KR100927877B1 - AC / NAC transmission and reception method and transmission / reception apparatus in frequency division multiple access system - Google Patents

Abstract

The present invention relates to a method and a transmission / reception apparatus for transmitting and receiving ACK / NACK for supporting retransmission of packet data received in a wireless communication system using frequency division multiple access (FDM). In the present invention, a channel for resolving a problem that occurs when the ACK / NACK transmission is repeatedly transmitted several times in order to increase the reliability in a system for mapping an ACK / NACK transmission channel to a packet data transmission channel or a common control channel. We propose a setting method and a transceiver. The present invention is a method for allocating an extra ACK / NACK channel for repetitive transmission in a system for repeatedly transmitting ACK / NACK so that the terminal is set to repeat transmission through the extra ACK / NACK channel. If the above method is used, ACK / NACK repetitive transmission is possible in an environment in which an ACK / NACK channel is mapped to a packet data channel or a common control channel in a FDM system and configured. Because of this, the coverage of the cell can be increased.

Description

ACC / NAC transmission / reception method and transmission apparatus in frequency division multiple access system {Method and Apparatus for ACK / NACK Transmission / Receiving in Frequency Division Multiplexing System}

The present invention relates to an apparatus and method for transmitting / receiving an ACK / NACK necessary for supporting complex retransmission of packet data received in a wireless communication system using a frequency division multiple access scheme.

First, a frequency division multiple access scheme (hereinafter referred to as FDM) will be described with reference to FIG. 1.

1 is a view for explaining a frequency division multiple access scheme.

FDMA refers to a method of distinguishing a transmission physical channel by assigning a frequency. In general, the total resource used (resource) is divided as shown in 101 in the frequency domain and time domain. The minimum block of 101 is composed of one symbol in the time domain and a sub-carrier unit in the frequency domain, which is called a time-frequency bin (TF bin). This is a unit in which a modulated symbol is transmitted during actual physical channel transmission. The total number of TF bins is determined by the size of the total frequency bandwidth of the system and the number of transmittable symbols in the transmission time interval (hereinafter referred to as TTI).

In the FDMA scheme, some different TF bins are allocated from the entire TF bins to the channel and the terminal to be transmitted. In the basic FDMA scheme, it is not possible to share a single TF bin between different channels or terminals. However, when a low-rate channel performs a process such as covering or spreading to obtain diversity in time-frequency space, it uses a code like CDM (Code Division Multiplexing). It is possible to share by. In the case of transmission of packet data having a high transmission rate, a method of purely dividing and allocating TF bins is mainly used. The mapping of the transmission symbol of the data to be transmitted and the TF bin is performed through sub-carrier mapping 102. Which TF bin a particular channel uses is determined by pre-signaled or predefined rules.

In case of transmission of packet data or signaling transmitted to each terminal among channels, the corresponding channel should be allocated to each terminal so that the TF bin allocated to each channel is allocated to each terminal again. The TF bin itself may be allocated for each terminal, but in order to facilitate the signaling, the TF bin allocated to a specific channel may be collected to form a logical channel again as shown in 103. This is called 'channel'. One channel is composed of a plurality of TF bins and the amount is determined in consideration of the characteristics of each channel. In other words, in the case of a packet data channel, the number of TF bins in a channel is determined in consideration of the minimum data rate of the packet data and the signaling overhead of informing the information of the scheduled channel in case of scheduling. In the case of a control channel, the number of TF bins of the control channel may be determined according to the number of transmission bits per TTI.

Which channel to use for a particular UE is scheduled for every TTI or configured through higher signaling. 1 illustrates an example in which channel # 1 is allocated to terminal # 1. In step 105, the packet data symbol of the terminal # 1 is mapped to the channel # 1 of the packet data channel through the channel mapping process 104, and is again mapped to the actual TF bin through the subcarrier mapping process 102. In subcarrier mapping, depending on the frequency diversity or TF bin allocation algorithm, when the channels are mapped to actual TF bins, they may be mapped to spread TF bins, such as 106 hatched blocks, and 103 hatched blocks. It may be mapped to adjacent TF bins, such as. Since the channel is a logical channel, in case of transmitting only a channel allocated to the terminal, such as a terminal, since only a corresponding transmission symbol is mapped to a predefined or assigned TF bin, channel mapping may not be necessary. .

Meanwhile, hybrid retransmission (hybrid ARQ, hereinafter referred to as HARQ) is a technique of increasing reception success rate by soft combining with retransmitted data without discarding previously received data. In more detail, the HARQ receiver determines whether an error exists in a received packet, and according to the presence of the error, a HARQ receiving acknowledgment signal is called a HARQ positive acknowledgment signal or a HARQ negative acknowledgment HARQ NACK signal. ) Transmit signal to sender. Therefore, the transmitter performs retransmission of the HARQ packet or transmission of a new HARQ packet according to the HARQ ACK / NACK signal. The HARQ receiving side soft combines the retransmitted packet with the previously received packet to reduce the probability of error occurrence.

In addition, the HARQ transmission scheme is classified into synchronous HARQ and asynchronous HARQ according to a time point when retransmission is performed. In synchronous HARQ, retransmission always proceeds after a predetermined time from the time when previous transmission is completed, and in asynchronous HARQ, retransmission proceeds regardless of the time when previous transmission is completed.

With reference to Figure 2 looks at the operation of the synchronous HARQ in more detail.

2 is a diagram illustrating the basic operation of HARQ.

Referring to FIG. 2, when the HARQ transmitting side first transmits a HARQ packet through the data channel 201 through a predetermined procedure (203), the HARQ receiving side receives and decodes the first transmitted HARQ packet and confirms a CRC. It is determined whether the error exists (204). If the determination result is an error, the HARQ packet is stored in a buffer and the HARQ NACK is transmitted to the HARQ transmitter through the ACKCH 202 (205). When the HARQ transmitting side receives the HARQ NACK, the HARQ packet is retransmitted (206), and the HARQ receiving side soft-combines and decodes the retransmitted HARQ packet with the packet stored in the buffer and checks the CRC (207). If there is still an error as a result of the CRC check, the HARQ receiver stores the HARQ packet in a buffer, retransmits the HARQ NACK to the HARQ transmitter, and generates and transmits an ACK when the decoding is successful (208).

