TOA Estimation Using Combined Subcarrier Correlation
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Solution Overview
Problem
Current wireless communication networks face challenges in accurately determining the time of arrival (TOA) of signals, which affects location estimation and positioning accuracy, especially in asynchronous networks where cell timing is not aligned.
Innovation Solution
The method involves each cell transmitting primary and secondary synchronization signals on contiguous subcarriers and reference signals on non-contiguous subcarriers across the system bandwidth, allowing user equipment (UE) to combine correlation results from multiple signals to determine TOA, thereby improving location estimation accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If TOA is determined based on a single signal transmitted on a single set of subcarriers, then the device complexity is reduced, but the measurement precision of TOA deteriorates
Solution Approach 1:
The patent combines correlation results from multiple signals transmitted on different sets of subcarriers (contiguous and non-contiguous subcarriers) to determine TOA. This merging of multiple measurement sources improves TOA estimation accuracy by averaging out errors and providing more robust positioning in asynchronous networks
Solution Approach 2:
The patent divides the system bandwidth into different sets of subcarriers (contiguous and non-contiguous) for transmitting multiple signals. This segmentation allows the system to exploit different frequency resources independently, enabling more accurate TOA estimation through combination of results from different subcarrier sets
2Measurement precision
If multiple signals are transmitted on different sets of subcarriers to improve TOA accuracy, then the measurement precision improves, but the device complexity increases
Solution Approach 1:
The patent merges correlation results from multiple signals by performing correlation on each signal separately and then combining the results. This approach improves location estimation accuracy while managing complexity through systematic combination of individual correlation outputs
3Adaptability or versatility
If TOA estimation uses signals from asynchronous networks, then the adaptability to different network types improves, but the measurement precision deteriorates due to timing misalignment
Solution Approach 1:
The patent changes the approach to TOA estimation by using multiple signals on different subcarrier sets with different characteristics. This parameter change in the estimation methodology enables the system to adapt to asynchronous networks while maintaining accuracy through diversified signal measurement
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AI summary
Techniques for determining time of arrivals (TOAs) of signals in a wireless communication network are described. Each cell may transmit (i) synchronization signals on a set of contiguous subcarriers in the center portion of the system bandwidth and (ii) reference signals on different sets of non-contiguous subcarriers distributed across the system bandwidth. A UE may determine TOA for a cell based on multiple signals transmitted on different sets of subcarriers. The UE may perform correlation for a first signal (e.g., a synchronization signal) from the cell to obtain first correlation results for different time offsets. The UE may perform correlation for a second signal (e.g., a reference signal) from the cell to obtain second correlation results for different time offsets. The UE may combine the first and second correlation results and may determine the TOA for the cell based on the combined correlation results.