KR20130055469A

KR20130055469A - Method and apparatus for transmisson of uplink time advanced response in wireless communications system

Info

Publication number: KR20130055469A
Application number: KR1020110121232A
Authority: KR
Inventors: 지형주; 한진규; 정경인
Original assignee: 삼성전자주식회사
Priority date: 2011-11-18
Filing date: 2011-11-18
Publication date: 2013-05-28

Abstract

The present invention proposes a method and apparatus for transmitting a control channel for uplink synchronization response of a terminal in a wireless communication system based on an orthogonal frequency division multiple access scheme.
To this end, a synchronization command for time alignment is prepared in a secondary cell, a control channel search area is configured for a synchronization response, and a random access response field of the synchronization command indicates an arbitrary point existing in the control channel search area. Send information to the terminal. Thereafter, when a synchronization signal is received from the terminal, a synchronization response is transmitted at the position indicated by the synchronization command.

Description

Method and apparatus for transmitting uplink sync response in wireless communication system {METHOD AND APPARATUS FOR TRANSMISSON OF UPLINK TIME ADVANCED RESPONSE IN WIRELESS COMMUNICATIONS SYSTEM}

The present invention relates to a control channel transmission method in a wireless communication system, and more particularly, to a method and apparatus for transmitting a control channel for uplink synchronization response of a terminal in an orthogonal frequency division multiplexing (OFDM) communication system. It is about.

Mobile communication systems using wireless communication technology have been developed to provide voice services while guaranteeing user activity. Mobile communication systems are gradually expanding to not only voice but also data services, and now they have evolved to provide high-speed data services. However, in a mobile communication system in which a service is currently provided, a lack of resources and users demand higher speed services, and therefore, a more advanced mobile communication system is required.

In response to these demands, one of the systems being developed as a next-generation mobile communication system, the specification work for Long Term Evolution-LTE (LTE-A) is under way in the 3rd generation partnership project (3GPP). LTE-A is a technology for implementing high-speed packet-based communication having a transmission rate of up to about 1 Gbps. Various techniques are discussed for this purpose, for example, a technique of multiplexing the structure of a network so that a plurality of base stations overlap service in a specific region, or a technique of increasing the number of frequency bands supported by one base station.

When a base station schedules a terminal using a plurality of bands, the terminal is designated one of the plurality of bands as P_cell and the other as S_cell. P_cell means primary cell and S_cell means secondary cell. In addition, the UE may transmit a PRACH (Physical Random Access Channel) signal for uplink synchronization limited to P_cell. This is based on the assumption that if the UE synchronizes with P_cell, the synchronization of the remaining cells is the same as that of P_cell. However, in more advanced systems, this assumption is difficult. Therefore, PRACH for uplink synchronization is transmitted in S_cell and signaling for this is required.

The present invention provides a method and apparatus for transmitting an uplink sync response of a terminal in a wireless communication system.

In addition, the present invention can maintain the uplink synchronization of multiple bands without increasing the complexity of the control channel reception of the wireless communication system,

The present invention also provides a method and apparatus for transmitting and receiving a plurality of bands of uplink synchronization in a wireless communication system using OFDM technology.

In a method for transmitting a control channel for uplink synchronization response of a terminal in a base station of an orthogonal frequency division multiple access communication system according to an embodiment of the present invention, a secondary cell prepares a synchronization command for time alignment and a synchronization response Configuring a control channel search region, transmitting information indicating an arbitrary point existing in the control channel search region to a terminal in a random access response field of the synchronization command, and receiving a synchronization signal from the terminal; Transmitting a sync response at the location indicated by the sync command.

A method for receiving a control channel for uplink synchronization response transmitted from a base station in a terminal of an orthogonal frequency division multiple access communication system according to an embodiment of the present invention includes: resource configuration information for uplink synchronization from the base station to an auxiliary cell; Receiving a synchronization command, Recognizing information on the position that the control channel for the synchronization response is transmitted in the random access response area of the synchronization command, and transmitting a physical random access channel for synchronization in the secondary cell And receiving, by the base station, a synchronization dedicated control channel for the synchronization response channel at a position indicated by the physical dedicated control channel in the control channel search region of the auxiliary cell, and present in the physical dedicated control channel for the synchronization response channel. The synchronization response information may be received from the data channel using scheduling information. It involves.

