MIMO Radar Leakage Cancellation via Digital Filtering
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Solution Overview
Problem
MIMO radar systems face challenges in effectively canceling Tx-to-Rx leakage, which degrades dynamic range and performance, particularly due to high power consumption, size, and cost issues with existing high-performance hardware and SISO analog Tx cancellation techniques, making them inefficient for MIMO configurations with multiple transmitters and receivers.
Innovation Solution
The implementation of an analog leakage cancellation technique that generates individual leakage cancellation signals for each receiver, using digital filtering of transmit signals to create samples of cancellation signals, which are injected in the baseband or RF section of the receiver, and dynamically calculating coefficients for digital filters to adaptively mitigate Tx-to-Rx leakage, thereby simplifying hardware implementation and improving accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If high-performance hardware and SISO analog Tx cancellation techniques are used, then leakage cancellation performance is improved, but power consumption, size, and cost increase
Solution Approach 1:
The patent replaces complex analog hardware cancellation systems with a digital signal processing approach. Digital filters are applied to transmit signals to generate cancellation signals, substituting mechanical/analog components with digital processing. This reduces power consumption and hardware complexity while maintaining leakage cancellation effectiveness in MIMO radar systems.
Solution Approach 2:
The patent changes the approach from analog domain cancellation to digital domain cancellation by modifying signal parameters. Digital filters with adjustable coefficients are used to dynamically adapt cancellation signals, changing the operational domain from analog to digital where parameter control is more efficient and less power-consuming.
2Reliability
If high-performance hardware and SISO analog Tx cancellation techniques are used, then leakage cancellation performance is improved, but device size and cost increase
Solution Approach 1:
The patent replaces complex analog hardware cancellation systems with a digital signal processing approach. Digital filters are applied to transmit signals to generate cancellation signals, substituting mechanical/analog components with digital processing. This reduces power consumption and hardware complexity while maintaining leakage cancellation effectiveness in MIMO radar systems.
Solution Approach 2:
The patent creates a universal digital filtering framework that can handle multiple transmit and receive antennas simultaneously. The same digital filter structure is applied across all MIMO channels, providing a multi-functional solution that replaces multiple specialized analog cancellation circuits, thereby reducing overall device complexity and size.
3Measurement precision
If digital filtering with dynamically calculated coefficients is used, then leakage cancellation accuracy is improved, but computational complexity increases
Solution Approach 1:
The patent performs preliminary calculations of digital filter coefficients based on known transmit signal characteristics and estimated leakage paths. By pre-calculating coefficients before the cancellation process, the system achieves high accuracy without requiring complex real-time computations during signal processing, thus balancing precision with computational feasibility.
Solution Approach 2:
The patent implements a feedback mechanism where cancellation signals are generated, combined with received signals, and the result is used to refine subsequent cancellation operations. This iterative feedback approach improves leakage cancellation accuracy progressively while keeping each computational step relatively simple, managing overall computational complexity through incremental refinement.
Data Source
AI summary
For example, a MIMO radar may include a plurality of Tx chains to process a plurality of digital Tx signals for transmission of a plurality of Tx RF signals; a plurality of Rx chains configured to output a plurality of digital Rx signals based on a plurality of Rx RF signals and a plurality of digital leakage-cancellation signals, wherein an Rx chain of the plurality of Rx chains is configured to output a digital Rx signal based on an Rx RF signal and a digital leakage-cancellation signal corresponding to the Rx chain; and a digital MIMO filter to generate the plurality of digital leakage-cancellation signals based on the plurality of digital Tx signals, the digital MIMO filter configured to generate the digital leakage-cancellation signal corresponding to the Rx chain by applying to the plurality of digital Tx signals a respective plurality of filters corresponding to the Rx chain.