Secondary Synchronization Sequence Design for Cell Group Detection
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Solution Overview
Problem
Current cell search schemes for 3G LTE systems require complex processing to detect cell group and frame timing using both primary and secondary synchronization signals, and there is a need to minimize interruption time during inter-frequency and inter-Radio Access Technology measurements by enabling detection using a single synchronization signal.
Innovation Solution
The solution involves designing secondary synchronization signals S1 and S2 such that they can be transmitted in alternating orders or on different sub-carriers, with each sequence being of equal length, and using weighted sums to uniquely define the cell group and frame timing, allowing detection using either signal alone.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If both S1 and S2 synchronization signals are used for cell group detection, then detection reliability is improved, but device complexity and processing time increase
Solution Approach 1:
The secondary synchronization signal is divided into two separate sequences S1 and S2, each carrying partial cell group information. The UE can process these sequences independently and combine the results, or use either sequence alone for initial detection, thereby reducing processing complexity while maintaining detection reliability through the segmented information structure.
2Measurement precision
If both S1 and S2 synchronization signals are processed, then frame timing accuracy is improved, but measurement interruption time increases
Solution Approach 1:
The synchronization signals S1 and S2 are designed such that each sequence alone contains sufficient information for preliminary cell group detection and frame timing indication. This preliminary capability allows the UE to perform quick initial measurements without requiring processing of both sequences, thereby reducing measurement interruption time while maintaining adequate timing accuracy for most applications.
3Loss of time
If a single synchronization signal is used for detection, then measurement interruption time is reduced, but detection reliability may deteriorate
Solution Approach 1:
Both synchronization signals S1 and S2 are designed with universal properties such that either signal can independently perform cell group detection and frame timing indication. This multi-functionality ensures that the UE can use a single signal for quick measurements without sacrificing detection reliability, as both signals carry equivalent and sufficient information for the detection task.
Data Source
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AI summary
Timing parameters and an identity of a particular one of a number of cell groups are indicated in a signal transmitted in a cellular communication system having a radio frame in a physical layer, the radio frame comprising a number of time slots. In a known one of the time slots, a synchronization signal, S