UWB Positioning Signal Waveform for Adjacent Path Separation
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Solution Overview
Problem
Conventional UWB positioning technologies face limitations in distinguishing between multiple paths with short delay intervals due to the use of symmetric waveforms, leading to reduced ranging precision.
Innovation Solution
Generating asymmetric waveforms with shorter rising edges than falling edges for positioning signals, allowing better differentiation between adjacent paths and improving ranging precision.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional symmetric waveforms (RRC pulse or Gaussian pulse) are used for UWB positioning signals, then the waveform meets standard requirements and is easy to generate, but the main lobe width is too wide to distinguish between multiple paths with short delay intervals, limiting ranging precision
Solution Approach 1:
The patent applies asymmetry by designing a positioning signal with an asymmetric main lobe waveform where the rising edge duration is shorter than the falling edge duration. This asymmetric shape narrows the main lobe width in the time domain, enabling the receiving device to distinguish between multiple propagation paths with short delay intervals, thereby improving ranging precision while maintaining compliance with power spectrum density constraints
Solution Approach 2:
The patent changes the waveform parameters by specifically controlling the duration of the rising edge to be shorter than the falling edge duration. This parameter modification transforms the conventional symmetric waveform into an asymmetric one, achieving narrower main lobe width and improved path distinction capability without violating standard requirements
2Measurement precision
If the main lobe width is narrowed to improve path distinction capability, then ranging precision improves, but the waveform design becomes more complex and harder to generate
Solution Approach 1:
The patent resolves this contradiction by introducing asymmetry into the waveform design, where the rising edge is deliberately made shorter than the falling edge. This asymmetric configuration achieves narrower main lobe width for improved path distinction while maintaining a structured format that can be generated through defined pulse shaping techniques, balancing performance improvement with implementation feasibility
3Measurement precision
If asymmetric waveforms with shorter rising edges are used, then the ability to distinguish adjacent paths improves and ranging precision enhances, but the waveform deviates from conventional symmetric designs
Solution Approach 1:
The patent changes the waveform parameters by setting the rising edge duration shorter than the falling edge duration, creating an asymmetric main lobe. This parameter change improves first arrival path determination accuracy by narrowing the main lobe width, while the waveform remains compatible with UWB standards through compliance with power spectrum density constraints and cross-correlation requirements with RRC pulse response
Data Source
AI summary
A positioning signal sending method and apparatus are provided. A first signal is generated, where duration of a first rising edge of the first signal is less than duration of a first falling edge, the duration of the first rising edge is duration of a rising edge of a main lobe waveform of the first signal, and the duration of the first falling edge is duration of a falling edge of the main lobe waveform of the first signal; and the first signal is sent. In embodiments of this application, rising time of a main lobe waveform of a signal generated is short, and shorter rising time of the main lobe waveform is more conducive to distinguishing two adjacent paths or identifying a first arrival path of a received signal.