The HARQ transmitting side receives the HARQ ACK from the HARQ receiving side or repeats the above process until the number of retransmissions for the HARQ packet reaches a predetermined allowable value.

Next, a method of transmitting ACK / NACK will be described.

In the conventional system, a method of setting a dedicated channel for each terminal has been mainly used as a method of transmitting ACK / NACK information indicating whether the receiving side normally receives packet data. In an environment where channels are non-orthogonal, such as code division multiplexing access (CDMA), the total amount of available resources is not directly related to the number of codes, Because it is limited, even if the code is assigned one by one for each terminal, it is not a big problem in terms of resource utilization unless it is used by the transmitting side. However, in the FDM system, since T-F resources are orthogonal, the amount of T-F resources directly affects the amount of available resources. Therefore, it is a waste in terms of resource utilization unless the T-F resource allocated as ACKCH is used. In other words, a method of exclusively allocating resources for ACK / NACK transmission for each terminal is inefficient in terms of resource utilization in an FDM system.

For the above reasons, in order to efficiently support HARQ in an FDM system, a method of one-to-one mapping of an ACK / NACK channel to a packet data channel or a common control channel has been proposed and discussed.

3 is a diagram for describing a method of one-to-one mapping of ACK / NACK channel information to a data channel.

Referring to FIG. 3, 302 ˜ 305 are channels for data transmission, and 307 ˜ 310 are channels for ACK / NACK transmission. One-to-one mapping is to set the same number of ACKCH as the data channel and to transmit ACK / NACK for a specific data channel only through a specific ACKCH. For example, in case of receiving packet data through data channel # 1 301, ACK / NACK is transmitted through ACKCH # 1 307, and in case of receiving packet data through data channel # 2 303, ACKCH #. ACK / NACK is transmitted through 2 (308). If the available ACKCH information is mapped to the packet data channel information as described above, ACK / NACK transmission is possible even if the frequency resource for ACK / NACK transmission is not exclusively allocated to the UE.

FIG. 18 illustrates a method of one-to-one mapping of ACK / NACK channel information to a shared control channel (SCCH) for transmitting scheduling information.

Referring to FIG. 18, 1802 to 1805 are common control channels for transmitting scheduling information, and 1807 to 1810 are channels (ACKCH) for ACK / NACK transmission. One-to-one mapping is to set the same number of ACKCHs as the common control channel, and when scheduled through a specific common control channel, transmit ACK / NACK of the corresponding data only through a specific ACKCH. For example, when scheduling information of packet data is received through SCCH # 1 1802, ACK / NACK is transmitted through ACKCH # 1 1807, and scheduling information of packet data is received through SCCH # 2 1803. In this case, ACK / NACK is transmitted through ACKCH # 2 1808.

Next, ACK / NACK repetition will be described.

In general, the ACK / NACK transmission TTI uses the same length as the TTI length of a typical downlink or uplink frame. However, when the required transmission power exceeds the maximum allowable power, the UEs located at the edge of the cell transmit as much as the maximum allowable power. In this case, the reception signal level drops and thus the reliability of the ACK / NACK is not satisfied. In order to solve this problem, HSDPA (High Speed Downlink Packet Access) system uses a method of repeatedly transmitting the same ACK / NACK information. When repeatedly transmitting ACK / NACK information, the power level required for the instantaneous number of repetitions is It will be reduced so that it can be sent within the maximum allowable power level. The ACK / NACK repetition setting information is configured from the network through a higher signaling message or a medium access control (MAC) level message.

For ACK / NACK repetition, a repetition factor for determining whether or not to repeat is required. For example, if the repetition factor is set to a value greater than 0, the number of repetitions is repeated. If the repetition factor is 0, ACK / NACK transmission is performed only once.

Next, a problem that occurs when ACK / NACK repetition is supported in a packet data channel or a system using SCCH and ACKCH resource information is described with reference to FIG. 4. In FIG. 4, for convenience of description, it is assumed that two UEs UE # 1 and 2 exist in one cell, UE # 1 is located at a cell edge, and UE # 2 is located near a cell center base station.

First, a case in which one-to-one mapping with a packet data channel is described.

Referring to FIG. 4, three ACK / NACK repetitions are applied to allow UE # 1 to transmit reliable ACK / NACK, and UE # 2 is configured to transmit ACK / NACK only once because of sufficient transmission power. . First, when UE # 1 receives packet data through data channel # 1 401 (405), it transmits an ACK response through ACKCH # 1 402 at k = 4 according to preset mapping information (407). At the next transmission time point, UE # 1 transmits ACK / NACK using ACKCH # 1 402 at k = 5 and k = 6 to repeatedly transmit ACK / NACK (408, 409). However, the base station may transmit the packet data through the data channel # 1 403 to the UE # 2 in the next TTI through scheduling (406). In this case, UE # 2 also sends ACK / NACK information through ACKCH # 1 404 at the time of ACK / NACK transmission (410). Then, when k = 5, the collision occurs because UE # 1 and UE # 2 simultaneously transmit ACK / NACK using ACKCH # 1. That is, since the ACKCH is shared between the terminals and the mapping rule is set using only the information of the packet data channel, data collision occurs.

In the above problem, in order to repeatedly transmit an ACKCH, an ACKCH must be allocated to a specific UE over several TTIs. When using an ACKCH mapped to a data channel, data is transmitted only for one TTI, so that an ACKCH is repeated. Occurs because it cannot be allocated. However, since the common control channel is also transmitted only for one TTI, the same problem occurs when the common control channel and the ACKCH are mapped one-to-one as shown in FIG. 18.

An object of the present invention is to provide a method and apparatus for supporting ACK / NACK repetition when an ACKCH is mapped to a data channel or a common control channel through which packet data is transmitted in a frequency division multiple access based wireless communication system. It is.

The present invention also provides a method and apparatus for enabling ACK / NACK repetition by allocating a larger number of ACKCHs than the actual data channel or common control channel in allocating ACK channel resources in a frequency division multiple access based wireless communication system. .

In addition, the present invention, in the allocation of ACK channel resources in the frequency division multiple access based wireless communication system allocates the basic ACKCH as many as the actual data channel or common control channel number and at the same time additional ACKCH additional and additional ACK / NACK repetition Provided are a method and an apparatus for determining an ACKCH.

