D2D Synchronization Signal Generation with Low Cross-Correlation
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Solution Overview
Problem
In device-to-device (D2D) communication systems, achieving quick and efficient synchronization between multiple user equipment (UE) transmitters is challenging due to differences in timing, requiring effective generation and detection of synchronization signals with good correlation to improve system performance.
Innovation Solution
A method for generating synchronization signals with small cross-correlation values, involving cyclic shifting and scrambling of sequences, is implemented, allowing for quick synchronization between transmit and receive ends in D2D communication scenarios, even without network coverage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple transmitting UEs send synchronization signals with different timing in D2D communication, then the system supports distributed communication without network coverage, but the synchronization detection complexity and time increase significantly
Solution Approach 1:
The synchronization signal is segmented into two distinct parts: primary synchronization signal (PSS) and secondary synchronization signal (SSS). The PSS provides coarse timing and frequency synchronization with simple correlation detection, while the SSS provides fine synchronization. This segmentation allows the receiver to first quickly acquire coarse synchronization using PSS, then perform more precise synchronization using SSS, significantly reducing overall detection time compared to using a single unified synchronization signal.
Solution Approach 2:
The patent employs different sequence parameters and structures for PSS and SSS. The PSS uses a specific sequence structure optimized for initial acquisition, while the SSS uses a different sequence structure optimized for fine synchronization. By changing parameters between the two signal types, the system achieves both quick initial synchronization and precise final synchronization, resolving the contradiction between detection speed and accuracy.
2Loss of time
If synchronization signals are designed for quick detection, then synchronization time is reduced, but the correlation performance and detection accuracy may deteriorate
Solution Approach 1:
By dividing the synchronization process into two stages with corresponding signals (PSS for coarse, SSS for fine), the system achieves both quick initial detection and high precision final synchronization. The segmentation allows each signal to be optimized for its specific function without compromise.
Solution Approach 2:
The PSS performs preliminary synchronization action by providing coarse timing and frequency alignment first. This preliminary action prepares the receiver for the subsequent fine synchronization using SSS, enabling the system to achieve high accuracy without requiring the entire process to be both fast and precise simultaneously.
3Reliability
If the synchronization signal sequence is scrambled with complex sequences, then the correlation properties improve, but the device complexity for generation and detection increases
Solution Approach 1:
The patent uses different scrambling approaches for PSS and SSS based on their respective requirements. The PSS uses a relatively simple sequence structure for fast correlation, while the SSS employs more complex scrambling for better correlation properties. This parameter differentiation allows the system to achieve good overall correlation performance without requiring both signals to use complex structures.
Solution Approach 2:
By segmenting the synchronization signal into PSS and SSS, the patent allows each segment to use an appropriately complex scrambling scheme matched to its function. The PSS uses simpler scrambling for speed, while the SSS uses more complex scrambling for precision, reducing the overall device complexity compared to using complex scrambling throughout.
Data Source
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AI summary
Embodiments of the present invention provide synchronization signal sending and receiving methods, apparatuses, and devices. The synchronization signal sending apparatus of the present invention includes: a synchronization signal generation module, configured to generate a synchronization signal according to one or more sequences, where a length or lengths of the one or more sequences are determined according to a length of the synchronization signal; a baseband signal obtaining module, configured to obtain a baseband signal according to the synchronization signal generated by the synchronization signal generation module; and a first sending module, configured to send, after performing radio frequency conversion, out the baseband signal obtained by the baseband signal obtaining module. In a D2D communication scenario, a value of cross-correlation between synchronization signals provided in the embodiments of the present invention is small, which can reduce synchronization detection time. Therefore, a receive end of the synchronization signals can implement quick synchronization with a transmit end according to the synchronization signals, thereby improving system performance.