Mobile Receiver Positioning via Virtual Transmitters
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Solution Overview
Problem
Existing methods for determining the position of a mobile receiver in a quasi-stationary environment with multipath signal propagation are limited by reduced accuracy due to the complexity of multipath reception, requiring synchronization with multiple transmitters and knowledge of their positions and surrounding geometry.
Innovation Solution
A method that determines the position and speed of a mobile receiver using signal components received via multiple transmission paths, assuming direct transmission from virtual transmitters, without requiring knowledge of the actual transmitter positions or geometry, employing SLAM algorithms and Bayesian filters to estimate relative positions, which can be converted to absolute positions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If standard synchronization methods (e.g., delay locked loop) are used for position determination, then the process is simple, but position determination accuracy is reduced due to multipath reception
Solution Approach 1:
The patent converts the harmful multipath signal components into useful information by introducing virtual transmitters that model the reflected and scattered signal paths. Instead of treating multipath signals as interference to be eliminated, the invention uses them to enhance position determination accuracy through additional geometric constraints provided by the virtual transmitter positions.
2Measurement precision
If methods based on channel impulse response estimation are used to improve accuracy in multipath reception, then position determination accuracy improves, but the requirement for synchronization with multiple transmitters and knowledge of their positions increases complexity
Solution Approach 1:
The patent creates virtual copies of transmitters by introducing virtual transmitters that represent the effective signal sources for reflected and scattered signal components. These virtual transmitters are positioned based on the geometry of reflectors and scatterers, allowing the system to process multipath signals as if they originated from additional known positions without requiring actual synchronization with multiple physical transmitters.
Solution Approach 2:
The patent segments the signal propagation paths into direct paths and multipath components, treating each multipath component as a separate transmission from a virtual transmitter. This segmentation allows the complex multipath environment to be modeled as multiple simpler transmission paths, each handled independently through the virtual transmitter concept.
3Adaptability or versatility
If indoor positioning methods using reflected signals are used, then position determination is enabled in indoor environments, but knowledge of spatial geometry and transmitter position is required
Solution Approach 1:
The patent enables the receiver to determine its position using only the received signal characteristics without requiring external knowledge of the environment geometry or transmitter positions. The virtual transmitter positions are derived automatically from the signal processing itself, allowing the system to adapt to any indoor environment without pre-loaded geometric information.
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 method improves position determination accuracy by simplifying the process and reducing dependency on external information, enabling precise relative and absolute positioning of the receiver without needing synchronization or geometry data.
Implementation Method 1
a signal s(kT) emitted by the transmitter TX is transmitted to the receiver RX via multipath propagation
Implementation Method 2
reflections of the signal components s i (τ) at reflectors
Implementation Method 3
scattering of the signal components s i (τ) at scatterers
Data Source
Figure 1a~2
Figure 3
Figure 4
AI summary
The invention relates to a method and a device for determining a position of a mobile receiver RX moving in an at least quasi-stationary environment on the basis of signals s(kT) emitted by a transmitter TX positioned immobile in the environment, wherein the receiver RX receives as reception signal (I) a signal s(kT) which is emitted by the transmitter TX and which is transmitted via N(k) transmission paths as signal components si(τ), where k:= time step, τ:= time delay, and i=0,..., N(k)-1, wherein as interactions: reflections of the signal components si(τ) at reflectors and/or scatterings of the signal components si(τ) at scatterers are taken into account on the transmission paths, wherein on the basis of the reception signals q(k,τ) the following are determined: a position ru(k) and a velocity vu(k) of the receiver RX, and for each of the N(k) transmission paths in each case a position rv,i(k) of a virtual transmitter vTXi, and a transmission path distance dv,i between the transmitter TX and a last scatterer SCATTERi lying on the i-th transmission path, provided that such a scatterer SCATTERi is present, wherein: a signal component si(τ) of the signal s(kT) that is transmitted on the i-th transmission path no longer experiences further scattering between the last scatterer SCATTERi and the receiver RX, and it is assumed that each signal component si(τ) received by the receiver RX is emitted by an assigned virtual transmitter vTXi and has reached the receiver RX directly without interaction, and at least the determined position ru(k) of the receiver and/or the velocity vu(k) of the receiver RX are/is provided and/or output for further evaluations.