The present invention also provides a method and a transmission apparatus for supporting ACK / NACK repetition by exclusively allocating an additionally allocated ACKCH to a terminal for ACK / NACK repetition.

According to an embodiment of the present invention, in a method for transmitting an ACK / NACK for supporting a retransmission of packet data received from a base station by a terminal in a wireless communication system using a frequency division multiple access scheme, the packet received by the terminal Generating an ACK / NACK for the data; checking whether the ACK / NACK repetitive transmission is set by the terminal; and if the repetitive transmission is not configured, the data channel or the packet data receiving the packet data. Transmitting the generated ACK / NACK through a basic response channel mapped to a common control channel through which the scheduling information of the transmission is transmitted; and if the repetitive transmission is configured, an additional response channel allocated for repetitive transmission for each repetitive transmission. Select one additional response channel, and generate the generated AC through the selected additional response channel. And repeatedly transmitting the K / NACK according to a preset repetition factor (R).

According to an embodiment of the present invention, in an apparatus for transmitting ACK / NACK for supporting retransmission of packet data received from a base station in a wireless communication system using a frequency division multiple access scheme, all the response channel information and the A response channel determiner for determining a response channel for transmitting the ACK / NACK according to the data channel information receiving the packet data or the common control channel information receiving the scheduling information about the packet data and a repetition factor for the ACK / NACK; A response generator for generating an ACK / NACK for the packet data and an ACK / NACK generated by the response generator through a response channel determined by the response channel determiner to a physical layer resource and transmitted as many times as the repetition factor It includes a multiplexer.

Further, according to an embodiment of the present invention, in a receiving apparatus supporting retransmission of packet data to a terminal in a wireless communication system using a frequency division multiple access scheme, all response channel information and data channel information transmitting packet data or A response channel determiner for determining the common control channel information transmitting the scheduling information for the packet data, a response channel for receiving the ACK / NACK according to a repetition factor for ACK / NACK, and a response channel determined from the response channel determiner The demultiplexer extracts an ACK / NACK signal from the signals received through the physical channel according to the information, and the ACK / NACK information on the packet data transmitted to the terminal by decoding the ACK / NACK signal extracted from the demultiplexer. It includes a response decoder to obtain.

Further, according to an embodiment of the present invention, in a method for receiving an ACK / NACK from the terminal to support the retransmission of packet data in a wireless communication system using a frequency division multiple access scheme, the repeated ACK / NACK repeated transmission setting of the terminal And if the repetitive transmission is not configured, through the basic response channel mapped to the data channel transmitting the packet data or the common control channel transmitting the scheduling information of the packet data, the generated ACK / Receiving a NACK and, if the repetitive transmission is set, selects one additional response channel among additional response channels allocated for repetitive transmission for each repetitive transmission, and generates the generated ACK through the selected additional response channel. Repeatedly receiving / NACK according to a preset repetition factor (R).

When the effect obtained by the typical thing of the invention disclosed below is demonstrated briefly, it is as follows.

The present invention supports repetitive transmission of ACK / NACK when the ACKCH is mapped to a data channel or SCCH for transmitting packet data in a frequency division multiple access based wireless communication system. This enables repeated transmission without conflict in ACK / NACK transmission between other terminals during repeated transmission of ACK / NACK, so that a terminal far from the base station can transmit reliable ACK / NACK, and thus a cell Can increase the coverage.

Hereinafter, with reference to the accompanying drawings will be described in detail the operating principle of the embodiment of the present invention. In the following description of the present invention, detailed descriptions of well-known functions or configurations will be omitted if it is determined that the detailed description of the present invention may unnecessarily obscure the subject matter of the present invention. Terms to be described later are terms defined in consideration of functions in the present invention, and may be changed according to intentions or customs of users or operators. Therefore, the definition should be made based on the contents throughout the specification.

The present invention provides a single ACK / NACK information in an environment in which channel resource information of the ACKCH is mapped to information of a data channel or a common control channel for transmitting packet data and shared among terminals in a frequency division multiple access based wireless communication system. We propose a method to solve the problem that occurs when sending repeatedly.

To this end, the present invention allocates more ACKCHs than the number of data channels or common control channels to support ACK / NACK repetitive transmission. That is, the present invention includes a method for additionally assigning an ACKCH, a method for selecting an ACKCH when the ACK / NACK repetition is applied, and a transmitter device and a receiver device for transmitting the ACK / NACK.

Detailed description of the present invention is described through the following embodiments, and the present invention can be applied to both ACK / NACK channel establishment method for downlink and uplink HARQ, but for convenience of description, uplink for downlink HARQ support It explains through ACK / NACK setting method.

<< first embodiment >>

According to the first embodiment of the present invention, a terminal that allocates additional ACKCHs and repeats ACK / NACK in addition to the basic ACKCH allocated to each terminal always transmits repeated ACK / NACK information using the additional ACKCH.

A method of setting ACKCH for a preferred implementation according to the first embodiment of the present invention will be described with reference to FIG. 5.

Referring to FIG. 5, it is assumed that three data channels or three common control channels 501 are allocated. Conventionally, only three ACKCHs need to be allocated when mapping with a data channel or a common control channel. In the first embodiment of the present invention, six ACKCHs 502 and 503 are allocated for ACK / NACK repetition. Three of these 502 are set as basic ACKCHs and the other three 503 are set as additional ACKCHs.

Next, a method of transmitting an ACK / NACK by the UE using the allocated ACKCH will be described with reference to FIG. 6.

In FIG. 6, UE # 1 is a terminal configured for ACK / NACK repetitive transmission, and UE # 2 is a terminal configured not to support repetitive transmission of ACK / NACK. The repetition factor R of UE # 1 is assumed to be 2. First, when the terminal receives the packet data through the data channel # 1 in the k = 1 frame or the scheduling information of the packet data through the SCCH # 1 (605), the terminal through the ACKCH # 1 in the k = 4th frame An ACK is sent (606). Next, since UE # 1 supports repeated transmission of ACK / NACK, the UE # 1 repeatedly transmits ACK in k = 5th frame with the same value as ACK / NACK information transmitted in k = 4th frame. According to the first embodiment of the present invention, the additional ACKCH configured for repetitive transmission is used at k = 5 and k = 6th time points. That is, among the plurality of additional ACKCHs, ACKCH # 4, which is an additional ACKCH corresponding to data channel # 1 or SCCH # 1, is selected and transmitted (607 and 608). In this case, a collision for ACK / NACK transmission does not occur between two terminals at k = 5 frames.

