Single Chirp Generator for Overlapping MIMO Radar Transmissions
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Solution Overview
Problem
Existing MIMO radar systems require multiple chirp generators to transmit overlapping chirps, which is impractical and increases complexity, while also suffering from Doppler ambiguity.
Innovation Solution
A single chirp generator is used to produce a base chirp, with frequency shifters and switches to generate overlapping chirp transmissions, where the base chirp and additional chirps overlap in time, and the frequency shift is determined by the bandwidth, chirp duration, and roundtrip delay, maintaining the same slope for all chirps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple chirp generators are used to transmit overlapping chirps, then detection range is increased and Doppler ambiguity is decreased, but device complexity increases
Solution Approach 1:
The patent merges the functionality of multiple chirp generators into a single chirp generator that produces a base chirp signal. Frequency shifters are then used to generate multiple frequency-shifted versions of this base chirp, which are transmitted by different transmitters. This combining approach achieves the same overlapping chirp transmission effect as multiple independent generators while reducing device complexity.
Solution Approach 2:
The patent introduces frequency shifters as intermediary devices between the single chirp generator and the multiple transmitters. These frequency shifters modify the base chirp signal to create the required frequency offsets for different transmitters, enabling overlapping chirp transmission without requiring multiple independent chirp generators.
2Device complexity
If non-overlapping chirps are transmitted sequentially, then system complexity is reduced, but detection range is limited and Doppler ambiguity increases
Solution Approach 1:
The patent employs periodic switching of the frequency shifters to enable different transmitters to transmit frequency-shifted chirps at different time intervals. This periodic action allows multiple transmitters to share a single chirp generator while maintaining overlapping chirp transmission, thereby improving detection performance without requiring permanently complex hardware for each transmitter.
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 increases detection range, reduces Doppler ambiguity, and simplifies the system by eliminating the need for multiple generators, while maintaining high angular resolution.
Implementation Method 1
one or more frequency shifters to generate respective one or more additional chirps from the base chirp... each of the one or more frequency shifters shifts a frequency of the base chirp by a different amount that is at least a minimum frequency fd
Data Source
AI summary
A radar system includes a signal generator to generate a linear frequency modulated continuous wave signal as a base chirp, and one or more frequency shifters to generate respective one or more additional chirps from the base chirp. The radar system also includes two or more switches. One of the two or more switches obtains a portion of the base chirp as a base transmit signal, and remaining ones of the two or more switches respectively obtain a portion of each of the one or more additional chirps as one or more additional transmit signals for transmission by the radar system. At least a portion of the base transmit signal and the one or more additional transmit signals overlaps in time.