# US 9,438,399 B2 · Method for receiving downlink control information in wireless access system and terminal therefor

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- Number: US 9,438,399 B2
- Document ID: US9438399B2
- Status: Granted
- Kind: B2
- Application number: 14/125,548
- Filed: 2012-06-15
- Published: 2014-08-21
- Granted: 2016-09-06
- Earliest claimed: 2011-06-15
- Assignees: LG Electronics Inc.
- Applicants: Jinmin Kim; Seunghee Han; Hyunwoo Lee
- Inventors: Jinmin Kim; Seunghee Han; Hyunwoo Lee
- Web page: https://patentgrep.com/patent/US9438399B2

## CPC

- H04L 5/0053: {Allocation of signalling, i.e. of overhead other than pilot signals}
- H04L 1/0046: {Code rate detection or code type detection (H04L1/0038 takes precedence; detection of the data rate H04L25/0262; for packet format H04L1/0091)}
- H04L 1/1854: {Scheduling and prioritising arrangements}
- H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M)

## Abstract

The present invention relates to a method for receiving Downlink Control Information (DCI) in a wireless access system and a terminal therefor. More specifically, the method comprises the steps of: performing blind decoding according to the transmission mode set for a terminal in a search space assigned to the terminal; and receiving DCI through a detected Physical Downlink Control Channel (PDCCH) via blind decoding, wherein the transmission mode is set to any one of a plurality of transmission modes, which have limitations dependent on the performance of the terminal, by a base station that supports a plurality of transmission modes.

## Claims

### Claim 1

A method of a user equipment (UE) receiving downlink control information (DCI) in a wireless access system, the method comprising:
performing blind decoding according to a transmission mode set for the UE in a search space assigned to the UE; and
receiving the DCI via a physical downlink control channel (PDCCH) identified by the blind decoding,
wherein the set transmission mode is one of a plurality of transmission modes supported by a base station (BS) that are restricted according to performance of the UE, and
wherein the blind decoding is performed using only half of total M control channel elements (CCE) aggregation levels for the search space, when the UE performs a machine type communication (MTC), where M corresponds to ‘4’ or ‘2’.

### Claim 2 (depends on 1)

The method of claim 1, wherein:
performing the blind decoding comprises using a format of the DCI according to a resource allocation type set for the UE; and
the resource allocation type is set to one of a plurality of resource allocation types supported by the BS according to the performance of the UE.

### Claim 3 (depends on 1)

The method of claim 1, wherein the search space is set to either a UE-specific search space or a common search space according to the performance of the UE.

### Claim 4 (depends on 1)

The method of claim 1, wherein the DCI is transmitted according to a format of the DCI in either a UE-specific search space or a common search space.

### Claim 5 (depends on 1)

The method of claim 1, wherein performing the blind decoding comprises using only formats of a plurality of Das supported by the BS that are restricted according to the performance of the UE.

### Claim 6 (depends on 1)

The method of claim 1, wherein the blind decoding is performed via candidates among a plurality of candidates of the PDCCH configuring the search space that are restricted according to the performance of the UE.

### Claim 7

A user equipment (UE) receiving downlink control information (DCI) in a wireless access system, the UE comprising:
an RF unit configured to transceive radio signals; and
a processor configured to:
perform blind decoding according to a transmission mode set for the UE in a search space assigned to the UE, and
control the RF unit to receive the DCI via a physical downlink control channel (PDCCH) identified by the blind decoding,
wherein the set transmission mode is one of a plurality of transmission modes supported by a base station (BS) that are restricted according to performance of the UE, and
wherein the blind decoding is performed using only half of total M control channel elements (CCE) aggregation levels for the search space, when the UE performs a machine type communication (MTC), where M corresponds to ‘4’ or ‘2’.

### Claim 8 (depends on 7)

The user equipment of claim 7, wherein:
performing the blind decoding comprises using a format of the DCI according to a resource allocation type set for the UE; and
the resource allocation type is set to one of a plurality of resource allocation types supported by the BS according to the performance of the UE.

### Claim 9 (depends on 7)

The user equipment of claim 7, wherein the search space is set to either a UE-specific search space or a common search space according to the performance of the UE.

### Claim 10 (depends on 7)

The user equipment of claim 7, wherein the DCI is transmitted according to a format of the DCI in either a UE-specific search space or a common search space.

### Claim 11 (depends on 7)

The user equipment of claim 7, wherein performing he blind decoding comprises using only formats of a plurality of Das supported by the BS that are restricted according to the performance of the UE.

### Claim 12 (depends on 7)

The user equipment of claim 7, wherein the blind decoding is performed via candidates among a plurality of candidates of the PDCCH configuring the search space that are restricted in accordance with the performance of the UE.