Management of variable-rate communication links

• US 8,315,574 B2
• Filed: 04/13/2007
• Issued: 11/20/2012
• Est. Priority Date: 04/13/2007
• Status: Active Grant

• Current Assignee: Maxlinear Israel Ltd. (Maxlinear Incorporated)
• Original Assignee: Broadcom Corporation (Broadcom, Inc.)
• Inventors: Ashkenazi, Ehud, Friedman, Jonathan
• Primary Examiner(s): Anderson, Matthew
• Assistant Examiner(s): HANIDU, GANIYU A
• Application Number:
  US11/787,059
• Publication Number:
  US 20080254749A1
• Time in Patent Office: 2,048 Days
• Field of Search: 455/67.15, 455/69, 455/703, 455/63.1, 455/464, 455/17, 375/267, 375/222, 375/219, 375/262, 375/142, 375/227, 370/232, 370/252, 370/465, 370/222, 370/347
• US Class Current: 455/69
• 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 1/0017 where the mode-switching is based on Quality of Service requirement
• CPC Class Codes: H04L 1/0026 Transmission of channel quality indication

Abstract

A method for communication includes transmitting data from a transmitter to a receiver using Adaptive Coding and Modulation (ACM). The data rate is set by selecting, based on feedback, an ACM profile defining a Forward Error Correction code and a modulation scheme. Upon detecting that the feedback is unusable, an operation of the transmitter is changed independently of the feedback.

In another method, data is exchanged over two opposite directions of a bidirectional link that uses ACM by communicating using two ACM profiles. A joint constraint is defined on the two directions. The two ACM profiles are set based on first and second measured reception quality metrics of the two link directions, to meet the joint constraint. In yet another method, a subset of the ACM profiles is temporarily disabled, and the data is transmitted using only the ACM profiles that are not disabled.

Claims

1. A method for communication, comprising:

exchanging data between first and second communication systems over first and second opposite directions of a bidirectional wireless communication link, such that transmission over both the first and second directions uses Adaptive Coding and Modulation (ACM) by communicating at respective first and second variable data rates that are determined by respective first and second ACM profiles;

measuring respective first and second reception quality metrics of the first and second directions of the communication link,

wherein the first reception quality metric is measured at the first communication system, and the second reception quality metric is measured at the second communication system, and

wherein the first and second reception quality metrics are measured at substantially simultaneous instances; and

setting at least the first ACM profile for the first direction based on current measurements of both the first and the second substantially simultaneously measured reception quality metrics.

2. The method according to claim 1, wherein setting at least the first ACM profile comprises selecting the first and second ACM prof les from a predefined set of possible ACM profiles that define respective FEC codes and modulation schemes.

3. The method according to claim 1, wherein the reception quality metrics comprise at least one metric type selected from a group of metric types consisting of a Received Signal Level (RSL), a Signal to Noise Ratio (SNR), a Signal to Interference and Noise Ratio (SINR), a Mean Square Error (MSE), a Bit Error Rate (BER), a Frame Error Rate (FER) and a metric produced by a decoding process of the FEC.

4. The method according to claim 1, wherein setting at least the first ACM profile comprises at least one of setting the first ACM profile to be equal to the second ACM profile, or setting both the first and the second directions of the communication link to meet a predefined Quality-of-Service (QoS) level.

5. The method according to claim 1, wherein setting at least the first ACM profile comprises selecting the first and second ACM profiles by the first communication system, and instructing the second communication system by the first communication system to set the selected ACM profiles.

6. The method according to claim 1, wherein setting at least the first ACM profile comprises selecting the first ACM profile by the first communication system, detecting the selected first ACM profile by the second communication system, and selecting the second ACM profile by the second communication system responsively to the first ACM profile.

7. The method according to claim 1, wherein the communication link is one of a plurality of bidirectional communication links in a point-to-multipoint system, and wherein setting at least the first ACM profile comprises setting the ACM profiles of the first and second directions of the communication links in the plurality.

8. The method according to claim 1, wherein the wireless communication link comprises one of a microwave link and a millimeter wave link.

9. The method according to claim 1, wherein the data exchanged in the first direction of the communication link is transmitted in first time intervals, and wherein the data exchanged in the second direction of the communication link is transmitted in second time intervals that do not overlap the first time intervals.

10. The method according to claim 1, wherein the data exchanged in the first direction of the communication link is transmitted in a first radio frequency, and wherein the data exchanged in the second direction of the communication link is transmitted in a second radio frequency that is different from the first radio frequency.

22. The method according to claim 1, wherein setting at least the first ACM profile comprises at least one of setting at least the first ACM profile to an ACM profile having a lowest ACM profile among the possible AMC profiles, setting at least the first ACM profile to an ACM profile having a next, lowest ACM profile among the possible AMC profiles, or selecting at least the first ACM profile from a partial subset of all the possible ACM profiles.

11. A bidirectional wireless communication link having first and second opposite directions, the link comprising first and second communication systems, which are arranged to exchange data over the first and second opposite directions, such that transmission over both the first and second directions uses Adaptive Coding and Modulation (ACM) by communicating at respective first and second variable data rates that are determined by respective first and second ACM profiles,

wherein the first and second communication systems are arranged to measure respective first and second reception quality metrics of the first and second directions of the communication link, and

wherein the first reception quality metric is measured at the first communication system, and the second reception quality metric is measured at the second communication system, and

wherein the first and second reception quality metrics are measured substantially simultaneously, and

wherein the first and second communication systems are arranged to set at least the first ACM profile for the first direction based on current measurements of both the first and the second substantially simultaneously measured reception quality metrics.

12. The link according to claim 11, wherein the first and second communication systems are arranged to select the first and second ACM profiles from a predefined set of possible ACM profiles that define respective FEC codes and modulation schemes.

13. The link according to claim 11, wherein the reception quality metrics comprise at least one metric type selected from a group of metric types consisting of a Received Signal Level (RSL), a Signal to Noise Ratio (SNR), a Signal to Interference and Noise Ratio (SINR), a Mean Square Error (MSE), a Bit Error Rate (BER), a Frame Error Rate (FER) and a metric produced by a decoding process of the FEC.

14. The link according to claim 11, wherein the first and second communication systems are arranged to set the first ACM profile to be equal to the second ACM profile.

15. The link according to claim 11, wherein the first and second communication systems are arranged to set both the first and the second directions to meet a predefined Quality-of-Service (QoS) level.

16. The link according to claim 11, wherein the first communication system is arranged to select the first and second ACM profiles and to instruct the second communication system to set the selected ACM profiles.

17. The link according to claim 11, wherein the first communication system is arranged to select the first ACM profile, and wherein the second communication system is arranged to detect the selected first ACM profile by the first communication system and to select the second ACM profile responsively to the first ACM profile.

18. The link according to claim 11, wherein the communication link is one of plurality of bidirectional communication links in a point-to multipoint system, and wherein one of the communication systems is arranged to set the ACM profiles of the first and second directions of the communication links in the plurality.

19. The link according to claim 11, wherein the wireless communication link comprises one of a microwave link and a millimeter wave link.

20. The link according to claim 11, wherein the first and second communication systems are arranged to exchange the data in the first direction of the communication link in the first time intervals, and to exchange to data in the second direction of the communication link in second time intervals that do not overlap the first time intervals.

21. The link according to claim 11, wherein the first and second communication systems are arranged to exchange the data in the first direction of the communication link in a first radio frequency, and to exchange the data in the second direction of the communication link in a second radio frequency that is different from the first radio frequency.