Delay Doppler Domain Channel State Information Estimation
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Solution Overview
Problem
Current 5G wireless systems face challenges in achieving centimeter-level accuracy for positioning and localization due to high overhead in reference signal design, which affects the estimation of range and velocity, particularly in millimeter wave new radio networks.
Innovation Solution
The proposed solution involves converting channel state information from the traditional time-frequency domain to the delay-doppler domain, allowing for more accurate estimation of ranging, velocity, and angle parameters with reduced overhead, using techniques such as symplectic Fast Fourier transforms and overlaying reference signals with data on the same resource elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional time-frequency domain reference signal design is used for channel state information estimation, then the system can maintain basic positioning functionality, but positioning accuracy is limited and overhead is high
Solution Approach 1:
The patent transforms channel state information from the traditional time-frequency domain to the delay-Doppler domain by changing the representation parameters. This domain transformation enables more accurate extraction of ranging and velocity parameters from the channel response, achieving centimeter-level positioning accuracy while reducing the number of reference signals required
Solution Approach 2:
The patent introduces a new dimensional perspective by using the delay-Doppler domain instead of the conventional time-frequency domain. This dimensional change allows the system to exploit the structure of channel responses in terms of delay and Doppler shift, enabling more efficient parameter estimation with reduced overhead
2Measurement precision
If more reference signals are deployed to improve positioning accuracy, then estimation precision improves, but system overhead and complexity increase
Solution Approach 1:
By changing the domain parameters from time-frequency to delay-Doppler, the patent enables more accurate channel state information estimation without increasing reference signal density. The transformation reveals structured patterns in the channel response that can be exploited for precise parameter estimation with fewer measurements
Solution Approach 2:
The patent replaces the mechanical approach of increasing reference signal quantity with a signal processing transformation approach. Instead of adding more reference signals, the system transforms the existing channel responses into the delay-Doppler domain to extract positioning parameters, reducing both overhead and system complexity
3Productivity
If reference signals are overlaid with data on the same resource elements to reduce overhead, then resource efficiency improves, but signal interference increases
Solution Approach 1:
The patent transforms the received signal from the time-frequency domain to the delay-Doppler domain, where the channel response exhibits structured patterns. This transformation allows the system to separate the reference signal components from data interference by exploiting the distinct delay-Doppler characteristics of different signal components, enabling reference signals and data to coexist on the same resource elements with reduced interference
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enhances positioning accuracy to centimeter levels with lower overhead, improving signal interference-to-noise ratio and reducing estimation errors, making it suitable for applications like autonomous driving and augmented reality.
Implementation Method 1
converting, by the base station, the reference signal to a doppler domain, resulting in a converted reference signal
Implementation Method 2
converting, by the base station, the reference signal to a doppler domain
Data Source
AI summary
A delay doppler domain transformation can be used to estimate characteristics of a channel between a base station and a user equipment or alternatively, between the user equipment and another user equipment. Thus, the velocity and the distance position of the user equipment can be calculated. For example, a signal received in the time-frequency domain, can be converted to the delay doppler domain by the base station. In response to the conversion, the base station can estimate the velocity of the user equipment. The velocity can be utilized by various applications. For example, the velocity can be utilized to alert the other user equipment to the location or an anticipated location of the user equipment.