Oscillator Drift Synchronization Using Temperature-Adaptive AR Filtering
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Solution Overview
Problem
Existing wireless communication systems face challenges in efficiently selecting AR filter coefficients and synchronization times, particularly due to oscillator drift caused by temperature changes, leading to increased power consumption and frequency errors in CDRX mode.
Innovation Solution
The UE determines AR filter coefficients and synchronization times based on temperature drift rates, using look-up tables and on-the-fly oscillator S-curve calibration, optimizing the selection of alpha coefficients and subframes for synchronization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a large AR filter is used to compensate oscillator drift quickly, then frequency estimation accuracy is improved, but noise suppression performance deteriorates
Solution Approach 1:
The patent applies dynamics by making the AR filter coefficient adaptive rather than fixed. The system dynamically adjusts the AR filter coefficient based on temperature drift rate conditions, allowing the filter to be stronger when drift is high and weaker when drift is low, thus resolving the contradiction between quick drift compensation and noise suppression
Solution Approach 2:
The patent changes the parameter of the AR filter coefficient based on temperature conditions. By monitoring temperature drift rate and selecting different coefficients from a predefined set, the system optimizes the balance between compensation speed and noise suppression for different thermal environments
2Measurement precision
If more reference signals are used to improve frequency estimation accuracy in low SNR, then estimation accuracy is improved, but power consumption increases
Solution Approach 1:
The patent makes the reference signal usage dynamic by adjusting the number of reference signals based on SNR conditions and temperature drift rate. The system adapts its resource consumption to match the actual estimation needs, reducing power consumption when high accuracy is not required
Solution Approach 2:
The patent applies partial action by using only the necessary number of reference signals required for adequate frequency estimation. Instead of always using maximum reference signals, the system uses a variable amount based on current conditions, avoiding excessive resource consumption while maintaining sufficient accuracy
3Measurement precision
If synchronization is performed more frequently to track temperature changes, then frequency tracking accuracy is improved, but power consumption increases
Solution Approach 1:
The patent implements periodic synchronization actions based on temperature drift rate thresholds. Instead of continuous synchronization, the system performs synchronization periodically when temperature changes exceed certain thresholds, maintaining frequency tracking accuracy while minimizing unnecessary power consumption during stable thermal conditions
Solution Approach 2:
The patent makes the synchronization timing dynamic by adjusting it based on real-time temperature monitoring. The system synchronizes more frequently when temperature drift is high and less frequently when temperature is stable, optimizing the balance between tracking accuracy and power consumption
Data Source
AI summary
Apparatus and methods are provided for determining AR filter coefficient and numbers of synchronization. In one novel aspect, the AR filter coefficient and times of synchronization are determined based on the temperatures of the oscillator. In one embodiment, the UE determines a temperature drift rate by collecting sets of temperatures before and after the UE in the sleep mode of the CDRX, generates one or more threshold look-up tables and performs an optimization selection based on the temperature drift rate and the one or more threshold of look-up tables, wherein the optimization selection comprising selecting an alpha coefficient and a number of subframes for synchronization. In another embodiment, the optimization selection is further determined based on a subcarrier spacing, and a channel type of being a static channel type and a fading channel type. The UE further performs an on-the-fly oscillator S-curve calibration based on the set of temperatures.