OTFS Interference Measurement via Delay-Doppler Domain
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current communication systems face challenges in accurately measuring interference and managing reference signals due to large resource overheads and complex protocol designs, particularly in scenarios with high-speed movement and multipath environments, where inter-symbol interference (ISI) and inter-carrier interference (ICI) are prevalent.
Innovation Solution
The implementation of an orthogonal time frequency space (OTFS) system for interference measurement, which maps signals to the delay-Doppler domain to avoid pilot pollution and enhance channel estimation accuracy, allowing for efficient interference management and reduced resource overheads by using a single-point pulse or sequence pilot.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional time-frequency domain pilot measurement methods are used, then interference measurement can be performed, but resource overheads increase and channel estimation accuracy deteriorates in high-speed movement and multipath environments
Solution Approach 1:
The patent transforms the interference measurement from the conventional time-frequency domain to the delay-Doppler domain by mapping pilots and signals through symplectic finite Fourier transform (SFFT). This dimensional transformation allows pilots to be concentrated at specific delay-Doppler grid points, avoiding pilot pollution and improving channel estimation accuracy while reducing the number of required pilots.
Solution Approach 2:
The patent changes the measurement domain parameter from time-frequency to delay-Doppler, and changes the pilot structure from traditional distributed pilots to single-point pulse or sequence pilots in the delay-Doppler domain. This parameter change enables better separation of signal and interference, improving measurement precision while reducing resource overhead.
2Measurement precision
If traditional reference signal designs are used, then communication functions can be supported, but protocol complexity increases and measurement accuracy deteriorates in high-speed scenarios
Solution Approach 1:
The patent designs a universal pilot structure in the delay-Doppler domain that can simultaneously support channel estimation, interference measurement, and positioning functions. The same single-point pulse or sequence pilot used for channel estimation also enables interference measurement by transforming to the time-frequency domain and measuring at appropriate locations, reducing protocol complexity.
Solution Approach 2:
The patent introduces the delay-Doppler domain as an intermediary transformation domain between transmission and measurement. By mapping signals to this intermediate domain, performing operations, and then transforming back, the system achieves accurate interference measurement without complex time-frequency domain protocol designs.
3Reliability
If conventional pilots are used in multipath environments, then basic channel estimation can be performed, but pilot pollution occurs and estimation accuracy deteriorates
Solution Approach 1:
The patent extracts the pilot signal to a single point or sequence in the delay-Doppler domain rather than distributing it across multiple time-frequency resources. This extraction concentrates the pilot energy at specific delay-Doppler grid points, making it resistant to multipath effects and preventing pilot pollution that occurs when pilots are scattered in the time-frequency domain.
Solution Approach 2:
By transforming the pilot representation from time-frequency domain to delay-Doppler domain, the patent separates the pilot from multipath interference. In the delay-Doppler domain, multipath components appear as distinct delayed copies at different grid points, allowing the original pilot to be cleanly extracted and used for reliable channel estimation.
Data Source
AI summary
An interference measurement method includes receiving, by a receiving side, a signal. The signal includes a second pilot sent by an interference sending side, and the interference sending side is an interference source when the receiving side performs receiving measurement on a first pilot of a sending side; and performing, by the receiving side, interference measurement on the interference sending side. The interference measurement includes measurement of the second pilot, and both the receiving side and the sending side use an OTFS system.