse auxiliary channel 1.

For example, the data rate at the initial transmission is 38.4 kbps, an error occurred in a frame transmitted to the receiver at this rate, and a NAK for that frame was transmitted from the receiver to the transmitter, thus, at the point when retransmission is determined. Assuming that the allowable data rate is 153.6 kbps by dedicated reverse rate control, an energy of 9.6 kbps is allocated upon retransmission. At this time, the energy at the time of retransmission was allocated to 25% of the initial transmission energy.

The remaining energy is allocated to the code symbol including the increased redundancy code and the remaining energy is allocated to the code symbol transmitted initially. In this case, the data rate for the initially transmitted code symbol may be determined to be 76.8kbps or may be determined at a data rate of 153.6kbps.

Assuming that the data rate of the reverse auxiliary channel 1 is determined to be 76.8 kbps, the current terminal does not use all of the licensed energy. If it transmits at 153.6 kbps, the total amount of energy that the terminal is allowed to use In comparison, 10log ((1 + 16) / 16) = 0.26dB of energy is used.

This additional energy may be determined as allowable energy, and may allow the terminal to select a data rate for the reverse auxiliary channel 1.

4 is a device block diagram illustrating a process of generating a transmission signal according to the CDM scheme of the present invention.

Referring to FIG. 4, reverse auxiliary channels (hereinafter, abbreviated as R-SCH1 and R-SCH2) are connected to other channels (R-PICH, R-DCCH, R-RICH, R-FCH, R-CQICH, R). -ACKCH) is divided into I and Q channels. That is, R-SCH1 and R-SCH2 are divided into I channels together with R-PICH, R-DCCH, and R-RICH, and are also divided into Q channels together with R-FCH, R-CQICH, and R-ACKCH. If R-SCH2 is not used, R-CCCH or R-EACH is transmitted.

Accordingly, the code symbols of the respective channels included in the I channel or the Q channel are provided to the respective relative gain units 50a and 50b to further include the relative gain. Then, by the adder 51a or 51b, one code symbol is synthesized for each of I and Q channels. This synthesized code symbol is referred to as I channel data and Q channel data.

The I channel data or Q channel data is multiplied by a code in which the long code generated by the long code generator 61 is multiplied by the I channel sequence (60) (either the adder of 52a or 52b).

The code in which the generated long code is delayed by one chip (61) is multiplied by the Q channel sequence (59), and then detected by the decimator 58 in units of 1/2 chip, and the Walsh cover and It is multiplied (57) and then multiplied by I channel data or Q channel data (another adder of 52a or 52b).

Code symbols generated by multiplying with I channel data among the finally multiplied code symbols and code symbols generated by multiplying with Q channel data are synthesized by respective adders 53a or 53b, and the first or second basis. Bandpassed by band filter 54a or 54b, multiplied by carriers (cos2πfct, sin2πfct) (55a, 55b), synthesized by adder 53c, provided to gain section 56 to further include gain Is generated as a typical transmission signal S (t).

On the other hand, how to manage the ACK and NAK commands In order to apply the reverse HARQ scheme, consideration should be given to where to manage the ACK command and the NAK command.

In other words, consideration should be given to whether the ACK and NAK commands are managed in a base transceiver system (hereinafter abbreviated as BTS) or managed by a base station controller (hereinafter abbreviated as BSC).

If the ACK and the NAK are managed by the base station controller, all the BTSs in the active set transmit the demodulated frames to the BSC. Accordingly, the BSC generates an ACK signal if any frame is a good frame and a NAK signal if the frames transmitted from all BTSs are bad frames, and transmits it to all BTSs in the active set.

Then all BTSs transmit the same ACK or NAK signal to the UE. In this manner, since the soft combining can be performed on the ACK and NAK signals from the terminal's point of view, the reliability of the ACK and NAK signals is increased, but the execution delay time of HARQ is increased.

On the contrary, if the ACK and NAK signals are directly managed by the BTS, the aforementioned delay problem between the BSC and the BTS does not occur. However, since all BTSs in the active set may generate different ACK or NAK signals, the terminal cannot apply soft combining to these signals.

If the terminal receives an ACK signal from only one BTS among the BTSs in the active set, retransmission of the frame is not performed.                     

In addition, the structure of the forward channel for transmitting ACK and NAK signals Various methods can be considered to form a forward channel for transmitting an ACK signal and a NAK signal to a terminal. The first conceivable method is to form one independent physical channel for transmitting ACK and NAK signals. Another method may be a method of sharing a channel and a physical channel for backward dedicated rate control.

By designing an efficient HARQ scheme on the reverse link of the current 1x-EV DV, the data throughput of the reverse link is increased.

In addition, it is possible to design an efficient combining method of the dedicated rate control method and the HARQ method for the reverse link. This is made possible by using a type II or type III HARQ scheme using an increased redundancy scheme.

Those skilled in the art will appreciate that various changes and modifications can be made without departing from the spirit of the present invention.

Therefore, the technical scope of the present invention should not be limited to the contents described in the examples, but should be defined by the claims.

Claims (32)

delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete A turbo encoder for encoding the initially transmitted frame and at least one or more retransmitted frames including different information previously transmitted with a turbo code, respectively; A first interleaver for rearranging the order of each coded code symbol, respectively; A symbol pruning block for cutting each of the rearranged code symbols to a desired length; A serial connection block for time multiplexing each truncated code symbol; A second interleaver for interleaving the multiplexed code symbols; A modulator for modulating the interleaved code symbol; A link adaptation system using a hybrid automatic retransmission request scheme in a reverse link configured to include a spreader for allocating and spreading one Walsh code to the modulated code symbol to generate a multiplexed frame A turbo encoder for encoding an initially transmitted frame and a retransmitted frame with a turbo code, An interleaver for interleaving the respective coded code symbol sequences; A symbol pruning block for cutting each of the rearranged code symbols to a desired length; A modulator for modulating each of the truncated code symbols, A link adaptation system using a hybrid automatic retransmission request scheme in a reverse link including a spreader for spreading by allocating at least two Walsh codes to each modulated code symbol and spreading the spreader In a mobile communication system supporting an automatic retransmission request method, Receiving a negative acknowledgment signal (NAK) in response to a packet initially transmitted or retransmitted from a receiving side; And And transmitting a retransmission packet to the receiver at a transmission energy corresponding to a predetermined ratio of transmission energy of the initially transmitted or retransmitted packet. The method of claim 23, wherein And transmitting a new packet to the receiving side. The method of claim 24, The transmission energy for the new packet is a link adaptation method using the automatic retransmission request method, characterized in that the remaining portion of the total transmission energy available except for the transmission energy for the retransmission packet. The method of claim 25, And the retransmission packet and the new packet are transmitted at the same time. The method of claim 26, And the retransmission packet and the new packet are transmitted by time division multiplexing (TDM). The method of claim 26, And the retransmission packet and the new packet are transmitted by code division multiplexing (CDM). 28. The method of claim 27, wherein the pre-transmission data processing for each of the retransmission packet and the new packet comprises: Channel coding the input data; Interleaving the order of the coded code symbols; Performing or repeating symbol repetition on the rearranged data. The method of claim 29, wherein the data processing process, Time-multiplexing the symbol repeated or truncated data and transmitting the same over a transmission channel. 29. The method of claim 28, wherein the pre-transmission data processing for each of the retransmission packet and the new packet comprises: Channel coding the input data; Interleaving the order of the coded code symbols; Performing or repeating symbol repetition on the rearranged data. The method of claim 31, wherein the data processing process, And performing code multiplexing on the symbol repeated or truncated data and transmitting the data over at least two transmission channels.

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