Error correction code parameter selection in a communication system

• US 7,032,159 B2
• Filed: 10/18/2002
• Issued: 04/18/2006
• Est. Priority Date: 02/28/2002
• Status: Active Grant

• Current Assignee: Texas Instruments, Inc.
• Original Assignee: Texas Instruments, Inc.
• Inventors: Bitran, Yigal, Shalvi, Ofir, Sommer, Naftali, Reznic, Zvi, Lusky, Itay, Yagil, Ariel, Haim, Eli, Bendel, Yosef, Wajcer, Daniel
• Primary Examiner(s): Torres, Joseph D.
• Application Number:
  US10/273,562
• Publication Number:
  US 20030188254A1
• Time in Patent Office: 1,278 Days
• Field of Search: 714/774, 714/784, 714/704, 714/708
• US Class Current: 714/774
• CPC Class Codes: H04L 1/0001 Systems modifying transmission characteristics according to link quality, e.g. power backoff adaptive data allocation for multicarrier modulation H04L5/0044; controlling transmission power for radio systems H04W52/04
• CPC Class Codes: H04L 1/0003 by switching between different modulation schemes
• CPC Class Codes: H04L 1/0017 where the mode-switching is based on Quality of Service requirement
• CPC Class Codes: H04L 1/0019 in which mode-switching is based on a statistical approach
• CPC Class Codes: H04L 1/20 using signal quality detector
• CPC Class Codes: Y02D 30/50 in wire-line communication networks, e.g. low power modes or reduced link rate

Abstract

A method is disclosed for providing data for automatically estimating channel performance if different parameters of a Reed-Solomon (RS) code are used in a communication system while transmission is occurring in the communication system without changing the current Reed-Solomon (RS) code parameters.

Claims

1. A method for estimating expected performance of a receiver in a communication system using different parameters of a Reed-Solomon (RS) code while transmission is occurring in the communication system without changing parameters of a current RS code, the method comprising:

receiving RS symbols in an input signal from the channel;

processing the input signal in a RS decoder to decode the received RS symbols and generate an RS coded output of “

N”

RS symbols;

selecting a virtual RS code comprising “

M”

sequential RS symbols,

determining a number of erred RS symbols in the virtual RS code;

determining length of RS error events by determining a number of sequential erred RS symbols in the virtual RS code, wherein RS error events are sequential erred RS symbols;

using the number of erred RS symbols in the virtual RS code and lengths of RS error events, developing a histogram to determine updated parameters including a minimum number “

t”

of RS symbols that must be corrected and a maximal information symbols “

K”

that can be transmitted in the virtual RS code of length “

M”

that provides a RS frame error rate that is lower than a predetermined target RS frame error rate, wherein M=K+2t; and

updating current parameters of the current RS code using the updated parameters.

2. A method according to claim 1, wherein “

M”

RS symbols are selected from the “

N”

RS symbols.

3. A method according to claim 1, wherein “

M”

is greater than “

N” and

the virtual RS code includes multiple of “

N”

RS symbols.

4. A method according to claim 1, wherein the number of erred RS symbols in the virtual RS code are determined using feedback from the RS decoder.

5. A method according to claim 1, wherein the histogram includes one or more of total number of erred RS symbols with RS codeword of virtual length “

M” and

a histogram counting one or more RS error events.

6. A method according to claim 1, wherein the virtual RS frame error rate is given as $\mathrm{FER}=\sum _{}^{}$

t=i+1t_Max+1⁢

⁢

RS_Error⁢

_Num⁢

_Histogram⁢

(i)<

FER_Target

wherein, FER is the RS frame error rate, “

t”

is the number of errors that can be corrected by the selected virtual RS code, t₁₃ Max is a maximum number of symbols that a strongest RS code can correct in the communication system, RS_Error_Num_Histogram is a RS number of errors histogram, and FER_Target is the predetermined target RS frame error rate.

7. A method according to claim 1, further comprising:

prior to developing the histogram,

processing the “

M”

RS symbols in a first interleaver using parameters of the current data burst, wherein an output of the first interleaver represents the input signal as transmitted on the channel; and

processing an output of the first interleaver in a deinterleaver using the virtual RS code.

8. A method according to claim 7, further comprising:

based on the histogram, processing the output of the deinterleaver using the virtual RS code size of length “

M”

that provides a RS frame error rate that is lower than a predetermined target RS frame error rate.

9. A method according to claim 1, further comprising:

iteratively selecting a different value for “

M”

to determine an optimal combination of the virtual RS code of size “

M”

with ability to correct “

t”

RS symbol that provides the RS frame error rate that is lower than the predetermined target RS frame error rate.

10. A method according to claim 1, further comprising:

processing the output of the RS decoder to generate binary vector symbols indicating error events caused by noise in the input signal wherein a value of “

1”

represents an erred symbol and a value of “

0”

represent that corresponding symbol is not erred; and

using the binary vector symbols to determine an optimal combination of the virtual RS code of size “

M”

with ability to correct “

t”

RS symbol that provides the RS frame error rate that is lower than the predetermined target RS frame error rate, wherein the binary vector symbols are used to determine parameters of an interleaver and a deinterleaver that provides an optimal size of the virtual RS code.