In the HARQ scheme described in the prior art, since the retransmission time is not fixed in the case of asynchronous HARQ, the 3TTI of the ACKCH transmission interval does not affect the retransmission time, but in the case of the synchronous HARQ, the retransmission time of the UE # 1 and the UE # 2 This may vary. In this case, a parameter for determining the number of repetitions is used by the terminal or the base station when calculating the retransmission time point to have an appropriate processing time.

Next, an operation procedure of a terminal according to the first embodiment of the present invention will be described with reference to FIG. 7.

Referring to FIG. 7, first, in step 701, the terminal receives and demodulates packet data and generates an ACK or a NACK according to whether the packet data is properly received. In operation 702, an ACKCH for transmitting an ACK or a NACK is determined. When determining the ACKCH, the UE checks whether ACK / NACK repetition is configured. The repetition mentioned above corresponds to a case where information indicating whether the signaled repetition is set to repetition or the repetition factor is greater than zero.

If the repetition is not set, the process proceeds to step 703 to transmit ACK / NACK using the basic ACKCH (703, 704). The basic ACKCH is determined according to the information of the data channel or SCCH to which the packet data is transmitted. If iteration is set, the flow proceeds to step 705. In this case, ACK / NACK transmission should be repeated as much as the repetition factor R in addition to the basic transmission. Therefore, the loop proceeds to (R + 1) times as shown in step 705. It is determined whether the first transmission. In the case of the first transmission (i = 0), the process proceeds to step 706 to select an ACKCH, and in step 708, general ACK / NACK transmission is performed using the selected ACKCH. From i = 1, the method proceeds to step 707 to select an additional ACKCH mapped to the received data channel or SCCH among the additional ACKCHs, and retransmits the ACK / NACK using the selected additional ACKCH in step 708.

The operation procedure of the base station according to the first embodiment of the present invention is similar to the operation procedure of the terminal. That is, the ACKCH for receiving ACK / NACK is selected in the same manner as the flowchart of FIG. 7, and the ACK / NACK is received and decoded through the selected channel.

8 shows a transmitter for transmitting ACK / NACK information according to the first embodiment of the present invention.

Referring to FIG. 8, the ACKCH determiner 801 receives the entire ACKCH information 806, the received packet data channel information, and the repetition factor 802 in order to determine the ACKCH information 807. It decides whether to transmit ACK / NACK. The entire ACKCH information 806 may be predefined or set through higher signaling. Packet data channel information or SCCH information is transmitted from a receiving end that receives packet data, and a repetition factor R is received through higher signaling.

The ACKCH generator 803 includes actual ACK / NACK information 807 and transmits it on the ACKCH. The ACKCH generator 803 performs coding or modulation in a format capable of actually transmitting the ACK / NACK bit information generated based on the reception result of the packet data.

The multiplexer 804 maps the ACK / NACK information coded and modulated by the ACKCH generator 803 to the corresponding physical layer resource according to the ACKCH information 807 received by the ACKCH determiner 801.

The IFFT 805 inverse Fourier transforms and outputs ACK / NACK information mapped to a physical layer resource.

9 illustrates a receiving apparatus for receiving ACK / NACK information according to the first embodiment of the present invention.

Referring to FIG. 9, the ACKCH determiner 906 receives the entire ACKCH information 905, the packet data channel information or the SCCH information, and the repetition factor 901 which have been transmitted, and determines the ACKCH information 907 that should be received at that time. do. The entire ACKCH information 905 may be predefined or set through higher signaling. Packet data channel information or SCCH information is transmitted from a transmitter that transmits packet data, and a repetition factor is transmitted through higher signaling.

The demultiplexer 903 may know which physical layer frequency resource is ACKCH based on the ACKCH information 907 received from the ACKCH determiner 906. That is, the demultiplexer 903 extracts only ACKCH information from all physical channel information received through the FFT 902 and sends it to the ACKCH decoder 904, and the ACKCH decoder 904 decodes and demodulates the actual ACK / NACK information. Obtain 908.

<< 2nd Example >>

According to the first embodiment of the present invention, since it is proposed to always use the same additional channel when repeatedly transmitting ACK / NACK, when UEs repeatedly transmitting ACK / NACK are continuously allocated to the same data subchannel, A collision may occur between repeated ACK / NACKs. In order to prevent this, the base station scheduler must allocate a channel such that terminals with repetition are not transmitted continuously using the same data channel. For example, if UE # 1 is configured for ACK / NACK repetitive transmission in FIG. 6, if UE # 2 that does not repeat transmission in the next TTI is scheduled to the channel allocated to UE # 1 in the previous TTI, k = 6th transmission time is performed. Both UE # 1 and UE # 2 may transmit ACK / NACK without collision.

Accordingly, the second embodiment of the present invention proposes a method for supporting ACK / NACK repetitive transmission by allocating an additional ACKCH by the number of repetitive transmissions per UE in order to avoid such a restriction.

10 illustrates a method of setting ACKCH according to a second embodiment of the present invention.

Referring to FIG. 10, it is assumed that three data channels or three SCCHs are allocated at 1001. In the case of mapping data channels or SCCHs and ACKCHs in the related art, only three ACKCHs equal to the number of data channels or SCCHs need to be allocated. However, in the second embodiment of the present invention, all nine ACKCHs are allocated for ACK / NACK repetitive transmission. Of the total ACKCHs, three ACKCHs 1002 are set as basic ACKCHs and six ACKCHs 1003 as additional ACKCHs. In this case, the ACK / NACK repetition factor that can be supported without collision in this cell becomes 2.

The following proposes an algorithm for selecting an ACKCH capable of transmitting ACK / NACK at a corresponding time point among a plurality of ACKCHs for implementing the second embodiment of the present invention. According to the second embodiment of the present invention, the ACKCH may be determined by the following equations (1, 2).

 ACKCH information = i * (total data channel or number of SCCH) + received data channel # or SCCH # (i = 0, .., R) during i-th ACK / NACK transmission

Equation 1 is the same ACK / NACK information using the number of ACK / NACK transmissions and data channel or SCCH information, but selects different ACKCHs for each repetition by selecting the ACKCH according to the number of repetitive transmissions.

