Supplementary Uplink Frequency Synchronization in NR-LTE Coexistence
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Solution Overview
Problem
In wireless communications, especially in 5G NR systems operating on high frequency bands, signal attenuation is severe, and there is a need for efficient frequency resource management to ensure network coverage and coexistence with 4G LTE systems, where NR-LTE co-existence is crucial for early commercial use but lacks a specific technical solution for frequency synchronization with supplementary uplink resources.
Innovation Solution
A synchronization method where a terminal sends an uplink signal to a network device on a supplementary uplink resource, receives indication information for frequency offset, and determines the frequency offset value to implement frequency synchronization, allowing orthogonal uplink signals and improved transmission performance without relying solely on downlink synchronization signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If 5G NR operates on high frequency band to improve data transmission capability, then transmission speed is improved, but signal attenuation increases and network coverage deteriorates
Solution Approach 1:
The patent segments the uplink resource into two parts: supplementary uplink resource for frequency synchronization and normal uplink resource for data transmission. This segmentation allows the terminal to perform frequency synchronization on the supplementary uplink resource before transmitting data on the normal uplink resource, thereby resolving the frequency offset problem caused by high frequency band operation and improving both transmission speed and coverage reliability
Solution Approach 2:
The patent implements preliminary frequency synchronization by sending a first uplink signal on the supplementary uplink resource before actual data transmission. The network device measures the frequency offset from this preliminary signal and feeds back adjustment information to the terminal. This preliminary action ensures that when the terminal transmits data on the normal uplink resource, the frequency offset has been corrected, thereby maintaining both high transmission speed and reliable network coverage
2Productivity
If 5G NR shares licensed spectrum with 4G LTE to improve resource utilization and network coverage, then resource utilization is improved, but frequency synchronization complexity increases
Solution Approach 1:
The patent segments the uplink resource into supplementary uplink resource for frequency synchronization and normal uplink resource for data transmission. This segmentation allows the terminal to perform frequency synchronization on the supplementary uplink resource before transmitting data on the normal uplink resource, thereby resolving the frequency offset problem caused by high frequency band operation and improving both transmission speed and coverage reliability
Solution Approach 2:
The patent enables the terminal to autonomously determine frequency offset based on indication information from the network device. The terminal sends a first uplink signal on the supplementary uplink resource, receives indication information containing frequency offset data, and automatically adjusts its frequency based on this information. This self-service mechanism simplifies the synchronization process and reduces the complexity of frequency synchronization in NR-LTE co-existence scenarios
3Device complexity
If terminal relies on downlink synchronization signal for frequency synchronization, then synchronization process is simplified, but uplink signal orthogonality cannot be ensured
Solution Approach 1:
The patent segments the uplink resource into supplementary uplink resource for frequency synchronization and normal uplink resource for data transmission. This segmentation allows the terminal to perform frequency synchronization on the supplementary uplink resource before transmitting data on the normal uplink resource, thereby resolving the frequency offset problem caused by high frequency band operation and improving both transmission speed and coverage reliability
Solution Approach 2:
The patent implements a feedback mechanism where the network device measures the frequency offset of the uplink signal received from the terminal and feeds back indication information containing frequency offset data to the terminal. The terminal uses this feedback information to adjust its transmission frequency, ensuring orthogonality of uplink signals from different terminals. This feedback loop maintains both signal orthogonality and reasonable synchronization process complexity
Data Source
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AI summary
This application provides a synchronization method and an apparatus. The method includes: sending, by a terminal, a first uplink signal to a network device on a supplementary uplink resource; and receiving indication information returned by the network device, to implement frequency synchronization with the supplementary uplink resource based on a frequency offset value indicated by the indication information. To be specific, the terminal in this application implements the frequency synchronization with the supplementary uplink resource based on the indication information sent by the network device, and does not totally rely on a synchronization signal received on a downlink resource. In this case, when the synchronization method in this application is applied to an NR-LTE co-existence case, an NR terminal can implement frequency synchronization with the supplementary uplink resource based on the indication information, so that uplink signals of different terminals are orthogonal to each other in frequency domain, and do not interfere with each other, and uplink transmission performance of an LTE terminal on the supplementary uplink resource is not affected.