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US 9,912,507 B2Granted
Orthogonal time frequency space communication system compatible with OFDM
AssigneeCohere Technologies, Inc.
InventorsSelim Shlomo Rakib, Ronny Hadani
Life of this patent
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Abstract
A system and method for orthogonal time frequency space communication and waveform generation. The method includes receiving a plurality of information symbols and encoding an N×M array containing the plurality of information symbols into a two-dimensional array of modulation symbols by spreading each of the plurality of information symbols with respect to both time and frequency. The two-dimensional array of modulation symbols is then transmitted using M mutually orthogonal waveforms included within M frequency sub-bands.
Claims14
A wireless device, comprising:
- a data modulator including an input for receiving a plurality of information symbols, the data modulator encoding an N×M array containing the plurality of information symbols into a two-dimensional array of modulation symbols by spreading each of the plurality of information symbols with respect to both time and frequency wherein the encoding performed by the data modulator includes:
- transforming the N×M array into an array of filtered OFDM symbols using at least one Fourier transform and a filtering process;
- transforming the array of filtered OFDM symbols into an array of orthonormal time-frequency shifting (OTFS) symbols using at least one two-dimensional Fourier transform wherein the array of OTFS symbols corresponds to the two-dimensional array of modulation symbols;
- and
- a transmitter configured to transmit the two-dimensional array of modulation symbols using M mutually orthogonal waveforms included within M frequency sub-bands.
2 more elements
A wireless device, comprising:
- a data modulator including an input for receiving a plurality of information symbols, the data modulator encoding an N×M array containing the plurality of information symbols into a two-dimensional array of modulation symbols by spreading each of the plurality of information symbols with respect to both time and frequency wherein the encoding performed by the data modulator includes combining an inverse symplectic transform with a windowing operation;
- and
- a transmitter configured to transmit the two-dimensional array of modulation symbols using M mutually orthogonal waveforms included within M frequency sub-bands.
A wireless device, comprising:
- a data modulator including an input for receiving a plurality of information symbols, the data modulator encoding an N×M array containing the plurality of information symbols into a two-dimensional array of modulation symbols by spreading each of the plurality of information symbols with respect to both time and frequency wherein the encoding is performed in accordance with the following relationship:
- X
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- k
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- N
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- =
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- M
- -
- 1
-
-
- x
-
- [
- l
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- k
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-
- b
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- ,
- l
-
- [
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- ,
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- b
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- l
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- =
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- 2
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- (
- ml
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- where x[l, k], k=0, . . . , N−1, l=0, . . . , M−1 represents the N×M array containing the plurality of information symbols, X[n, m], n=0, . . . , N−1, in =0, . . . , M−1 represents the two-dimensional array of modulation symbols, Mtr[n, m] is a windowing function, and bk,l[n, m] represent a set of basis functions;
- and
- a transmitter configured to transmit the two-dimensional array of modulation symbols using M mutually orthogonal waveforms included within M frequency sub-bands.
82 more elements
A wireless device, comprising:
- a data modulator including an input for receiving a plurality of information symbols, the data modulator encoding an N×M array containing the plurality of information symbols into a two-dimensional array of modulation symbols by spreading each of the plurality of information symbols with respect to both time and frequency wherein the encoding performed by the data modulator includes-spreading each of the plurality of data symbols using a set of cyclically time-shifted and frequency-shifted basis functions;
- and
- a transmitter configured to transmit the two-dimensional array of modulation symbols using M mutually orthogonal waveforms included within M frequency sub-bands.
A communication device, comprising:
- a wireless transmitter;
- a processor;
- and
- a memory including program code executable by the processor, the program code including code for causing the processor to:
- receive a plurality of information symbols;
- encode the plurality of information symbols into a two-dimensional array of modulation symbols by spreading each of the plurality of information symbols with respect to both time and frequency;
- generate M mutually orthogonal waveforms based upon the two-dimensional array of modulation symbols;
- and
- transmit the M mutually orthogonal waveforms wherein the M mutually orthogonal waveforms are included within M frequency sub-bands;
- wherein the code for causing the processor to encode includes code for causing the processor to:
- transform the N×M array into an array of filtered OFDM symbols using at least one Fourier transform and a filtering process;
- transform the array of filtered OFDM symbols into an array of orthonormal time-frequency shifting (OTFS) symbols using at least one two-dimensional Fourier transform.
9 more elements
A communication device, comprising:
- a wireless transmitter;
- a processor;
- and
- a memory including program code executable by the processor, the program code including code for causing the processor to:
- receive a plurality of information symbols;
- encode an N×M array containing the plurality of information symbols into a two-dimensional array of modulation symbols by spreading each of the plurality of information symbols with respect to both time and frequency;
- generate M mutually orthogonal waveforms based upon the two-dimensional array of modulation symbols;
- and
- transmit the M mutually orthogonal waveforms wherein the M mutually orthogonal waveforms are included within M frequency sub-bands;
- wherein the code for causing the processor to encode includes code for causing the processor to combine an inverse symplectic transform with a windowing operation.
7 more elements
A method of receiving data transmitted over a communication channel, the method comprising:
- receiving M mutually orthogonal waveforms included within M frequency sub-bands;
- demodulating the M mutually orthogonal waveforms to recover an estimate of a two-dimensional array of orthonormal time-frequency shifting (OTFS) symbols;
- and
- decoding the two-dimensional array of OTFS symbols in order to generate an estimate of an N×M array containing a plurality of information symbols, the N×M array having been encoded prior to transmission of the data by spreading each of the plurality of information symbols with respect to both time and frequency.
1 more element
Dependencies are inferred from the claim text.