KR101345505B1 - Method and apparatus for transmitting and receiving uplink control signalling channels in wireless communication systems - Google Patents

Abstract

The present invention relates to a method and apparatus for transmitting and receiving a control channel capable of optimizing the amount of resources used for uplink control channel transmission in a wireless communication system. The present invention relates to a frequency resource for transmitting a control channel continuously according to downlink data. Multiplexing control channels such as an uplink ACK / NACK channel and the like, and an SR channel and the like generated aperiodically depending on the situation of the UE. Control information symbols for transmission on the control channels are code division multiplexed (CDM) by being multiplied by orthogonal sequences having different indices assigned to the control channels.

SC-FDMA, ACK / NACK, CQI, Zadoff-Chu

Description

METHOD AND APPARATUS FOR TRANSMITTING AND RECEIVING UPLINK CONTROL SIGNALLING CHANNELS IN WIRELESS COMMUNICATION SYSTEMS}

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram illustrating the structure and slot structure of a general SC-FDMA based transmitter. FIG.

BACKGROUND OF THE INVENTION Field of the Invention [0001]

3 is a diagram showing an example of channel assignment of a control channel and a data channel in a frequency domain.

4 illustrates an example of code division multiplexing control channels.

5 is a diagram illustrating multiplexing of an ACK / NACK channel and an SR channel according to the first embodiment of the present invention.

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

7 is a diagram illustrating a control channel generation method according to a first embodiment of the present invention.

8 illustrates another example of an ACK / NACK channel and an SR channel multiplexing according to a preferred embodiment of the present invention.

9 is a diagram showing the structure of a terminal transmission apparatus according to a preferred embodiment of the present invention.

10 is a diagram showing the structure of a base station receiving apparatus according to a preferred embodiment of the present invention.

The present invention relates to a frequency division multiple access (FDMA) based wireless communication system, and more particularly, to a method and apparatus for multiplexing and transmitting uplink control information.

Recently, in a mobile communication system, a method that is useful for high-speed data transmission in a wireless channel is known as an Orthogonal Frequency Division Multiplex (OFDM) scheme or a Single Carrier-Frequency division Multiple Access: hereinafter referred to as SC-FDMA) is actively researched.

OFDM and SC-FDMA technologies are applied to downlink and uplink of the Evolved UMTS Terrestrial Radio Access (EUTRA) standard based on 3rd Generation Partnership Project (3GPP) Universal Mobile Telecommunication Services (UMTS). Like OFDM, SC-FDMA guarantees orthogonality among multiple access users, and also has the advantage of having a very low Peak to Average Power Ratio (PAPR) of a transmission signal as a technology based on single carrier transmission. Therefore, when the SC-FDMA is applied to a mobile communication system, cell coverage can be improved due to a low PAPR compared with OFDM technology.

1 shows a structure and a slot structure of a general SC-FDMA transmitter, which includes a Fast Fourier Transform (FFT) 103 and an Inverse Fast Fourier Transform (IFFT) (Hereinafter referred to as " a ") 105 is shown.

1, the difference between OFDM and SC-FDMA in the transmitter structure is that, in addition to the IFFT 105 used for multi-carrier transmission in the OFDM transmitter, the FFT 103 in the SC- It is additionally present in the front end. M modulation symbols 100 are collected to form a block, and the block is input to an FFT 103 having a size M. The block is hereinafter referred to as an LB (Long Block), and the seven LBs constitute one 0.5 ms slot 102.

The signal output from the FFT 103 is applied to the inputs of the IFFT 105 having a continuous index 104, subjected to an inverse Fourier transform, and then converted into an analog signal 106 and transmitted. The input / output size N of the IFFT 105 has a larger value than the input / output size M of the FFT 103. The SC-FDMA transmission signal has a lower PAPR than the OFDM signal because the signal processed through the FFT 103 and the IFFT 105 has a single carrier characteristic as described above.

2 shows an example of resource partitioning in the frequency and time domain in an EUTRA SC-FDMA system. Referring to FIG. 2, the system bandwidth 201 is 10 MHz, and there are a total of 50 resource units (RUs) 202 within the system bandwidth 201. Each RU 202 is made up of 12 subcarriers 203 and can have 14 LBs 204 and is a basic unit of data transmission scheduling. The fourteen LBs 204 gather to form one 1-ms sub-frame 205.

FIG. 3 shows resource allocation for control channel and data channel transmission in the EUTRA uplink according to the resource partitioning structure of FIG.

3, ACK (ACK) / NACK (Negative ACK) for Hybrid Automatic Repeat reQuest (HARQ) operation for downlink data, Channel Quality Indication (CQI) information for channel data for downlink data scheduling The same control information is transmitted in RUs located at both ends of the system band, such as RU # 1 and RU # 50. In most cases, information of data, RACH (Random Access Channel), and other control channels is transmitted in the middle 302 of the system band. The control information transmitted in the first slot 308 of the RU # 1 is repeatedly transmitted through the RU # 50 (311) by frequency hopping in the next slot to obtain the frequency diversity gain. Similarly, the control information transmitted using the first slot 309 of the RU # 50 is repeatedly transmitted through the RU # 1 310 by frequency hopping in the next slot.

