Method and apparatus for transmitting and receiving MCS index for 256QAM in wireless access system

Patent metadata

Field	Value
Publication number	US-9698960-B2
Application number	US-201615208096-A
Country	US
Kind code	B2
Filing date	Jul 12, 2016
Priority date	Dec 17, 2012
Publication date	Jul 4, 2017
Grant date	Jul 4, 2017

Abstract

A method is provided for decoding data in a wireless access system. A user equipment (UE) receives a higher layer signal including an indication that 256 quadrature amplitude modulation (256 QAM) is to be enabled. The UE further receives, via a physical downlink control channel (PDCCH), downlink control information (DCI) including an index field representing a modulation and coding scheme (MCS). The UE also receives data via a physical downlink shared channel (PDSCH) scheduled by the PDCCH, and decodes the received data using the MCS represented by the index field. The UE has a first MCS index table supporting up to 64 quadrature amplitude modulation (64 QAM) and a second MCS index table supporting up to the 256 QAM.

First claim

What is claimed is:

1. A method for decoding data in a wireless access system, the method performed by a user equipment (UE) and comprising:
receiving a higher layer signal including an indication that 256 quadrature amplitude modulation (256QAM) is to be enabled;
receiving, via a physical downlink control channel (PDCCH), downlink control information (DCI) including an index field representing a modulation and coding scheme (MCS);
receiving data via a physical downlink shared channel (PDSCH) scheduled by the PDCCH; and
decoding the received data using the MCS represented by the index field,
wherein the UE has a first MCS index table supporting up to 64 quadrature amplitude modulation (64QAM) and a second MCS index table supporting up to the 256QAM, and
wherein the received data is decoded based on the first MCS index table even though the second MCS index table has been enabled to the UE, when the DCI has been scrambled with a semi persistent scheduling radio network temporary identifier (SPS-RNTI).

2. The method according to claim 1 , further comprising:
determining a modulation order and a transport block size (TBS) index depending upon an MCS index in the first MCS index table.

3. The method according to claim 1 , wherein the UE decodes the received data using a modulation scheme indicated by the index field at the first MCS index table.

4. The method according to claim 1 , wherein the first MCS index table and the second MCS index table are represented by 5 bits.

5. A user equipment (UE), comprising:
a receiver configured to:
receive a higher layer signal including an indication that 256 quadrature amplitude modulation (256QAM) is to be enabled,
receive, via a physical downlink control channel (PDCCH), downlink control information (DCI) including an index field representing a modulation and coding scheme (MCS), and
receive data via a physical downlink shared channel (PDSCH) scheduled by the PDCCH; and
a processor configured to decode the received data using the MCS represented by the index field,
wherein the UE has the first MCS index table supporting up to 64 quadrature amplitude modulation (64QAM) and a second MCS index table supporting up to 256QAM, and
wherein the received data is decoded by the processor based on the first MCS index table even though the second MCS index table has been enabled to the UE, when the DCI has been scrambled with a semi persistent scheduling radio network temporary identifier (SPS-RNTI).

6. The UE according to claim 5 , wherein the processor is further configured to determine a modulation order and a transport block size (TBS) index depending upon an MCS index in the first MCS index table.

7. The UE according to claim 5 , wherein the UE decodes the received data using a modulation scheme indicated by the index field at the first MCS index table.

8. The UE according to claim 5 , wherein the first MCS index table and the second MCS index table are represented by 5 bits.

9. A method for transmitting downlink data in a wireless access system, the method performed by an evolved Node B (eNB) and comprising:
transmitting a higher layer signal including an indication that 256 quadrature amplitude modulation (256QAM) is to be enabled;
transmitting, via a physical downlink control channel (PDCCH), downlink control information (DCI) including an index field representing a modulation and coding scheme (MCS); and
transmitting data via a physical downlink shared channel (PDSCH) scheduled by the PDCCH,
wherein the eNB has a first MCS index table supporting up to 64 quadrature amplitude modulation (64QAM) and a second MCS index table supporting up to the 256QAM, and
wherein the transmitted data is encoded based on the first MCS index table even though the second MCS index table has been enabled, when the DCI has been scrambled with a semi persistent scheduling radio network temporary identifier (SPS-RNTI).

10. The method according to claim 9 , wherein the data is decoded by a user equipment (UE) using the MCS represented by the index field, and
a modulation order and a transport block size (TBS) index is determined depending upon an MCS index in the first MCS index table.

11. The method according to claim 9 , wherein the first MCS index table and the second MCS index table are represented by 5 bits.

12. An evolved Node B (eNB), comprising:
a transmitter configured to:
transmit a higher layer signal including an indication that 256 quadrature amplitude modulation (256QAM) is to be enabled,
transmit, via a physical downlink control channel (PDCCH), downlink control information (DCI) including an index field representing a modulation and coding scheme (MCS), and
transmit data via a physical downlink shared channel (PDSCH) scheduled by the PDCCH; and
a processor configured to encode the data using the MCS represented by the index field,
wherein the eNB has the first MCS index table supporting up to 64 quadrature amplitude modulation (64QAM) and a second MCS index table supporting up to 256QAM, and
wherein the data is encoded by the processor based on the first MCS index table even though the second MCS index table has been enabled, when the DCI has been scrambled with a semi persistent scheduling radio network temporary identifier (SPS-RNTI).

13. The eNB according to claim 12 , wherein the data is decoded by a user equipment (UE) using the MCS represented by the index field, and
a modulation order and a transport block size (TBS) index is determined depending upon an MCS index in the first MCS index table.

14. The eNB according to claim 12 , wherein the first MCS index table and the second MCS index table are represented by 5 bits.

Assignees

• Lg Electronics Inc

Inventors

• Kim Bonghoe
• Seo Dongyoun
• Yi Yunjung
• Ahn Joonkui

Classifications

• H04W72/23 Primary

  in the downlink direction of a wireless link, i.e. towards a terminal · CPC title

• H04L1/0016

  involving special memory structures, e.g. look-up tables · CPC title

• H04L27/361

  Modulation using a single or unspecified number of carriers, e.g. with separate stages of phase and amplitude modulation · CPC title

• H04L5/0092 Primary

  Indication of how the channel is divided · CPC title

• H04L5/0053

  Allocation of signalling, i.e. of overhead other than pilot signals · CPC title