Multipath Separation Using Toeplitz SVD for Noisy OFDM Signals
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Solution Overview
Problem
The noise sensitivity of the MUSIC algorithm in multipath separation deteriorates in noisy environments, particularly in OFDM systems due to the discontinuity of signal distribution in the frequency domain caused by zero frequencies, leading to poor noise adaptability and reduced multipath separation precision.
Innovation Solution
A method involving the construction of Toeplitz matrices from frequency domain response characteristics of signals in multiple frequency bands, combining these matrices into a synthesized matrix, performing singular value decomposition to separate signal and noise spaces, and determining delays based on inner product thresholds to achieve precise multipath separation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the MUSIC algorithm is used for multipath separation, then multipath recognition accuracy is improved under ideal conditions, but noise sensitivity causes severe deterioration in noisy environments
Solution Approach 1:
The patent transforms the multipath separation problem from the time domain to the frequency domain by applying FFT to received signals. This dimensionality change enables the use of frequency domain response characteristics and Toeplitz matrix construction, which provides better noise robustness compared to traditional time-domain MUSIC algorithm while maintaining multipath recognition accuracy.
Solution Approach 2:
The patent changes the parameter representation from time-domain signal amplitudes to frequency-domain response characteristics. By constructing Toeplitz matrices from frequency domain data and using singular value decomposition, the algorithm achieves improved noise adaptability while maintaining the ability to accurately recognize multipath components.
2Area of stationary object
If OFDM systems are used for cellular network positioning, then coverage is improved, but zero frequency destroys signal distribution uniformity in the frequency domain
Solution Approach 1:
The patent extracts and separately processes the frequency domain response characteristics from OFDM signals. By constructing Toeplitz matrices from the frequency domain data and using singular value decomposition to separate signal and noise subspaces, the algorithm compensates for the non-uniform signal distribution caused by zero frequency, maintaining accurate multipath separation in OFDM systems.
Data Source
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AI summary
Provided are a multipath separation method and device, and a storage medium. The multipath separation method includes: extracting frequency domain response characteristics of received reference signals in at least two different frequency bands; for each of the at least two different frequency bands, constructing a Toeplitz matrix; combining Toeplitz matrixes corresponding to the at least two different frequency bands; performing singular value decomposition on the synthesized Toeplitz matrix; determining a signal space matrix and a noise space matrix according to the decomposed matrix; constructing a plurality of frequency domain response vectors according to frequency domain response characteristics of local signals having different delays and are the same as the received reference signals; and comparing a first preset threshold with inner products between each of the plurality of frequency domain response vectors and the noise space matrix respectively, and determining a delay corresponding to each of a plurality of frequency domain response vectors in which inner products satisfy the first preset threshold to be a delay of one path in the multipath.