KR20130039638A - Method and apparatus for transmitting downlink control information - Google Patents

Abstract

PURPOSE: A method for transmitting downlink control information and an apparatus thereof are provided to allocate part of a PDSCH(physical downlink shared channel) resource region to an E-PDCCH(enhanced physical downlink control channel) region for performing cooperative scheduling between PDCCH and E-PDCCH. CONSTITUTION: A common search space DCI(downlink control information) including a system, paging, RACH(random access channel) response signal, group power control information, and the like is transmitted through a PDCCH. A UE(User Equipment)-specific search space DCI including scheduling information for data transmission of a UE is transmitted through an E-PDCCH as each divided downlink control information. The scheduling information for data transmission of the user equipment includes a resource allocation method, resource size, modulation technique, pre-coding information, and the like. The UE-specific search space DCI for the cooperative scheduling such as a CoMP(coordinated multi-point operation), multi user MIMO(MU-MIMO), and the like is transmitted through the PDCCH or E-PDCCH. The DCI is transmitted through the PDCCH or E-PDCCH according to downlink or uplink channel information. [Reference numerals] (AA,DD) PDSCH resource; (BB) E-PDCCH resource; (CC) PDCCH resource;

Description

METHOD AND APPARATUS FOR TRANSMITTING DOWNLINK CONTROL INFORMATION}

The present invention relates to the field of LTE systems, and more particularly, to a method and apparatus for transmitting downlink control information.

"This study was carried out as a result of the study of the original technology development project of the next generation communication network of the Korea Communications Commission" (KCA-2011-10913-04002)

Recently, communication standards for improving performance in terms of throughput, latency, and coverage in mobile communication systems have been developed. A widely used standard is the UMTS (Universal Mobile Telecommunications System) which was developed as part of the 3rd generation (3G) mobile communication system and is maintained by the 3rd Generation Partnership Project (3GPP). Among these, 3GPP Long Term Evolution (LTE) is a communication standard driven by 3GPP to achieve high data rate, low latency, packet optimized system performance and wide coverage in UMTS systems.

In the 3GPP LTE Release 8/9/10 system, as shown in FIG. 1, a control channel (PDCCH) and a data channel (PDSCH) are allocated in a frequency-time domain on the downlink. Allocate and use The PDCCH is used to transmit various types of downlink control information formats according to uplink scheduling assignment information and downlink control information (DCI) such as a power control command. Since a physical resource capable of transmitting a PDCCH is limited to a maximum of 4 symbols, the capacity of the PDCCH itself may also be limited according to the limitation of the physical resource. CoMP (coordinated multi-point operatoin), which will be introduced in the system after LTE 11, is expected to require more scheduling information. In addition, in carrier aggregation (CA) introduced in LTE release 10, PDCCH capacity that can be used by one carrier increases. In addition, multi-user access schemes are available for downlink antennas that have increased since release 10, which is also a factor of increasing PDCCH capacity.

As such, while physical resources for the PDCCH are limited, there is a need for additional physical resource allocation in consideration of the increase in information to be transmitted using the PDCCH.

The present invention provides a method and apparatus for transmitting downlink control information.

The apparatus for transmitting downlink control information according to the present invention allocates a portion of a physical downlink shared channel (PDSCH) resource region to an enhanced physical downlink control channel (E-PDCCH) region to control downlink information (DCI) for the mobile communication terminal. send information).

A method of transmitting downlink control information according to the present invention includes: a) allocating a portion of a physical downlink shared channel (PDSCH) resource region to an enhanced physical downlink control channel (E-PDCCH); And b) transmitting downlink control information (DCI) for the mobile communication terminal using PDCCH or E-PDCCH.

According to the present invention, efficient cooperative scheduling between PDCCH and E-PDCCH can be performed.

1 is an exemplary view showing a PDCCH and a PDSCH resource region in an LTE system.
2 is an exemplary view showing the configuration of an LTE-Advanced system according to an embodiment of the present invention.
3 is an exemplary view showing an E-PDCCH resource region according to an embodiment of the present invention.
4 is an exemplary view showing an E-PDCCH PRB structure according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, well-known functions or constructions will not be described in detail if they obscure the subject matter of the present invention.

2 is an exemplary view showing the configuration of an LTE-Advanced system according to an embodiment of the present invention.

