Synchronization Signal Subcarrier Selection for Efficient NR Detection
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Solution Overview
Problem
In wireless communication networks, efficiently enabling synchronization with multiple subcarrier spacings for synchronization signals is challenging due to the flexibility of the OFDM scheme, especially in the new radio (NR) technology, where UEs may lack information about the applied subcarrier spacing and transmitting with every possible spacing is resource-inefficient.
Innovation Solution
A method for a UE to select a subset of supported subcarrier spacings for synchronization signal detection by identifying frequency ranges, mapping, priority order, power levels, and stored information, and for base stations to coordinate and transmit synchronization signals using a subset of subcarrier spacings based on frequency ranges and priority, facilitating efficient synchronization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If synchronization signals are transmitted with every possible subcarrier spacing, then the UE can detect synchronization signals for all supported subcarrier spacings, but resource efficiency deteriorates due to excessive transmission overhead
Solution Approach 1:
The set of all possible subcarrier spacings is segmented into multiple subsets, with each subset associated with specific frequency ranges. The base station transmits synchronization signals only for the subset corresponding to the actual frequency range being used, rather than transmitting for all possible subcarrier spacings. This segmentation approach maintains comprehensive detection capability while significantly reducing resource overhead.
Solution Approach 2:
Different subsets of subcarrier spacings are assigned to different frequency ranges (local regions of the spectrum). The base station transmits synchronization signals with subcarrier spacings appropriate to the local frequency range characteristics, ensuring optimal detection performance for each local scenario without wasting resources on inappropriate subcarrier spacings for that region.
2Loss of energy
If a default subcarrier spacing is used for synchronization signals, then resource efficiency improves by reducing transmission overhead, but adaptability deteriorates when multiple subcarrier spacings are needed for different frequency ranges and use cases
Solution Approach 1:
The system dynamically selects which subset of subcarrier spacings to use for synchronization signal transmission based on the actual operating conditions, including frequency range and detected signals. The base station can adaptively choose from multiple predefined subsets, and the UE can adaptively determine which subset is being used by analyzing received signals and decoding subset indication information. This dynamic selection maintains adaptability while avoiding the overhead of transmitting all possible subcarrier spacings simultaneously.
Solution Approach 2:
The synchronization signal transmission mechanism is designed to be universal across different frequency ranges and use cases. By defining multiple subsets that cover different subcarrier spacing options and using subset indication to select the appropriate subset, the system achieves multi-functionality - it can efficiently support various frequency ranges (FR1, FR2, FR3), different use cases (eMBB, URLLC, mMTC), and different subcarrier spacing configurations without requiring separate mechanisms for each scenario.
3Reliability
If the UE monitors all possible subcarrier spacings for synchronization signals, then detection reliability improves, but device complexity increases due to multiple decoding attempts
Solution Approach 1:
The UE performs preliminary actions to determine which subset of subcarrier spacings is being used before attempting full decoding of synchronization signals. By first detecting the subset indication and identifying the active subset, the UE can limit its subsequent decoding attempts to only the subcarrier spacings within that subset, rather than attempting to decode all possible subcarrier spacings. This preliminary identification step significantly reduces decoding complexity while maintaining detection reliability.
Solution Approach 2:
The subset indication acts as an intermediary that bridges the gap between the multiple possible subcarrier spacing configurations and the UE's decoding process. This intermediary information provides the UE with guidance on which specific subset to focus on, eliminating the need for the UE to independently evaluate and attempt decoding of all possible subcarrier spacing options. The intermediary reduces the search space and simplifies the detection process.
Data Source
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AI summary
Subcarrier spacing selection for synchronization signals A wireless communication device (100) identifies a set of multiple different subcarrier spacings which are supported for transmission of synchronization signals. From the set of different subcarrier spacings, the wireless communication device (100) selects a subset of one or more subcarrier spacings. Further, the wireless communication device (100) receives signals (10) from the wireless communication network. On the basis of the subcarrier spacings of the subset, the wireless communication device monitors the received signals (10) for synchronization signals.