Windowing for OTFS-based communication systems under fractional delay-doppler and adjacent channel interference
View Patent ↗Disclosed is a windowing method for OTFS-based wireless signals to mitigate interference due to fractional delay and Doppler cases and to control out-of-band emission. The method provides for suitable windowing mechanisms for the multicarrier orthogonal time frequency space (OTFS) scheme in order to manage out-of-band emission and interference due to the limited time and frequency resolution of the OTFS frame.
1 . A method for preparing a windowing of a multicarrier orthogonal time frequency (OTFS) signal, the method comprising:
applying an N-point inverse Fast Fourier Transform (IFFT) and an Inverse Symplectic Fast Fourier Transform (ISFFT) over rows and columns of data;
converting the IFFT and ISFFT as data symbols to a time-frequency domain;
utilizing a cyclic prefix (CP) extension and a cyclic suffix (CS) extension in order to perform an OTFS transmission;
performing an Heisenberg Transform by using the ISFFT over the time-frequency domain data symbols such that the OTFS signal undergoes a time-varying wireless channel;
performing a Wigner transform at a receiver side in order to recover a time frequency representation of a received signal;
controlling an interference due to fractional delay-Doppler and removing the CP and the CS at a receiver;
performing a Symplectic Fast Fourier transform operation in order to produce the received signal in a delay-Doppler domain; and
mapping the received signal into the data information.
2 . The method of claim 1 , wherein the rows and columns of data have N number of symbols and M number of subcarriers with a T symbol duration and fa subcarrier spacing.
3 . The method of claim 1 , wherein the OTFS signal is for use in a 5G system.