MIMO Radar Angle Estimation Under Multipath Reflections
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing MIMO radar systems struggle with multipath propagation, leading to inaccurate angle estimation and the inability to distinguish between actual targets and mirror objects, which can cause undesirable system behavior and target object losses.
Innovation Solution
A radar device and method using a transceiver apparatus with at least three transmit and three receive antennas, or two-dimensional beam forming, employs a multitarget angle estimation model that considers radar radiation propagation along at least four paths to differentiate between direct and reflected signals, allowing suppression of mirror objects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If MIMO radar systems use traditional angle estimation methods, then angle estimation can be performed, but accuracy deteriorates in multipath propagation environments leading to errors of several degrees
Solution Approach 1:
The patent changes the fundamental parameter of the signal model by incorporating multipath propagation effects into the angle estimation algorithm. Instead of assuming direct line-of-sight propagation, the system models and compensates for reflected paths, transforming the estimation problem to account for multiple propagation scenarios simultaneously, thereby maintaining accuracy in challenging environments
Solution Approach 2:
The patent introduces an intermediary signal processing step that separates and identifies direct path signals from reflected path signals before final angle estimation. This intermediary processing stage acts as a mediator that filters out multipath interference and isolates the true target signal, preventing angle estimation errors
2Ease of operation
If MIMO radar systems use virtual array model for beam forming, then transmit-beam and receive-beam forming can be performed, but the model becomes invalid in multipath propagation conditions
Solution Approach 1:
The patent extracts and removes the invalid virtual array model assumptions from the beam forming process when operating in multipath environments. By identifying and eliminating the portions of the model that become invalid under reflection conditions, the system maintains operational capability while avoiding erroneous results from the compromised model
3Device complexity
If only two transmit antennas are used in MIMO radar, then device complexity is reduced, but the advantages of MIMO such as larger virtual aperture and improved angle separation cannot be utilized with multipath propagation
Solution Approach 1:
The patent converts the harmful effect of multipath propagation into a beneficial signal source. By treating reflected paths as additional information carriers rather than interference, the system can achieve improved angle separation and virtual aperture effects even with limited transmit antennas, transforming the previously problematic multipath environment into an asset for enhanced measurement precision
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 accurate angle estimation and recognition of reflective surfaces, effectively distinguishing between actual targets and mirror objects, thereby improving the reliability of radar systems in multipath environments.
Implementation Method 1
a transceiver apparatus that comprises at least three transmit antennas and at least three receive antennas... emits radar radiation using the transmit antennas, to receive radar radiation using the receive antennas
Implementation Method 2
In the event of multipath propagation, four paths arise, specifically a direct or reflected first path portion during emission in combination with a direct or reflected second path portion during receipt
Data Source
AI summary
A radar device. The radar device includes a transceiver apparatus that comprises at least three transmit antennas and at least three receive antennas or comprises at least two transmit antennas and at least two receive antennas having two-dimensional beam forming, wherein the transceiver apparatus is configured to emit radar radiation using the transmit antennas, to receive radar radiation using the receive antennas, and to generate radar data on the basis of the received radar radiation. The radar device further comprises an evaluation apparatus that is configured to establish whether radar radiation has propagated between the transceiver apparatus and the at least one target either directly or at least partly by way of at least one reflection by evaluating the radar data using a multitarget angle estimation model, wherein the multitarget angle estimation model takes the propagation of radar radiation along at least four paths into consideration.