Achieving synchronization in an orthogonal time frequency space signal receiver
Methods, systems and device for achieving synchronization in an orthogonal time frequency space (OTFS) signal receiver are described. An exemplary signal reception technique includes receiving an OTFS modulated wireless signal comprising pilot signal transmissions interspersed with data transmissions, calculating autocorrelation of the wireless signal using the wireless signal and a delayed version of the wireless signal that is delayed by a pre-determined delay, thereby generating an autocorrelation output, processing the autocorrelation filter through a moving average filter to produce a fine timing signal. Another exemplary signal reception technique includes receiving an OTFS modulated wireless signal comprising pilot signal transmissions interspersed with data transmissions, performing an initial automatic gain correction of the received OTFS wireless signal by peak detection and using clipping information, performing coarse automatic gain correction on results of a received and initial automatic gain control (AGC)-corrected signal.
1. A signal reception method implemented on a receiver, comprising:
receiving an orthogonal time frequency space (OTFS) modulated wireless signal comprising pilot signal transmissions and data transmissions;
calculating an autocorrelation of the wireless signal using the wireless signal and a delayed version of the wireless signal that is delayed by a pre-determined delay, thereby generating an autocorrelation output, wherein the pre-determined delay is equal to a time spacing between successive pilot signal transmissions;
performing, based on the autocorrelation output, a coarse adjustment to a gain of the receiver, wherein the coarse adjustment comprises a gain increment or a gain decrement; and
digitizing, prior to calculating the autocorrelation, the OTFS modulated wireless signal using an analog-to-digital converter (ADC),
wherein statistics associated with the OTFS modulated wireless signal being clipped by the ADC are collected.
2. The method of claim 1 , further comprising:
processing, prior to performing the coarse adjustment, the autocorrelation output through a moving average filter.
3. The method of claim 2 , wherein the moving average filter operates over a number of samples equal to sum of lengths of a cyclic prefix field and a cyclic suffix field.
4. The method of claim 1 , wherein the coarse adjustment comprises the gain decrement in response the statistics indicating that the OTFS modulated wireless signal was clipped.
5. The method of claim 1 , further comprising:
determining magnitudes of autocorrelation peaks; and
adjusting, based on the magnitudes of autocorrelation peaks, the gain of the receiver.
6. The method of claim 5 , wherein the autocorrelation peaks are determined using an exponential windowing function.
7. A signal reception method implemented on a receiver, comprising:
receiving an orthogonal time frequency space (OTFS) modulated wireless signal comprising pilot signal transmissions and data transmissions;
calculating an autocorrelation of the wireless signal using the wireless signal and a delayed version of the wireless signal that is delayed by a pre-determined delay, thereby generating an autocorrelation output, wherein the pre-determined delay is equal to a time spacing between successive pilot signal transmissions;
performing, based on the autocorrelation output, a coarse adjustment to a gain of the receiver, wherein the coarse adjustment comprises a gain increment or a gain decrement; and
performing a fine adjustment to the gain of the receiver in response to a carrier phase-locked loop (PLL) of the receiver being in a tracking mode.
8. The method of claim 7 , further comprising:
processing, prior to performing the coarse adjustment, the autocorrelation output through a moving average filter.
9. The method of claim 8 , wherein the moving average filter operates over a number of samples equal to sum of lengths of a cyclic prefix field and a cyclic suffix field.
10. The method of claim 9 , further comprising:
determining magnitudes of autocorrelation peaks; and
adjusting, based on the magnitudes of autocorrelation peaks, the gain of the receiver.
11. The method of claim 10 , wherein the autocorrelation peaks are determined using an exponential windowing function.
12. A signal reception method implemented on a receiver, comprising:
receiving an orthogonal time frequency space (OTFS) modulated wireless signal comprising pilot signal transmissions and data transmissions;
calculating an autocorrelation of the wireless signal using the wireless signal and a delayed version of the wireless signal that is delayed by a pre-determined delay, thereby generating an autocorrelation output, wherein the pre-determined delay is equal to a time spacing between successive pilot signal transmissions;
performing, based on the autocorrelation output, a coarse adjustment to a gain of the receiver, wherein the coarse adjustment comprises a gain increment or a gain decrement wherein adjustments to the gain of the receiver are tracked using a phase-locked loop (PLL).
13. The method of claim 12 , further comprising:
processing, prior to performing the coarse adjustment, the autocorrelation output through a moving average filter.
14. The method of claim 13 , wherein the moving average filter operates over a number of samples equal to sum of lengths of a cyclic prefix field and a cyclic suffix field.
15. The method of claim 12 , further comprising:
determining magnitudes of autocorrelation peaks; and
adjusting, based on the magnitudes of autocorrelation peaks, the gain of the receiver.
