KR20080073616A - Method and apparatus for transmitting and receiving uplink control signalling channels in wireless communication systems - Google Patents

Abstract

A transceiving method of an uplink control channel in a wireless communication system and a device thereof are provided to efficiently multiplex SR(Scheduling Request) channel resources and ACK/NACK channel resources continuously generated according to downlink data, thereby improving uplink resource usage efficiency. A terminal receives notification on resource information about NCCCHs(Non-coherent signaling Control Channels) to be used when the terminal transmits 1-bit control information(600). The terminal confirms whether an event occurs(601). If so, the terminal generates a 1-bit modulation symbol indicative of the control information(602). The terminal repeats the modulation symbol as many as the number of LBs(Long Blocks) of assigned NCCCH resources(603). The terminal multiplies the modulation symbol and each symbol of orthogonal sequence by each symbol of ZC sequence in LB unit, and sends the symbols at assigned slot timing(604).

Description

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

1 illustrates the structure and slot structure of a typical SC-FDMA based transmitter.

2 is a diagram illustrating an example of a structure of resource division in the frequency and time domain in a typical SC-FDMA system.

3 shows an example of channel allocation of a control channel and a data channel in the 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.

In recent mobile communication systems, orthogonal frequency division multiple access (OFDM), or a similar method, is useful for high-speed data transmission in a wireless channel, or a single carrier frequency division multiple access (single carrier). Multiple Access (hereinafter referred to as SC-FDMA) is actively being studied.

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. Accordingly, when the SC-FDMA is applied to a mobile communication system, cell coverage may be improved due to lower PAPR than OFDM technology.

FIG. 1 illustrates a structure and slot structure of a typical SC-FDMA transmitter, and includes a fast Fourier transform (FFT) 103 and an inverse fast Fourier transform (IFFT). 105 is shown.

Referring to FIG. 1, the difference between OFDM and SC-FDMA is described in terms of a transmitter structure. In addition to the IFFT 105 used for multi-carrier transmission in an OFDM transmitter, the FFT 103 uses an IFFT 105 in an SC-FDMA transmitter. In addition to the shear. 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 Long Block (LB), and 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) through 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 reason why the SC-FDMA transmission signal has a lower PAPR than the OFDM signal is that the signal processed through the FFT 103 and the IFFT 105 as described above has a single carrier characteristic.

2 illustrates an example of resource division 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 consists of twelve subcarriers 203 and may have fourteen LBs 204, which is a scheduling unit of basic data transmission. The fourteen LBs 204 gather to form one 1 ms subframe 205.

FIG. 3 illustrates resource allocation for control channel and data channel transmission in the EUTRA uplink according to the resource partitioning structure of FIG. 2.

Referring to FIG. 3, an ACK (Acknowledge) / NACK (Negative ACK) for a hybrid automatic repeat reQuest (HARQ) operation on downlink data, channel quality indication (CQI) information, which is channel state information for downlink data scheduling, and the like. 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, data, information of the random access channel (RACH) and other control channels are transmitted in the middle 302 of the system band. The control information transmitted in the first slot 308 of RU # 1 is repeatedly transmitted through RU # 50 311 by frequency hopping in the next slot, thereby obtaining frequency diversity gain. Similarly, control information transmitted using the first slot 309 of RU # 50 is repeatedly transmitted through 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 terminals 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 a value larger than the maximum transmission delay of the radio transmission path, orthogonality between 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. Like the control information of ACKCH # 1 and ACKCH # 2, the RS is also transmitted by CDM according to the corresponding ZC sequence. Meanwhile, in FIG. 4, b ₁ and b ₂ are repeated over several LBs, respectively, in order to allow a terminal located at a cell boundary to transmit an ACK / NACK signal having sufficient power 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, in a method for transmitting an uplink control channel in a wireless communication system,

Multiplying the control information symbols to be transmitted through control channels by orthogonal sequences for long division (LB) units for code division multiplexing (CDM) of the control channels;

And multiplying the control information symbols multiplied by the orthogonal sequences with a ZC (Zadoff Chu) sequence cyclically shifted by a cyclic shift value assigned to a terminal and transmitting the same to a base station through an assigned frequency resource unit.

