APPLICATION-AWARE DYNAMIC BIT-LEVEL ERROR PROTECTION FOR MODULATION-BASED COMMUNICATION

• US 20130215942A1
• Filed: 02/22/2012
• Published: 08/22/2013
• Est. Priority Date: 02/22/2012
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Addepalli, Sateesh K., Lee, Kevin C., Sudhaakar, Raghuram S., Vasseur, Jean-Philippe, Bonomi, Flavio
• Granted Patent: US 8,761,285 B2
• Time in Patent Office: Days
• US Class Current: 375/224
• CPC Class Codes: H04L 1/007 Unequal error protection for format H04L1/0078; for codes per se H03M13/35
• CPC Class Codes: H04L 1/0075 Transmission of coding parameters to receiver H04L1/0023 takes precedence
• CPC Class Codes: H04L 27/345 Modifications of the signal space to allow the transmission of additional information
• CPC Class Codes: H04L 27/3472 by switching between alternative constellations
• CPC Class Codes: H04L 5/005 of common pilots, i.e. pilots destined for multiple users or terminals
• CPC Class Codes: H04L 5/0055 Physical resource allocation for ACK/NACK for physical mapping arrangements in ARQ protocols H04L1/1861

Abstract

In one embodiment, a device (e.g., a transmitter) determines a level of error protection of each bit position within symbols of a particular constellation map used for modulation-based communication, and also determines priority levels of application data bits to be placed into a communication frame. Application data bits may then be placed into symbols of the communication frame, where higher priority application data bits are placed into bit positions with greater or equal levels of protection than bit positions into which lower priority application data bits are placed. The communication frame may then be transmitted to one or more receivers with an indication of how to decode the placement of the application data bits within the symbols. In another embodiment, the particular constellation map may be dynamically selected from a plurality of available constellation maps, such as based on communication channel conditions and/or applications generating the data.

Claims

1. A method, comprising:

determining a level of error protection of each bit position within symbols of a particular constellation map used for modulation-based communication;

determining priority levels of application data bits to be placed into a communication frame;

placing the application data bits into symbols of the communication frame, wherein higher priority application data bits are placed into bit positions with greater or equal levels of protection than bit positions into which lower priority application data bits are placed; and

transmitting the communication frame to one or more receivers with an indication of how to decode the placement of the application data bits within the symbols.

2. The method as in claim 1, further comprising:

dynamically selecting the particular constellation map from a plurality of available constellation maps; and

informing the one or more receivers of which particular constellation map to use to decode the symbols of the communication frame.

3. The method as in claim 2, further comprising:

dynamically selecting the particular constellation map based on one or more applications corresponding to the application data bits.

4. The method as in claim 2, further comprising:

dynamically selecting the particular constellation map based on communication channel conditions.

5. The method as in claim 4, further comprising:

determining the communication channel conditions by;

transmitting known pilot symbols to the one or more receivers, wherein the receivers are configured to decode the pilot symbols using the plurality of constellation maps; and

receiving from the one or more receivers a bit error rate (BER) value for each of the bit positions of the pilot symbols for each of the plurality of constellation maps.

6. The method as in claim 5, further comprising:

receiving the BER values in an acknowledgment message from the one or more receivers.

7. The method as in claim 1, wherein the particular constellation map is dynamically selected by a network management device, the method comprising:

receiving the particular constellation map from the network management device, wherein the particular constellation map is shared among all devices of a communication network.

8. The method as in claim 1, further comprising:

placing bits in order of priority into bit positions in order of levels of protection.

9. The method as in claim 1, wherein the indication comprises a number of bits in each priority level, wherein the one or more receivers are configured to decode the placement of the application data bits within the symbols by partitioning the placement of application data bits in reverse according to the number of bits in each priority level.

10. The method as in claim 1, wherein control-based application data bits have a higher priority that data-based application data bits.

11. The method as in claim 1, wherein modulation-based communication is selected from a group consisting of:

Quadrature Amplitude Modulation (QAM);

Phase Shift Keying (PSK);

Pulse Position Modulation (PPM); and

Frequency Shift Keying (FSK).

