2D Scrambled FMCW Object Sensing for Signal Artifact Rejection
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Solution Overview
Problem
Existing RF sensing technologies face challenges in mitigating interference effects caused by signal artifacts during object sensing operations, which can lead to inaccurate detection and tracking of target objects.
Innovation Solution
The use of a two-dimensional (2D) scrambled frequency modulated continuous wave (FMCW) signal, generated with a range-domain scrambling code and a Doppler-domain scrambling sequence, to mitigate interference and enhance object sensing accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If traditional RF sensing signals are used, then the sensing operation can be performed, but interference effects from signal artifacts reduce measurement precision
Solution Approach 1:
The patent applies 2D scrambling by multiplying the FMCW signal with two independent scrambling sequences: one in the time domain and one in the frequency domain. This dimensional expansion transforms the signal representation from 1D to 2D, enabling independent optimization of interference mitigation in each domain and improving object detection accuracy by separating target signals from artifacts across multiple dimensions
Solution Approach 2:
The patent modifies signal parameters by applying phase scrambling codes with specific properties (orthogonality, low cross-correlation) to the FMCW signal. By changing the phase parameters in both time and frequency domains through carefully designed scrambling sequences, the system enhances signal distinguishability and reduces interference effects while maintaining the fundamental FMCW sensing capability
2Reliability
If 2D scrambled FMCW signal is used, then interference mitigation is improved, but device complexity increases
Solution Approach 1:
The patent applies scrambling sequences to the FMCW signal before transmission and reception. By pre-applying the scrambling codes in the time and frequency domains before the sensing operation, the system prepares the signal in advance to be inherently resistant to interference, eliminating the need for complex post-processing interference mitigation techniques and reducing overall device complexity
Solution Approach 2:
The patent uses scrambled copies of the original FMCW signal structure with applied phase codes. By creating these scrambled signal copies with known statistical properties and orthogonal characteristics, the system can reliably distinguish between actual targets and interference artifacts through correlation processing, improving reliability without requiring complex adaptive processing
Data Source
AI summary
Methods, devices, and systems pertaining to object sensing operations are disclosed herein. In one embodiment, a sensing device can perform a sensing operation by using a 2D modulated PC-FMCW signal for distinguishing a target object from signal artifacts. In another embodiment, a sensing device can perform a two-step sensing operation. A first step of the sensing operation involves using a PC-FMCW signal to sense a target object. If the target object is uniquely sensed and no signal artifacts are present, the second step can be omitted. If not, the second step can be used. The second step involves the use of a 2D scrambled FMCW signal that is based on a 2D modulation of an FMCW signal with a range-domain scrambling code and a Doppler-domain scrambling sequence. The target device may be uniquely sensed based on using the scrambling code and the scrambling sequence to demodulate an echo signal.