In one RU, several control channels are transmitted by Code Domain Multiplexing (CDM). 4 shows the CDM structure of the control channels in detail.

Referring to FIG. 4, ACKCH # 1 and ACKCH # 2 allocated to different UEs transmit corresponding ACK / NACK signals using the same Zadoff-Chu (hereinafter referred to as ZC) sequence for each LB. The symbols of the ZC sequence 412 applied to ACKCH # 1 are s ₁ , s ₂ ,... , symbols of the ZC sequence 414 transmitted in the order of s ₁₂ and applied to ACKCH # 2 are s ₃ , s ₄ ,... , s ₁₂ , s ₁ , s ₂ . That is, the ZC sequence applied to ACKCH # 2 is cyclically shifted by 2 symbols of the ZC sequence of ACKCH # 1. (Δ (Delta) = 2 symbols) ZC sequences having cyclic shift values 0 (Zero) 408 and Δ (Delta) 410 are orthogonal to each other. By setting the difference between the cyclic shift values 408 and 410 to be larger than the maximum transmission delay of the wireless transmission path, orthogonality between the channels can be maintained.

The corresponding ZC sequences of ACKCH # 1 and ACKCH # 2 are multiplied by b ₁ and b _2, which are ACK / NACK symbols to be transmitted for each LB. Due to the orthogonality of the ZC sequences, even when ACKCH # 1 and ACKCH # 2 are transmitted at the same slot timing in the same RU, the base station receiver can detect b ₁ and b ₂ , which are ACK / NACK symbols of the two channels, without mutual interference, respectively. have. In this case, in the LBs 405 and 406 located in the middle of the slot, a reference signal (RS) for channel estimation is transmitted when the ACK / NACK symbols are detected. The RS is also CDM transmitted by the corresponding ZC sequence in the same manner as the control information of ACKCH # 1 and ACKCH # 2. In FIG. 4, b ₁ and b ₂ are repeated over several LBs in order to allow a terminal located at the cell boundary to transmit a sufficient ACK / NACK signal to the base station.

Similarly, the CQI channel transmits one modulation symbol for each LB, and different CQI channels may be CDM by applying ZC sequences having different cyclic shift values. In the uplink, in addition to the ACK / NACK channel and the CQI channel, there are a scheduling request channel (hereinafter referred to as SR) and an RACH for requesting uplink data transmission to the base station. In an orthogonal multiple access based system such as OFDM and SC-FDMA, the amount of available resources is limited, so if too many resources are used for control channel transmission, there is not enough resources for data transmission. Therefore, it is important to optimize resources for control channel transmission.

The present invention provides an uplink control channel transmission and reception method and apparatus for efficiently using uplink resources in a wireless communication system.

The present invention provides a transmission and reception method and apparatus for improving resource use efficiency of a control channel for transmitting only one information symbol.

The present invention provides a method and apparatus for increasing the number of control channels that can be transmitted within a given resource when different numbers of LBs are allocated to the control channel and the RS channel.

The present invention provides a method and apparatus for efficiently using resources by transmitting control channels and RS channels and efficiently allocating other resources to other control channels, particularly control channel transmissions that are transmitted aperiodically upon event occurrence. to provide.

According to a preferred embodiment of the present invention, there is provided a method of transmitting uplink control channels in a wireless communication system using at least one first control channel using coherent modulation and non-coherent modulation. Control information symbols to be transmitted through control channels including at least one second control channel are long for each symbol of orthogonal sequences having different indices having the same length, for code division multiplexing (CDM) of the control channels. Combining each block (LB) and combining control information symbols combined with the orthogonal sequences with a ZC (Zadoff Chu) sequence cyclically shifted to at least one cyclic shift value allocated to a terminal for CDM between users; Generating a control channel signal and transmitting the control channel signal through a frequency resource unit allocated for the control channels; In that it comprises the step of transmitting to the features.

According to a preferred embodiment of the present invention, in the apparatus for transmitting uplink control channels in a wireless communication system, at least one first control channel using coherent modulation and non-coherent modulation are used. Control information symbols to be transmitted through control channels including at least one second control channel, and for each symbol of orthogonal sequences having the same length and different indices for code division multiplexing (CDM) of the control channels; ZC (Zadoff Chu) cyclically shifted control channel generators for each long block (LB) and control information symbols combined with the orthogonal sequences to at least one cyclic shift value assigned to a terminal for CDM between users A ZC sequence combiner for combining a sequence to generate a control channel signal, and assigning the control channel signal for the control channels And a transmitter for transmitting to the base station via the frequency resource unit.

According to a preferred embodiment of the present invention, in a method of receiving uplink control channels in a wireless communication system, at least one signal allocated to a terminal for CDM between users is configured to receive a signal received through a frequency resource unit allocated for control channels. Acquiring a control channel signal by demultiplexing using a ZC (Zadoff Chu) sequence cyclically shifted to a cyclic shift value, and having the same length and different indices for code division multiplexing (CDM) of the control channels. By demultiplexing the control channel signal using orthogonal sequences, at least one first control channel using coherent modulation and at least one second control channel using non-coherent modulation And detecting the control information symbols.