16. The method of claim 15 , wherein the autocorrelation peaks are determined using an exponential windowing function.
17. A wireless communication device comprising:
a processor; and
a transceiver circuitry; wherein the transceiver circuitry is configured for:
receiving an orthogonal time frequency space (OTFS) modulated wireless signal comprising pilot signal transmissions and data transmissions; and
wherein the processor is configured for:
calculating an autocorrelation of the wireless signal using the wireless signal and a delayed version of the wireless signal that is delayed by a pre-determined delay, thereby generating an autocorrelation output, wherein the pre-determined delay is equal to a time spacing between successive pilot signal transmissions; and
performing, based on the autocorrelation output, a coarse adjustment to a gain of the receiver, wherein the coarse adjustment comprises a gain increment or a gain decrement; and
digitizing, prior to calculating the autocorrelation, the OTFS modulated wireless signal using an analog-to-digital converter (ADC),
wherein statistics associated with the OTFS modulated wireless signal being clipped by the ADC are collected.
18. The wireless communication device of claim 17 , wherein the processor is further configured for:
processing, prior to performing the coarse adjustment, the autocorrelation output through a moving average filter.
19. The wireless communication device of claim 18 , wherein the moving average filter operates over a number of samples equal to sum of lengths of a cyclic prefix field and a cyclic suffix field.
20. The wireless communication device of claim 17 , wherein the coarse adjustment comprises the gain decrement in response the statistics indicating that the OTFS modulated wireless signal was clipped.
21. The wireless communication device of claim 17 , wherein the processor is further configured for:
determining magnitudes of autocorrelation peaks; and
adjusting, based on the magnitudes of autocorrelation peaks, the gain of the receiver.
22. The wireless communication device of claim 21 , wherein the autocorrelation peaks are determined using an exponential windowing function.
23. A wireless communication device comprising:
a processor; and
a transceiver circuitry; wherein the transceiver circuitry is configured for:
receiving an orthogonal time frequency space (OTFS) modulated wireless signal comprising pilot signal transmissions and data transmissions; and
wherein the processor is configured for:
calculating an autocorrelation of the wireless signal using the wireless signal and a delayed version of the wireless signal that is delayed by a pre-determined delay, thereby generating an autocorrelation output, wherein the pre-determined delay is equal to a time spacing between successive pilot signal transmissions; and
performing, based on the autocorrelation output, a coarse adjustment to a gain of the receiver, wherein the coarse adjustment comprises a gain increment or a gain decrement; and
performing a fine adjustment to the gain of the receiver in response to a carrier phase-locked loop (PLL) of the receiver being in a tracking mode.
24. The wireless communication device of claim 23 , wherein the processor is further configured for:
processing, prior to performing the coarse adjustment, the autocorrelation output through a moving average filter.
25. The wireless communication device of claim 24 , wherein the moving average filter operates over a number of samples equal to sum of lengths of a cyclic prefix field and a cyclic suffix field.
26. The wireless communication device of claim 23 , wherein the processor is further configured for:
determining magnitudes of autocorrelation peaks; and
adjusting, based on the magnitudes of autocorrelation peaks, the gain of the receiver.
27. The wireless communication device of claim 26 , wherein the autocorrelation peaks are determined using an exponential windowing function.
28. A wireless communication device comprising:
a processor; and
a transceiver circuitry; wherein the transceiver circuitry is configured for:
receiving an orthogonal time frequency space (OTFS) modulated wireless signal comprising pilot signal transmissions and data transmissions; and
wherein the processor is configured for:
calculating an autocorrelation of the wireless signal using the wireless signal and a delayed version of the wireless signal that is delayed by a pre-determined delay, thereby generating an autocorrelation output, wherein the pre-determined delay is equal to a time spacing between successive pilot signal transmissions; and
performing, based on the autocorrelation output, a coarse adjustment to a gain of the receiver, wherein the coarse adjustment comprises a gain increment or a gain decrement,
wherein adjustments to the gain of the receiver are tracked using a phase-locked loop (PLL).
29. The wireless communication device of claim 28 , wherein the processor is further configured for:
processing, prior to performing the coarse adjustment, the autocorrelation output through a moving average filter.
30. The wireless communication device of claim 29 , wherein the moving average filter operates over a number of samples equal to sum of lengths of a cyclic prefix field and a cyclic suffix field.
31. The wireless communication device of claim 28 , wherein the processor is further configured for:
determining magnitudes of autocorrelation peaks; and
adjusting, based on the magnitudes of autocorrelation peaks, the gain of the receiver.
32. The wireless communication device of claim 31 , wherein the autocorrelation peaks are determined using an exponential windowing function.