ACKCH information in i-th ACK / NACK transmission = ((frame number at the time of i = 0th ACK / NACK transmission) Modular (R + 1)) * (total number of data channels or total number of SCCH) + received data channel # Or SCCH #

Equation 2 is an algorithm for allowing the terminal to select a different ACKCH when the packet data reception time is different using a frame number instead of the repetition frequency information during ACK / NACK transmission. The frame number is an absolute value for the UE to count the frame order, and corresponds to, for example, a system frame number or a connection frame number of the WCDMA system. It is also possible to use frame number information at the time of packet data reception instead of the frame number at the time of i = 0th ACK / NACK transmission in the above equation.

Next, a method of transmitting an ACK / NACK by the UE using the allocated ACKCH and the algorithm for determining the ACKCH as described above will be described with reference to FIG. 11.

In FIG. 11, UE # 1 and UE # 2 are terminals configured for ACK / NACK repeat transmission. The repetition factor R of UE # 1 and UE # 2 is assumed to be 2. First, when the UE receives data in the k = 1 th frame, the ACK / NACK is transmitted through the ACKCH in the k = 4 th frame. The ACKCH is determined through Equation 1 or Equation 2.

The ACKCH information determined through Equation 1 is equal to 1109. UE # 1 selects ACKCH # 1 when data channel # = 1 when i = 0, and selects ACKCH # 4 when i = 1 and ACKCH # 7 when i = 2. Likewise, when UE # 2 selects the ACKCH using Equation 1, ACK / NACK is transmitted using the same ACKCHs as UE # 1 (1115). However, since the ACK / NACK transmission time points of the two terminals are different, a collision does not occur between the two terminals.

In addition, when ACKCH is selected through Equation 2, since UE # 1 transmits the i = 0th ACK / NACK at k = 4, ACKCH # 4 is selected regardless of the number of repetitions of i = 0,1,2. (1110). Since UE # 2 receives data at k = 2 and transmits the first ACK / NACK at k = 5, UE # 2 selects ACKCH # 7 according to Equation 2 (1116).

Next, an operation procedure of a terminal according to the second embodiment of the present invention will be described with reference to FIG. 12.

First, as shown in 1201, the terminal receives and demodulates packet data and generates an ACK or a NACK according to whether the packet data is properly received. After generating ACK / NACK information, the ACKCH to be transmitted is determined. When determining the ACKCH, the UE checks whether ACK / NACK repeat transmission is set (1202). The above-mentioned repetitive transmission is set when the information indicating whether the signaled repetitive transmission is configured is set to repetitive transmission or the repetition factor is greater than zero. If repetitive transmission is not configured, the procedure proceeds to 1203 to select a basic ACKCH using a general ACKCH determination method, and then transmits ACK / NACK through the selected ACKCH (1204). The basic ACKCH is determined according to the information of the data channel on which the packet data is transmitted or the information of the SCCH on which the scheduling information of the data is transmitted. If repetition is set next, the process proceeds to step 1205. In addition to the basic transmission, since the ACK / NACK repeated transmission should be repeated as much as the repetition factor R, the loop proceeds (R + 1) times as shown in 1205, and is required by using Equation 1 or Equation 2 as shown in 1206 at each ACK / NACK transmission. After determining the ACKCH, it proceeds to 1207 and transmits ACK / NACK through the determined ACKCH.

The operation procedure of the base station according to the second embodiment of the present invention is similar to the operation procedure of the terminal. That is, the ACKCH for receiving ACK / NACK is selected in the same manner as the flowchart of FIG. 12, and the ACK / NACK is received and decoded through the selected channel.

Since the transmitting apparatus and the receiving apparatus according to the second embodiment of the present invention are the same as those of the first embodiment of the present invention, repeated description thereof will be omitted. However, when using Equation 2 in the second embodiment of the present invention, input of a frame number value is additionally required as an input of the ACKCH determiner.

<< third embodiment >>

In the second embodiment of the present invention, the UEs using the same data channel or the common control channel can perform ACK / NACK repetitive transmission without collision, but there is a disadvantage in that ACKCH is additionally required as a repetition factor. Since the actual ACK / NACK repetitive transmission is likely to be supported for the UEs at the edge of the cell, there will be many cases in which an additional ACKCH for ACK / NACK repetitive transmission is not used. Therefore, in the third embodiment, a method of allocating a limited number of ACKCHs for each repetitive transmission number is limited in order to increase the efficiency of resource utilization.

First, the ACKCH allocation method according to the third embodiment of the present invention will be described with reference to FIG.

Referring to FIG. 13, M0 basic ACKCHs are allocated for each data channel or SCCH (1302). M0 is equal to the number of data channels or SCCH. Next, M1 ACKCHs used for the first ACK / NACK repeated transmission are allocated (1303), and M2 ACKCHs used for the second ACK / NACK repeated transmission are allocated (1304). M3, M4,… only if you allow more iterations. It can also be assigned as: The ACKCH information, M0, M1, M2 ... is a value that can be set or predefined through higher signaling.

When the ACKCH is allocated as described above, an algorithm for selecting an ACKCH capable of transmitting ACK / NACK at a corresponding time point among a plurality of ACKCHs is shown in Equation 3 below.

ACKCH information = (i * M (i-1) + received data channel # or SCCH #) Modular (Mi) (i = 0, .., R)

Equation 3 is based on the number of ACK / NACK transmissions, information on the data channel or SCCH, and ACKCH information allocated for each repetitive transmission, and the same ACK / NACK information is different depending on the number of repeated transmissions. An algorithm for selecting ACKCH.

As shown in Equation 3, since the number of ACKCHs for repetitive transmission is smaller than M0, that is, the total number of data channels, a collision may occur during ACK / NACK transmission, which is repeated when the scheduler allocates a data channel. Conflicts can be avoided by controlling UEs not to select the same ACKCH. In other words, if data channel # 1 or SCCH # 1 and data channel # 3 or SCCH # 3 are simultaneously allocated to two UEs performing ACK / NACK repetition, a collision occurs in ACK / NACK repetitive transmission. ACK / NACK if allocating data channel # 1 or SCCH # 1 and data channel # 2 or SCCH # 2 to the performing terminals, and allocating data channel # 3 or SCCH # 3 to a terminal that does not support repetitive transmission The transmission can be performed without collision.

