Multipolarized Array Response Sub-path Parameter Estimation
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Solution Overview
Problem
Conventional multipath parameter estimation methods struggle to effectively resolve a large number of sub-paths in dense multipath environments, particularly when the number of sub-paths exceeds the number of array elements, and fail to accurately estimate cross-polarization ratios due to the complexity of radio wave propagation characteristics.
Innovation Solution
A method using multipolarized broadband extended array responses to estimate sub-path delay, two-dimensional departure and arrival angles, initial phase, amplitude, and cross-polarization ratio, involving the transmission of multiple signal sequences, processing channel responses, and applying frequency domain smoothing to reduce dimensionality and improve parameter estimation accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the number of antenna array elements is increased to resolve more sub-paths in the space domain, then the number of resolvable sub-paths increases, but the system complexity increases
Solution Approach 1:
The patent transitions from conventional single-polarization array processing to multipolarized array processing, adding the polarization dimension to the spatial domain. This allows the system to resolve more sub-paths by exploiting polarization diversity rather than simply increasing the number of spatial elements, thereby improving measurement precision without proportionally increasing device complexity
Solution Approach 2:
The patent changes the processing parameters by introducing polarization parameters (cross-polarization ratios, polarization angles) alongside traditional spatial parameters. This parameter expansion enables the system to distinguish and resolve more sub-paths using the same physical array elements, effectively increasing the number of resolvable paths without linearly increasing system complexity
2Measurement precision
If conventional smoothing preprocessing is applied in the space domain followed by ESPRIT or MUSIC, then the space-domain angle information is obtained, but the number of resolved sub-paths is limited by the number of antenna array elements
Solution Approach 1:
The patent applies smoothing in the polarization domain rather than the spatial domain, and uses polarization-diverse array responses to extend the effective number of resolvable sub-paths beyond the number of physical antenna elements. This dimensional shift allows overcoming the fundamental limitation of conventional methods where the number of resolved paths cannot exceed the number of array elements
3Measurement precision
If the 90-degree turn method is used to acquire cross-polarization ratio, then the measurement is obtained, but the process is rough and time-consuming with less accurate results
Solution Approach 1:
The patent performs polarization parameter estimation simultaneously with spatial parameter estimation using the multipolarized array responses, rather than performing a separate 90-degree turn measurement afterward. The cross-polarization ratios are extracted directly from the received multipolarized signals through joint processing, eliminating the need for time-consuming mechanical rotations while maintaining or improving accuracy
Solution Approach 2:
The patent replaces the mechanical 90-degree rotation method with a signal processing-based approach. Instead of physically rotating the antenna to measure cross-polarization, the system uses the inherent polarization diversity in the multipolarized array responses and extracts cross-polarization ratios through mathematical processing, eliminating mechanical movement and associated time losses
Data Source
AI summary
Disclosed is a method for estimating dense multipath parameters by means of multipolarized broadband extended array responses, which includes: first transmitting multiple different transmitted signal sequences via a multipolarized antenna array, and processing received data in multiple snapshots according to the known transmitted signals, to obtain channel responses of multipolarized antenna components at all frequency points in a frequency band; extending the obtained channel response matrixes of multiple frequency points in multiple snapshots into a large two-dimensional channel response matrix; then, acquiring a delay parameter regarding multipath propagation by using a reference array element, and estimating two-dimensional departure and arrival angles by using a channel matrix subjected to frequency domain smoothing and dimensionality reduction; and afterwards, pairing the estimated departure and arrival angles, and estimating parameters such as the cross-polarization ratios, the initial phases, and the amplitudes of the sub-paths by using the estimated parameters.