11. A communication device for estimating performance of a channel in a communication system using different parameters of a Reed-Solomon (RS) code while transmission is occurring in the communication system without changing parameters of a current RS code, the device comprises:

means for receiving RS symbols in an input signal from the channel;

means for processing the input signal in a RS decoder, to decode the received RS symbols and generate an RS coded output of “

N”

RS symbols;

means for selecting a virtual RS code comprising “

M”

sequential RS symbols,

means for determining a number of erred RS symbols in the virtual RS code;

means for determining length of RS error events by determining a number of sequential erred RS symbols in the virtual RS code, wherein RS error events are sequential erred RS symbols;

means for using the number of erred RS symbols in the virtual RS code and lengths of RS error events to develop a histogram to determine updated parameters including a minimum number “

t”

of RS symbols that must be corrected and a maximal information symbols “

K”

that can be transmitted in the virtual RS code of length “

M”

that provides a RS frame error rate that is lower than a predetermined target RS frame error rate, wherein M=K+2t; and

means for updating current parameters of the current RS code using the updated parameters.

12. A communication device according to claim 11, wherein “

M”

RS symbols are selected from the “

N”

RS symbols.

13. A communication device according to claim 11, wherein “

M”

is greater than “

N” and

the virtual RS code includes multiple of “

N”

RS symbols.

14. A method according to claim 11, wherein the number of erred RS symbols in the virtual RS code are determined using feedback from the RS decoder.

15. A communication device according to claim 11, wherein the histogram includes one or more of total number of erred RS symbols with RS codeword of virtual length “

M” and

a histogram counting one or more RS error events.

16. A communication device according to claim 11, wherein the RS frame error rate is given as $\mathrm{FER}=\sum _{}^{}$

t=i+1t_Max+1⁢

⁢

RS_Error⁢

_Num⁢

_Histogram⁢

(i)<

FER_Target

wherein, FER is the RS frame error rate, “

t”

is the number of errors that can be corrected by the selected virtual RS code, t_Max is a maximum number of symbols that a strongest RS code can correct in the communication system, RS_Error_Num_Histogram is a RS number of errors histogram, and FER₁₃ Target is the predetermined target RS frame error rate.

17. A communication device according to claim 11, further comprising:

means for processing the “

M”

RS symbols in a first interleaver using parameters of the current data burst, wherein an output of the first interleaver represents the input signal as transmitted on the channel; and

means for processing an output of the first interleaver in a deinterleaver using the virtual RS code.

18. A communication device according to claim 17, further comprising:

means for processing the output of the deinterleaver using the virtual RS code size of length “

M”

that provides a RS frame error rate that is lower than a predetermined target RS frame error rate.

19. A communication device according to claim 11, further comprising:

means for iteratively selecting a different value for “

M”

to determine an optimal combination of the virtual RS code of size “

M”

with ability to correct “

t”

RS symbol that provides the RS frame error rate that is lower than the predetermined target RS frame error rate.

20. A communication device according to claim 11, further comprising:

means for processing the output of the RS decoder to generate binary vector symbols indicating error events caused by noise in the input signal wherein a value of “

1”

represents an erred symbol and a value of “

0”

represent that corresponding symbol is not erred; and

means for using the binary vector symbols to determine an optimal combination of the virtual RS code of size “

M”

with ability to correct “

t”

RS symbol that provides the RS frame error rate that is lower than the predetermined target RS frame error rate, wherein the binary vector symbols are used to determine parameters of an interleaver and a deinterleaver that provides an optimal size of the virtual RS code.

21. A communication receiver comprising:

a RS decoder configured to decode RS symbols in an input signal received from a channel and further configured to generate an RS coded output of “

N”

RS symbols;

a histogram unit coupled to the RS decoder, the histogram unit is configured to develop a histogram to determine updated parameters for the RS decoder including a minimum number “

t”

of RS symbols that must be corrected and a maximal information symbols “

K”

that can be transmitted in a virtual RS code of length “

M”

sequential RS symbols that provides a RS frame error rate that is lower than a predetermined target RS frame error rate, wherein M =K+2t.

22. The communication receiver of claim 21, wherein “

M”

sequential RS symbols are selected from the “

N”

RS symbols.

23. A communication receiver according to claim 21, wherein M is greater than N and the virtual RS code includes multiple of “

N”

symbols.

24. A communication receiver according to claim 21, wherein the histogram includes one or more of total number of erred RS symbols with RS codeword of virtual length “

M” and

a histogram counting one or more RS error events.

25. A communication receiver according to claim 21, wherein the RS frame error rate is given as $\mathrm{FER}=\sum _{}^{}$

t=i+1t_Max+1⁢

⁢

RS_Error⁢

_Num⁢

_Histogram⁢

(i)<

FER_Target

wherein, FER is the RS frame error rate, “

t”

is the number of errors that can be corrected by the selected virtual RS code, t_Max is a maximum number of symbols that a strongest RS code can correct in the communication system, RS_Error_Num_Histogram is a RS number of errors histogram, and FER_Target is the predetermined target RS frame error rate.

26. A communication receiver according to claim 21, further comprising:

a first deinterleaver coupled to the RS decoder and configured to process the input signal received from the channel;

a first interleaver coupled to the RS decoder and configured to process an output of the RS decoder using properties of a current burst profile.

27. A communication receiver according to claim 26, further comprising:

a second deinterleaver coupled to the first interleaver and configured to process the output of the second interleaver using the virtual RS code size of length “

M”

that provides a RS frame error rate that is lower than a predetermined target RS frame error rate.

28. A communication receiver according to claim 21, further comprising:

a binary vector generator unit coupled to the channel and configured to generate binary vector symbols indicating error events caused by noise in the input signal.