MODULATION AND EQUALIZATION IN AN ORTHONORMAL TIME-FREQUENCY SHIFTING COMMUNICATIONS SYSTEM

• US 20140169437A1
• Filed: 06/25/2013
• Published: 06/19/2014
• Est. Priority Date: 05/26/2011
• Status: Active Grant

• Current Assignee: Cohere Technologies Inc
• Original Assignee: Cohere Technologies Inc
• Inventors: Hadani, Ronny, Rakib, Salim Shlomo
• Granted Patent: US 9,071,286 B2
• Time in Patent Office: Days
• US Class Current: 375/232
• CPC Class Codes: H04B 7/005 Control of transmission; Equalising
• CPC Class Codes: H04L 23/02 adapted for orthogonal signalling
• CPC Class Codes: H04L 25/03343 Arrangements at the transmitter end
• CPC Class Codes: H04L 25/03834 using pulse shaping
• CPC Class Codes: H04L 27/01 Equalisers baseband equalizers at the transmitter end H04L25/03343; in analogue transmission systems H04B3/04, H04B7/005
• CPC Class Codes: H04L 27/10 Frequency-modulated carrier systems, i.e. using frequency-shift keying H04L27/32 takes precedence
• CPC Class Codes: H04L 27/2639 Modulators using other transforms, e.g. discrete cosine transforms, Orthogonal Time Frequency and Space [OTFS] or hermetic transforms
• CPC Class Codes: H04L 27/26532 Demodulators using other transforms, e.g. discrete cosine transforms, Orthogonal Time Frequency and Space [OTFS] or hermetic transforms
• CPC Class Codes: H04L 27/2655 Synchronisation arrangements
• CPC Class Codes: H04L 27/2697 in combination with other modulation techniques
• CPC Class Codes: H04L 5/0005 Time-frequency
• CPC Class Codes: H04L 5/0016 Time-frequency-code
• CPC Class Codes: H04L 5/0044 allocation of payload

Abstract

A method for modulating data for transmission within a communication system. The method includes establishing a time-frequency shifting matrix of dimension N×N, wherein N is greater than one. The method further includes combining the time-frequency shifting matrix with a data frame to provide an intermediate data frame. A transformed data matrix is provided by permuting elements of the intermediate data frame. A modulated signal is generated in accordance with elements of the transformed data matrix.

Claims

1. A method of providing a modulated signal useable in a signal transmission system, the method comprising:

establishing an original data frame having a first dimension of at least N elements and a second dimension of at least N elements, wherein N is greater than one;

transforming the original data frame in accordance with a time-frequency transformation so as to provide a transformed data matrix; and

generating the modulated signal in accordance with elements of the transformed data matrix.

2. The method of claim 1 wherein the generating includes using a first of the elements of the transformed data matrix to control a time-variant signal during a first time period and using a second of the elements of the transformed data matrix to control the time-variant signal during a second time period different from the first time period.

3. The method of claim 1 wherein the transforming includes:

combining the original data frame with a time-frequency shifting matrix so as to provide an intermediate data frame; and

permuting elements of the intermediate data matrix.

4. The method of claim 1 wherein the transforming includes:

combining the original data frame with a time-frequency shifting matrix so as to provide an intermediate data matrix; and

combining the intermediate data matrix with a spectral shaping matrix.

5. The method of claim 3 wherein the providing the transformed data matrix includes combining, subsequent to the permuting, the intermediate data matrix with a spectral shaping matrix.

6. The method of claim 4 further including permuting elements of the intermediate data matrix.

7. The method of claim 1 wherein the time-frequency shifting matrix is of a first dimension having N elements and of a second dimension having N elements, where N is greater than one.

8. The method of claim 1 wherein the transformed data matrix includes N columns and N rows and wherein the generating the modulated signal includes selecting ones of the N columns.

9. The method of claim 1 wherein the transformed data matrix includes N columns and N rows, the generating including selecting elements of a first of the N columns to control a time-variant signal during a first spreading interval and selecting elements of a second of the N columns to control the time-variant signal during a second spreading interval wherein the first spreading interval includes a set of N time slices associated with a corresponding set of N elements of the first of the N columns.

10. The method of claim 9 wherein the first spreading interval is separated from the second spreading interval by a guard interval.

11. A method for modulating data for transmission within a communication system, the method comprising:

establishing a time-frequency shifting matrix of dimension N×

N, wherein N is greater than one;

combining the time-frequency shifting matrix with a data frame to provide an intermediate data frame;

providing a transformed data matrix by permuting elements of the intermediate data frame; and

generating a modulated signal in accordance with elements of the transformed data matrix.