According to a preferred embodiment of the present invention, in the apparatus for receiving uplink control channels in a wireless communication system, at least one signal allocated through a frequency resource unit allocated for control channels to a terminal for CDM between users is provided. A first correlator for obtaining a control channel signal by demultiplexing by using a ZC (Zadoff Chu) sequence cyclically shifted to a cyclic shift value, and a same length and different index for code division multiplexing (CDM) of the control channels By demultiplexing the control channel signal using orthogonal sequences having at least one, the at least one first control channel using synchronous modulation and the at least one second control using non-coherent modulation And control channel receivers for detecting control information symbols of the channel.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. The following terms are defined in consideration of the functions of the present invention, and may be changed according to the intentions or customs of the user, the operator, and the like. Therefore, the definition should be based on the contents throughout this specification.

Further, in describing the embodiments of the present invention in detail, an OFDM-based cellular wireless communication system, in particular, the 3GPP EUTRA standard will be the main target, but the main subject of the present invention is another technical background and channel type. The communication system can be applied with a slight modification without departing from the scope of the present invention without departing from the scope of the present invention, which will be determined by those skilled in the art.

The main subject of the present invention is to provide a method and apparatus for transmitting and receiving a control channel capable of optimizing the amount of resources used for uplink control channel transmission in a wireless communication system. In particular, the proposed technique uses only one modulation symbol such as binary phase shift keying (BPSK), quadrature phase shift keying (QPSK), or on-off keying (OOK) to control one or two bits of control information such as ACK / NACK and SR. It can be usefully applied when transmitting by using. In addition, when the terminal allocates resources for a control channel transmitted only when necessary, such as an SR channel, it may be usefully applied.

When a channel resource of a channel transmitted according to an event occurrence situation such as an SR channel is dedicated to each UE, a lot of uplink resources may be consumed as compared to the frequency of occurrence of traffic of the channel. Thus, the present invention efficiently multiplexes the uplink ACK / NACK channel continuously generated according to the downlink data and the SR channel generated aperiodically depending on the situation of the UE within the frequency resource for transmitting the control channel. We propose a control channel multiplexing technique that can improve uplink resource usage efficiency. In the present specification, the present invention will mainly be described for the ACK / NACK channel and the SR channel, but the following description may be applied to the case of other control channels as well.

The following embodiments describe in detail the uplink control channel transmission technique proposed by the present invention.

<< first embodiment >>

5 is a diagram illustrating a multiplexing method of an ACK / NACK channel and an SR channel according to the first embodiment of the present invention, and the subject of the present invention is not limited to the ACK / NACK and SR channels. Describe the technique.

FIG. 5 shows a structure in which five control channels 500 to 504 are multiplexed in one RU during one slot of 0.5 ms. That is, three controls for transmitting one bit (1-bit) control information by applying two ACKCH # 1 and # 2 (500,501) and synchronous non-coherent modulation. Non-coherent signaling control channels (NCCCH) # 1, # 2, # 3 (502, 503, 504) are shown. The ACKCH # 1 500 and the ACKCH # 2 502 transmit RS signals for channel estimation in the second and sixth LBs (hereinafter referred to as RS LBs) 511, 512 and 513 and 514, respectively, and control the remaining LBs (hereinafter referred to as control). ACK / NACK symbols 515 are transmitted in the information LBs, and the NCCCHs 502, 503, 504 transmit only control information in the 1st, 3rd, 4th, 5th, and 7th LBs.

ACKCH # 1 500 and ACKCH # 2 501 apply the same cyclic shift value? 510 to the ZC sequences transmitted in each LB. In addition, the same cyclic shift value 510 is applied to the LBs 511 to 514 for transmitting the RS signal between the two channels 500 and 501. In FIG. 5, the channels are multiplexed on a slot basis, but as shown in FIG. 3, the control channels are multiplexed on a subframe basis and frequency hopping may be applied between slots. There is no restriction on.

Signals multiplexed with a ZC sequence of ACKCH # 1 500 and ACKCH # 2 501 for orthogonal detection of b ₁ and b ₂ , which are ACK / NACK symbols transmitted on the two channels 500 and 501, Orthogonal sequences {S _{m, n} } of different index m of length N (n is a sequence symbol index, sequence symbols of n = 1, ..., N) 516 are applied in LB units. That is, orthogonal sequences of different indices are used for each ACKCH, and the symbols of each orthogonal sequence are combined with ACK / NACK symbols for each LB. As an example, a Fourier sequence such as Equation 1 below may be used as the orthogonal sequence.

The Fourier sequence satisfies mutual orthogonality among sequences of different index m, and N = 5 in the structure shown in FIG. As the orthogonal sequence, other sequences of length 5, such as ZC (Zadoff-Chu), GCL (Generalized Chirp-Like) sequences, etc., may be used in addition to the Fourier sequence.

