Base Station Random-Access Preamble Position Estimation
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Solution Overview
Problem
In wireless communication systems, accurately estimating the position of a terminal apparatus is challenging when the receiving timing of the radio signal deviates significantly from the expected timing, especially in scenarios where the terminal is close to some base stations and far from others, leading to inaccurate signal reception and estimation.
Innovation Solution
The technique involves using a random-access preamble with a longer guard time compared to the cyclic prefix of standard signals, allowing base stations to accurately receive and measure the preamble, even when the distance differences between the terminal and base stations are large. This is achieved by instructing the terminal to transmit the preamble using a specific sequence and resource, and designating sufficient transmission power to ensure accurate measurement by multiple base stations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the terminal apparatus transmits a radio signal at a timing aligned with one base station apparatus, then that base station can accurately receive the signal, but other base station apparatuses cannot accurately receive the signal due to timing deviation
Solution Approach 1:
The base station apparatus pre-calculates and notifies other base stations of the expected reception timing for the random-access preamble, taking into account the terminal's transmission timing and propagation delays. This preliminary timing coordination ensures all base stations are prepared to accurately receive the signal regardless of distance variations.
Solution Approach 2:
The patent uses a random-access preamble with a longer guard time compared to standard signals. This parameter change in the signal structure provides a larger timing margin, allowing base stations to accurately receive and measure the preamble even when there are timing deviations due to distance differences from the terminal.
2Measurement precision
If the terminal apparatus is located close to some base station apparatuses and distant from others, then signal strength varies significantly, but timing alignment cannot be achieved for all base stations simultaneously
Solution Approach 1:
The base station apparatus that receives the random-access preamble pre-calculates the expected reception timing for other base stations based on the terminal's transmission timing and the known geometric relationships. This preliminary timing information is notified to all participating base stations, enabling them to accurately measure the preamble arrival timing and direction despite varying distances from the terminal.
Solution Approach 2:
The patent employs a random-access preamble with an extended guard time parameter. This longer guard time provides sufficient timing margin for base stations at various distances from the terminal to accurately receive and measure the signal, enabling position estimation adaptability across different spatial configurations.
Data Source
AI summary
A base station apparatus notifies another base station apparatus of information indicating an instruction instructing that a random-access preamble transmitted by a terminal apparatus be measured for measuring a position of the terminal apparatus and a sequence to be used for transmission of the random-access preamble, designates the sequence and instructs the terminal apparatus to transmit the random-access preamble, and measures the random-access preamble transmitted by the terminal apparatus, using the sequence in order to measure the position of the terminal apparatus. The position of the terminal apparatus is estimated based on results of measurement of the random-access preamble performed by the base station apparatus and the other base station apparatus.