According to the disclosed embodiment of the present invention, the base station issues a control channel command to the terminal to support uplink synchronization for the S_cell, indicating the position of the control channel for receiving the synchronization response to the control channel command. Allows blind decoding to be received without increasing it. In addition, when the UE has more than one S_cell, even when more than one synchronization task is performed, the synchronization response can be received without increasing blind decoding. This is done by instructing the control channel command for synchronization of the position of the actual transmission in the control channel candidate region for receiving the synchronization response. In addition, when a plurality of terminals perform synchronization at the same time, the resource efficiency is increased by allowing a plurality of terminals to receive a synchronization response at the same location.

1 is a diagram showing an example of a multi-carrier system based on the OFDM scheme;
2 illustrates an example of transmission of an uplink sync response channel in an OFDM system;
3 to 7 show examples of transmission of a response channel for multiple uplink synchronization in an OFDM system;
8 to 12 illustrate examples of control channel transmission for an uplink synchronization response according to each of the first to fourth embodiments proposed by the present invention;
13 is a diagram illustrating a control flow performed by a base station according to an embodiment of the present invention;
14 is a view showing a control flow performed by a terminal according to an embodiment of the present invention.

Hereinafter, preferred 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.

Hereinafter, a technique for performing efficient resource allocation in a wireless communication system will be described. The following description will be made based on the LTE system and the LTE-A system, but the present invention can be applied equally to other wireless communication systems to which the base station scheduling is applied.

A. OFDM System and LTE System

OFDM transmission is a method of transmitting data using a multi-carrier, that is, a multi-carrier, in which a plurality of multi-carriers having parallel symbols and serially orthogonal relations with each other. In other words, it is a type of multi-carrier modulation that modulates and transmits a plurality of sub-carrier channels.

Such a system using a multicarrier modulation scheme was first applied to military high frequency radios in the late 1950s, and the OFDM scheme of overlapping a plurality of orthogonal subcarriers began to develop in the 1970s, but the implementation of orthogonal modulation between multicarriers was implemented. Since this was a difficult problem, there was a limit to the actual system application. However, in 1971, Weinstein et al. Announced that modulation and demodulation using the OFDM scheme can be efficiently processed using a Discrete Fourier Transform (DFT). Also known is the use of guard intervals and the insertion of cyclic prefix (CP) symbols into the guard intervals, further reducing the negative effects of the system on multipath and delay spread. .

Thanks to these technological advances, OFDM technology has been developed for Digital Audio Broadcasting (DAB), Digital Video Broadcasting (DVB), Wireless Local Area Network (WLAN), and Wireless Asynchronous Transmission Mode (Wireless). It is widely applied to digital transfer technologies such as Asynchronous Transfer Mode (WATM). In other words, the OFDM method has not been widely used due to hardware complexity, and recently, various digital signal processing technologies including fast fourier transform (FFT) and inverse fast fourier transform (IFFT) have been used. It is made possible by the development.

The OFDM scheme is similar to the typical frequency division multiplexing (FDM) scheme, but most of all, the orthogonality between a plurality of tones is maintained to obtain optimal transmission efficiency in high-speed data transmission. In addition, the OFDM scheme has high frequency usage efficiency and strong characteristics in multi-path fading, thereby obtaining optimal transmission efficiency in high-speed data transmission.

In addition, the OFDM scheme uses an overlapping frequency spectrum, which makes efficient use of frequency, resists frequency selective fading, resists multipath fading, and inter-symbol interference using protection intervals. It is possible to reduce the influence, to simply design an equalizer structure in hardware, and to be strong in impulsive noise, and thus it is being actively used in a communication system structure.

The factors that hamper high-speed, high-quality data services in wireless communication are largely due to the channel environment. In wireless communication, in addition to the additive white Gaussian noise (AWGN), the channel environment is based on Doppler due to power variation, shadowing, movement of the terminal, and frequent speed changes of the received signal caused by fading. ), Frequent changes due to interference by other users and multi-path signals. Therefore, in order to support high-speed and high-quality data services in wireless communication, it is necessary to effectively overcome the above-mentioned obstacles in the channel environment.

In the OFDM scheme, a modulated signal is located in a two-dimensional resource composed of time and frequency. The resources on the time axis are divided into different OFDM symbols and they are orthogonal to each other. Resources on the frequency axis are divided into different tones (or subcarriers) and they are also orthogonal to each other. That is, in the OFDM scheme, if a specific OFDM symbol is designated on the time axis and a specific tone is designated on the frequency axis, it may indicate one minimum unit resource, which is called a resource element (RE). Different REs have orthogonality to each other even though they pass through a frequency selective channel, so that signals transmitted to different REs may be received at a receiving side without causing mutual interference.