12. The method as in claim 1, wherein the constellation map is arranged according to a mapping selected from a group consisting of:

Gray code; and

block code.

13. An apparatus, comprising:

one or more network interfaces to communicate with receivers in a communication network;

a processor coupled to the network interfaces and adapted to execute one or more processes; and

a memory configured to store a process executable by the processor, the process when executed operable to;

determine a level of error protection of each bit position within symbols of a particular constellation map used for modulation-based communication;

determine priority levels of application data bits to be placed into a communication frame;

place the application data bits into symbols of the communication frame, wherein higher priority application data bits are placed into bit positions with greater or equal levels of protection than bit positions into which lower priority application data bits are placed; and

transmit the communication frame to one or more receivers with an indication of how to decode the placement of the application data bits within the symbols.

14. The apparatus as in claim 13, wherein the process when executed is further operable to:

dynamically select the particular constellation map from a plurality of available constellation maps; and

inform the one or more receivers of which particular constellation map to use to decode the symbols of the communication frame.

15. The apparatus as in claim 14, wherein the process when executed is further operable to:

dynamically select the particular constellation map based on one or more applications corresponding to the application data bits.

16. The apparatus as in claim 14, wherein the process when executed is further operable to:

dynamically select the particular constellation map based on communication channel conditions.

17. The apparatus as in claim 16, wherein the process when executed to determine the communication channel conditions is further operable to:

transmit known pilot symbols to the one or more receivers, wherein the receivers are configured to decode the pilot symbols using the plurality of constellation maps; and

receive from the one or more receivers a bit error rate (BER) value for each of the bit positions of the pilot symbols for each of the plurality of constellation maps.

18. A tangible, non-transitory, computer-readable media having software encoded thereon, the software when executed by a processor operable to:

determine a level of error protection of each bit position within symbols of a particular constellation map used for modulation-based communication;

determine priority levels of application data bits to be placed into a communication frame;

place the application data bits into symbols of the communication frame, wherein higher priority application data bits are placed into bit positions with greater or equal levels of protection than bit positions into which lower priority application data bits are placed; and

transmit the communication frame to one or more receivers with an indication of how to decode the placement of the application data bits within the symbols.

19. The computer-readable media as in claim 18, wherein the software when executed is further operable to:

dynamically select the particular constellation map from a plurality of available constellation maps; and

inform the one or more receivers of which particular constellation map to use to decode the symbols of the communication frame.

20. The computer-readable media as in claim 19, wherein the software when executed is further operable to:

dynamically select the particular constellation map based on one or more applications corresponding to the application data bits.

21. The computer-readable media as in claim 19, wherein the software when executed is further operable to:

transmit known pilot symbols to the one or more receivers, wherein the receivers are configured to decode the pilot symbols using the plurality of constellation maps;

receive from the one or more receivers a bit error rate (BER) value for each of the bit positions of the pilot symbols for each of the plurality of constellation maps;

determine communication channel conditions based on the BER values; and

dynamically select the particular constellation map based on the communication channel conditions.

22. A method, comprising:

transmitting known pilot symbols to one or more receivers to cause the receivers to decode the pilot symbols using a plurality of constellation maps used for modulation-based communication;

receiving from the one or more receivers a bit error rate (BER) value for each bit position of the pilot symbols for each of the plurality of constellation maps;

determining communication channel conditions based on the BER values;

dynamically selecting a particular constellation map from the plurality of available constellation maps based on the communication channel conditions; and

informing the one or more receivers of which particular constellation map to use to decode symbols of a transmitted communication frame.

23. The method as in claim 22, further comprising:

determining a level of error protection of each bit position within symbols of the particular constellation map;

determining priority levels of application data bits to be placed into the communication frame;

placing the application data bits into symbols of the communication frame, wherein higher priority application data bits are placed into bit positions with greater or equal levels of protection than bit positions into which lower priority application data bits are placed; and

transmitting the communication frame to one or more receivers with an indication of how to decode the placement of the application data bits within the symbols.