Next, a method of transmitting an ACK / NACK by the terminal according to the third embodiment of the present invention will be described with reference to FIG. 14.

In FIG. 14, UE # 1 and UE # 2 are terminals configured for ACK / NACK repeat transmission. The repetition factor R was assumed to be 2. Assume that M0 = 3, M1 = 2, M2 = 1. First, when the UE receives data in the k = 1 th frame, the ACK / NACK is transmitted through the ACKCH in the k = 4 th frame. The ACKCH to transmit the ACK / NACK is determined through Equation 3 below. UE # 1 selects ACKCH # 1 when i = 0 because data channel # or SCCH # = 1 (1406), ACKCH # 4 when i = 1 (1407), and ACKCH # 6 when i = 2. Select each one (1408). Since UE # 2 is the data channel # or SCCH # = 2, select ACKCH # 2 when i = 0 according to Equation 3 (1410), and ACKCH # 5 (1411) when i = 1, i = 2 If each ACKCH # 6 is selected (1412).

The operation procedure of the terminal and the base station according to the third embodiment of the present invention is the same as that of the second embodiment of the present invention, except that in step 1206 of FIG. Equation 3 is used.

In addition, since the transmitting apparatus and the receiving apparatus according to the third embodiment of the present invention are the same as those of the first embodiment of the present invention, repeated description thereof will be omitted.

<< fourth embodiment >>

When the number of terminals supporting ACK / NACK repetitive transmission is very small, according to the first to third embodiments of the present invention in which the ACKCH is shared in common, it is wasted without using the ACKCH for repetition. The fourth embodiment proposes a method for exclusively allocating an ACKCH to a terminal supporting ACK / NACK repetitive transmission.

Next, an ACKCH allocation method according to the fourth embodiment of the present invention will be described with reference to FIG.

Referring to FIG. 15, first, a basic ACKCH mapped with a data channel or SCCH is allocated (1502). Next, ACKCHs for UEs supporting ACK / NACK repetitive transmission are allocated (1503 and 1504). In FIG. 15, UE # 1 and UE # 3 are terminals for performing ACK / NACK repetitive transmission. Since the basic ACKCH is a channel commonly used in the cell, the information on the basic ACKCH is provided as a system information or a fixed resource in advance. In case of UEs that support ACK / NACK repetitive transmission, such as UE # 1 and UE # 3, ACKCH information is also provided when channel information of each UE is provided through higher signaling. Although different ACKCHs are allocated to UE # 1 and UE # 3 in FIG. 15, the base station scheduler may allocate the same ACKCH to UE # 1 and UE # 3 and schedule ACK / NACK transmissions so that collisions do not occur.

Next, a method of transmitting an ACK / NACK by the UE using an allocated ACKCH according to the third embodiment of the present invention will be described with reference to FIG. 16.

In FIG. 16, UE # 1 is a terminal for which ACK / NACK repetitive transmission is configured and UE # 2 is a terminal for which repetitive transmission is not configured. Iteration factor R of UE # 1 assumes 2. First, when UE # 1 receives data in k = 1 frame, it transmits ACK / NACK using ACKCH in k = 4 frame, and receives packet data through data channel # 1 or data through SCCH # 1. In case of receiving scheduling information, ACK / NACK should be transmitted using ACKCH # 1. However, since UE # 1 is a terminal supporting ACK / NACK repetition, ACKCH # 4, which is an ACKCH allocated exclusively for the terminal, is transmitted. ACK / NACK is transmitted by the repetition factor (1606, 1607, 1608). UE # 2 transmits ACK / NACK when receiving packet data through data channel # 1 or scheduling information of the corresponding data through SCCH # 1. UE # 2 transmits ACK / NACK. Therefore, ACK / NACK is transmitted through ACKCH # 1 (1610).

Next, an operation procedure of a terminal according to the fourth embodiment of the present invention will be described with reference to FIG. 17.

First, in step 1701, the terminal receives and demodulates the packet data, generates an ACK or NACK according to whether the packet data is properly received, and then proceeds to the next step to determine the ACKCH to transmit the ACK / NACK. When determining the ACKCH in step 1702, the UE checks whether ACK / NACK repeated transmission is set. The above-described repetitive transmission is set when the information indicating whether the signaled repetitive transmission is set is set to repetitive transmission or the repetition factor is greater than zero. If repetitive transmission is not configured, the process proceeds to step 1703 to select a basic ACKCH using a general ACKCH determination method. In operation 1704, the ACK / NACK is transmitted through the selected ACKCH. The basic ACKCH is determined according to the information of the data channel or SCCH information on which the packet data is transmitted. If repetitive transmission is set, step 1705 is reached. In addition to the basic transmission, since the ACK / NACK transmission should be repeated as much as the repetition factor R, the terminal proceeds to the loop (R + 1) in step 1705. At the time of transmitting each ACK / NACK, the terminal does not select the basic ACKCH as shown in step 1706. ACK / NACK transmission is performed using a dedicated ACKCH.

The operation procedure of the base station according to the fourth embodiment of the present invention is similar to the operation procedure of the terminal. That is, the ACKCH for receiving ACK / NACK is selected in the same manner as the flowchart of FIG. 17, and the ACK / NACK is received and decoded through the selected channel.

Since the transmitting apparatus and the receiving apparatus according to the fourth embodiment of the present invention are the same as those of the first embodiment of the present invention, repeated description thereof will be omitted. In the fourth embodiment of the present invention, however, ACKCH information allocated exclusively as an input of the ACKCH determinant is required.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

1 is a diagram illustrating a frequency division multiple access scheme.

2 is a diagram illustrating a basic procedure of HARQ

3 illustrates a method of one-to-one mapping with resources of a data channel;

FIG. 4 is a diagram illustrating a problem that occurs when ACK / NACK repetition is supported in a method in which a data channel and an ACKCH are configured by one-to-one mapping.

5 illustrates ACKCH channel allocation according to a first embodiment of the present invention.

6 shows an example of ACK / NACK transmission according to the first embodiment of the present invention.

7 is a flowchart illustrating a procedure for determining an ACKCH according to a first embodiment of the present invention.