A physical channel is a channel of a physical layer for transmitting a modulation symbol modulating one or more encoded bit streams. In Orthogonal Frequency Division Multiple Access (OFDMA) systems, a plurality of physical channels are configured and transmitted according to the purpose of the information string to be transmitted or the receiver. The transmitter and the receiver must promise in advance which RE to arrange and transmit a physical channel. The rule is called mapping.

The LTE system and the LTE-A system, which is an extension thereof, are a representative system in which OFDM is applied to the downlink, and SC-FDMA (Single Carrier-Frequency Division Multiple Access) is applied to the uplink.

In the LTE system, the control channel is transmitted through search space and received using blind decoding. The control channel is largely divided into a common control channel and a dedicated control channel for a terminal. In the case of a common control channel, the control channel is transmitted to a common search space and all terminals search for the same area. The UE-specific control channel is transmitted through a UE-specific search space, and each terminal has a different search region. The UE blindly decodes a control channel in a search area that the UE should look at in order to recognize a location to be transmitted, a size of a transmitted control channel, and a transmission rate of a transmitted control channel. Since the base station does not inform the three pieces of information in advance, the base station should recognize that the terminal performs various demodulations. In the case of the control channel, the size of the control channel is two, and the transmission rate is determined by the amount of control channel elements (CCEs). One, two, four, or eight CCEs are possible. The location to be transmitted varies depending on the CCE. In the case of the common control channel, the CCE is 4, the four transmission locations are CCE at 8, and in the case of the terminal dedicated control channel, the CCE is 1, 2 and 6, 4 2 and 8 are present. Therefore, the number of demodulation of the terminal that the terminal should see in one cell is 44 times, which is the 12 common control channels and the 22 dedicated control channels. In addition, when the terminal has a plurality of carriers, since the terminal does not have a common control channel in S_cell, a number of times for receiving the terminal dedicated control channel is additionally added.

There are a plurality of formats of the control channel (PDCCH), each of which informs the UE of downlink and uplink data and scheduling information. This format is called DCI format, and a synchronization order (order) uses DCI format 1A for uplink synchronization and formats 1A and 1C for synchronization response.

In the LTE-A system, a base station may support a plurality of carriers at the same time. In this case, the base station may designate a carrier as a primary and secondary to each terminal. In this case, the terminal performs uplink synchronization through the primary, which assumes that the base station can use the same uplink synchronization established by the terminal in the primary in the secondary cell. For uplink synchronization, the UE transmits a PRACH in uplink, which is indicated by the base station through a control channel command (PDCCH order). Upon receiving this, the UE transmits the PRACH to the P_cell, and the sync response informs the location of the data channel through which the sync response information is transmitted through the control channel.

If the terminal has more than one carrier, the base station is a self-scheduling scheduling method that transmits the control channel to all of the carriers used when transmitting the control channel to the terminal and the control channel for multiple carriers in one cell A cross-carrier scheduling method for transmitting may be configured.

B. Multi-carrier with multiple timing advanced

In a more advanced multi-carrier system, the base station may not be able to use the same uplink synchronization established by the UE in P_cell in other carriers.

1 and 2, reference numeral 101 denotes a base station using two frequencies, F1 (reference numeral 107) and F2 (reference numeral 109). In this case, reference numeral 109 and reference numeral 107 are bands in the same frequency band as reference numeral 113. Therefore, the terminal transmits and receives both bands with one transceiver. In addition, F1 may cover all regions of the entire cell. However, F2 cannot be covered by the base station with the reference numeral 101 in a specific area within the cell.

Therefore, as shown by reference numeral 105, a signal is transmitted to a terminal of reference numeral 111 by drawing a base station signal to a wire (reference numeral 103) with a repeater. In this case, the terminal F1 109 transmits and receives from the base station 101, and in the case of F2 107, transmits and receives through the repeater 105. In this case, the uplink signal transmitted by the terminal has a great difference between the time of arrival at the base station 101 and the time of arrival at the base station 105. Therefore, the base station cannot receive the signal received by F2 by performing the uplink synchronization only in F1 in the existing system. Accordingly, the terminal 111 needs additional synchronization for the signal received by the reference numeral 105.

