Direct Wave Propagation Delay Estimation Using Reflected Waves
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Solution Overview
Problem
Current indoor wireless communication systems face challenges in accurately estimating the air propagation delay of direct waves due to system response delays, which affect the accuracy of ranging and positioning, especially in complex indoor environments with multiple users and network congestion.
Innovation Solution
A method that estimates the air propagation delay of a direct wave using a radio wave receiving device by obtaining the azimuth, elevation angle, and total delay of both direct and reflected waves, selecting a hypothetical point, calculating the propagation distance of the reflected wave, and minimizing the difference between calculated and actual distances to isolate the air propagation delay.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple access points are used for positioning, then positioning coverage is improved, but system complexity and synchronization requirements increase
Solution Approach 1:
The invention extracts and eliminates system response delay from the total measured delay by using reflected wave signals as a reference. By calculating the difference between direct wave delay and reflected wave delay, the method isolates the air propagation delay of the direct wave, removing the need for complex multi-access point synchronization systems.
2Ease of operation
If system response delay is included in delay measurement, then measurement is simpler, but air propagation delay estimation accuracy deteriorates
Solution Approach 1:
The invention converts the harmful system response delay into a useful reference by measuring it through the reflected wave path. Since the reflected wave experiences the same system response delay as the direct wave, subtracting the reflected wave delay from the direct wave delay eliminates the system response component, leaving only the air propagation delay.
3Measurement precision
If reflected wave information is used, then air propagation delay estimation accuracy is improved, but calculation complexity increases
Solution Approach 1:
The reflected wave serves as an intermediary that carries information about the system response delay. By using the reflected wave as a mediator, the method indirectly obtains the system response delay component without requiring direct measurement, simplifying the overall processing while maintaining accuracy.
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 enables accurate estimation of air propagation delay using a single receiving end, improving indoor positioning and ranging accuracy without requiring synchronization of multiple access points, thus overcoming the limitations of existing technologies.
Implementation Method 1
obtaining a received signal through a radio wave receiving device, and estimating an azimuth of arrival, an elevation angle and a total delay of each path of a multipath wave arriving at a receiving end
Implementation Method 2
obtaining a departure angle of the reflected wave according to the geometric principle of wave reflection and an arrival angle of the reflected wave measured by the radio wave receiving device
Data Source
AI summary
The invention discloses a method for estimating the air propagation delay of a direct wave, wherein an azimuth, an elevation angle and a total delay of a multipath wave reaching a receiving end are obtained through a receiving device; a departure angle of a reflected wave is obtained using a geometric relationship of wave reflection; a hypothetical point on a direct wave ray is selected as a transmitting end, and hereby the air propagation delay of the direct wave and the position of a reflection point of the reflected wave are calculated; the propagation delay and distance of the reflected wave are calculated according to the total delay of the direct wave and the reflected wave and the position of the hypothetical point. The invention can obtain the air propagation delay of the direct wave, thereby obtaining a propagation distance of the direct wave and fulfilling the requirements of ranging and positioning.