Positioning Receiver Phasor Correlation for Multipath Suppression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing radio signal receivers, particularly in GNSS-based positioning systems, face challenges with multi-path effects and spoofing, leading to reduced positioning accuracy and reliability, especially in urban environments, and conventional solutions like CRPAs are large and expensive, unsuitable for low-cost devices.
Innovation Solution
A method and apparatus that utilize phasor sequences to enhance desired signal gain and suppress undesired signal interference by generating a third phasor sequence through a weighted combination of first and second phasor sequences, indicative of desired and undesired directions, to improve correlation accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If motion compensation is applied to enhance the desired straight-line signal, then the signal-to-noise ratio of the desired signal is improved, but the receiver may still lock onto stronger non-straight-line or spoofing signals
Solution Approach 1:
The patent applies preliminary anti-action by generating phasor sequences that represent both desired and undesired signal directions, then combining them with weights that actively suppress undesired signals before the correlation process. This preemptive suppression prevents the receiver from locking onto wrong signals in the first place, rather than attempting to correct locking errors afterward.
Solution Approach 2:
The patent changes the parameters of the correlation process by introducing weighted phasor sequences that modify the correlation output. The weights are adjusted to enhance desired signals and suppress undesired signals, effectively changing the correlation landscape to make the correct signal peak more prominent and reliable.
2Measurement precision
If Controlled Reception Pattern Antennas (CRPAs) are used to provide spatial discrimination of signals, then positioning accuracy is improved, but the device size and cost increase significantly
Solution Approach 1:
The patent replaces the mechanical/physical CRPA system with a signal-processing-based solution. Instead of using multiple antennas with specific geometric arrangements to achieve spatial discrimination, the patent uses phasor sequences and weighted combinations in the correlation process to achieve the same effect, thereby eliminating the need for complex antenna structures.
Solution Approach 2:
The patent creates a virtual representation of spatial signal characteristics through phasor sequences that model the expected signal behavior from different directions. These phasor copies are then combined with weights to replicate the spatial filtering effect of CRPAs without requiring the physical antenna array.
3Productivity
If conventional correlation is performed without direction-based signal suppression, then the receiver can acquire signals quickly, but positioning accuracy deteriorates in multi-path environments
Solution Approach 1:
The patent performs preliminary action by pre-computing phasor sequences for both desired and undesired signal directions before the correlation process. These pre-computed sequences are then combined with appropriate weights to create a enhanced correlation output that maintains acquisition speed while improving positioning accuracy through directional signal suppression.
Data Source
AI summary
A method and apparatus for improving signal reception in a radio signal receiver is provided. The method comprises: receiving a signal from one or more remote sources; determining movement of the receiver; obtaining first and second phasor sequences indicative of the determined movement of the receiver in first and second directions; generating a third phasor sequence based on a weighted combination of the first and second phasor sequences in accordance with the first and second directions; and providing a correlation signal using the third phasor sequence, wherein providing the correlation signal comprises correlating a local signal with the received signal, and combining at least one of the local signal, received signal, and the result of the correlation with the third phasor sequence, such that a signal received along the second direction is suppressed relative to a signal received along the first direction. A corresponding positioning system is also disclosed.