In another example, when the base station 119 has frequencies of two F1 109 and F3 101 and two cell regions are the same, but the F1 109 belongs to Band A as shown by reference numeral 113, F3 at 117 belongs to Band B as shown at 115 so that F1 and F3 are separated in frequency. Therefore, the terminal should transmit using different transceivers. In this case, since the terminal uses different transmitting and receiving devices, it is difficult to assume that the synchronization established from one cell is applied to the band through another device exactly. In addition, when the difference in the frequency band is large, because the signal propagation characteristics are different, it is difficult to assume the same synchronization because of this difference. Therefore, the UE needs uplink synchronization transmission in all cells.

C. Current RAR (Random access response) for Uplink time advanced

In the current system, uplink synchronization is possible only in the P_cell, system information can be transmitted only in the P_cell, and in order to reduce the control channel demodulation number of the UE, the S_cell has not defined a common search space.

Referring to FIG. 3, a command for uplink synchronization is transmitted in DCI format 1A as shown by reference numerals 209 and 207, and this control channel is scrambled by C-RNTI. The command for synchronization can be transmitted in both CSS and UESS of the P_cell, as shown by reference numeral 201 and 203, and the terminal receiving the transmission transmits the PRACH for synchronization in the uplink of the P_cell. As shown in Fig. 211, DCI format 1A or 1C is scrambled to RA-RNTI on the common control channel of P_cell of reference number 201 and transmitted.

D. Proposal for RAR

As described above, in order to transmit the uplink synchronization in the S_cell, a method of transmitting a control channel for a synchronization command and a response is required. For this, the following four methods are considered. Among them, D-1 is a self-scheduling scheme, and D-2, 3, and 4 are cross-carrier scheduling schemes.

D-1 Msg2 PDCCH adressed to RA-RNTI (CSS) on the same S_cell as Msg1

Referring to Figure 4, the method of D-1 is a method that can be utilized for self-scheduling. That is, when the synchronization command is transmitted in the S_cell, the synchronization response is transmitted using the format 1A or 1c to the common control channel region of the S_cell to which the synchronization command is transmitted. It is also a method of being scrambled and transmitted to the RA-RNTI of this control channel. In this case, the terminal should read the control channel in the common search space of the S_cell that did not exist previously. In this case, the terminal should additionally perform 12 blind decoding. However, the number of blind decoding of the terminal is limited and cannot be added. Therefore, in this case, the UE-specific search area of S_cell can be reduced and a common search area can be used. However, in this case, the transmission area of the transmission control channel of the terminal is reduced and data channel scheduling is impossible.

D-2 Msg2 PDCCH adressed to RA-RNTI (CSS) on the P_cell

D-2 is a case where the terminal is configured to cross-carrier scheduling.

Referring to FIG. 5, when the synchronization command 233 occurs in the UESS (reference number 231) of the S_cell, the UE always receives the synchronization response 237 from the CSS 223 of the P_cell. In this case, since the UE originally received the synchronization response 239 at reference numeral 227, the number of blind decoding does not increase additionally.

D-3 Msg2 PDCCH is addressed to RA-RNTI (CSS) on a scheduling P / S_cell of the S_cell of Msg1

D-3 is another example where the terminal is configured to perform cross-carrier scheduling.

Referring to FIG. 6, the synchronization command 245 is transmitted from the UESS 243 of the S_cell. In this case, the synchronization response is synchronized from the common search area 241 or 251 of the P_cell or S_cell to which the UE is scheduled. How to receive a response. In this case, as in D-2, additional blind decoding does not occur.

D-4 Msg2 PDCCH is addressed to C-RNTI (USS) on the P_cell or on a S_cell configured with PDCCH

D-4 is another example where the terminal is configured to perform cross-carrier scheduling.

Referring to FIG. 7, when the synchronization order 267 is transmitted in the UESS 263 of the S_cell, the synchronization response is a method of transmitting the UESS of the P_cell or the UESS of the S_cell. In this case, the synchronous response transmitted to the terminal uses DCI format 1A and is scrambled with C-RNTI and transmitted. In this case, additional blind decoding does not occur.

As described above, in the case of supporting the cross-carrier, synchronization response can be received without increasing blind decoding through various methods. However, when self-scheduling is required, such as D-1, blind decoding increases. The present invention is a method of receiving a synchronization order and a sync response in the control channel of S_cell without blind decoding in the case of self-scheduling.

8 shows a control channel structure of a conventional synchronization command.

Reference numeral 301 is an information field of a synchronization command, and this field consists of three fields. The first is resource allocation information as shown by reference numeral 303, reference numeral 305 is PRACH information for synchronization, and reference numeral 307 is also PRACH information for synchronization. To adjust the size of the control channel, fill the remaining fields with “0” as shown at 309.

