Locating Signal Encoder Orthogonal Partial Signals
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Solution Overview
Problem
Conventional radar systems face limitations in simultaneously monitoring both short-range and long-range targets due to blind ranges and ambiguous Doppler frequency measurements, especially when detecting very fast-moving objects, as they require trade-offs between pulse duration and repetition frequency that compromise range and velocity resolution.
Innovation Solution
A locating signal coder that encodes a transmission signal with orthogonal partial signals, using a frequency-modulated coding method like Costas codes, allowing for simultaneous detection of speed and distance of fast-moving objects across various ranges by optimizing the pulse structure and coding parameters to improve range and Doppler frequency resolution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If long transmission pulses are used to monitor distant targets, then long-range detection capability is improved, but blind range increases and short-range monitoring is compromised
Solution Approach 1:
The transmission pulse is segmented into multiple sub-pulses with different encoding parameters. Each sub-pulse can be independently processed to provide both long-range and short-range detection capabilities, eliminating the blind range problem while maintaining long-distance monitoring capability.
Solution Approach 2:
Different sub-pulses use different encoding parameters (frequency modulation patterns, pulse repetition frequencies) optimized for specific range zones. This allows the system to adaptively monitor both near and far targets within a single transmission cycle.
2Measurement precision
If short transmission pulses are used to monitor nearby targets, then short-range detection capability is improved, but long-range detection capability deteriorates
Solution Approach 1:
The pulse train is divided into sub-pulses where certain sub-pulses are optimized for short-range detection with appropriate pulse width and repetition frequency, while other sub-pulses handle long-range monitoring, allowing both ranges to be monitored simultaneously without compromise.
3Measurement precision
If high pulse repetition frequency is used to improve velocity measurement, then Doppler frequency resolution is improved, but duty cycle increases causing hardware overheating
Solution Approach 1:
The pulse repetition frequency is segmented across different sub-pulses rather than applying a uniformly high PRF to all pulses. This allows velocity measurement through Doppler analysis of specific sub-pulses while keeping the overall duty cycle low enough to prevent hardware overheating.
4Use of energy by moving object
If low pulse repetition frequency is used to reduce duty cycle, then hardware overheating is prevented, but Doppler frequency measurement capability deteriorates
Solution Approach 1:
Different sub-pulses use different pulse repetition frequencies tailored to their specific detection needs. Sub-pulses dedicated to velocity measurement use higher PRF for good Doppler resolution, while the overall averaged duty cycle remains low due to the segmented structure, preventing hardware overheating.
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
Enables unambiguous surveillance of fast-moving targets over a wide range by improving range resolution and peak-to-sidelobe ratio, allowing for accurate distance and speed determination without the limitations of conventional radar systems.
Implementation Method 1
A locating signal coder that encodes a transmission signal with orthogonal partial signals, using a frequency-modulated coding method like Costas codes
Implementation Method 2
The echo signal is a delayed and attenuated copy of the transmitted signal and is also Doppler-modulated due to the relative speed between the radar and the target
Implementation Method 3
A signal, transmitted, for example, by a high-frequency radar, is reflected by a very fast-moving, point-like target located at an unknown distance
Data Source
Figure 1
Figure 2
Figure 3~5
AI summary
A location signal encoder (5) for a location device (40) is shown, which operates based on a location signal with a first partial signal and a second partial signal. The location signal encoder (5) is configured to encode the location signal in a first partial region and a second partial region orthogonal to the first partial signal. The encoding of the first partial signal, which occupies the first partial region and a portion of the second partial region, comprises a first encoding parameter, and the encoding of the second partial signal, which occupies the remainder of the second partial region, comprises a second encoding parameter. The location signal encoded in the second partial region is orthogonal to every possible reflected location signal, since the partial signals are already orthogonal to each other.