Distance Estimation Using LOS NLOS Channel Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for estimating the distance between a transmitter and a receiver using received power are inaccurate due to environmental influences and require complex hardware synchronization or GPS, especially in non-line-of-sight conditions.
Innovation Solution
A method and apparatus that determine whether the signal has propagated through a line-of-sight (LOS) or non-line-of-sight (NLOS) radio channel by analyzing signal characteristics such as fading, power delay profile, and Doppler spectrum, using these determinations to select appropriate pathloss model parameters for accurate distance estimation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If received power is used to estimate distance, then hardware and signal processing requirements are minimized, but distance estimation accuracy deteriorates due to environmental influences
Solution Approach 1:
The patent changes the parameter used for distance estimation from simple received power to received power combined with channel type identification (LOS/NLOS). By detecting signal characteristics and determining whether the channel is line-of-sight or non-line-of-sight, the system selects appropriate pathloss model parameters, thereby improving distance estimation accuracy while keeping hardware requirements minimal
Solution Approach 2:
The patent introduces an intermediary step of channel type detection between received power measurement and distance calculation. The signal characteristics analysis acts as a mediator that provides information about propagation conditions, enabling the selection of appropriate pathloss models and improving overall estimation accuracy
2Ease of operation
If pathloss model is used for distance estimation, then distance can be calculated from received power, but accuracy deteriorates due to propagation distortion from buildings and walls
Solution Approach 1:
The patent changes the pathloss model parameters based on detected channel type. By identifying signal characteristics and determining LOS or NLOS conditions, the system selects appropriate pathloss exponent values and model parameters that account for propagation distortion from buildings and walls, thereby maintaining calculation ease while improving accuracy
Solution Approach 2:
The patent makes the pathloss model dynamic by allowing parameter selection based on real-time channel conditions. The system adapts the pathloss model parameters according to the detected radio channel type, enabling the model to respond to changing propagation environments and maintain accuracy in both LOS and NLOS conditions
3Measurement precision
If GPS receivers are used at transmitter and receiver, then accurate distance can be obtained through coordinate exchange, but device complexity and cost increase
Solution Approach 1:
The patent replaces expensive GPS receivers with a cheaper signal characteristic analysis approach. Instead of using high-precision positioning systems, the system uses standard RF signal processing to detect channel type and estimate distance, achieving acceptable accuracy without the complexity and cost of GPS hardware
Solution Approach 2:
The patent substitutes the mechanical/GPS-based positioning system with an electromagnetic signal analysis approach. By analyzing RF signal characteristics and pathloss properties, the system replaces the need for GPS receivers and coordinate exchange protocols, simplifying the overall system architecture
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 minimizes errors caused by propagation distortion and improves distance estimation accuracy by distinguishing between LOS and NLOS channels, providing more reliable distance calculations even in obstructed environments.
Implementation Method 1
The characteristics may include any one or more of fading characteristics, power delay profile, Doppler spectrum characteristics
Implementation Method 2
Doppler spectrum characteristics
Implementation Method 3
determining whether the signal more likely propagated through a line-of-sight (LOS) radio channel or a non-line-of-sight (NLOS) radio channel
Implementation Method 4
A commonly-used model for pathloss (PL) is PL=−10·γ·log10(r)+PL0
Data Source
AI summary
The invention relates to an apparatus and method for estimating the distance between a transmitter and a receiver. A method comprising obtaining a signal from a receiver; determining whether the signal more likely propagated through a line-of-sight (LOS) radio channel or a non lme-of-sight (NLOS) radio channel; using a model including parameters selected according to the radio channel to estimate the distance between the receiver and a transmitter which sent the signal.