Method and apparatus for transmitting and receiving downlink control information

Patent metadata

Field	Value
Publication number	US-2015271794-A1
Application number	US-201514664854-A
Country	US
Kind code	A1
Filing date	Mar 21, 2015
Priority date	Mar 21, 2014
Publication date	Sep 24, 2015
Grant date	—

Abstract

The present disclosure relates to a method and an apparatus for transmitting and receiving DCI for supporting 256QAM. Particularly, the method for receiving DCI by a user equipment, may include: transmitting, to a base station, channel state information including information obtained by measuring a channel quality state; receiving, from the base station, the DCI including an MCS index value selected based on the channel state information in a predetermined MCS index table including an MCS index value corresponding to a 256QAM modulation method; and identifying modulation information on downlink data on the basis of the selected MCS index value.

First claim

What is claimed is:

1 . A method for receiving downlink control information by a user equipment, the method comprising:
transmitting, to a base station, channel state information including information obtained by measuring a channel quality state; receiving, from the base station, the downlink control information including a Modulation and Coding Scheme (MCS) index value selected based on the channel state information in a predetermined MCS index table including at least one MCS index value corresponding to a 256-state Quadrature Amplitude Modulation (256QAM) modulation method; and identifying modulation information on downlink data on the basis of the selected MCS index value.

2 . The method of claim 1 , wherein the predetermined MCS index table comprises:
five MCS index values corresponding to a Quadrature Phase Shift Keying (QPSK) modulation method; six MCS index values corresponding to a 16QAM modulation method; nine MCS index values corresponding to a 64QAM modulation method; and eight MCS index values corresponding to the 256QAM modulation method.

3 . The method of claim 1 , wherein the MCS index table comprises:
four MCS index values for Hybrid Automatic Repeat reQuest (HARQ) retransmission; and 28 MCS index values for HARQ initial transmission.

4 . The method of claim 1 , wherein one of the MCS index values corresponding to the 256QAM modulation method is configured to have transmission efficiency identical to maximum transmission efficiency in an MCS index table where a maximum modulation order is set to 6.

5 . The method of claim 1 , wherein one of the MCS index values corresponding to the 256QAM modulation method is configured to have a value of a coding rate identical to a coding rate having maximum transmission efficiency in an MCS index table where a maximum modulation order is set to 6.

6 . The method of claim 1 , wherein the predetermined MCS index table is formed to have the MCS index values corresponding to the 256QAM modulation method and each of the MCS index values for the 256QAM modulation method is associated with a coding rate defined in a table below:

Coding rate

MCS index value
(R = code rate*1024)
Modulation method

21
711
256QAM

22
754
256QAM

23
797
256QAM

24
841
256QAM

25
885
256QaM

26
916.5
256QAM

27
948
256QAM

7 . The method of claim 1 , wherein the predetermined MCS index table is formed to have the MCS index values corresponding to the 256QAM modulation method, and each of the MCS index values for the 256QAM is associated with transmission efficiency defined in a table below:

Transmission

MCS index value
efficiency
Modulation method

21
5.5547
256QAM

22
5.8906
256QAM

23
6.2266
256QAM

24
6.5703
256QaM

25
6.9141
256QAM

26
7.1602
256QAM

27
7.4063
256QAM

8 . A method for transmitting downlink control information by a base station, the method comprising:
receiving, from a user equipment, channel state information including information obtained by measuring a channel quality state; selecting a Modulation and Coding Scheme (MCS) index value on the basis of the channel state information in a predetermined MCS index table including at least one MCS index value corresponding to a 256-state Quadrature Amplitude Modulation (256QAM) modulation method; and transmitting the downlink control information including the selected MCS index value.

9 . The method of claim 8 , wherein the MCS index table comprises:
five MCS index values corresponding to a Quadrature Phase Shift Keying (QPSK) modulation method; six MCS index values corresponding to a 16QAM modulation method; nine MCS index values corresponding to a 64QAM modulation method; and eight MCS index values corresponding to the 256QAM modulation method.

10 . The method of claim 8 , wherein the predetermined MCS index table comprises:
four MCS index values for Hybrid Automatic Repeat reQuest (HARQ) retransmission; and 28 MCS index values for HARQ initial transmission.

11 . The method of claim 8 , wherein one of the MCS index values corresponding to the 256QAM modulation method is configured to have transmission efficiency identical to maximum transmission efficiency in an MCS index table where a maximum modulation order is set to 6.

12 . The method of claim 8 , wherein one of the MCS index values corresponding to the 256QAM modulation method is configured to have a value of a coding rate identical to a coding rate having maximum transmission efficiency in an MCS index table where a maximum modulation order is set to 6.

13 . The method of claim 8 , wherein the predetermined MCS index table is formed to have the MCS index values corresponding to the 256QAM modulation method and each of the MCS index values is associated with a coding rate defined in a table below:

Coding rate

MCS index value
(R = code rate*1024)

Assignees

• Kt Corp

Inventors

• Kang Seung Hyun
• Choi Woo-Jin

Classifications

• H04W72/042 Primary

  Electricity · mapped topic

• H04L27/3411

  reducing the peak to average power ratio or the mean power of the constellation; Arrangements for increasing the shape gain of a signal set · CPC title

• H04L27/3405 Primary

  Modifications of the signal space to increase the efficiency of transmission, e.g. reduction of the bit error rate, bandwidth, or average power · CPC title

• H04L1/0003 Primary

  by switching between different modulation schemes · CPC title

• H04L27/362

  Modulation using more than one carrier, e.g. with quadrature carriers, separately amplitude modulated (H04L27/366 takes precedence) · CPC title