Receiver Processing Module Secure Ranging via Cross-Correlation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current IR-UWB communication systems are vulnerable to attacks that manipulate channel estimation, leading to inaccurate distance measurements, and face challenges in secure ranging applications due to inefficiencies in frame formats and error correction, particularly in automotive Passive Keyless Entry systems.
Innovation Solution
A processing module for receiver and transmitter devices that employs cross-correlation with a predetermined modulation sequence to accurately identify start-of-frame symbols and uses a Secure Training Sequence for secure channel impulse response estimation, along with adaptive coding and pilot-symbol insertion to enhance security and link budget.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If synchronization symbols are used for deriving channel estimate, then time and frequency synchronization is achieved, but the system becomes vulnerable to attacks that manipulate channel estimation
Solution Approach 1:
The frame structure is segmented into distinct parts: synchronization symbols for timing recovery, and start-of-frame symbols with predetermined modulation sequences for channel estimation. This segmentation allows the system to use different symbol types for different purposes, reducing the vulnerability of channel estimation to attacks targeting synchronization symbols.
Solution Approach 2:
Start-of-frame symbols act as an intermediary between synchronization symbols and data symbols. These symbols contain predetermined modulation sequences that enable accurate channel estimation without relying solely on synchronization symbols, thereby providing a secure intermediate layer that prevents direct manipulation of channel estimates by attacking devices.
2Ease of operation
If repeating synchronization symbols are used for channel estimation, then time synchronization is achieved, but distance measurement accuracy deteriorates due to attack manipulation
Solution Approach 1:
The frame is divided into synchronization symbols for timing and start-of-frame symbols for channel estimation. This segmentation ensures that distance measurement accuracy is not compromised by attacks on synchronization symbols, as channel estimation now relies on the separate start-of-frame symbols with known modulation sequences.
Solution Approach 2:
The system changes the modulation parameter of start-of-frame symbols to predetermined sequences that are distinct from synchronization symbols. This parameter change enables the receiver to differentiate between synchronization and channel estimation functions, improving distance measurement accuracy by preventing attack manipulation.
3Adaptability or versatility
If standard frame formats are used for communication, then compatibility is maintained, but security against ranging attacks is reduced
Solution Approach 1:
The frame format incorporates local quality variations by assigning specific predetermined modulation sequences to start-of-frame symbols that differ from standard synchronization patterns. This local differentiation maintains overall frame structure compatibility while enhancing security against ranging attacks in the channel estimation portion.
Solution Approach 2:
The start-of-frame symbols are prepared in advance with predetermined modulation sequences known to legitimate devices. This preliminary action allows the system to establish secure channel estimation before data transmission begins, preventing attacks that would otherwise compromise ranging security during normal operation.
Data Source
Figure 1~4
Figure 5~8
Figure 9~10
AI summary
A processing module for a receiver device configured to provide for processing of a frame received by the receiver device from a transmitter device, the at least one frame comprising a plurality of repeating predetermined synchronization symbols for providing synchronization between the processing module and the transmitter device and one or more start-of-frame symbols defining the end of the synchronization symbols, the processing module configured to: perform cross correlation to obtain a cross-correlation function on i) at least a part of the received frame; with ii) a predetermined modulation sequence used to modulate the one or more start-of-frame symbols and not the synchronization symbols; and determine the location of the start-of-frame symbols based on an increase, above a threshold increase, in the cross-correlation function from a negative cross-correlation with the synchronization symbols to a greater cross-correlation with the part of the received frame containing the start-of-frame symbols.