The control channels may include a first control channel applying asynchronous modulation and a second control channel applying synchronous modulation.

Hereinafter, embodiments of the present invention will be described in detail with the accompanying drawings. In addition, in describing the present invention, when it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted. 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.

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.

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.

The ACKCH # 1 500 and the ACKCH # 2 501 apply the same cyclic shift value Δ 510 to 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) are sequence symbols of 516 multiplied by LB units. As the orthogonal sequence, for example, a Fourier sequence such as Equation 1 below may be applied.

The Fourier sequence satisfies mutual orthogonality among sequences having different indices m, and in the structure shown in FIG. 5, N = 5. As the orthogonal sequence, other sequences of length 5, such as Zadoff-Chu (ZC), Generalized Chirp-Like (GCL) 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 sequentially multiplied with signals of control information LBs of ACKCH # 1 and ACHCH # 2, respectively. More specifically, LB (520) in the ACKCH # 1 and ACKCH # 2 of the first symbol of ACHCH # 1 to each symbol of the ZC sequence that is common to ACK / NACK symbols b ₁ and 1 are Fourier sequences S _1,1 Multiply. Similarly, in the LB 521, each symbol of the ZC sequence is multiplied by the ACK / NACK symbol b ₂ of ACHCH # ₂ and the first symbol S _1,1 of the Fourier sequence 2.

Meanwhile, since there are two RS LBs 511 to 514 in one slot, Walsh sequences having different indices of length 2 in the RS LBs 511 to 514 may include ACKCH # 1 500 and ACKCH. Applies to # 2 (501). As described above, when the ACKCH # 1 500 and the ACKCH # 2 501 are multiplexed using the ZC sequence and the Walsh sequences 517, a method of detecting b ₁ and b ₂ without mutual interference is shown in FIG. 10. The device 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 RS in a slot, when the same ZC sequence is applied to the control information LBs, additional RS signals other than ACKCH # 1 500 and ACHCK # 2 501 may be generated. 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 ZC sequence of the same cyclic shift value.

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 state only when the channel condition of the terminal is not good, and transmits the 1-bit CQI information when necessary to the NCCCH to transmit the CQI information. 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.

As another embodiment, when the base station sends a message indicating that the base station has successfully received the RACH in response to the RACH from the terminal, NCCCH may be usefully used for transmitting ACK / NACK information for the message. . When a plurality of terminals simultaneously transmit the same preamble code through the RACH, when a base station wants to transmit a message indicating that the preamble code has been successfully received to one specific terminal among the plurality of terminals, A specific NCCCH is allocated for ACK / NACK transmission for the message using the OOK, and only the specific terminal receiving the message transmits an ACK signal through the assigned NCCCH. In this case, the remaining terminals that transmit the preamble do not receive the message or determine that the message is for another terminal and do not transmit any signal. Therefore, the base station can receive 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 1 bit control information by a terminal according to the first embodiment of the present invention.

Referring to FIG. 6, in step 600, the UE may transmit resources (RU, slot, ZC) for NCCCHs to be used when the UE transmits 1-bit control information through high layer signaling or L1 / L2 signaling from a base station. Information such as sequence and cyclic shift values). In step 601, the terminal determines whether an event for signaling the control information or the like has occurred or is a transmission period. When the control information is signaled, the terminal generates a 1-bit modulation symbol indicating the control information in step 602. . As an example, an event for transmitting an SR may include data to be transmitted in a buffer of a terminal, and an event for transmitting a CQI may have a change in channel status compared to previously informed channel state information. In step 603, the UE repeats the modulation symbols by the number of LBs of the allocated NCCCH resources, and in step 604, multiplies each symbol of the allocated ZC sequence by each symbol of the modulation symbol and the orthogonal sequence in LB units and then allocates the slot. Transmit using the assigned RU in timing.

