Channel acquisition using orthogonal time frequency space modulated pilot signals

Patent metadata

Field	Value
Publication number	US-12445247-B2
Application number	US-202418628558-A
Country	US
Kind code	B2
Filing date	Apr 5, 2024
Priority date	Mar 31, 2016
Publication date	Oct 14, 2025
Grant date	Oct 14, 2025

Abstract

Techniques for performing channel estimation in an orthogonal time, frequency and space (OTFS) communication system include receiving a wireless signal comprising a data signal portion and a pilot signal portion in which the pilot signal portion includes multiple pilot signals multiplexed together in the OTFS domain, performing two-dimensional channel estimation in a time-frequency domain based on a minimum mean square error (MMSE) optimization criterion, and recovering information bits using a channel estimate obtained from the two-dimensional channel estimation.

First claim

What is claimed is:

1. A wireless communication method implemented by a transmitter of wireless signals, comprising:
transmitting a wireless signal comprising a data signal portion and a reference signal portion multiplexed in a delay-Doppler domain, wherein the reference signal portion is sent on a first time-frequency lattice that is coarser than a second time-frequency lattice on which data portion is sent, and wherein the first time-frequency lattice is a subset of the second time-frequency lattice.

2. The method of claim 1 , wherein Delay-Doppler (τ,ν) torus associated with the first time-frequency lattice is represented as:

C
τ
P

=

1
/

(
Mdf
)

C
v
P

=

1
/

(
Ndt
)

and wherein a Delay-Doppler torus associate with the second time-frequency lattice is represented as:

C
τ
D

=

1
/
df

C
v
D

=

1
/
dt

where M and N are positive integers, t represents time, and f represents frequency.

3. The method of claim 1 , wherein the first time-frequency lattice forms a sublattice of the second time-frequency lattice.

4. The method of claim 3 , wherein the reference signal portion is generated by packing in the delay-Doppler domain, starting from a finest time-frequency pilot lattice that meets an allowed overhead.

5. The method of claim 3 , wherein the reference signal portion is generated by packing in time-frequency domain, starting from a coarsest time-frequency pilot lattice that supports transmission of at least one reference signal.

6. The method of claim 1 , wherein the first time-frequency lattice is a non-structured subset of the second time-frequency lattice.

7. The method of claim 1 , wherein the wireless signal is transmitted in a downlink direction from a base station to user equipment.

8. The method of claim 1 , wherein the wireless signal is transmitted in an uplink direction from a user equipment to a base station.

9. The method of claim 1 , wherein the wireless signal is transmitted in a time division duplexing (TDD) system.

10. The method of claim 1 , wherein the wireless signal is transmitted in a frequency division duplexing (FDD) system.

11. A transmitter of wireless signals, comprising one or more processors configured to cause the transmitter to implement a method comprising:
transmitting a wireless signal comprising a data signal portion and a reference signal portion multiplexed in a delay-Doppler domain, wherein the reference signal portion is sent on a first time-frequency lattice that is coarser than a second time-frequency lattice on which data portion is sent, and wherein the first time-frequency lattice is a subset of the second time-frequency lattice.

12. The transmitter of claim 11 , wherein Delay-Doppler (τ,ν) torus associated with the first time-frequency lattice is represented as:

C
τ
P

=

1
/

(
Mdf
)

C
v
P

=

1
/

(
Ndt
)

and wherein a Delay-Doppler torus associate with the second time-frequency lattice is represented as:

C
τ
D

=

1
/
df

C
v
D

=

1
/
dt

where M and N are positive integers, t represents time, and f represents frequency.

13. The transmitter of claim 11 , wherein the first time-frequency lattice forms a sublattice of the second time-frequency lattice.

14. The transmitter of claim 13 , wherein the reference signal portion is generated by packing in the delay-Doppler domain, starting from a finest time-frequency pilot lattice that meets an allowed overhead.

15. The transmitter of claim 13 , wherein the reference signal portion is generated by packing in time-frequency domain, starting from a coarsest time-frequency pilot lattice that supports transmission of at least one reference signal.

16. The transmitter of claim 11 , wherein the first time-frequency lattice is a non-structured subset of the second time-frequency lattice.

17. The transmitter of claim 11 , wherein the transmitter is configured to transmit the wireless signal in a downlink direction from a base station to user equipment.

18. The transmitter of claim 11 , wherein the transmitter is configured to transmit the wireless signal is transmitted in an uplink direction from a user equipment to a base station.

19. The transmitter of claim 11 , wherein the transmitter is configured to transmit the wireless signal in a time division duplexing (TDD) system.

20. The transmitter of claim 11 , wherein the transmitter is configured to transmit the wireless signal in a frequency division duplexing (FDD) system.

Assignees

• Cohere Tech Inc

Inventors

• Hebron Yoav
• Rakib Shlomo Selim
• Hadani Ronny
• Tsatsanis Michail
• Ambrose Clayton
• Delfeld Jim
• Fanfelle Robert

Classifications

• H04L25/0202

  Channel estimation · CPC title

• H04B17/373

  Predicting channel quality {or other radio frequency [RF]} parameters · CPC title

• H04L27/2647

  Arrangements specific to the receiver only (equalisation H04L27/01) · CPC title

• H04B7/005

  Control of transmission; Equalising · CPC title

• H04L25/0204

  of multiple channels · CPC title