8 is an ACK / NACK transmission apparatus according to a first embodiment of the present invention

9 is an ACK / NACK receiving apparatus according to a first embodiment of the present invention

10 illustrates ACKCH channel allocation according to a second embodiment of the present invention.

11 illustrates an example of ACK / NACK transmission according to a second embodiment of the present invention.

12 is a flowchart illustrating a procedure for determining an ACKCH according to a second embodiment of the present invention.

13 illustrates ACKCH channel allocation according to a third embodiment of the present invention.

14 illustrates an example of ACK / NACK transmission according to a third embodiment of the present invention.

15 illustrates ACKCH channel allocation according to a fourth embodiment of the present invention.

16 shows an example of ACK / NACK transmission according to the fourth embodiment of the present invention.

17 is a flowchart illustrating a procedure of determining an ACKCH according to a fourth embodiment of the present invention.

18 illustrates a method of one-to-one mapping with resources of a common control channel.

Claims (36)

A method of transmitting an ACK / NACK for supporting a retransmission of packet data received from a base station by a terminal in a wireless communication system using a frequency division multiple access scheme, Generating an ACK / NACK for the packet data received by the terminal; Checking, by the terminal, whether repeat transmission is set for the ACK / NACK; If the repetitive transmission is not configured, transmitting the generated ACK / NACK through a basic response channel mapped to a data channel receiving the packet data or a common control channel through which scheduling information of the packet data is transmitted; If the repetitive transmission is configured, one additional response channel among the additional response channels allocated for repetitive transmission is selected for each repetitive transmission, and a preset repetition factor is generated for the generated ACK / NACK through the selected additional response channel. ACK / NACK transmission method comprising the step of repeatedly transmitting according to (R). The method of claim 1, The repeated transmission process, In case of initially transmitting the ACK / NACK, the basic response channel mapped to the data channel or the common control channel is selected. And repetitively transmitting the ACK / NACK, selecting the additional response channel mapped to the data channel or the common control channel. The method of claim 1, The repeated transmission process, The additional response channel is selected according to the information on the data channel or the common control channel and the number (i) of transmitting the ACK / NACK, or the information on the data channel or the common control channel and the ACK / NACK are selected. The ACK / NACK transmission method for selecting the additional response channel according to the transmission time. Claim 4 was abandoned when the registration fee was paid. The method of claim 3, In the i-th ACK / NACK transmission, the additional response according to the total number of data channels or the total number of common control channels, and the data channel number for receiving packet data or the common control channel number for receiving scheduling information for packet data. ACK / NACK transmission method to select a channel. Claim 5 was abandoned upon payment of a set-up fee. The method of claim 3, When transmitting the i-th ACK / NACK, the frame number at the time of i = 0th ACK / NACK transmission, the total number of data channels or the total number of common control channels, and the data channel number or packet data for which packet data is received. The ACK / NACK transmission method of selecting the additional response channel according to the common control channel number receiving the scheduling information. The method of claim 1, The repeated transmission process, ACK / NACK for selecting one additional response channel among additional response channels allocated for each repetitive transmission number according to the information on the data channel or the common control channel and the number (i) of transmitting the ACK / NACK. Transmission method. Claim 7 was abandoned upon payment of a set-up fee. The method of claim 6, the i-th ACK / NACK transmission, the number of additional response channels allocated to the (i-1) th transmission, the data channel number receiving the packet data or the common control channel number receiving the scheduling information for the packet data, ACK / NACK transmission method for selecting the additional response channel according to the number of additional response channels allocated to the i-th transmission. Claim 8 was abandoned when the registration fee was paid. The method of claim 7, wherein And the number of additional response channels allocated to the i-th ACK / NACK transmission is smaller than the number of additional response channels allocated to the i-th transmission. The method of claim 1, The repeated transmission process, ACK / NACK transmission method for selecting an additional response channel allocated exclusively to the terminal. A method for receiving an ACK / NACK from a terminal for supporting retransmission of packet data in a wireless communication system using a frequency division multiple access scheme, Confirming whether repeating transmission is set for the ACK / NACK by the terminal; If the repetitive transmission is not configured, receiving the ACK / NACK through a basic response channel mapped to a data channel transmitting the packet data or a common control channel transmitting the scheduling information of the packet data; If the repetitive transmission is set, one additional response channel among the additional response channels allocated for repetitive transmission is selected for each repetitive transmission, and a preset repetition factor R is set for the ACK / NACK through the selected additional response channel. ACK / NACK receiving method comprising the step of repeatedly receiving according to. The method of claim 10, The repeated receiving process, When the ACK / NACK is initially transmitted, select the basic response channel mapped to the data channel or the common control channel, And when the ACK / NACK is repeatedly transmitted, selecting the additional response channel mapped to the data channel or the common control channel. The method of claim 10, The repeated receiving process, The additional response channel is selected according to the information about the data channel or the common control channel and the number of times of receiving the ACK / NACK, or the information about the data channel or the common control channel and the ACK / NACK are selected. The ACK / NACK receiving method for selecting the additional response channel according to the time point. Claim 13 was abandoned upon payment of a registration fee. The method of claim 12, Upon receiving the i-th ACK / NACK, the additional response channel according to the number of all data channels or the number of all common control channels, and the number of data channels for receiving packet data or the number of common control channels for receiving scheduling information on packet data. ACK / NACK receiving method for selecting. Claim 14 was abandoned when the registration fee was paid. The method of claim 12, When receiving the i-th ACK / NACK, the frame number at the time of i = 0th ACK / NACK transmission, the total number of data channels or the total number of common control channels, the scheduling of the data channel number or packet data receiving the packet data ACK / NACK receiving method for selecting the additional response channel according to the common control channel number receiving the information. The method of claim 10, The repeated receiving process, ACK / NACK for selecting one additional response channel among additional response channels allocated for each repetitive transmission number according to the information on the data channel or the common control channel and the number (i) of receiving the ACK / NACK. Receiving method. Claim 16 was abandoned upon payment of a setup registration fee. The method of claim 15, when receiving the i-th ACK / NACK, the number of additional response channels allocated to the (i-1) th transmission, the data channel number receiving the packet data or the common control channel number receiving the scheduling information for the packet data, and i And selecting the additional response channel according to the number of additional response channels allocated to the first transmission. Claim 17 was abandoned upon payment of a registration fee. The method of claim 16, And the number of additional response channels allocated to the i-th ACK / NACK transmission is smaller than the number of additional response channels allocated to the i-th