UWB Pulse Stream Processing with Dummy Pulses for Secure Ranging
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Solution Overview
Problem
The existing IEEE 802.15.4 standard for Ultra-Wideband (UWB) communication systems is vulnerable to attacks and inefficient in secure distance bounding, preamble injection, and lacks flexibility in channel length adjustment, leading to security and link budget issues in applications like automotive Passive Keyless Entry systems.
Innovation Solution
A processing module for transmitter and receiver devices that generates and processes frames with a Secure Training Sequence (STS) and adaptive coding, allowing for secure channel estimation and flexible data-rate selection, while reducing peak power consumption and system cost through dummy pulse insertion and binary synchronization symbols.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If synchronization symbols are used for channel estimation in UWB systems, then time and frequency synchronization is achieved, but the system becomes vulnerable to attacks that can influence channel estimation and ToF calculations
Solution Approach 1:
The patent introduces a secure training sequence (STS) as an intermediary element that works together with the traditional synchronization symbols. The STS is scrambled using a device-specific secret key, creating a mediator that provides both channel estimation capability and security protection. The receiver uses the STS to derive a secure channel estimate that cannot be easily manipulated by attackers, thus resolving the contradiction between measurement precision and reliability.
Solution Approach 2:
The patent changes the parameter of the training sequence from a standard known pattern to a scrambled sequence generated by a pseudo-random number generator using a secret key. This parameter change transforms the synchronization symbols into a secure form that maintains their synchronization function while adding security properties that prevent attacks on channel estimation.
2Reliability
If dummy pulses are inserted to prevent attacks and improve security, then security against distance reduction attacks is enhanced, but the pulse stream complexity and processing overhead increase
Solution Approach 1:
The patent applies preliminary action by inserting dummy pulses into the pulse stream before transmission. These dummy pulses are strategically placed based on the polarity of consecutive pulses to prevent attacks in advance. The receiver is pre-configured to recognize and ignore these dummy pulses, so while the transmission side requires additional processing, the reception side maintains simplicity. This resolves the contradiction by shifting the complexity burden to the transmission side where it can be managed through pre-computed insertion rules.
3Reliability
If the input pulse stream is divided into groups with dummy pulse insertion, then security is improved and attacks are prevented, but the processing time and computational overhead increase
Solution Approach 1:
The patent changes the parameter of pulse grouping from a complex adaptive process to a fixed rule-based system. Pulses are grouped into fixed-size groups (e.g., groups of 3), and dummy pulse insertion follows simple polarity-based rules. This parameter change from adaptive to fixed processing reduces computational complexity and processing time while maintaining security effectiveness, thus resolving the contradiction between reliability and time loss.
Data Source
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AI summary
A processing module for a transmitter device configured to provide for generation of a signal comprising at least one frame for transmission by the transmitter device to a receiver device, the processing module configured to provide for processing of an input pulse stream comprising a stream of pulses representative of data, to provide an output pulse stream, each pulse of the pulse streams having one of two states defining the phase with which a carrier wave is modulated; the processing module configured to; divide the input pulse stream into consecutive groups of pulses; and for each group of pulses, based on determination that the first two or more consecutive pulses of the group have the same polarity, provide for addition of at least one dummy pulse to the group directly after the first two or more consecutive pulses, with an opposite polarity.