In the example of FIG. 5, symbols of a sequence of length 5 having indexes 1 and 2 are applied to signals of ACKCH # 1 and ACHCH # 2 for each LB. Specifically, the ACKCH # 1 and the ACK / NACK symbol b The first symbol of the _first and once Fourier sequence of ACKCH # 2 ACHCH # 1 to each symbol of the ZC sequence that is common to the first LB (520) of ACKCH # 1 S _1,1 is multiplied. Similarly, in the first LB 521 of ACKCH # 2, each symbol of the ZC sequence is multiplied by the ACK / NACK symbol b2 of ACHCH # ₂ and the first symbol S2,1 of the Fourier sequence ₂ .

Meanwhile, since there are two RS LBs 511 to 514 in one slot, Walsh sequences of different indexes of length 2 in the RS LBs 511 to 514 are transmitted to ACKCH # 1 500 and ACKCH # 2 (501). Specifically, the first symbol W _0,1 of the Walsh sequence having index 0 is used in the second LB 511 of ACKCH # 1, and the second symbol of the Walsh sequence having index 0 is used in the sixth LB 512 of ACKCH # 1. The symbol W _0,2 is used, and in the second LB 513 of ACKCH # 2, the first symbol W _1,1 of the Walsh sequence of index 1 is used, and in the second LB 514 of ACKCH # 2, the index 1 is used. The second symbols W _1,2 of the in Walsh sequence are used.
As described above, when ACKCH # 1 500 and ACKCH # 2 501 are multiplexed using ZC sequences 516 and Walsh sequences 517, a method of detecting b ₁ and b ₂ without mutual interference is illustrated in FIG. A base station receiver device of 10 will be described later.

As described above, when the ZC sequence of the same cyclic shift value 510 is applied to the ACKCH # 1 500 and the ACKCH # 2 501, since the orthogonal sequence {S _m , _n } has a length of 5, three Orthogonal sequences may further be used. However, since there are only two LBs capable of transmitting RSs, when applying the same ZC sequence to control information LBs, it is possible to generate additional RS signals in addition to ACKCH # 1 500 and ACHCK # 2 501 There is no.

Therefore, the remaining three orthogonal sequences {S _{m, n} } (m = 3,4,5) applied to the ACK / NACK channels 500 and 501 are used for transmission of additional control channels applying an asynchronous modulation scheme. do. That is, in FIG. 5, NCCCH # 1 to # 3 (502, 503, 504) transmit corresponding control information using only other LBs without using RS LBs. For example, NCCCH # 1 502 repeatedly transmits modulation symbol b ₃ of the corresponding control information in five LBs. Five times of orthogonal sequence {S _{3 , n} } (n = 1,…, 5) of index 3 is transmitted. The symbols are multiplied by the modulation symbols of the five LBs respectively. Similarly, NCCCH # 2 503 and NCCCH # 3 504 repeatedly transmit corresponding modulation symbols b ₄ and b ₅ in five LBs, and the remaining two orthogonal sequences {S _{4 , n} } and {S _{5 ,} The symbols of _n } are multiplied by the signals per LB. Since RS is not transmitted in the NCCCHs, 1-bit modulation symbols are transmitted by applying an asynchronous modulation scheme such as OOK. For example, in the NCCCHs, control information such as SR or CQI may be transmitted in the form of 1-bit modulation symbol. Thus, by multiplexing the ACKCHs and NCCCHs as described above, it is possible to transmit five control channels orthogonally to each other, while applying the same cyclic shift value ZC sequence.

Meanwhile, as shown in FIG. 5, in addition to the SR transmitted through the NCCCH configured of five LBs, a cyclic shift value different from the cyclic shift value Δ 510 is applied, and an orthogonal sequence of length 7 is applied to the seven LBs in the slot. It is also possible to configure the NCCCH and transmit the SR. Unlike the FIG. 5, the SR channel is not multiplexed with the ACK / NACK channel and is only multiplexed between the SR channels. Since the applied orthogonal sequence length is 7, a total of 7 SR channels can be created for cyclic shift values. have.

In general, in the case of SR, detailed information such as buffer status and idle power information of the UE is indicated using a plurality of bits. However, for example, only one or two bits are used as the SR to provide a simple information to the BS. In this case, the base station may further allocate resources for transmitting detailed scheduling request information to the terminal that has transmitted the SR. A CQI channel for informing downlink channel state information to a base station also generally requires a large number of information bits.However, when one resource is continuously allocated to one terminal, such as in case of Voice over Internet Protocol (VoIP) traffic, By using only one bit of CQI information, the terminal informs the base station of the channel only when the channel condition of the terminal is not good. The amount of resources needed can be minimized.

In another embodiment, ACK / NACK information may be transmitted over the NCCCH. That is, in case of a downlink data service in which one of NACK or ACK is frequently generated, an OFF is assigned to a NACK or ACK signal with a high frequency and the terminal transmits an ACK / NACK signal to the OOK through NCCCH. It is possible to reduce the average power used for the transmission of the / NACK signal.

