Radar Apparatus Doppler Multiplexing Phase Rotation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current radar apparatuses, particularly MIMO radars, face challenges in accurately sensing target objects over a wide Doppler frequency range due to ambiguity and interference issues in Doppler multiplexing transmission, which limits their ability to detect relative velocities without causing aliasing.
Innovation Solution
The radar apparatus employs a method of Doppler multiplexing transmission with phase rotation and coding, where different Doppler shift amounts and orthogonal code sequences are applied to transmission signals, allowing for simultaneous transmission from multiple antennas and improved separation of signals in the Doppler frequency domain, thereby enhancing target-object sensing accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If Doppler multiplexing transmission is used to extend the Doppler frequency range, then the sensing range is improved, but ambiguity and interference issues occur
Solution Approach 1:
The transmit antennas are divided into multiple groups, with each group assigned a specific Doppler shift amount. This segmentation allows the system to extend the overall Doppler frequency range while maintaining clear signal separation and avoiding ambiguity within each segment.
Solution Approach 2:
Orthogonal codes are introduced as an intermediary mechanism to further differentiate signals from different antenna groups. By combining Doppler shift amounts with orthogonal code sequences, the system achieves enhanced signal separation and eliminates interference issues.
2Area of stationary object
If multiple transmit antennas are used for multiplexing transmission, then the wide-angle sensing capability is improved, but signal separation becomes difficult
Solution Approach 1:
The system changes signal parameters by assigning different Doppler shift amounts and orthogonal code sequences to different antenna groups. This parameter differentiation enables effective signal separation even when multiple antennas transmit simultaneously, resolving the signal separation difficulty.
3Ease of manufacture
If uniform number of multiplexes is applied to all Doppler shift amounts, then the system is simple to implement, but sensing accuracy is reduced
Solution Approach 1:
The system applies different numbers of multiplexes to different Doppler shift amounts based on local requirements. Antenna groups operating in different Doppler frequency ranges can use different multiplexing levels, optimizing sensing accuracy for each specific frequency band while maintaining overall system performance.
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 extends the range of Doppler frequencies without ambiguity, improving the radar's ability to accurately detect target objects and reducing interference, leading to enhanced sensing performance and accuracy.
Implementation Method 1
combinations of Doppler shift amounts and code sequences has at least one different from other combination
Data Source
AI summary
A radar apparatus includes: a plurality of transmission antennas which transmit a plurality of transmission signals at every transmission period using a multiplexing transmission; and a transmission circuit which applies frequency offsets and phase rotations to the transmission signals for each transmission period during which the transmission signals are transmitted. A combination of the phase rotations varies for each transmission period and is repeatedly applied for a first number of transmission periods, and is different for each of the transmission antennas in each transmission period. The first number is larger than a number of the transmission antennas, and the frequency offsets are same for the transmission signals in each transmission period.