E. Embodiments of the Invention

[First Embodiment]

According to the first embodiment proposed by the present invention, a method of indicating the position of a control channel through which a sync response is transmitted in 4 bits is added to the control channel structure of a conventional sync command. The common control channel requires a total of 12 blind decoding times and is a method of indicating this in 4 bits in advance.

Referring to FIG. 9, the number of twelve times is composed of six locations in which the common control channel can be transmitted and two formats in which the common control channel can be transmitted as shown in FIG. 8, and since each format has a different size, a total of 12 demodulation attempts are performed. need.

More specifically, the CCEs of the control channel available in the common control channel are 4 and 8, 4 positions are 4 positions of 329, 331, 333, 335, and 8 are 2 positions such as 337 and 339. Location is possible. Since two control channels of different sizes are possible in each position, a total of 12 logical resources are possible, and the 4-bit information of 313 indicates one of these 12 resources so that the terminal receives a synchronous response in common. Although the control channel area is 12, the synchronization response may be received at exactly one position. Therefore, no additional demodulation occurs.

In addition, since the same method is used even when the terminal has a plurality of S_cells, additional demodulation does not occur even in this case.

[Second Embodiment]

According to the second embodiment of the present invention, a method of indicating a position of a control channel through which a sync response is transmitted in 3 bits in addition to the control channel structure of an existing sync command, and preconfiguring a format of a control channel used for the sync response to be. The common control channel requires a total of 12 blind decoding times and is a method of indicating this in advance in 3 bits.

Referring to FIG. 10, the number of twelve times is composed of six locations in which the common control channel can be transmitted and two formats that can be transmitted as shown in FIG. 8, and since each format is configured in a different size, a total of 12 demodulation attempts are performed. need.

The CCEs of the control channel that can be described in more detail and in the common control channel are 4 and 8, four positions of 421, 423, 425, and 427 in case of 4, and two positions such as 429 and 431 in case of eight. Location is possible. Here, the base station configures the format of the control channel to be used for the synchronization response in advance in the terminal to prevent demodulation occurring in different formats. In this case, a synchronization response is transmitted to one of a total of six resources, and the terminal informs one of six resource positions using a total of three bits in the region 403. Since one control channel of different size is possible in each position, a total of six logical resources are possible, and the 3-bit information of 403 indicates one of these six resources so that the terminal receives a synchronous response in common. Although the control channel area is 12, the synchronization response may be received at exactly one position. Therefore, no additional demodulation occurs. In addition, since the same method is used even when the terminal has a plurality of S_cells, additional demodulation does not occur even in this case.

[Third Embodiment]

In the third embodiment proposed by the present invention, in addition to the control channel structure of the existing synchronization command, the position of the control channel through which the synchronization response is transmitted is indicated by 2 bits, and the format of the control channel used for the synchronization response is previously configured. It is a method of transmitting using a part of an area where a synchronous response is transmitted. The common control channel requires a total of 12 blind decoding times and is a method of indicating this in advance in 2 bits.

Referring to FIG. 11, as shown in FIG. 8, a total of 12 demodulation attempts are required because the common control channel is composed of six locations for transmission and two formats for transmission, and each format has a different size. Do.

More specifically, the CCEs of the control channel available in the common control channel are 4 and 8, 4 positions are 4 positions 519, 521, 523, 525, and 8 are 2 positions such as 527 and 529. Location is possible. Here, the base station configures the format of the control channel to be used for the synchronization response in advance in the terminal to prevent demodulation occurring in different formats.

In addition, only a part of the search area is used as a candidate to indicate 2 bits. In order to support both CCE sizes 4 and 8, two positions of reference numeral 519 and 521 are candidates for transmitting CCE size 4 and 527. The synchronization response is transmitted to one of a total of four resources using two positions of and 529 as candidates for transmitting CCE size 8.

The terminal informs one of the resource positions among four using two bits in the area of the reference number 503. Since one control channel of different size is possible in each position, a total of four logical resources are possible, and two-bit information of reference number 503 indicates one of these four resources so that the terminal receives a synchronous response in common. Although the control channel area is 12, it is only necessary to receive the synchronization response at exactly one position. Therefore, no additional demodulation occurs. In addition, since the same method is used even when the terminal has a plurality of S_cells, additional demodulation does not occur even in this case.

