Synchronization Signal Segmentation in Shared Spectrum
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Solution Overview
Problem
Wireless communication systems face challenges in efficiently transmitting synchronization signals in shared radio frequency spectrum bands, particularly due to contention for access and variability in signal alignment, which affects data transmission capacity and coverage.
Innovation Solution
The use of distinct types of synchronization signals, including a first type aligned with LBT frame boundaries and a second type for opportunistic transmissions, allows user equipment to differentiate between discovery signal periods and frame boundaries, enabling efficient channel access and measurement in shared radio frequency spectrum bands.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If synchronization signals are transmitted at predetermined times in every radio frame in a dedicated radio frequency spectrum band, then timing synchronization and frequency synchronization are achieved reliably, but in a shared radio frequency spectrum band, transmission depends on winning contention which causes variability in signal alignment and affects synchronization reliability
Solution Approach 1:
The patent segments synchronization signals into two distinct types: a first type transmitted at predetermined times in every radio frame for reliable timing synchronization, and a second type transmitted opportunistically when channel access is won for frequency synchronization. This segmentation allows each signal type to serve its specific function optimally without being constrained by the other's transmission conditions.
Solution Approach 2:
The base station performs multiple functions using the same transmission infrastructure: it transmits both predetermined synchronization signals and opportunistic synchronization signals, and also performs LBT procedures and data transmissions. The system universally handles both licensed and unlicensed spectrum requirements through a unified architecture that adapts transmission behavior based on channel access outcomes.
2Productivity
If offloading of data traffic to a shared radio frequency spectrum band is performed, then data transmission capacity is enhanced, but contention for channel access and variability in signal alignment affect synchronization and measurement procedures
Solution Approach 1:
The patent segments synchronization signals into two distinct types: a first type transmitted at predetermined times in every radio frame for reliable timing synchronization, and a second type transmitted opportunistically when channel access is won for frequency synchronization. This segmentation allows each signal type to serve its specific function optimally without being constrained by the other's transmission conditions.
Solution Approach 2:
The patent employs different signal characteristics (analogous to color changes) to differentiate between the first type and second type of synchronization signals. The UE can identify and process each signal type based on its distinct characteristics, enabling differentiated handling of timing and frequency synchronization requirements without confusion.
3Measurement precision
If a UE monitors for synchronization signals to perform cell acquisition and measurements, then cell search and frequency reselection are enabled, but variability in signal alignment due to LBT contention affects measurement accuracy and acquisition reliability
Solution Approach 1:
The patent segments synchronization signals into two distinct types: a first type transmitted at predetermined times in every radio frame for reliable timing synchronization, and a second type transmitted opportunistically when channel access is won for frequency synchronization. This segmentation allows each signal type to serve its specific function optimally without being constrained by the other's transmission conditions.
Solution Approach 2:
The first type of synchronization signal acts as an intermediary that provides a stable, predictable reference for timing synchronization. This intermediary signal enables the UE to establish a reliable timing baseline before processing the second type of synchronization signal, thereby improving overall measurement accuracy despite LBT-induced variability.
Data Source
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AI summary
Techniques are described for wireless communication. A first method includes generating a first type of synchronization signal based at least in part on a first type of transmission in a shared radio frequency spectrum band, and generating a second type of synchronization signal based at least in part on a second type of transmission in the shared radio frequency spectrum band. The second type of synchronization signal is different from the first type of synchronization signal. A second method includes receiving a synchronization signal associated with a type of transmission in a shared radio frequency spectrum band; determining a type of the synchronization signal; and determining one or more cell parameters based at least in part on the synchronization signal.