Receiver Timing Synchronization for Bursty Signal Re-Acquisition
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Wireless receivers face challenges in accurately synchronizing with bursty signals, particularly in beam-hopping satellite systems where illumination periods are intermittent, leading to issues with timing re-synchronization and data demodulation errors due to uncertainty in framing grids and incorrect detection of signal start and end times.
Innovation Solution
A receiver system that employs an adjustable sample provider and a feedback path with a loop filter, along with a replacement value provider to smooth timing information over longer periods, allowing for accurate synchronization even during non-illumination periods by using a feedforward strategy, reducing jitter and maintaining sampling accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a timing loop is used for synchronizing with continuous signals, then synchronization accuracy is improved, but for bursty signals the loop feedback must be frozen which causes re-synchronization errors and framing grid uncertainty
Solution Approach 1:
The patent applies preliminary action by pre-calculating and storing replacement timing values before signal bursts occur. The system prepares alternative timing information in advance that can be quickly deployed when bursts are detected, eliminating the need for slow loop re-convergence and ensuring immediate accurate synchronization upon burst arrival.
Solution Approach 2:
The patent introduces an intermediary mechanism - a replacement value provider that supplies pre-calculated timing values to the adjustable sample provider. This intermediary bypasses the frozen loop feedback path during burst periods, providing clean timing references without the errors accumulated from loop freezing and enabling reliable re-synchronization.
2Use of energy by moving object
If the loop feedback is frozen during non-illumination periods for bursty signals, then energy consumption is reduced, but timing accuracy deteriorates due to accumulation of errors
Solution Approach 1:
The system performs preliminary calculation of timing values during illumination periods when energy is available, storing these pre-computed replacement values for later use. This shifts the computational burden to periods when energy consumption is already necessary, allowing the loop to remain frozen during non-illumination without sacrificing timing accuracy.
Solution Approach 2:
The patent dynamically changes the timing parameter source based on signal presence. During illumination, the system uses active loop feedback with full computational resources. During non-illumination, it switches to using pre-stored replacement values, effectively changing the parameter source from real-time calculation to stored values, maintaining accuracy while reducing energy consumption.
3Loss of time
If quick re-synchronization is implemented at the beginning of each bursty signal reception, then response time is improved, but framing grid uncertainty increases causing data demodulation errors
Solution Approach 1:
The patent applies preliminary action by pre-calculating timing values during previous illumination periods and storing them as replacement values. When a burst arrives, the system immediately retrieves and applies these pre-computed values, achieving quick re-synchronization without the need for slow loop convergence, thereby preventing framing grid uncertainty and data demodulation errors.
Solution Approach 2:
The system creates copies of timing values from previous successful synchronization periods and stores them as replacement values. These copied timing references are then applied during subsequent bursts, providing immediate accurate synchronization without requiring re-convergence, thus maintaining framing grid accuracy and preventing demodulation errors.
4Measurement precision
If power level detection and known-sequence detection are both used to generate freezing signal, then detection accuracy is improved, but device complexity increases
Solution Approach 1:
The patent merges two detection methods - power level detection and known-sequence detection - into a unified freezing signal generation mechanism. Both detectors operate in parallel and their outputs are combined to control the freezing function, leveraging the strengths of each method (power detection for energy efficiency, sequence detection for accuracy) to achieve superior overall detection performance.
Solution Approach 2:
The detection system is designed with multi-functionality where the same receiver architecture supports both power level detection and known-sequence detection. This universal design allows the system to utilize multiple detection strategies without requiring separate dedicated hardware for each method, achieving high detection accuracy while controlling complexity through shared resources.
Data Source
AI summary
There are provided examples of receivers, controller units and related methods, wherein one receiver includes: an adjustable sample provider configured to provide samples of an input signal using an adjustable sample timing; a feedback path configured to provide a feedback signal to the adjustable sample provider on the basis of a timing error, wherein the feedback path includes a loop filter configured to provide sample timing information to the adjustable sample provider; and a replacement value provider configured to provide a replacement sample timing information replacing the sample timing information provided by the feedback path when an input signal does not fulfil a predetermined requirement for a feedback-based sample timing adaptation, wherein the replacement value provider is configured to provide the replacement sample timing information considering a timing error information, or a quantity derived from the timing error information, over a longer time period when compared to a time period considered by the loop filter for a provision of the sample timing information.