Pull-in Signal for Synchronization Channel Location
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Solution Overview
Problem
Blindly searching for a synchronization channel in wireless communication systems is inefficient, leading to increased initial acquisition time for user equipment (UE) in accessing wireless networks, especially in scenarios with sparse frequency rasters and longer synchronization channel transmission periods.
Innovation Solution
Transmitting pull-in signals on raster points of a frequency raster to assist UE in locating the synchronization channel, which includes information about the timing and location of the synchronization channel transmissions, allowing the UE to transition between power states based on this information.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the UE performs blind search for synchronization channel at various time and frequency locations, then the UE can locate the synchronization channel, but the initial acquisition time is increased
Solution Approach 1:
The network access device transmits pull-in signals before the synchronization channel at known time offsets. These pull-in signals contain information about the synchronization channel's time-frequency location, allowing the UE to perform preliminary detection and obtain guidance information before actually searching for the synchronization channel, thus reducing the blind search time.
Solution Approach 2:
The pull-in signal acts as an intermediary between the network access device and the UE during the initial access process. It carries indication information about the synchronization channel's location and provides a reference signal that facilitates the UE's detection process, serving as a mediator that bridges the gap between the network and UE without requiring the UE to perform exhaustive blind searching.
2Measurement precision
If the UE searches for synchronization channel at multiple raster points, then the synchronization channel can be located, but the search complexity and time consumption increase
Solution Approach 1:
The pull-in signal serves as an intermediary that provides the UE with indication information about the synchronization channel's specific raster point location. This mediator reduces the search space from multiple raster points to a specific or limited set of raster points, thereby reducing search complexity while maintaining detection accuracy.
Solution Approach 2:
The initial access process is segmented into two stages: first detecting the pull-in signal to obtain indication information, then using this information to guide the search for the synchronization channel. This segmentation divides the complex blind search across multiple raster points into a simpler two-step process, reducing overall search complexity.
3Adaptability or versatility
If the synchronization channel is transmitted at unknown time and frequency, then the network can flexibly allocate resources, but the UE's initial acquisition time increases
Solution Approach 1:
The network access device performs preliminary action by transmitting pull-in signals that contain indication information about the synchronization channel's time-frequency location. This allows the UE to obtain advance notice of where to find the synchronization channel, reducing the time required for initial acquisition while the network retains flexibility in choosing the actual transmission time and frequency based on resource availability.
Solution Approach 2:
The pull-in signal provides feedback information to the UE about the synchronization channel's location. This feedback mechanism allows the network to maintain flexible resource allocation for the synchronization channel while still enabling the UE to quickly locate it by providing indicative information in advance through the pull-in signal.
Data Source
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AI summary
Techniques are described for wireless communication. One method includes searching for a synchronization channel on a first raster point of a frequency raster identified for synchronization channel transmission. The frequency raster includes a plurality of raster points in a radio frequency spectrum. The method also includes identifying a pull-in signal on the first raster point; determining, from the pull-in signal, a second raster point of the frequency raster on which the synchronization channel is transmitted; and receiving the synchronization channel on the second raster point. Another method includes transmitting the pull-in signal and the synchronization channel.