Radar Phase Modulation Using True Random Sequences
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Solution Overview
Problem
Fast FMCW radars face challenges in detecting deception attacks without adversely affecting target position, speed, or angle measurements, and existing phase modulation sequences are vulnerable to guessing, compromising interference countermeasures.
Innovation Solution
The radar device employs a fast FMCW scheme and MIMO technology, using a true random number sequence and a pseudo-random number sequence to generate a modulation code sequence for phase modulation, which reduces the risk of sequence guessing and maintains measurement accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a fast FMCW radar collectively processes multiple waveforms to measure target position and speed, then measurement capability is improved, but the radar becomes vulnerable to deception attacks because it cannot detect them without modifying the FMCW signal slope
Solution Approach 1:
The patent segments the phase modulation sequence into multiple independent blocks, each processed separately. This segmentation allows the radar to maintain its fast FMCW measurement capabilities while introducing multiple detection opportunities, as each block can be independently analyzed for deception attacks without disrupting the overall measurement process.
Solution Approach 2:
The patent performs preliminary deception detection by analyzing phase differences between adjacent waveform blocks before final target measurement. This preliminary action enables the radar to identify deception attacks early in the processing chain, allowing it to maintain measurement capability while establishing a detection mechanism that does not require modifying the FMCW signal slope.
2Object-affected harmful factors
If conventional pseudo-random number sequences (M sequence or Gold sequence) are used for phase modulation in MIMO radar, then interference countermeasures are implemented, but the sequences are vulnerable to guessing attacks due to limited variations
Solution Approach 1:
The patent creates a composite phase modulation sequence by combining conventional pseudo-random sequences with additional randomization elements. This composite approach maintains the desirable autocorrelation properties of M/Gold sequences for interference suppression while introducing sufficient complexity to resist guessing attacks, effectively merging the benefits of both structured and unstructured sequences.
Solution Approach 2:
The patent adds an additional dimension of complexity to the phase modulation sequence by introducing block-based segmentation and multi-stage randomization. This transforms the sequence from a simple one-dimensional pseudo-random pattern into a multi-dimensional structure with increased entropy, making it significantly more difficult to guess while preserving the fundamental interference countermeasure capabilities.
3Reliability
If the slope of FMCW signal is modified to detect deception attacks, then deception detection capability is improved, but measurement of target position, speed, or angle is adversely affected
Solution Approach 1:
The patent introduces phase difference analysis as an intermediary detection mechanism that operates on the existing FMCW signal structure. Instead of modifying the signal slope, the system uses the phase relationship between adjacent waveform blocks as an intermediary indicator of deception attacks, allowing detection without disrupting the measurement process.
Solution Approach 2:
The patent replaces the mechanical approach of modifying FMCW signal slope with a signal processing-based approach. By substituting the physical signal modification with computational phase difference analysis, the system achieves deception detection through software-based processing that does not interfere with the underlying measurement physics.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach effectively reduces the risk of deception attacks by making it difficult for attackers to guess the phase modulation sequence, while ensuring that target measurements are not compromised.
Implementation Method 1
A radar is a device which irradiates electric waves to a target and measures reflected waves from the target, thereby measuring a relative distance between the radar and the target, a relative speed of the target, or the like.
Implementation Method 2
a phase modulation unit that modulates a phase of transmission signals by using a modulation code sequence
Data Source
AI summary
A radar device (10) includes a signal generation unit (100) to generate a signal as an original signal, a pseudo-random number generation unit (102) to generate a pseudo-random number sequence formed of a pseudo-random number, a true random number generation unit (101) to generate a true random number sequence formed of a true random number, a modulation code synthesizing unit (103) to generate a modulation code sequence for use in modulating a signal phase by synthesizing the pseudo-random number sequence and the true random number sequence, and a phase modulation unit (104) to generate a transmission signal by modulating a phase of the original signal by using the modulation code sequence.