In another embodiment, when the base station sends a response message that the base station has successfully received the request message of the RACH in response to the RACH from the terminal, NCCCH is also used to transmit ACK / NACK information for the response message. It can be usefully used. When a plurality of terminals simultaneously transmit the same preamble code through the RACH, the base station transmits a response message indicating that the preamble code has been successfully received to one specific terminal of the plurality of terminals. At this time, a specific NCCCH determined according to the preamble code is allocated for ACK / NACK transmission for the response message using OOK, and only the specific terminal receiving the response message receives the ACK signal through the assigned NCCCH. send. At this time, the remaining terminals that transmit the preamble do not receive the response message or determine that the response message is for another terminal and do not transmit any signal. Therefore, the base station can distinguish the ACK from the specific terminal.

As described above, by using NCCCHs for transmission of control information transmitted only when a terminal is needed, performance degradation due to interference between adjacent cells caused by multiplexing control channels to the same RU is minimized. In addition, while preventing an excessive amount of uplink resources from being allocated to the control channels as compared with the transmission frequency of the control information, it is possible to exclusively allocate resources to each terminal to prevent mutual interference.

6 is a flowchart illustrating a procedure of transmitting control information by a terminal according to the first embodiment of the present invention.

Referring to FIG. 6, in step 600, a UE performs resource (RU, slot, ZC sequence and cyclicity) for asynchronous signaling control channels, that is, NCCCHs, through high layer signaling or L1 / L2 signaling from a base station. Information such as shift value). In step 601, the terminal checks whether an event for signaling the control information or the like has occurred or is a transmission period. If the control information is to be signaled, the terminal generates a modulation symbol indicating the control information in step 602. As an example, an event for transmitting an SR over an NCCCH may include data to be transmitted in a buffer of a terminal, and an event for transmitting a CQI, when a channel state changes compared to previously informed channel state information. There is. In step 603, the UE repeats the modulation symbol by the number of LBs of the allocated NCCCH resources, and in step 604, multiplies the allocated ZC sequence by each symbol of the modulation symbol and orthogonal sequence by LB and then allocates the slot at the allocated slot timing. The transmitted RU.

In generalizing the uplink control channel multiplexing structure illustrated in FIG. 5, when multiplexing control channels using M RS LBs and N control information LBs, one RU is used as a coherent modulation scheme. 7 illustrates a method of generating ACK / NACK channels and control channels transmitted in an asynchronous modulation scheme. Where N> M.

Referring to FIG. 7A, when an orthogonal sequence of length M is applied in LB units to M RS LBs 700, a total of M orthogonal RS channels 704 are generated. Similarly, when the orthogonal sequence of length N is applied to the N control information LBs 701 in units of LBs (703), a total of N orthogonal control information channels 705 are generated. M = 2 and N = 5 when applied to the structure of FIG. 5. By the M orthogonal RS channels 704, M out of N control information channels 705 are used as synchronization channel 706 and the remaining (NM) control information channels are asynchronous modulation signaling channel ( NCCCHs) 707.

The above-described process describes the case where the control channels 704 ˜ 707 have the same cyclic shift value with the same ZC sequence. Additional control channels may be orthogonalized by applying different cyclic shift values to the same ZC sequence in the LB. As shown in FIG. 7B, K cyclic shift values among the maximum L different cyclic shift values 711 applicable to the ZC sequence applied within the LB of one RU are shown in FIG. 5. If applied to the same ACKCH and NCCCH, (LK) cyclic shift values may be used for the multi-bit CQI channel 716. Then, M synchronization modulation control channels 706 are generated for each of the K cyclic shift values, so that up to K × M ACK / NACK transmission synchronization modulation control channels 714 are generated in one RU.

Similarly, up to K × (N-M) asynchronous modulation control channels 715 are generated in one RU for (N-M) asynchronous modulation control channels 707 for each K cyclic shift value. If the base station exclusively allocates the K × (NM) asynchronous modulation control channels 715 to each terminal explicitly or implicitly, each terminal may control the allocated control whenever an event occurs. One-bit control information can be transmitted through the channel without interference with other terminals. As an example, if N = 7, M = 2, and K = 12, a total of 60 SR channels may be generated in one RU. When the 60 SR channels are allocated to each UE, each UE generates a resource (RU, slot, ZC sequence and cyclic shift value) of the pre-allocated SR channel whenever data to be transmitted is generated in a buffer and needs to be scheduled by the base station. Etc.) may be used to transmit the SR information to the base station.

8 shows another example of an ACK / NACK channel and an SR channel multiplexing according to a preferred embodiment of the present invention. Here, only one RS LB 810 exists in one slot, and control information is transmitted to the other six LBs.

Referring to FIG. 8, since only one RS LB 801 exists in one slot, there is one synchronous modulation control channel ACKCH # 1 800 for a given cyclic shift value Δ 811 of the ZC sequence. Since six LBs can transmit control information, when the orthogonal sequence {S _{m, n} } of length 6 having a different index for each NCCCH is applied in LB units, a total of five NCCCHs 801 to 805 are generated. do. This is the case when M = 1 and N = 6. Thus, when cyclic shift for 12 ZC sequences is possible in a slot of one RU, up to 12 ACK / NACK channels and up to 60 NCCCHs are generated.

