Modulation and equalization in an orthonormal time-frequency shifting communications system

• US 9,548,840 B2
• Filed: 05/20/2015
• Issued: 01/17/2017
• Est. Priority Date: 05/28/2010
• Status: Active Grant

• Current Assignee: Cohere Technologies Inc
• Original Assignee: Cohere Technologies Inc
• Inventors: Hadani, Ronny, Rakib, Salim Shlomo
• Primary Examiner(s): NEFF, MICHAEL R
• Application Number:
  US14/717,886
• Publication Number:
  US 20160191217A1
• Time in Patent Office: 608 Days
• Field of Search: 375/260
• US Class Current: 1/1
• 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 defined by a first plurality of elements and a second dimension defined by a second plurality of elements;

transforming the original data frame in accordance with a time-frequency transformation so as to provide a transformed data matrix wherein the time-frequency transformation is performed using a time-frequency shifting matrix wherein the time-frequency shifting matrix is of a first dimension having N elements and of a second dimension having M elements, where N and M are greater than one; and

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

3. The method of claim 1 wherein the transformed data matrix includes a plurality of columns and wherein the generating the modulated signal includes selecting ones of the plurality of columns.

4. The method of claim 1 wherein the transformed data matrix includes a plurality of columns, the generating including selecting elements of a first of the plurality of columns to control a time-variant signal during a first spreading interval and selecting elements of a second of the plurality of columns to control the time-variant signal during a second spreading interval.

5. The method of claim 4 wherein the first spreading interval is separated from the second spreading interval by a guard interval.

2. The method of claim wherein each element of the transformed data matrix includes a contribution from a plurality of elements of the original data frame.

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

establishing a time-frequency shifting matrix of dimension N×

M, wherein N and M are greater than one;

combining the time-frequency shifting matrix with a data frame to provide a transformed data matrix; and

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

7. The method of claim 6 wherein each element of the transformed data matrix includes a contribution from a plurality of elements of the data frame.

8. The method of claim 6 wherein the transformed data matrix includes a plurality of columns, the generating the modulated signal including selecting a first set of modulation elements comprising a first of the plurality of columns and subsequently selecting a second set of modulation elements comprising a second of the plurality of columns.

9. The method of claim 8 wherein the generating further includes selecting ones of the first set of modulation elements to control a time-variant signal during a first spreading interval and selecting ones of the second set of modulation elements to control the time-variant signal during a second spreading interval.

10. 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 defined by a first plurality of elements and a second dimension defined by a second plurality of elements;

code for transforming the original data frame in accordance with a time-frequency transformation so as to provide a transformed data matrix wherein the time-frequency transformation is performed using a time-frequency shifting matrix and wherein the time frequency shifting matrix is of a first dimension having N elements and of a second dimension having M elements, where N and M are greater than one; and

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

11. The signal transmitter of claim 10 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.

12. The signal transmitter of claim 10 wherein the first plurality is equal to the second plurality.

13. 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 and for including the input data within a data frame having a first dimension defined by a first plurality of data elements and a second dimension defined by a second plurality of data elements;

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

M, wherein N and M are greater than one;

code for combining the time-frequency shifting matrix with a data frame containing the input data in order to provide a transformed data matrix; and

code for generating a modulated signal in accordance with elements of the transformed data matrix 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 for 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 signal transmitter of claim 13 wherein each element of the transformed data matrix includes a contribution from a plurality of elements of the data frame.

15. The signal transmitter of claim 13 wherein the transformed data matrix includes a plurality of columns, the code for generating further including code for selecting a first plurality of modulation elements comprising a first of the plurality of columns and subsequently selecting a second plurality of modulation elements comprising a second of the plurality of columns.

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

17. 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 defined by a first plurality of elements and a second dimension defined by a second plurality of elements;

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

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

18. The non-transitory computer readable medium of claim 17 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.

19. The non-transitory computer readable medium of claim 17 wherein each element of the transformed data matrix includes a contribution from a plurality of elements of the original data frame.