Coherent Multicarrier Correlation for Signal Parameter Estimation
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Solution Overview
Problem
Existing PNT systems face accuracy degradation and high computational complexity when estimating signal parameters using correlation functions, especially with smooth autocorrelation functions and closely spaced multipaths, leading to errors in noise and channel distortion.
Innovation Solution
A system and method employing coherent multicarrier correlation techniques, involving carrier removal, baseband processing, and carrier restoration to generate multi-carrier correlation signals, which reduces computational complexity while maintaining high estimation accuracy by leveraging wide-bandwidth signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If correlation functions are used to estimate signal parameters, then measurement precision can be achieved, but computational complexity increases significantly
Solution Approach 1:
The patent segments the wideband signal into multiple narrowband sub-signals using filter banks, processes each sub-signal separately through correlation functions, and then combines the results. This segmentation reduces the computational complexity of correlation operations while maintaining measurement precision through coherent integration of sub-signal correlations.
2Measurement precision
If wideband signals are used for correlation, then measurement precision improves, but computational complexity increases
Solution Approach 1:
The patent divides the wideband signal into multiple narrowband frequency sub-signals using a filter bank with overlapping frequency ranges. Each narrowband sub-signal is then processed through correlation functions separately. This segmentation allows the system to achieve wideband localization accuracy while reducing computational complexity, as correlation operations on narrowband signals require fewer multiplications than direct wideband correlation.
Solution Approach 2:
The patent combines the correlation results from multiple narrowband sub-signals through coherent integration to achieve the final time localization estimate. By merging the results from multiple frequency sub-bands, the system achieves wideband signal performance with reduced computational burden compared to direct wideband correlation.
3Measurement precision
If correlation functions are used with smooth autocorrelation functions, then measurement can be performed, but measurement precision degrades due to noise and distortion
Solution Approach 1:
The patent segments the signal into multiple narrowband sub-signals, each with its own autocorrelation function. By processing multiple sub-signals and combining their correlation results coherently, the system achieves sharper effective autocorrelation peaks that are more resistant to noise and channel distortion than individual narrowband autocorrelations alone.
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
The approach significantly reduces computational complexity while achieving high accuracy in estimating time-of-arrival and angle-of-arrival parameters, even in multipath environments with short delay separations, by utilizing multicarrier modulation and efficient processing techniques.
Implementation Method 1
The one or more carrier removal components can be configured to remove a nominal carrier component by frequency-mixing a received RF signal with a RF oscillation signal to generate the respective baseband signal
Implementation Method 2
The one or more carrier restoration components can be configured to incorporate the nominal carrier component by frequency-mixing the correlation signal associated with the received RF signal with a delayed version of the RF oscillation signal
Data Source
AI summary
System and methods for generating and employing coherent multicarrier correlation can include receiving, from a transmitter, a plurality of radio frequency (RF) signals associated with a respective plurality of nominal carrier components. A processing circuitry can remove from each received RF signal the respective nominal carrier component to generate a corresponding baseband signal. The processing circuitry can generate, for each baseband signal, a respective correlation signal using the baseband signal and a reference signal. The processing circuitry can incorporate, to each correlation signal, the respective nominal carrier component of the RF signal associated with that correlation signal to generate a respective single-carrier correlation signal. The processing circuitry can aggregate the single-carrier correlation signals to generate a multi-carrier correlation signal. The processing circuitry can determine one or more attributes of the transmitter or the received RF signals based on the generated multi-carrier correlation signal.