9 illustrates the structure of a terminal transmission apparatus according to a preferred embodiment of the present invention.

Referring to FIG. 9, an ACK / NACK symbol is generated in the ACK / NACK symbol generator 900 for an ACKCH, and the ACK / NACK symbol is repeated in the repeater 902 by the number of allocated LBs in one slot, and then ACK / NACK symbol is generated. The NACK orthogonal sequence multiplier 903 multiplies each symbol of the orthogonal sequence in units of LBs. The ACK / NACK symbol generator 900 is controlled by the controller 910 to determine when to generate an ACK / NACK symbol. The RS signal for the ACK / NACK symbol is generated by an RS symbol generator 901, and the RS signal is multiplied by each symbol of the corresponding orthogonal sequence in LB units by an RS orthogonal sequence multiplier 904, and then a multiplexer (MUX). 905 is time domain multiplexed (TDM) with the output of the ACK / NACK orthogonal sequence multiplier 903. Here, the multipliers 903, 904, and 913 are apparatuses for generating input symbols into multiplexed signals according to orthogonal sequences, and may be replaced with other apparatuses that perform equivalent functions.

Similarly for the SR channel, the SR symbol generated by the SR symbol generator 911 is repeated in the repeater 912 and multiplied by each symbol of the orthogonal sequence in LB units by the orthogonal sequence multiplier 913, followed by the MUX 905. Is entered. Since the SR channel and the ACK / NACK channels are determined according to whether uplink and downlink data are transmitted, the timing at which the channels are generated in one terminal is independent of each other. If only one channel signal is present, the channel signal is output as it is through the MUX 905. The signal multiplexed in the MUX 905 under the control of the controller 910 is multiplied by a ZC sequence having a cyclic shift value assigned to the terminal for the user-to-user CDM in the ZC sequence multiplier 906, thereby combining control channels. Generated as a signal. Similarly, the multiplier 906 is a device for generating a signal multiplexed by the MUX 905 as a CDM multiplexed signal according to a corresponding ZC sequence, and may be replaced by another device that performs an equivalent function.
The combined control channel signal is formed in LB units in an LB formatter 907 and then passes through an FFT 908 for SC-FDMA transmission and then corresponds to an IFFT 909 corresponding to an RU allocated for control channels. ) Is mapped to the input. The IFFT 909 performs IFFT conversion on the input from the FFT 908 and transmits it on the corresponding carrier.

10 illustrates a structure of a base station receiver according to a preferred embodiment of the present invention. Here, a structure of a receiver for detecting an SR channel and an ACK / NACK channel signal from a UE is shown.

Referring to FIG. 10, the receiver extracts a signal of an RU including control information of a corresponding UE from a received signal through the FFT 1000 and the IFFT 1001. In order to detect the control information of the terminal from the extracted signal, the ZC sequence correlator 1002 extracts a signal of each LB by correlating the received signal with the ZC sequence applied to the control channel of the terminal. The extracted signals are obtained by multiplying control information symbols of a control channel by symbols of an orthogonal sequence for the control channel and reflecting fading in a wireless channel.

By the control of the controller 1010, the extracted symbols are separated into signals for each control channel through the de-multiplexer (DEMUX) 1003. For example, in the SR channel, the extracted SR channel signal in LB unit is correlated with symbols of an orthogonal sequence allocated to the SR channel in the SR orthogonal sequence correlator 1010. At this time, signals of other control channels transmitted from other terminals using the ZC sequence of the same cyclic shift value as the SR channel are removed by orthogonality of the orthogonal sequence. The SR symbol detector 1011 determines that the terminal transmits the SR symbol when the correlation value, which is the output of the correlator 1010, exceeds a predetermined threshold. Since an asynchronous modulation scheme such as OOK is applied to the SR channel and the SR channel is transmitted aperiodically when the terminal is needed, the SR symbol detector 1011 may determine whether the terminal transmits the SR by the threshold check. do.

In the case of the ACK / NACK channel, the ACK / NACK channel signal passing through the DEMUX 1003 is channel-compensated by the channel compensator 1004 and then is orthogonal to the ACK / NACK channel orthogonal sequence correlator 1005 assigned to the ACK / NACK channel. Correlations with the symbols of the sequence are taken to remove other channel signals, and the ACK / NACK symbol detector 1007 detects ACK / NACK symbols from the output of the correlator 1005. In the case of the ACK / NACK channel, a channel compensator 1004 is required because synchronous modulation such as BPSK and QPSK is applied.

The channel information necessary for the channel compensation operation of the channel compensator 1004 is provided from the channel information generator 1008. That is, the RS orthogonal sequence correlator 1006 correlates with another channel signal by correlating with the symbols of the orthogonal sequence allocated to the RS signal output from the DEMUX 1003 by the control of the controller 1010 at the timing of receiving the RS signal. The channel information generator 1008 generates channel information indicating a channel impulse response by performing channel estimation using the output of the correlator 1006 and provides the channel information to the channel compensator 1004.