Referring to FIG. 2, the LTE-Advanced system includes a base station 10 and a terminal 20. The base station 10 may provide a communication service through a wireless link to the terminal 20 in a coverage region where the base station provides a network access service.

When Carrier Aggregation is applied to a plurality of carrier PCells (Primary Cells) and SCells (Secondary Cells), UE 1 (20a) can transmit downlink control information to the E-PDCCH. The S-CH may include a physical downlink shared channel (PDSCH) or a physical uplink shared channel (PUSCH) that carries user data.

When one UE 10a simultaneously serves different UEs using a MU-MIMO (Multi User MIMO) scheme, downlink control information may be transmitted through an E-PDCCH.

Downlink control when CoMP (Coordinated Multi-Point operation) is applied to one terminal 20d while sharing scheduling information or data between different sectors in one base station or between different nodes connected by X2 interface. The information may be transferred to the E-PDCCH.

In the 3GPP LTE Release 8/9/10 system, the control channel (PDCCH) and the data channel (PDSCH) for the terminals 30a to 30c are allocated and used in the frequency-time domain on the downlink. The PDCCH is used to transmit various types of downlink control information formats according to uplink scheduling assignment information and downlink control information (DCI) such as a power control command. The PDCCH includes common purpose such as transmission of system information, power control command, and response information for random access attempt, and uplink and downlink allocation information for scheduling user request data. On the other hand, since a physical resource capable of transmitting a PDCCH is limited to a maximum of 4 symbols, the capacity itself of the PDCCH may be limited accordingly. CoMP (coordinated multi-point operatoin), which will be introduced in the system after LTE 11, is a technology that improves system performance by utilizing cooperation between transmission points. Joint processing and coordinated scheduling Since such a technique is used, more scheduling information will be needed than in the present. In addition, carrier aggregation (CA) introduced in LTE release 10 supports cross carrier scheduling, which enables scheduling of all carriers in a component carrier having a good channel state. The capacity of the PDCCH that can be used in the carrier increases. In addition, since multi-user access schemes are available for downlink antennas increased after release 10, this also increases the PDCCH capacity.

3 is an exemplary view showing an Enhanced-Physical Downlink Control Channel (E-PDCCH) resource region according to an embodiment of the present invention.

The apparatus for transmitting downlink control information according to the present invention may transmit downlink control information for the mobile communication terminal by allocating a part of the PDSCH resource region to the E-PDCCH.

Due to the capacity problem of the downlink control information, an improved control channel (E-PDCCH) is being discussed in order to improve the capacity of the control channel by introducing the downlink control information into the data region as shown in FIG. 3. The capacity of the E-PDCCH is extended as much as the added physical resource region, and the transmission scheme of the PDSCH can be utilized. Referring to the physical resource block (PRB) region of FIG. 3, the PDCCH uses a Quadrature Phase Shift Keying (QPSK) modulation and demodulation technique based on a Cell Reference Signal (CRS), whereas the E-PDCCH is a DM-RS (modulation reference) like PDSCH. signal and / or link adaptive modulation and demodulation techniques may cause capacity and performance differences between PDCCH and E-PDCCH. In this case, PDCCH and E- for effective cooperative scheduling when applying a multi-user access method such as MU-MIMO (MU-MIMO) that can be supported in Release 9 or 10, or CoMP, which will be introduced in Release 11, etc. A method of allocating downlink control information between PDCCHs is required.

The present invention describes a method of allocating downlink control information to the E-PDCCH and the PDCCH.

There are a plurality of PRBs as radio resources for the PDSCH, and in the present invention, some of the PRB resources for the PDSCH are allocated for the E-PDCCH. Some or all of the resources of the PRB time domain allocated for the E-PDCCH may be used for the E-PDCCH.

The PDCCH is a physical channel using orthogonal frequency division multiplexing (OFDM) symbols within first to fourth in a subframe for the entire PRB region. In the present embodiment, any one of the following methods or a combination of the following methods is used to transmit downlink control information for the E-PDCCH and the PDCCH.

1. Downlink control information for a terminal supporting LTE release (Release) 11 or more standard is transmitted using a PDCCH or an E-PDCCH.

2. The downlink control information of the common search space including the system, paging, random access control channel (RACH) response, group power control information, etc. is transmitted using the PDCCH, and the user Downlink control information of a UE-specific search space including scheduling information for data transmission of a user equipment is separately transmitted using E-PDCCH. The scheduling information for data transmission of the user terminal includes a resource allocation method, a resource size, a modulation scheme, precoding information, and the like.

