Orthogonal time frequency space communication system compatible with OFDM
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.
1. A method of receiving a modulated signal, the method comprising:
receiving a plurality of signal components of the modulated signal;
generating, by performing an OFDM demodulation operation using the plurality of signal components, a plane of estimated time-frequency modulation symbols; and
providing an estimated data frame by performing an inverse of a two dimensional time-frequency transformation with respect to the plane of estimated time-frequency modulation symbols,
wherein the performing the inverse of the two dimensional time-frequency transformation includes performing a windowing operation and a symplectic Fourier transform; and
wherein the windowing operation either uses a window that is matched to a transmitter-side window, selected to randomize phases of symbols in the modulated signal, or uses a 2D window function.
2. The method of claim 1 , wherein the windowing operation uses a window that is matched to a transmitter-side window.
3. The method of claim 1 , wherein the windowing operation is selected to randomize phases of symbols in the modulated signal.
4. The method of claim 1 , wherein the windowing operation uses a 2D window function.
5. A method of receiving a modulated signal, the method comprising:
receiving a plurality of signal components of the modulated signal;
generating, by performing a Multicarrier Filter Bank (MCFB) demodulation operation using the plurality of signal components, a plane of estimated time-frequency modulation symbols; and
providing an estimated data frame by performing an inverse of a two dimensional time-frequency transformation with respect to the plane of estimated time-frequency modulation symbols, wherein the performing the inverse of the two dimensional time-frequency transformation includes performing a windowing operation and a symplectic Fourier transform.
6. The method of claim 5 , wherein the windowing operation uses a window that is matched to a transmitter-side window.
7. The method of claim 5 , wherein the windowing operation is selected to randomize phases of symbols in the modulated signal.
8. The method of claim 5 , wherein the windowing operation uses a 2D window function.
9. A receiver apparatus, the apparatus comprising:
a receiver front end, the receiver front end being configured to receive a plurality of signal components of a modulated signal;
an OFDM demodulator configured to generate a plane of estimated time-frequency modulation symbols based upon the plurality of signal components; and
an Orthogonal Time Frequency Space (OTFS) post-processing unit operative to provide an estimated data frame, the OTFS post-processing unit performing an inverse of a two dimensional time-frequency transformation with respect to the plane of estimated time-frequency modulation symbols;
wherein the inverse of the two dimensional time-frequency transformation comprises a windowing operation and a symplectic Fourier transform; and
wherein the windowing operation either uses a window that is matched to a transmitter-side window, selected to randomize phases of symbols in the modulated signal, or uses a 2D window function.
10. The apparatus of claim 9 , wherein the windowing operation uses a window that is matched to a transmitter-side window.
11. The apparatus of claim 9 , wherein the windowing operation is selected to randomize phases of symbols in the modulated signal.
12. The apparatus of claim 9 , wherein the windowing operation uses a 2D window function.
13. The apparatus of claim 9 , wherein the apparatus is included in a cell phone.
14. A receiver apparatus, the apparatus comprising:
a receiver front end, the receiver front end being configured to receive a plurality of signal components of a modulated signal;
a MCFB demodulator configured to generate a plane of estimated time-frequency modulation symbols based upon the plurality of signal components; and
an OTFS post-processing unit operative to provide an estimated data frame, the OTFS post-processing unit performing an inverse of a two dimensional time-frequency transformation with respect to the plane of estimated time-frequency modulation symbols;
wherein the inverse of the two dimensional time-frequency transformation comprises a windowing operation and a symplectic Fourier transform.
15. The apparatus of claim 14 , wherein the windowing operation uses a window that is matched to a transmitter-side window.
16. The apparatus of claim 14 , wherein the windowing operation is selected to randomize phases of symbols in the modulated signal.
17. The apparatus of claim 14 , wherein the windowing operation uses a 2D window function.
18. The apparatus of claim 14 , wherein the apparatus is included in a cell phone.