<< 2nd Example >>

The second embodiment of the present invention relates to a method of additionally operating another type of channel for SR transmission in addition to sending the SR to the NCCCH as shown in FIG. 5 in the uplink.

Specifically, when one of the channel quality values transmitted through the CQI channel is reserved for the purpose of SR, and the UE wants to send the SR to the base station, the CQI is set to the reserved value at the timing of transmitting the CQI and transmitted. The base station interprets that the terminal transmits the SR when the channel quality value of the CQI received from the terminal is the reserved value. Alternatively, one field for sending an SR is defined in the CQI channel, and when the UE wants to transmit the SR, the field is set when the CQI channel is transmitted.

Two channels of NCCCH and CQI channel can be set as above, and the CQI channel should be used for SR transmission without allocating NCCCH for SR transmission to a UE which frequently uses CQI channel periodically. Can be. As an example, since a terminal in a stationary state or moving at a slow speed sends a CQI frequently, NCCCH allocation for SR transmission may not be necessary. On the other hand, when the terminal sending a CQI (Seldom) uses the CQI channel for SR transmission, SR transmission from the terminal may not occur quickly, which may affect uplink data scheduling. Therefore, in this case, it is preferable to allocate one NCCCH exclusively for the UE for SR transmission.

As described above, according to the CQI channel transmission situation of each terminal, by differently allocating a channel for transmitting the SR, the number of NCCCHs required for SR transmission in the system, that is, the amount of resources required can be reduced.

Thus, if all the terminals in the system frequently transmit the CQI channel, NCCCH for SR transmission may not be required at all, and vice versa, a large number of NCCCH may be needed. The base station may inform the transmission period and resources of the CQI channel and which channel of the CQI channel or the NCCCH through the upper signaling for each terminal.

Meanwhile, one terminal may use both NCCCH and CQI channels for SR transmission. When the terminal is allocated to use both channels for SR transmission, the terminal needs to schedule the base station so that the data to be transmitted is generated in the buffer, and then the terminal may arrive at one of the first channels that can arrive after the NCCCH or CQI channel. After transmitting the SR information, the base station may send a scheduling command for uplink data transmission to the terminal according to the detected SR information. When either one of the two channels overlaps the ACK / NACK channel transmission timing from the terminal, SR information is transmitted to an NCCCH or CQI channel to be transmitted at a different timing from the ACK / NACK channel in order to satisfy the short-carrier transmission characteristic in uplink. Can be transmitted.

While the present invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments, but is capable of various modifications within the scope of the invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined by the scope of the appended claims, and equivalents thereof.

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

The present invention improves the efficiency of uplink resource usage by efficiently multiplexing the ACK / NACK channel resource continuously generated according to the downlink data and the SR channel resource generated aperiodically depending on the situation of the UE. This can lead to an increase in the resources available for data transmission, contributing to system capacity improvement.

Claims (24)