12. The method of claim 11 wherein the providing the transformed data matrix includes combining a result of the permuting with a spectral shaping matrix.

13. The method of claim 11 wherein the generating includes using a first of the elements of the transformed data matrix to control a time-variant signal during a first time period and using a second of the elements of the transformed data matrix to control the time-variant signal during a second time period different from the first time period.

14. The method of claim 11 wherein the transformed data matrix includes N columns and N rows, the generating the modulated signal including selecting a first set of N modulation elements comprising a first of the N columns and subsequently selecting a second set of N modulation elements comprising a second of the N columns.

16. The method of claim 15 wherein the generating further includes selecting ones of the first set of N modulation elements to control a time-variant signal during a first spreading interval and selecting ones of the second set of N modulation elements to control the time-variant signal during a second spreading interval wherein the first spreading interval includes a set of N time slices respectively associated with the ones of the first set of N modulation elements.

17. A signal transmitter for use in a communication system, the signal transmitter comprising:

an input port;

an output port;

a processor;

a memory including program code executable by the processor, the program code including;

code for receiving, at the input port, input data;

code for establishing, using the input data, an original data frame having a first dimension of at least N elements and a second dimension of at least N elements, wherein N is greater than one;

code for transforming the original data frame in accordance with a time-frequency transformation so as to provide a transformed data matrix; and

code for generating a modulated signal in accordance with elements of the transformed data matrix.

18. The signal transmitter of claim 17 wherein the program code includes code for using a first of the elements of the transformed data matrix to control a time-variant signal during a first time period and using a second of the elements of the transformed data matrix to control the time-variant signal during a second time period different from the first time period.

19. The signal transmitter of claim 17 wherein the program code includes:

code for combining the original data frame with a time-frequency shifting matrix so as to provide an intermediate data frame; and

code for permuting elements of the intermediate data matrix.

20. The signal transmitter of claim 17 wherein the program code includes:

code for combining the original data frame with a time-frequency shifting matrix so as to provide an intermediate data matrix; and

code for combining the intermediate data matrix with a spectral shaping matrix.

21. The signal transmitter of claim 19 wherein the program code includes code for combining, subsequent to the permuting, the intermediate data matrix with a spectral shaping matrix.

22. The signal transmitter of claim 20 wherein the program code includes code for permuting elements of the intermediate data matrix.

23. The signal transmitter of claim 17 wherein the time-frequency shifting matrix is of a first dimension having N elements and of a second dimension having N elements, where N is greater than one.

24. The signal transmitter of claim 17 wherein the transformed data matrix includes N columns and N rows and wherein the generating the modulated signal includes selecting ones of the N columns.

25. The signal transmitter of claim 17 wherein the transformed data matrix includes N columns and N rows, the program code including code for selecting elements of a first of the N columns to control a time-variant signal during a first spreading interval and selecting elements of a second of the N columns to control the time-variant signal during a second spreading interval wherein the first spreading interval includes a set of N time slices associated with a corresponding set of N elements of the first of the N columns.

26. The signal transmitter of claim 25 wherein the first spreading interval is separated from the second spreading interval by a guard interval.

27. A signal transmitter for use in a communication system, the signal transmitter comprising:

an input port;

an output port;

a processor;

a memory including program code executable by the processor, the program code including;

code for receiving, at the input port, input data;

code for establishing a time-frequency shifting matrix of dimension N×

N, wherein N is greater than one;

code for combining the time-frequency shifting matrix with a data frame to provide an intermediate data frame wherein the data frame includes the input data;

code for providing a transformed data matrix by permuting elements of the intermediate data frame; and

code for generating a modulated signal in accordance with elements of the transformed data matrix.

28. The signal transmitter of claim 27 wherein program code includes code for combining a result of the permuting with a spectral shaping matrix.

29. The signal transmitter of claim 27 wherein the code for generating includes code for using a first of the elements of the transformed data matrix to control a time-variant signal during a first time period and using a second of the elements of the transformed data matrix to control the time-variant signal during a second time period different from the first time period.

30. The signal transmitter of claim 27 wherein the transformed data matrix includes N columns and N rows, the code for generating further including code for selecting a first set of N modulation elements comprising a first of the N columns and subsequently selecting a second set of N modulation elements comprising a second of the N columns.

