Apparatus and method for transmitting/receiving data in a communication system

• US 20070191024A1
• Filed: 01/18/2007
• Published: 08/16/2007
• Est. Priority Date: 01/18/2006
• Status: Active Grant

• Current Assignee: Korea Advanced Institute of Science and Technology, Samsung Electronics Co. Ltd.
• Original Assignee: Korea Advanced Institute of Science and Technology, Samsung Electronics Co. Ltd.
• Inventors: Hong, Young-Jun, Kim, Yung-Soo, Kim, Dong-Ho, Jung, Bang-Chul, Sung, Dan-Keun, Cho, Sung-Soo
• Granted Patent: US 8,711,764 B2
• Time in Patent Office: Days
• US Class Current: 455/456.2
• CPC Class Codes: H04L 1/0003 by switching between different modulation schemes
• CPC Class Codes: H04L 1/0009 by adapting the channel coding H04L1/1812 takes precedence
• CPC Class Codes: H04L 1/0015 characterised by the adaptation strategy
• CPC Class Codes: H04L 1/0026 Transmission of channel quality indication
• CPC Class Codes: H04L 1/0027 Scheduling of signalling, e.g. occurrence thereof
• CPC Class Codes: H04L 1/0041 Arrangements at the transmitter end
• CPC Class Codes: H04L 1/0053 specially adapted for power saving
• CPC Class Codes: H04L 1/1819 with retransmission of additional or different redundancy
• CPC Class Codes: H04L 2001/0093 Point-to-multipoint

Abstract

A method and apparatus for transmitting/receiving data in a communication system are provided, in which an MCS level is determined for data, a codeword including the data and a parity is generated by encoding the data using the determined MCS level, code symbols are generated from the codeword using IR scheme, and each of the code symbols is sent in a corresponding subframe.

Claims

1. A method for transmitting data in a communication system, comprising:

determining a Modulation and Coding Scheme (MCS) level for data;

generating a codeword including the data and a parity by encoding the data using the determined MCS level;

generating code symbols from the codeword using Incremental Redundancy (IR) scheme; and

sending each of the code symbols in a corresponding subframe.

2. The method of claim 1, wherein determining the MCS level for data comprises selecting the most robust of available MCS levels in the communication system as the MCS level for the data.

3. The method of claim 1, wherein determining the MCS level for data comprises selecting an MCS level according to the channel status of a data receiver having the most inferior channel status among data receivers for receiving the data as the MCS level for the data.

4. The method of claim 3, further comprising commanding a first data receiver having the most inferior channel status among the data receivers to report a channel status in a first period, and commanding the other data receivers to report channel statuses in a second period.

5. The method of claim 1, wherein generating code symbols from the codeword using IR scheme comprises:

generating a first code symbol to include the data and parity so that the first code symbol is self-decodable; and

generating the other code symbols to include only additional parities for the data.

6. The method of claim 1, wherein the data is Multicast/Broadcast Service (MBS) data.

7. A method for receiving data in a communication system, comprising:

decoding a signal received in a subframe using a first Modulation and Coding Scheme (MCS) level; and

recovering data according to the result of the decoding, if the decoding is successful.

8. The method of claim 7, further comprising:

if the decoding fails combining a signal received in at least one subframe following the received subframe with the received signal;

decoding the combined signal using a second MCS level; and

if the decoding is successful recovering the data according to the result of the decoding.

9. The method of claim 8, wherein combining a signal received in at least one subframe following the received subframe with the received signal comprises combining signals received in all following subframes with the received signal.

10. The method of claim 9, wherein the second MCS level is the most robust of available MCS levels in the communication system.

11. The method of claim 9, wherein the second MCS level is an MCS level determined according to the channel status of a data receiver having the most inferior channel status among data receivers which receive the data.

12. The method of claim 7, further comprising reporting a channel status of a data receiver to a data transmitter in one of a first period and a second period, while simultaneously receiving the subframe.

13. The method of claim 12, wherein the first period is determined when the data receiver is having the most inferior channel status among the data receivers that receive the data, and the second period is determined when the data receiver does not have the most inferior channel status among the data receivers.

14. The method of claim 7, wherein the data is Multicast/Broadcast Service (MBS) data.

15. A data transmitter in a communication system, comprising:

a controller for determining a Modulation and Coding Scheme (MCS) level for data;

an encoder for generating a codeword including the data and a parity by encoding the data using the determined MCS level, and generating code symbols from the codeword using Incremental Redundancy (IR) scheme; and

a transmitter for sending each of the code symbols in a corresponding subframe.

16. The data transmitter of claim 15, wherein the controller selects the most robust of available MCS levels in the communication system as the MCS level for the data.

17. The data transmitter of claim 15, further comprising a Channel Quality Information (CQI) receiver for receiving feedback CQIs each representing the channel status of a data receiver from data receivers for receiving the data.

18. The data transmitter of claim 17, wherein the controller selects an MCS level according to the channel status of a data receiver having the most inferior channel status among data receivers for receiving the data as the MCS level for the data.

19. The data transmitter of claim 18, wherein the controller determines that a data receiver having the most inferior channel status among the data receivers is to report a channel status in a first period and the other data receivers are to report channel statuses in a second period, and controls the transmitter to send one of information about the first period and information about the second period for CQI report to the data receivers.

20. The data transmitter of claim 15, wherein the encoder generates the first of the code symbols to include the data and parity so that the first code symbol is self-decodable, and generate the other code symbols to include only additional parities for the data.

21. The data transmitter of claim 15, wherein the data is Multicast/Broadcast Service (MBS) data.

22. A data receiver in a communication system, comprising:

a receiver for receiving signals in subframes; and

a decoder for decoding a signal received in a subframe using a first Modulation and Coding Scheme (MCS) level, and if the decoding is successful recovering data according to the result of the decoding.

23. The data receiver of claim 22, wherein if the decoding is fails the decoder combines a signal received in at least one subframe following the received subframe with the received signal, decodes the combined signal using a second MCS level, and if the decoding is successful recovers the data according to the result of the decoding.

24. The data receiver of claim 23, wherein the decoder combines signals received in all following subframes with the received signal.

25. The data receiver of claim 24, wherein the second MCS level is the most robust of available MCS levels in the communication system.

26. The data receiver of claim 24, wherein the second MCS level is an MCS level determined according to the channel status of a data receiver having the most inferior channel status among data receivers which receive the data.

27. The data receiver of claim 22, further comprising a Channel Quality Information (CQI) transmitter for reporting the channel status of the data receiver to a data transmitter in one of a first period and a second period.

28. The data receiver of claim 27, wherein the first period is determined when the data receiver is having the most inferior channel status among the data receivers that receive the data, and the second period is determined when the data receiver not having the most inferior channel status among the data receivers.

29. The data receiver of claim 22, wherein the data is Multicast/Broadcast Service (MBS) data.