LTE Sub-Frame Position Difference Method for Frame Boundary Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for frame boundary detection in LTE systems, such as SCH-based, BCH-based, and reference signal-based detection, are inefficient due to the need for extensive correlation, signal reception, and dependency on signal waveforms, leading to increased time and complexity in cell search procedures.
Innovation Solution
The sub-frame position difference method identifies frame boundaries by calculating the differences in positions or number of slots/sub-frames between subsequent identical SCHs, allowing for direct signaling of sub-frame IDs without relying on SCH, BCH, or reference signals, thereby simplifying frame boundary detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If SCH-based detection is used to detect frame timing by detecting cell-specific SCH sequences in the frequency domain, then frame timing can be estimated, but the detection process becomes time-consuming and requires storing 512 or more cell-specific sequences
Solution Approach 1:
The patent extracts only the necessary timing information from the SCH sequences by using correlation detection in the time domain rather than requiring full frequency domain processing. This eliminates the need to store and process all 512 cell-specific sequences, reducing detection time while maintaining frame timing detection accuracy through selective correlation with a limited set of known sequences.
Solution Approach 2:
The patent uses copied versions of a small set of known SCH sequences for correlation detection in the time domain. Instead of storing all possible cell-specific sequences, the UE maintains copies of a limited number of reference sequences that can be correlated against received signals to identify frame timing, significantly reducing memory requirements and processing time.
2Measurement precision
If BCH-based detection is used to detect frame timing by decoding the BCH, then frame timing can be detected, but BCH reception is required for initial cell search which increases complexity
Solution Approach 1:
The patent segments the cell search process into two independent stages: first, frame timing detection using SCH sequence correlation without requiring BCH reception; second, cell identification using the detected timing information. This segmentation allows initial cell search to proceed without BCH decoding, reducing device complexity while maintaining accurate frame timing detection through the correlation-based SCH method.
3Measurement precision
If reference signal-based detection is used to detect frame timing by reference signal waveform, then frame timing information can be detected, but the repetition interval of 10 milliseconds imposes additional delay
Solution Approach 1:
The patent performs preliminary frame timing detection using SCH sequence correlation before the reference signal waveform becomes available. By detecting frame timing early through correlation of SCH sequences in the time domain, the system obtains timing information immediately without waiting for the 10-millisecond reference signal repetition interval, thereby eliminating the detection delay while maintaining accurate frame timing identification.
Data Source
AI summary
The present invention provides a unique manner of identifying the Frame boundaries in multiple identical/non-identical Synchronization Channels (SCHs) in different sub-frames via a new sub frame position difference method. The method implements the differences between the different sub-frames carried by the SCH. The sub frame identity, and hence the frame boundary, can be identified by calculating the difference between the positions, based on time or number of slots/sub-frames or any data packets, of the two subsequent slots/sub-frames or any identical data packets.