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. In the structure of FIG. 5, M = 2 and N = 5. By the M orthogonal RS channels, M out of N control information channels are used as channels 706 for applying synchronous modulation and the remaining (NM) control information channels are asynchronous modulation signaling control channels (NCCHs). 707 is used.

The above-described process is a case in which the control channels 704 ˜ 707 have the same ZC sequence and the same cyclic shift value. Additional control channels may be orthogonalized by applying different cyclic shift values to the same ZC sequence in the LB. Thus, as shown in FIG. 7B, when up to L different cyclic shift values 711 are applicable to the ZC sequence transmitted in the LB of one RU, K cyclic shift values of these are applied. When applied to the ACKCH and NCCCH as shown in FIG. 5, (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 K cyclic shift value, and thus up to K × M ACK / NACK transmission modulation modulation 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, when transmitting ACK / NACK information, an ACK / NACK symbol is generated by the ACK / NACK symbol generator 900, and the ACK / NACK symbol is repeated by the number of LBs in one slot in the repeater 902. Then, each symbol of the orthogonal sequence is multiplied by LB by the ACK / NACK orthogonal sequence multiplier 903. Which ACK / NACK symbol should be transmitted when is controlled by the controller 910. 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.

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 the ZC sequence of the cyclic shift value assigned to the terminal in the ZC sequence multiplier 906 and formed in the LB unit in the LB former 907. After the FFT 908 for SC-FDMA transmission, it is mapped to an IFFT 909 input corresponding to the allocated RU. 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.

If the terminal reserves one of the channel quality values transmitted through the CQI channel to the SR, and the terminal wants to send the SR to the base station, the terminal sets the channel quality value to the reserved value at the timing of transmitting the CQI. And, if the channel quality value received from the terminal is the reserved value may be interpreted that the terminal has transmitted the SR. Alternatively, a field for sending an SR is reserved in the CQI channel, and when the UE wants to transmit the SR, the value of the field may be set accordingly 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. That is, when a terminal is allocated to use both channels for SR transmission, the terminal needs to schedule the base station so that data to be transmitted is generated in a buffer and then to one of the first NCCCH or CQI channels that arrive first. After transmitting the SR information, the base station may send an uplink data transmission scheduling command to the terminal according to the detected SR information. Alternatively, when either one of the two channels overlaps the ACK / NACK channel transmission timing from the terminal, the 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. SR information can be transmitted.

Meanwhile, in the detailed description of the present invention, specific embodiments have been described, but various modifications are possible without departing from the scope of the present invention. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be defined not only by the scope of the following claims, but also by those equivalent to the scope of the claims.

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

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 (5)

A method of transmitting an uplink control channel in a wireless communication system, Orthogonal sequences for code division multiplexing (CDM) of the control channels to transmit control information symbols to be transmitted through control channels including a first control channel applying asynchronous modulation and a second control channel applying synchronous modulation; Multiplying by a long block (LB) unit, The frequency information unit allocated for the control channels by performing code division multiplexing (CDM) by multiplying the control information symbols multiplied by the orthogonal sequences with a ZC (Zadoff Chu) sequence cyclically shifted by a cyclic shift value assigned to a terminal. Transmitting method comprising the step of transmitting to the base station via. The method of claim 1, wherein the first control channel carries 1-bit signaling information generated by an asynchronous modulation method. The transmission method according to claim 1, wherein the first control channel carries uplink control information (SR) generated aperiodically according to a situation of a terminal. The method of claim 1, wherein the second control channel carries continuously uplink control information (ACK / NACK). The method of claim 4, wherein the second control channel, A non-coherent signaling control channel (NCCCH) determined according to the preamble code, carrying an ACK / NACK for a message indicating that the terminal has successfully received the preamble code from the base station in response to the preamble code transmitted through the RACH. Transmission method, characterized in that consisting of.

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