Time-of-Arrival Estimation Using Separated Frequency Components
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Solution Overview
Problem
Existing methods for high accuracy time of arrival estimation in multipath radio environments require wide bandwidth signals, which are not freely available and expensive, limiting the accuracy of distance determination.
Innovation Solution
A method involving correlating a signal with separated frequency components, using intermediate frequency ranges devoid of signal components to enhance time resolution without increasing effective bandwidth, thereby narrowing correlation peaks for precise time of arrival estimation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a wide bandwidth signal is used to achieve high time resolution and accurate ToA estimation, then measurement precision is improved, but the cost and difficulty of obtaining the signal increases significantly
Solution Approach 1:
The patent divides the wide bandwidth signal into multiple narrowband signal components that are separated in frequency. Each narrowband component can be transmitted independently through different frequency channels, making the system more practical and cost-effective while still achieving the desired time resolution through the combined effect of multiple components.
Solution Approach 2:
The patent transitions from using a single wide bandwidth signal in the frequency domain to using multiple narrowband signal components separated in frequency. By introducing the frequency separation dimension with intermediate gaps, the system achieves virtual bandwidth expansion without requiring a continuously wide bandwidth, thus resolving the contradiction between measurement precision and signal availability.
2Measurement precision
If the signal bandwidth is increased to narrow the correlation peak width, then measurement precision is improved, but the effective bandwidth requirement becomes extremely high and costly
Solution Approach 1:
The patent introduces frequency separation as an additional dimension by placing intermediate frequency ranges between narrowband signal components. This allows the system to achieve a large frequency span (virtual bandwidth) without requiring a continuously occupied wide bandwidth, thus narrowing the correlation peak while using less bandwidth resource.
Solution Approach 2:
The intermediate frequency ranges that are devoid of signal components serve multiple functions: they enable virtual bandwidth expansion, facilitate the separation of narrowband components, and can potentially be used for other purposes such as interference avoidance or future signal allocations, making the bandwidth resource more versatile.
3Loss of time
If a continuously occupied wide bandwidth is used, then time resolution is improved, but the cost and spectrum availability becomes prohibitive
Solution Approach 1:
The patent segments the continuous wide bandwidth into multiple discrete narrowband components separated by intermediate frequency ranges. This segmentation allows the system to achieve the time resolution benefits of wide bandwidth while using only specific frequency channels that are actually available and affordable, making the solution practical for real-world deployment.
Solution Approach 2:
By introducing frequency separation with intermediate ranges between narrowband components, the patent creates a multi-dimensional frequency structure. This allows the system to achieve a large effective frequency span for time resolution without requiring continuous spectrum occupation, thus resolving the contradiction between time resolution and spectrum availability.
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
This approach allows for accurate time of arrival determination with narrow correlation peaks, enhancing distance measurement precision without the need for extensive bandwidth, utilizing available frequency ranges opportunistically.
Implementation Method 1
correlating the signal as transmitted by the transmitter device and the signal as received by the receiver device with each other
Data Source
AI summary
A method is disclosed for determining a signal's time of arrival at a receiver device, the signal being transmitted by a transmitter device to the receiver device. The method comprises correlating the signal as transmitted by the transmitter device and the signal as received by the receiver device with each other. The signal comprises in its frequency spectrum a first signal component spanning a first frequency range, a second signal component spanning a second frequency range and a third signal component spanning a third frequency range. The first frequency range and second frequency range are separated by a first intermediate frequency range that does not contain a signal component of the signal. The second frequency range and third frequency range are separated by a second intermediate frequency range that does not contain a signal component of the signal. The method further comprises, based on the performed correlation, determining said time of arrival.