[Fourth Embodiment]

In the fourth embodiment proposed by the present invention, in addition to the control channel structure of the existing synchronization command, the position of the control channel through which the synchronization response is transmitted is indicated by 1 bit, and the format of the control channel used for the synchronization response is configured in advance. It is a method of transmitting using a part of an area where a synchronous response is transmitted. The common control channel requires a total of 12 blind decoding times and is a method of indicating this in advance by 1 bit.

Referring to FIG. 12, the number of twelve times is composed of six locations in which the common control channel can be transmitted and two formats in which the common control channel can be transmitted as shown in FIG. 8. need.

More specifically, the CCEs of the control channels available in the common control channel are 4 and 8, 4 positions 4 for 619, 621, 623, and 625, and 8 for 2 positions as shown in 627 and 629. Dog positions are possible. Here, the base station configures the format of the control channel to be used for the synchronization response in advance in the terminal to prevent demodulation occurring in different formats.

In addition, only a part of the search area is used as a candidate to indicate 2 bits. In order to support both CCE sizes 4 and 8, one position of reference number 619 is used as a candidate for transmitting CCE size 4 and one position of reference number 627. Using the CCE size 8 as a candidate for transmission, a synchronization response is transmitted to one of two resources. The terminal informs one of two resource locations using two bits in the region 603. Since one control channel of different size is possible in each position, a total of two logical resources are possible, and one bit information of reference numeral 603 indicates one of these two resources. Thus, the terminal may receive the synchronization response at exactly one position, even though the area of the common control channel is 12 when receiving the synchronization response. Therefore, no additional demodulation occurs. In addition, since the same method is used even when the terminal has a plurality of S_cells, additional demodulation does not occur even in this case.

E. Flowchart

E-1 Flow of transmitter (Figure 7)

When the base station according to an embodiment of the present invention is described with reference to FIG. 13, the base station prepares for transmission of a synchronization command for timing alignment through uplink synchronization in S_cell in step 701. In step 703, the base station configures a control channel search region for the synchronization response. This is the common control channel region of S_cell. In step 705, the base station indicates an arbitrary point in the control channel search region to the RAR field of the synchronization command, and transmits the synchronization command to the terminal. The random position is to prevent transmission between blocks in the control channel in the region. Thereafter, the base station receives the synchronization signal from the terminal in step 707, and when the synchronization signal is received, the base station transmits the synchronization response to the position indicated by the synchronization command in step 705.

E-2 Flow of receiver (Figure 8)

Referring to FIG. 14, a flowchart of a terminal according to an embodiment of the present invention is described. In step 801, a terminal receives resource configuration information for uplink synchronization in an S_cell from a base station. This includes not only PRACH configuration information for synchronization but also a format for a synchronization response proposed in the second to fourth embodiments. In step 803, the UE receives a synchronization order for uplink synchronization of the S_cell from the base station. Thereafter, in step 805, the UE recognizes information on which position the control channel for the synchronization response is transmitted in the common control channel search region of S_cell in the RAR region of the synchronization command. Thereafter, in step 807, the UE transmits a PRACH signal for synchronization to S_cell in uplink according to a synchronization command. Thereafter, in step 809, the UE receives the synchronization response control channel at the position indicated by the RAR of the synchronization command in the control channel search region of S_cell. Thereafter, in step 811, the UE recognizes scheduling information for receiving a data channel including the synchronization response information in the control channel of the received synchronization response, and receives the data channel.

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. Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined not only by the scope of the following claims, but also by the equivalents of the claims.

Claims

A method for transmitting a control channel for uplink synchronization response of a terminal in a base station of an orthogonal frequency division multiple access communication system,
Preparing a synchronization command for time alignment in the secondary cell, configuring a control channel search region for the synchronization response;
Transmitting information indicating an arbitrary point existing in the control channel search region to the terminal in the random access response field of the synchronization command;
And transmitting a sync response at a location indicated by the sync command when a sync signal is received from the terminal.

A method for receiving a control channel for uplink synchronization response transmitted from a base station in a terminal of an orthogonal frequency division multiple access communication system,
Receiving resource configuration information and synchronization command for uplink synchronization from the base station to an auxiliary cell;
Recognizing information about a location where a control channel for a synchronization response is transmitted in a random access response region of the synchronization command;
Transmitting a physical random access channel for synchronization in the secondary cell;
Receiving, by the base station, a synchronization dedicated control channel for a synchronization response channel at a position indicated by a physical dedicated control channel in a control channel search region of the auxiliary cell;
And receiving synchronization response information in a data channel using scheduling information present in a physical dedicated control channel for the synchronization response channel.