SELF-ADAPTIVELY IMPROVING SYSTEM STABILITY

• US 20150029952A1
• Filed: 03/12/2013
• Published: 01/29/2015
• Est. Priority Date: 03/12/2013
• Status: Active Grant

• Current Assignee: Empire Technology Development LLC (Allied Inventors Management, LLC)
• Original Assignee: Empire Technology Development LLC (Allied Inventors Management, LLC)
• Inventors: Huang, Anpeng
• Granted Patent: US 9,729,270 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• 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 1/1812 Hybrid protocols; Hybrid automatic repeat request [HARQ]
• CPC Class Codes: H04L 1/1819 with retransmission of additional or different redundancy

Abstract

In a wireless communication system, a base station may adopt AMC and HARQ mechanisms to improve the system stability and may further be configured to combine the feedback features of AMC and HARQ to save computing resources.

Claims

1. A method, comprising:

transmitting data wirelessly; and

implementing link adaptation in subsequent wireless data transmission by using a combination of features from a hybrid automatic repeat request (HARQ) procedure and an adaptive modulation and coding (AMC) technique.

2. The method of claim 1, wherein the combination of features from the HARQ procedure and the AMC technique comprises:

receiving, by a transmitter, one or more acknowledgement (ACK) messages or one or more negative-acknowledgement (NACK) messages from a receiver in accordance with the HARQ procedure with respect to the data transmitted;

determining a number of the received ACK messages and a number of the received NACK messages during a predefined period of time; and

adjusting a modulation and coding scheme (MCS) used in the subsequent wireless data transmission based on the number of ACK messages or the number of NACK messages received during the predefined period of time.

3. The method of claim 2, wherein the adjusting the MCS comprises:

increasing the MCS to a higher level in response to the number of ACK messages received during the predefined period of time being greater than a number of ACK messages received during a previous predefined period of time.

4. The method of claim 2, wherein the adjusting the MCS comprises:

decreasing the MCS to a lower level in response to the number of NACK messages received during the predefined period of time being greater than a number of NACK messages received during a previous period of time.

5. The method of claim 2, wherein the adjusting the MCS comprises:

increasing the MCS to a higher level in response to the number of ACK messages received during the predefined period of time being greater than a first ACK threshold value; and

decreasing the MCS to a lower level in response to the number of ACK messages received during the predefined period of time being less than a second ACK threshold value.

6. The method of claim 2, wherein the adjusting the MCS comprises:

increasing the MCS to a higher level in response to the number of NACK messages received during the predefined period of time being less than a first NACK threshold value; and

decreasing the MCS to a lower level in response to the number of NACK messages received during the predefined period of time being greater than a second NACK threshold value.

7. The method of claim 1, wherein the transmitting data wirelessly comprises transmitting the data in accordance with the Long Term Evolution (LTE) standard.

8. A method, comprising:

transmitting data wirelessly using a hybrid automatic repeat request (HARQ) procedure in which one or more acknowledgement (ACK) messages or one or more negative-acknowledgement (NACK) messages, or both, are received by a transmitter from a receiver in accordance with the HARQ procedure with respect to the data transmitted;

monitoring a number of ACK messages or a number of NACK messages received by the transmitter from the receiver during each of a plurality of durations of a given length; and

adjusting a modulation and coding scheme (MCS) used in wireless data transmission based on changes in the number of ACK messages or the number of NACK messages received from one duration to a next duration of the plurality of durations.

9. The method of claim 8, wherein the adjusting the MCS comprises:

increasing the MCS to a higher level in response to an increase in the number of ACK messages received from the one duration to the next duration of the plurality of durations.

10. The method of claim 9, further comprising:

decreasing the MCS to a lower level in response to a decrease in the number of ACK messages received from the one duration to the next duration of the plurality of durations.

11. The method of claim 8, wherein the adjusting the MCS comprises:

decreasing the MCS to a lower level in response to an increase in the number of NACK messages received from the one duration to the next duration of the plurality of durations.

12. The method of claim 11, further comprising:

increasing the MCS to a higher level in response to a decrease in the number of NACK messages received from the one duration to the next duration of the plurality of durations.

13. The method of claim 8, wherein the transmitting data wirelessly comprises transmitting the data in accordance with the Long Term Evolution (LTE) standard.

14. A computer-readable medium storing instructions that, when executed, cause one or more processors to perform operations comprising:

transmitting data wirelessly using a hybrid automatic repeat request (HARQ) procedure in which one or more acknowledgement (ACK) messages or one or more negative-acknowledgement (NACK) messages, or both, are received by a transmitter from a receiver in accordance with the HARQ procedure with respect to the data transmitted;

determining a number of ACK messages and a number of NACK messages received during a predefined period of time; and

adjusting a modulation and coding scheme (MCS) used in data transmission based on the number of ACK messages or the number of NACK messages received during the predefined period of time.

15. The computer-readable medium of claim 14, wherein the adjusting the MCS comprises:

increasing the MCS to a higher level in response to the number of ACK messages received during the predefined period of time being greater than a number of ACK messages received during a previous period of time.

16. The computer-readable medium as recited in claim 14, wherein the adjusting the MCS comprises:

decreasing the MCS to a lower level in response to the number of NACK messages received during the predefined period of time being greater than a number of NACK messages received during a previous period of time.

17. The computer-readable medium of claim 14, wherein the adjusting the MCS comprises:

increasing the MCS to a higher level in response to the number of ACK messages received during the predefined period of time being greater than a first ACK threshold value; and

decreasing the MCS to a lower level in response to the number of ACK messages received during the predefined period of time being less than a second ACK threshold value.

18. The computer-readable medium of claim 14, wherein the adjusting the MCS comprises:

increasing the MCS to a higher level in response to the number of NACK messages received during the predefined period of time being less than a first NACK threshold value; and

decreasing the MCS to a lower level in response to the number of NACK messages received during the predefined period of time being greater than a second NACK threshold value.

19. The computer-readable medium of claim 14, wherein the transmitting data wirelessly comprises transmitting the data in accordance with the Long Term Evolution (LTE) standard.