A method of transmitting uplink control channels in a wireless communication system, Control information symbols to be transmitted through control channels including at least one first control channel using coherent modulation and at least one second control channel using non-coherent modulation, Combining each symbol and long block (LB) of orthogonal sequences having different indices having the same length for code division multiplexing (CDM) of the control channels; Generating a control channel signal by combining control information symbols combined with the orthogonal sequences with a ZC (Zadoff Chu) sequence cyclically shifted to at least one cyclic shift value assigned to a terminal for CDM between users; And transmitting the control channel signal to a base station through a frequency resource unit allocated for the control channels. The method of claim 1, wherein the second control channel is a scheduling request (SR) symbol for requesting uplink data transmission to the base station, a channel quality indication (CQI) symbol indicating a downlink channel state, and downlink data for And transmitting one of an ACK / NACK symbol, an ACK / ANCK symbol for a response message of a random access channel (RACH), and a control information symbol aperiodically generated by the terminal. The method of claim 2, wherein the SR symbol, The transmission method according to the situation of the terminal characterized in that it is transmitted through the second control channel or using a reserved value of the channel quality indication (CQI) channel. The method of claim 1, wherein the control information symbols of the second control channel are combined with the ZC sequence cyclically shifted to a cyclic shift value different from that of the first control channel. The method of claim 1, wherein the first control channel carries uplink control information continuously generated according to ACK / NACK symbols or downlink data for downlink data. The method of claim 1, wherein the second control channel, Carries the RS signal through at least one LB allocated to the RS signal for channel estimation in a slot composed of a plurality of long blocks (LBs), The RS signal is combined with each symbol of one Walsh sequence allocated to each second control channel among the Walsh sequences having different indices having the same length in LB units and then at least one cyclic shift value allocated to the terminal. And a cyclically shifted ZC sequence. In the apparatus for transmitting uplink control channels in a wireless communication system, Control information symbols to be transmitted through control channels including at least one first control channel using coherent modulation and at least one second control channel using non-coherent modulation, Control channel generators for combining the respective symbols and long blocks (LB) of orthogonal sequences having the same length and different indices for code division multiplexing (CDM) of the control channels; A ZC sequence combiner for generating control channel signals by combining control information symbols combined with the orthogonal sequences with a ZC (Zadoff Chu) sequence cyclically shifted to at least one cyclic shift value allocated to a terminal for CDM between users; , And a transmitter for transmitting the control channel signal to a base station through a frequency resource unit allocated for the control channels. 8. The method of claim 7, wherein the second control channel is a scheduling request (SR) symbol for requesting uplink data transmission to the base station, a channel quality indication (CQI) symbol indicating a downlink channel state, and And one of an ACK / NACK symbol, an ACK / ANCK symbol for a response message of a random access channel (RACH), and a control information symbol aperiodically generated by the terminal. The method of claim 8, wherein the SR symbol, The transmission apparatus according to the situation of the terminal, characterized in that the transmission is transmitted through the second control channel or using a reserved value of the channel quality indication (CQI) channel. 8. The apparatus of claim 7, wherein the control information symbols of the second control channel are combined with the ZC sequence cyclically shifted to a cyclic shift value different from the first control channel. The apparatus of claim 7, wherein the first control channel carries uplink control information continuously generated according to ACK / NACK symbols or downlink data for downlink data. The method of claim 7, wherein the second control channel, Carries the RS signal through at least one LB allocated to the RS signal for channel estimation in a slot composed of a plurality of long blocks (LBs), The RS signal is combined with each symbol of one Walsh sequence allocated to each second control channel among the Walsh sequences having different indices having the same length in LB units and then at least one cyclic shift value allocated to the terminal. And a cyclically shifted ZC sequence. In the method of receiving uplink control channels in a wireless communication system, Control channel signal by demultiplexing a signal received through a frequency resource unit allocated for control channels using a ZC (Zadoff Chu) sequence cyclically shifted to at least one cyclic shift value allocated to a terminal for CDM between users The process of acquiring At least one first using coherent modulation by demultiplexing the control channel signal using orthogonal sequences having the same length and different indices for code division multiplexing (CDM) of the control channels And detecting control information symbols of at least one second control channel using non-coherent modulation with the control channel. 15. The method of claim 13, wherein the second control channel includes a scheduling request (SR) symbol, a channel quality indication (CQI) symbol indicating a downlink channel state, an ACK / NACK symbol for downlink data, and a random access channel (RACH). And one of an ACK / ANCK symbol for a response message and a control information symbol aperiodically generated by the need of the terminal. The method of claim 14, wherein the SR symbol, The reception method according to claim 1, wherein the transmission is performed through the second control channel or by using a reserved value of a channel quality indication (CQI) channel. The method of claim 13, wherein the obtaining of the control channel signal comprises: Demultiplexing the received signal using the ZC sequence cyclically shifted to a cyclic shift value different from the first control channel to obtain a signal including the control information symbols of the second control channel Reception method to do. The method of claim 13, wherein the first control channel carries uplink control information continuously generated according to ACK / NACK symbols or downlink data for downlink data. The method of claim 13, wherein the second control channel, Carries the RS signal through at least one LB allocated to the RS signal for channel estimation in a slot composed of a plurality of long blocks (LBs), The RS signal is detected by demultiplexing the control channel signal using each symbol of one Walsh sequence assigned to each second control channel among Walsh sequences having different indices having the same length. Way. An apparatus for receiving uplink control channels in a wireless communication system, Control channel signal by demultiplexing a signal received through a frequency resource unit allocated for control channels using a ZC (Zadoff Chu) sequence cyclically shifted to at least one cyclic shift value allocated to a terminal for CDM between users A first correlator for obtaining At least one first using coherent modulation by demultiplexing the control channel signal using orthogonal sequences having the same length and different indices for code division multiplexing (CDM) of the control channels And control channel receivers for detecting control information symbols of at least one second control channel using non-coherent modulation with the control channel. 20. The method of claim 19, wherein the second control channel includes a scheduling request (SR) symbol, a channel quality indication (CQI) symbol indicating a downlink channel state, an ACK / NACK symbol for downlink data, and a random access channel (RACH). And one of an ACK / ANCK symbol for a response message and a control information symbol aperiodically generated by the need of the terminal. The method of claim 20, wherein the SR symbol, The reception device, characterized in that transmitted through the second control channel or the reserved value of the channel quality indication (CQI) channel according to the situation of the terminal. The method of claim 19, wherein the first correlator, Demultiplexing the received signal using the ZC sequence cyclically shifted to a cyclic shift value different from the first control channel to obtain a signal including the control information symbols of the second control channel Receiver device. 20. The receiver of claim 19, wherein the first control channel carries uplink control information continuously generated according to ACK / NACK symbols or downlink data for downlink data. The method of claim 19, wherein the second control channel, Carries the RS signal through at least one LB allocated to the RS signal for channel estimation in a slot composed of a plurality of long blocks (LBs), The RS signal is detected by demultiplexing the control channel signal using each symbol of one Walsh sequence assigned to each second control channel among Walsh sequences having different indices having the same length. Device.

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