Sliding Correlation for UWB Signal Synchronization
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Solution Overview
Problem
Current Ultra Wide Band (UWB) signal processing techniques face challenges in achieving efficient and low-complexity synchronization, particularly in disturbed communication mediums, due to high circuit complexity and sensitivity to clock imperfections, which are exacerbated by the IEEE 802.15.4a standard's constraints on clock precision and long data packets.
Innovation Solution
A method for processing rectified sampled UWB signals using a sliding correlation technique between the received signal and a correlation sequence, which involves elementary correlation steps and summing of intermediate samples to produce a correlation vector, allowing for robust and low-complexity detection of data frames in non-coherent reception architectures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If correlation-based synchronization techniques are used, then synchronization speed is improved, but circuit complexity increases significantly
Solution Approach 1:
The patent segments the correlation process into multiple stages: coarse synchronization using a reduced-rate signal, followed by fine synchronization using the full-rate signal. This segmentation allows fast initial acquisition without requiring complex full-rate correlation circuits, thereby reducing overall circuit complexity while maintaining synchronization speed.
Solution Approach 2:
The patent introduces an intermediary reduced-rate signal path that performs initial correlation operations at lower complexity. This intermediary processing stage prepares the synchronization state before transitioning to the full-rate signal for final precise synchronization, avoiding the need for directly implementing complex full-rate correlation from scratch.
2Device complexity
If energy detection architectures are used to reduce circuit complexity, then detection capability is improved, but synchronization accuracy deteriorates
Solution Approach 1:
The patent segments the synchronization process into two phases: an initial energy detection phase using reduced-rate sampling that provides coarse timing information, followed by a fine correlation phase that refines the synchronization accuracy. This segmentation allows the system to benefit from the low complexity of energy detection while ultimately achieving high synchronization accuracy through the subsequent refinement stage.
3Productivity
If long data packets are used as per IEEE 802.15.4a standard, then data transmission capability is improved, but sensitivity to clock imperfections increases
Solution Approach 1:
The patent implements a feedback mechanism where the correlation process continuously monitors the received signal and adjusts the local correlation sequence timing based on detected timing offsets. This feedback loop compensates for clock drift and imperfections that accumulate over the long data packet duration, maintaining synchronization accuracy throughout the extended transmission.
4Device complexity
If rectified sampled signal processing is used, then circuit complexity is reduced, but detection performance may deteriorate
Solution Approach 1:
The patent changes the processing parameters by performing correlation operations on the rectified signal at a reduced sampling rate for the initial coarse synchronization stage. This parameter change (reduced rate processing) maintains adequate detection performance for timing acquisition while significantly reducing the computational complexity compared to full-rate processing of the rectified signal.
Data Source
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AI summary
The invention relates to a method for processing, in an ultra-wide band receiver, a received sampled rectified ultra-wide band signal, characterised in that it comprises: at least one step of slippery correlation (5) between a sample selection of the received sampled ultra-wide band signal (E) and a correlation sequence (R), the slippery correlation comprising a succession of n elementary correlation steps and n being an integer higher than or equal to 2, at a frequency f between the sample selection and the correlation sequence (R), an elementary correlation step generating a series of intermediate correlation samples; and adding (6) the intermediate correlation samples provided by each of the n elementary correlation steps for forming n correlation samples defining a correlation vector (V, V1, V2).