transmission. The method of claim 10, The repeated receiving process, ACK / NACK receiving method for selecting an additional response channel allocated exclusively to the terminal. An apparatus for transmitting ACK / NACK for supporting retransmission of packet data received from a base station in a wireless communication system using a frequency division multiple access scheme, Response channel for transmitting the ACK / NACK according to all response channel information, the data channel information receiving the packet data or the common control channel information receiving the scheduling information for the packet data, and the repetition factor for the ACK / NACK. A response channel determiner for determining A response generator for generating ACK / NACK for the packet data; And a multiplexer for mapping the ACK / NACK generated by the response generator to a physical layer resource and transmitting the number of times according to the repetition factor through the response channel determined by the response channel determiner. The method of claim 19, The response channel determiner, In case of initial transmission, select a default response channel mapped to the data channel or the common control channel, In the case of repetitive transmission, the transmitting apparatus selects an additional response channel mapped to the data channel or the common control channel. The method of claim 19, The response channel determiner, In case of initial transmission, select a default response channel mapped to the data channel or the common control channel, In the case of repetitive transmission, an additional response channel is selected according to the information on the data channel or the common control channel and the number of times of transmitting the ACK / NACK, or the information on the data channel or the common control channel and the And a transmitter for selecting the additional response channel according to a time point of transmitting ACK / NACK. Claim 22 was abandoned upon payment of a registration fee. The method of claim 21, The response channel determiner, In the i-th ACK / NACK transmission, the additional response according to the total number of data channels or the total number of common control channels, and the data channel number for receiving packet data or the common control channel number for receiving scheduling information for packet data. Transmitter to select the channel. Claim 23 was abandoned upon payment of a set-up fee. The method of claim 21, The response channel determiner, When transmitting the i-th ACK / NACK, the frame number at the time of i = 0th ACK / NACK transmission, the total number of data channels or the total number of common control channels, and the data channel number or packet data for which packet data is received. And the additional response channel is selected according to a common control channel number which has received scheduling information. The method of claim 19, The response channel determiner, In case of initial transmission, select a default response channel mapped to the data channel or the common control channel, In the case of repetitive transmission, one additional response channel among the additional response channels allocated for each repetitive transmission number is selected according to the information on the data channel or the common control channel and the number of transmissions of the ACK / NACK (i). Transmitting device. Claim 25 was abandoned upon payment of a registration fee. The method of claim 24, The response channel determiner, the i-th ACK / NACK transmission, the number of additional response channels allocated to the (i-1) th transmission, the data channel number receiving the packet data or the common control channel number receiving the scheduling information for the packet data, and transmitting the additional response channel according to the number of additional response channels allocated to the i &lt; th &gt; transmission. Claim 26 was abandoned upon payment of a registration fee. The method of claim 25, And the number of additional response channels allocated to the i-th ACK / NACK transmission is smaller than the number of additional response channels allocated to the i-th transmission. The method of claim 19, The response channel determiner, In case of initial transmission, select a default response channel mapped to the data channel or the common control channel, In the case of repetitive transmission, the transmitting apparatus selects an additional response channel allocated exclusively to the terminal. A receiving apparatus supporting retransmission of packet data to a terminal in a wireless communication system using a frequency division multiple access scheme, A response channel for receiving the ACK / NACK according to all response channel information, data channel information for transmitting packet data or common control channel information for transmitting scheduling information for the packet data, and a repetition factor for ACK / NACK. A response channel determiner to determine, A demultiplexer for extracting an ACK / NACK signal from signals received through a physical channel according to the response channel information determined by the response channel determiner; And a response decoder for decoding the ACK / NACK signal extracted by the demultiplexer and obtaining ACK / NACK information on the packet data transmitted to the terminal. The method of claim 28, The response channel determiner, In case of initial transmission, select a default response channel mapped to the data channel or the common control channel, In the case of repetitive transmission, the reception device selecting the additional response channel mapped to the data channel or the common control channel. The method of claim 28, The response channel determiner, In case of initial transmission, select a default response channel mapped to the data channel or the common control channel, In the case of repetitive transmission, the additional response channel is selected according to the information on the data channel or the common control channel and the number of times of receiving the ACK / NACK, or the information on the data channel or the common control channel and the And a receiver for selecting the additional response channel according to a time point for receiving ACK / NACK. Claim 31 was abandoned upon payment of a registration fee. The method of claim 30, The response channel determiner, Upon receiving the i-th ACK / NACK, the additional response channel according to the number of all data channels or the number of all common control channels, and the number of data channels for receiving packet data or the number of common control channels for receiving scheduling information on packet data. Receiving device to select. Claim 32 was abandoned upon payment of a registration fee. The method of claim 30, The response channel determiner, When receiving the i-th ACK / NACK, the frame number at the time of i = 0th ACK / NACK transmission, the total number of data channels or the total number of common control channels, the scheduling of the data channel number or packet data receiving the packet data And the additional response channel is selected according to the common control channel number which has received the information. The method of claim 28, The response channel determiner, In case of initial transmission, select a default response channel mapped to the data channel or the common control channel, In the case of repetitive transmission, one additional response channel among the additional response channels allocated for each repetitive transmission number is selected according to the information on the data channel or the common control channel and the number (i) of receiving the ACK / NACK. Receiving device. Claim 34 was abandoned upon payment of a registration fee. The method of claim 33, wherein The response channel determiner, the i-th ACK / NACK transmission, the number of additional response channels allocated to the (i-1) th transmission, the data channel number receiving the packet data or the common control channel number receiving the scheduling information for the packet data, and receiving the additional response channel according to the number of additional response channels allocated to the i &lt; th &gt; transmission. Claim 35 was abandoned upon payment of a registration fee. The method of claim 34, wherein And the number of additional response channels allocated to the i-th ACK / NACK transmission is smaller than the number of additional response channels allocated to the i-th transmission. The method of claim 28, The response channel determiner, In case of initial transmission, select a default response channel mapped to the data channel or the common control channel, In the case of repetitive transmission, the reception device selects an additional response channel allocated exclusively to the terminal.

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