31. The signal transmitter of claim 30 wherein the code for generating further includes code for selecting ones of the first set of N modulation elements to control a time-variant signal during a first spreading interval and selecting ones of the second set of N modulation elements to control the time-variant signal during a second spreading interval wherein the first spreading interval includes a set of N time slices respectively associated with the ones of the first set of N modulation elements.

32. A non-transitory computer readable medium including program instructions for execution by a processor in a signal transmitter, the program instructions comprising instructions for causing the processor to:

receive, at an input port of the signal transmitter, input data;

establish, using the input data, an original data frame having a first dimension of at least N elements and a second dimension of at least N elements, wherein N is greater than one;

transform the original data frame in accordance with a time-frequency transformation so as to provide a transformed data matrix; and

generate a modulated signal in accordance with elements of the transformed data matrix.

33. The non-transitory computer readable medium of claim 32 wherein the program instructions further include instructions for causing the processor to use a first of the elements of the transformed data matrix to control a time-variant signal during a first time period and to use a second of the elements of the transformed data matrix to control the time-variant signal during a second time period different from the first time period.

34. The non-transitory computer readable medium of claim 32 wherein the instructions for causing the processor to transform further include instruction for causing the processor to:

combine the original data frame with a time-frequency shifting matrix so as to provide an intermediate data frame; and

permute elements of the intermediate data matrix.

35. The non-transitory computer readable medium of claim 32 wherein the instructions for causing the processor to transform further include instruction for causing the processor to:

combine the original data frame with a time-frequency shifting matrix so as to provide an intermediate data matrix; and

combine the intermediate data matrix with a spectral shaping matrix.

36. The non-transitory computer readable medium of claim 34 wherein the instructions for causing the processor to provide the transformed data matrix include instructions for causing the processor to combine, subsequent to the permuting, the intermediate data matrix with a spectral shaping matrix.

37. The non-transitory computer readable medium of claim 35 wherein the instructions further include instructions for causing the processor to permute elements of the intermediate data matrix.

38. The non-transitory computer readable medium of claim 32 wherein the time-frequency shifting matrix is of a first dimension having N elements and of a second dimension having N elements, where N is greater than one.

39. The non-transitory computer readable medium of claim 32 wherein the transformed data matrix includes N columns and N rows and wherein the instructions for causing the processor to generate the modulated signal include instructions for causing the processor to select ones of the N columns.

40. The non-transitory computer readable medium of claim 32 wherein the transformed data matrix includes N columns and N rows, the instructions for causing the processor to generate including instructions for causing the processor to select elements of a first of the N columns to control a time-variant signal during a first spreading interval and to select elements of a second of the N columns to control the time-variant signal during a second spreading interval wherein the first spreading interval includes a set of N time slices associated with a corresponding set of N elements of the first of the N columns.

41. The non-transitory computer readable medium of claim 40 wherein the first spreading interval is separated from the second spreading interval by a guard interval.

42. A non-transitory computer readable medium including program instructions for execution by a processor in a signal transmitter, the program instructions comprising instructions for causing the processor to:

receive, at an input port of the signal transmitter, input data;

establish a time-frequency shifting matrix of dimension N×

N, wherein N is greater than one;

combine the time-frequency shifting matrix with a data frame to provide an intermediate data frame wherein the data frame includes the input data;

provide a transformed data matrix by permuting elements of the intermediate data frame; and

generate a modulated signal in accordance with elements of the transformed data matrix.

43. The non-transitory computer readable medium of claim 42 wherein the instructions for causing the processor to provide the transformed data matrix include instructions for causing the processor to combine a result of the permuting with a spectral shaping matrix.

44. The non-transitory computer readable medium of claim 42 wherein the instructions for causing the processor to generate include instructions for causing the processor to use a first of the elements of the transformed data matrix to control a time-variant signal during a first time period and to use a second of the elements of the transformed data matrix to control the time-variant signal during a second time period different from the first time period.

45. The non-transitory computer readable medium of claim 42 wherein the transformed data matrix includes N columns and N rows, the instructions for causing the processor to generate including instructions for causing the processor to select a first set of N modulation elements comprising a first of the N columns and to subsequently select a second set of N modulation elements comprising a second of the N columns.

46. The non-transitory computer readable medium of claim 45 wherein the instructions for causing the processor to generate further include instructions for causing the processor to select ones of the first set of N modulation elements to control a time-variant signal during a first spreading interval and to select ones of the second set of N modulation elements to control the time-variant signal during a second spreading interval wherein the first spreading interval includes a set of N time slices respectively associated with the ones of the first set of N modulation elements.