Cross-RAT Doppler-Aided Channel Estimation for High-Speed NR
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Solution Overview
Problem
In high-speed wireless communication scenarios, particularly in environments like trains or vehicles, significant Doppler shifting occurs due to high mobility, which complicates channel estimation, especially in high-frequency NR systems, leading to substantial processing overhead.
Innovation Solution
A user equipment (UE) leverages Doppler information generated from a first radio access technology (RAT) like LTE to support communications in a second RAT like NR by applying a Doppler value to a frequency or time tracking loop, potentially using a scaling factor based on channel conditions, to improve channel estimation and reduce processing overhead.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If channel estimation is performed independently for each RAT in high-speed scenarios, then measurement precision is maintained, but processing overhead increases substantially
Solution Approach 1:
The patent applies universality by using a single Doppler value derived from LTE channel estimation to serve multiple purposes: it corrects Doppler shifts in both LTE and NR communications, and is applied to tracking loops for both RATs. This multi-functional use of one measurement result reduces redundant processing while maintaining estimation precision across different radio access technologies.
Solution Approach 2:
The patent merges the channel estimation processes of LTE and NR by using the Doppler value obtained from LTE to also correct NR communications. Instead of performing separate independent estimations for each RAT, the solution combines the Doppler correction functionality across both systems, reducing overall processing overhead while maintaining measurement accuracy.
2Reliability
If Doppler correction is applied to both LTE and NR tracking loops, then communication reliability improves in high-speed scenarios, but device complexity increases
Solution Approach 1:
The Doppler value derived from LTE serves a universal function by being applied to correct tracking errors in both LTE and NR systems. This single measurement supports multiple correction functions across different RATs, improving communication reliability without proportionally increasing device complexity, as the same Doppler value is reused rather than requiring separate measurements for each system.
3Measurement precision
If independent channel estimation is performed for NR in high-speed scenarios, then channel acquisition accuracy is improved, but processing time increases
Solution Approach 1:
The patent applies preliminary action by performing channel estimation and obtaining the Doppler value through LTE first, before applying it to NR communications. This preliminary measurement from LTE provides the necessary Doppler correction information for NR, reducing the time required for separate NR channel estimation while maintaining acquisition accuracy through the pre-obtained Doppler value.
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 channel estimation and acquisition in high-band NR communications by utilizing Doppler values from LTE, reducing processing overhead and improving communication efficiency across multiple RATs.
Implementation Method 1
significant Doppler shifting occurs due to high mobility
Data Source
AI summary
Methods, systems, and devices for wireless communications are described. The described techniques provide for a user equipment (UE) using information identified via radio access technology (RAT) (e.g., Long Term Evolution (LTE)) to support communications in another RAT (e.g., New Radio (NR)). For example, the UE may receive, from a first base station operating according to a first radio access technology an indication of a high speed associated with a first wireless connection of the UE with the first base station. The UE may perform a channel estimation procedure for the first wireless connection to generate a Doppler value based on receiving the indication. The UE may apply the generated Doppler value to a frequency tracking loop or a time tracking loop for communications with a second base station via a second wireless connection, wherein the second base station is operating according to a second RAT.