Method for early decoding of control channel information

• US 20040179586A1
• Filed: 03/14/2003
• Published: 09/16/2004
• Est. Priority Date: 03/14/2003
• Status: Active Grant

• Current Assignee: WSOU Investments, LLC (WSOU Holdings, LLC)
• Original Assignee: Lucent Technologies, Inc. (Nokia Corporation)
• Inventors: Yang, Yunsong, Vasudevan, Subramanian, Zhang, Wenfeng
• Granted Patent: US 7,430,241 B2
• Time in Patent Office: Days
• US Class Current: 375/219
• 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 1/001 applied to control information
• CPC Class Codes: H04L 1/0032 Without explicit signalling
• CPC Class Codes: H04L 1/0038 Blind format detection for detection of modulation format H04L27/0012
• CPC Class Codes: H04L 1/0046 Code rate detection or code type detection H04L1/0038 takes precedence; detection of the data rate H04L25/0262; for packet format H04L1/0091
• CPC Class Codes: H04L 1/0059 Convolutional codes
• CPC Class Codes: H04L 1/0071 Use of interleaving interleaving per se H03M13/27
• CPC Class Codes: H04L 1/0072 Error control for data other than payload data, e.g. control data
• CPC Class Codes: H04L 1/08 by repeating transmission, e.g. Verdan system H04L1/1858 and H04L1/189 take precedence

Abstract

A system and method for transmitting and receiving control information over a control channel of a wireless communication system where the conveyed information is coded and then transformed by a set of transform function selected from a plurality of sets of transform functions. The control information is transmitted as replicated sub-frames containing replicated code words and such a string of transformed replicated code words is referred to as a control message. At a receive end inverse transform functions from different sets of functions are applied to a sub-frame of a control message so that if the sub-frame is successfully decoded the inverse transform function applied to such frame allows the timing of the control message to be determined.

Claims

1. A method for transmitting information comprising:

applying to a number of replicated information blocks a set of transform functions forming a string of transformed replicated information blocks where each transformed block is transmitted during time periods of equal length.

2. The method of claim 1 where the set of transform functions has a certain number of functions equal to the number of replicated coded blocks.

3. The method of claim 1 where a different transform function from the set is consecutively applied to each information block.

4. The method of claim 1 wherein each transformed block is transmitted during time periods of equal length.

5. The method of claim 1 where the step of applying a set of distinct transform function to a number of replicated information blocks comprises the steps of:

selecting one set of transform functions from a plurality of sets where such selection is based on an algorithm;

coding the information to be transmitted; and

replicating the coded information a certain number of times equal to the number of transform functions in the selected set.

6. The method of claim 1 where the step of applying further comprises generating K sets of transform functions each denoted as T_<

M,m>

(·

) indicating an m^th transform function from a total of M transform functions in a set and where m=0, . . . , M-1 where M is referred to as a repetition factor and M and K, are integers equal to 1 or greater and further the transform functions of the K sets meet the following criteria;

(a) each transform function of the K sets of transform function is unique;

(b) each transform function of the K sets of transform function has an associated inverse transform function such that when the inverse transform function is applied to its associated transform function, the two transform functions neutralize each other;

(c) applying an inverse transform function to a non-associated transfer function that is applied to a block of information will not yield the block of information.

7. The method of claim 1 where the transform functions are implemented with linear operations.

8. The method of claim 7 where the linear operations are implemented with interleaving operations and/or scrambling operations.

9. The method of claim 8 where a decimated scrambling operation is performed prior to the interleaving operation.

10. The method of claim 7 where the linear operations are implemented as a circular shift operation.

11. The method of claim 1 where the string of transformed replicated coded blocks is a transformed control message and the time periods of equal lengths are sub-frames and such transformed control message is transmitted over a control channel of a wireless communication system.

12. A method for receiving information by a receiver, the method comprising:

applying to one or more blocks of received information, which information has a certain timing, inverse transform functions from different sets of functions, resulting in processed blocks for the different sets where a successful decoding of a sum of processed blocks from one of the sets allows the timing of the received information to be determined.

13. The method of claim 12 where a decoding operation is performed after a boundary of a block of received information is detected and the received blocks have equal time periods.

14. The method of claim 12 where a sum of the processed blocks is a sum of the current processed block and all the previous processed blocks for a particular set of inverse transform functions.

15. The method of claim 12 where the inverse transform functions are implemented with linear operations.

16. The method of claim 15 where the linear operations are deinterleaving and descrambling operations.

17. The method of claim 12 where the received block is a sub-frame of a control message having a plurality of sub-frames where a transform function from a set of transform functions has been applied to each sub-frame and where such control message is transmitted over a control channel of a wireless communication system and the timing of the control message is determined from the set of inverse transforms that allowed a successful decoding operation.

18. The method of claim 17 where the control message'"'"'s length and start time are part of the timing of the control message and are not known by the receiver.

19. A system for transmitting information comprising:

a transform processor having at least one transmitter processing unit configured to perform certain operations on coded information in accordance with one of a plurality of sets of transform functions generated by the transform processor where the one set has at least one function; and

the one set is selected by the transform processor based on an algorithm and the transform processor applies each function of the set consecutively to a replicated string of coded information

20. The system of claim 19 where the at least one transmitter processing unit comprises a scrambler coupled to an interleaver.

21. A system for receiving information comprising:

an inverse transform processor having at least one receiver processing unit configured to perform linear operations on a block of received information in accordance with a plurality of sets of inverse transform functions generated by the transform processor where the at least one receiver processing unit is configured to apply inverse transform functions from the different sets to the received block of information yielding a processed received block for each of the different sets;

and the at least one receiver processing unit is further configured to sum the processed received blocks from each of the sets and determine the timing of the received information based on the set of inverse transform functions from which a successful decode of a sum was obtained.

22. The system of claim 21 where early decoding can occur in that a successful decode occurs without having to decode an entire string of received blocks of information

23. The system of claim 21 where the at least one receiver processing unit comprises a deinterleaver coupled to a descrambler.

24. The system of claim 21 where the at least one receiver processing unit is configured to detect boundaries between received blocks of information.