3. The user search region downlink control information of a UE involved in cooperative scheduling such as coordinated multi-point operatoin (CoMP) and multi-user MIMO (MU-MIMO) is transmitted through a PDCCH or an E-PDCCH.

4. The downlink control information is transmitted to the PDCCH or the E-PDCCH according to the downlink or uplink channel information.

While the above methods have been described through specific embodiments, the methods may also be implemented as computer readable code on a computer readable recording medium. A computer-readable recording medium includes all kinds of recording apparatuses in which data that can be read by a computer system is stored. Examples of the computer-readable recording medium include a ROM, a RAM, a CD-ROM, a magnetic tape, a floppy disk, an optical data storage device, and the like, and may be implemented in the form of a carrier wave (for example, transmission over the Internet) . In addition, the computer-readable recording medium may be distributed over network-connected computer systems so that computer readable codes can be stored and executed in a distributed manner. In addition, functional programs, codes, and code segments for implementing the above embodiments can be easily deduced by programmers of the present invention.

Although the present invention has been described in connection with some embodiments thereof, it should be understood that various changes and modifications may be made therein without departing from the spirit and scope of the invention as understood by those skilled in the art. something to do. It is also contemplated that such variations and modifications are within the scope of the claims appended hereto.

10: base station 20: relay
30: terminal

Claims (16)

An apparatus for transmitting downlink control information,
Downlink control information transmission for transmitting downlink control information (DCI) for a mobile communication terminal by allocating a part of a physical downlink shared channel (PDSCH) resource region to an enhanced physical downlink control channel (E-PDCCH) region Device. The method of claim 1,
And transmitting common search region down control information using a PDCCH and transmitting user search region down control information using an E-PDCCH. The method of claim 1,
And downlink control information of the mobile communication terminal involved in cooperative scheduling of coordinated multi-point operatoin (CoMP) and multi-user MIMO is transmitted through PDCCH or E-PDCCH. The method of claim 1,
And determining the downlink control information transmission channel as a PDCCH or an E-PDCCH according to downlink or uplink channel information. 5. The method according to any one of claims 1 to 4,
The mobile communication terminal,
An apparatus for transmitting downlink control information supporting LTE (Long Term Evolution) Release 11 or later standard. 5. The method according to any one of claims 1 to 4,
The PDSCH resource,
An apparatus for transmitting downlink control information, comprising a physical resource block (PRB). The method of claim 2,
The joint search region downlink control information includes a system, paging, random access control channel (ACH) response, and group power control information.
The user search region downlink control information includes scheduling information for data transmission of user equipment (user equipment), downlink control information transmission apparatus. The method of claim 7, wherein
Scheduling information for data transmission of the user terminal,
An apparatus for transmitting downlink control information comprising a resource allocation method, a resource size, a modulation scheme, and precoding information. A method of transmitting downlink control information,
a) allocating a portion of a physical downlink shared channel (PDSCH) resource region to an enhanced physical downlink control channel (E-PDCCH) region; And
b) transmitting downlink control information (DCI) for the mobile communication terminal using a PDCCH or an E-PDCCH. 10. The method of claim 9,
The step b)
Transmitting common search region downlink control information using a PDCCH; And
Transmitting user search region downlink control information using the E-PDCCH. 10. The method of claim 9,
The step b)
Transmitting downlink control information of the mobile communication terminal involved in cooperative scheduling of coordinated multi-point operatoin (CoMP) and multi-user MIMO to PDCCH or E-PDCCH. How to send information. 10. The method of claim 9,
The step b)
And determining the downlink control information transmission channel according to downlink or uplink channel information as a PDCCH or an E-PDCCH. 13. The method according to any one of claims 9 to 12,
The mobile communication terminal,
A method of transmitting downlink control information supporting LTE (Long Term Evolution) Release 11 or later standard. 13. The method according to any one of claims 9 to 12,
The PDSCH resource,
A downlink control information transmission method comprising a physical resource block (PRB). The method of claim 10,
The joint search region downlink control information includes a system, paging, random access control channel (ACH) response, and group power control information.
The user search region downlink control information includes scheduling information for data transmission of user equipment (user equipment), downlink control information transmission method. 16. The method of claim 15,
Scheduling information for data transmission of the user terminal,
A method for transmitting downlink control information, including resource allocation method, resource size, modulation scheme, and precoding information.

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