Wireless Terminal Localization via Signal Reconstruction
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Solution Overview
Problem
Existing wireless communication network methods for localizing terminal devices are hindered by collisions on radio channels, which reduce the Signal-to-Interference-plus-Noise Ratio (SINR) and accuracy of localization, limiting the effectiveness of position determination.
Innovation Solution
A method that reconstructs superposed radio signals received by spatially separated receivers to estimate the spatial positions of terminal devices, allowing for localization even in protocols that permit collisions, by decoding and encoding packets and using channel estimation to improve signal separation and interference suppression.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If collisions are allowed on radio channels to increase channel utilization, then channel access efficiency is improved, but localization accuracy deteriorates due to reduced SINR
Solution Approach 1:
The patent converts the harmful effect of signal collisions into a beneficial one by using compressed sensing techniques to reconstruct individual terminal signals from the collided composite signal. Instead of avoiding collisions, the system embraces them and mathematically separates the overlapping signals, thereby maintaining high channel utilization while recovering accurate localization data from what would traditionally be considered interference.
Solution Approach 2:
The patent transforms the problem from the time-frequency domain where collisions occur into the spatial domain by utilizing signal subspace decomposition. By representing signals in terms of their spatial characteristics and using the fact that terminal signals arrive from different directions, the system can separate collided signals by exploiting the additional spatial dimension, thus resolving the contradiction between allowing collisions and maintaining localization accuracy.
2Reliability
If collision-free measurements are required to maintain localization accuracy, then measurement reliability is improved, but channel utilization deteriorates due to restricted access protocols
Solution Approach 1:
The system converts the previously harmful collided signals into useful information sources. By applying compressed sensing and subspace decomposition, the patent extracts reliable localization data from signals that would traditionally be discarded as interference, thereby maintaining measurement reliability while allowing full channel utilization without requiring collision-free periods.
Solution Approach 2:
The patent introduces signal subspace decomposition and compressed sensing algorithms as intermediary processing steps between signal reception and localization. These mathematical tools act as mediators that separate the mixed collided signals and extract reliable positioning information, enabling the system to achieve both high channel utilization and reliable localization without requiring collision-free measurements.
3Measurement precision
If signal reconstruction is performed to separate superposed radio signals, then localization accuracy is improved, but processing complexity increases
Solution Approach 1:
The patent performs preliminary signal decomposition and subspace separation before the actual localization calculation. By pre-processing the received signals to separate the signal subspaces corresponding to different terminals, the system reduces the complexity of subsequent localization operations. This preliminary action organizes the complex collided signals into manageable separated components that are easier to process for position estimation.
Solution Approach 2:
The patent segments the composite received signal into individual terminal signal components through subspace decomposition. By dividing the complex superposed signal into separate signal subspaces, each corresponding to a specific terminal, the system simplifies the localization process. This segmentation transforms a single complex processing task into multiple simpler tasks, each handling a separate signal component, thereby reducing overall processing complexity while maintaining high localization precision.
Data Source
AI summary
A method is provided for localizing a plurality of wireless terminal devices of a communication network, wherein the method comprises: providing reception signals (s; s_AP1, s_AP2, s_AP3) which respectively comprise superposed radio signals which were wirelessly received by a respective one of a plurality of receivers which are arranged spatially separated from one another, wherein the plurality of superposed radio signals originates from different ones of the wireless terminal devices; reconstructing the radio signals in the form of reconstructed radio signals (rs; rs1, rs2), as a function of the respective reception signal (s; s_AP1, s_AP2, s_AP3); and estimating the spatial positions (pos; pos_UE1, pos_UE2) of the wireless terminal devices as a function of the reconstructed radio signals (rs; rs1, rs2).