Robust Radio Packet Acquisition Against Continuous Wave Interference
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Bluetooth Low Energy (BLE) home automation systems face challenges in robustly detecting data packets in environments with continuous wave interference, leading to false detections and missed packets due to increased computational complexity and hardware requirements in existing solutions.
Innovation Solution
A method that continuously correlates a preamble code with a received signal to determine frequency and timing estimates, allowing for parallel access code correlation, reducing hardware complexity and improving robustness against continuous wave interference by using a sub-sequence part of the access code and peak detection to discern actual data packets.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple parallel access code correlations are performed to improve robustness against continuous wave interference, then detection reliability improves, but hardware complexity increases
Solution Approach 1:
The access code correlation is divided into two stages: first a preamble correlation is performed to obtain initial frequency and timing estimates, then a subsequent access code correlation is performed using these estimates to reduce the search space. This segmentation allows robust detection without requiring multiple parallel correlations, thus reducing hardware complexity while maintaining reliability
Solution Approach 2:
The preamble correlation is performed as a preliminary step before the access code correlation. This preliminary action provides frequency and timing estimates that are used to configure the subsequent access code correlation, eliminating the need for exhaustive parallel searches and reducing hardware requirements
2Measurement precision
If the entire access code is used for correlation to improve interference robustness, then detection accuracy improves, but computational complexity increases
Solution Approach 1:
The correlation process is segmented into two parts: preamble correlation followed by access code correlation. The preamble correlation provides initial estimates that guide the access code correlation, allowing the system to achieve robust detection without correlating against the entire access code in parallel, thus reducing computational complexity while maintaining accuracy
Solution Approach 2:
Instead of performing correlation against the entire access code, the invention uses a partial approach where the preamble correlation provides sufficient initial information, and then a reduced access code correlation is performed using the obtained estimates. This partial action achieves the necessary detection accuracy with significantly reduced computational complexity
3Reliability
If continuous wave interference is present in the environment, then false detections increase, but using robust detection methods increases hardware requirements
Solution Approach 1:
The harmful continuous wave interference is effectively filtered out by extracting and utilizing the known preamble structure. The preamble correlation selectively detects the intended signal by correlating with the known preamble sequence, rejecting uncorrelated interference. This extraction approach provides robustness without requiring complex interference rejection hardware
Solution Approach 2:
The preamble correlation acts as an intermediary step between the received signal and the final detection decision. It provides frequency and timing estimates that mediate the subsequent access code correlation, enabling robust detection in the presence of interference while avoiding the need for multiple parallel correlation channels
Data Source
AI summary
Method and receiver for acquiring a data packet in a signal transmission like Bluetooth Low Energy (BLE), wherein the data packet comprises a preamble code (2) followed by an access code (3) and has a symbol period. The following steps are executed: —executing a preamble correlation (8) continuously on a received signal (10) using the preamble code (2); —determining a frequency estimate (14) and a timing estimate (13) from the preamble correlation (8); —using the frequency estimate (14) to execute a frequency correction (15) on the received signal; —performing an access code correlation (9) on the frequency corrected received signal, in parallel with the continuous execution of the preamble correlation (8); and —detecting a data packet (19) when the access code correlation (9) is higher than a predetermined access code threshold (18) at an expected time relative to the timing estimate (13). Thereby packet loss due to false detection is minimized since the preamble correlation is continuously performed even when peaks are detected. Furthermore the frequency estimate obtained from the preamble correlation is used to reduce the complexity of the access code correlation.