Base Station Synchronization Using Multiplexed RFIC
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Solution Overview
Problem
Existing methods for synchronization between base stations are costly due to the need for independent RFICs or resource wastage with special MBSFN subframes, which are not conducive to wide application and efficient radio resource utilization.
Innovation Solution
A method where a slave base station multiplexes a primary RFIC and performs synchronization listening using a special subframe in a TD-LTE system, receiving a cell reference signal (CRS) sent by a master base station through a downlink pilot time slot symbol (DwPTS symbol) to achieve synchronization, allowing for automatic acquisition of neighboring cell information and reducing hardware costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If independent RFICs are deployed in base stations for synchronization, then synchronization reliability is improved, but hardware cost increases
Solution Approach 1:
The primary RFIC is made to serve multiple functions: it handles both normal communication tasks and synchronization listening. By configuring the primary RFIC to monitor MBSFN subframes containing synchronization signals from neighboring base stations, the system eliminates the need for separate independent RFICs while maintaining synchronization capability. This multi-functional use of the primary RFIC resolves the contradiction between reliability and hardware cost.
2Reliability
If a special MBSFN subframe is configured for synchronization listening, then synchronization is achieved, but radio resource utilization deteriorates
Solution Approach 1:
Instead of continuously monitoring for synchronization, the system uses periodic MBSFN subframes configured at specific intervals (e.g., every 40ms or 80ms). The slave base station only needs to switch to reception mode during these periodic MBSFN subframes to acquire synchronization signals, rather than continuously monitoring. This periodic approach maintains synchronization reliability while significantly improving radio resource utilization by minimizing the time the RFIC spends in reception mode.
3Device complexity
If the primary RFIC is multiplexed for synchronization listening, then hardware cost is reduced, but listening accuracy deteriorates
Solution Approach 1:
The system performs preliminary switching of the primary RFIC to reception mode before the MBSFN subframe arrives, ensuring the RFIC is ready to capture synchronization signals immediately when they are transmitted. This preliminary preparation, combined with accurate timing information about when MBSFN subframes occur, ensures that even though the same RFIC is used for both communication and synchronization, the listening accuracy is not compromised.
Solution Approach 2:
The synchronization listening function is extracted from continuous operation and isolated to specific MBSFN subframe periods. By separating the synchronization function into dedicated time slots (MBSFN subframes) rather than mixing it continuously with normal communication, the system maintains listening accuracy while using the same primary RFIC for both purposes.
Data Source
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Figure 3
Figure 4A~4B
AI summary
The present invention relates to the field of communications, and discloses a method and device for synchronization between base stations to reduce listening costs and to make the best use of radio resources. The method is: a slave base station receiving, on a designated symbol of a special sub-frame via a primary radio frequency integrated circuit (RFIC), a cell reference signal (CRS) sent by a master base station (301); and performing synchronization between the slave base station and the master base station according to the acquired CRS. The slave base station performs listening on the master base station by multiplexing the primary RFIC, such that the need to provide a separate RF circuit is eliminated, thereby effectively reducing hardware costs; in addition, the slave base station performing listening on the master base station on the designated symbol of the special sub-frame ensures that only data transmission on one symbol of the special sub-frame is lost in one synchronization tracking period, such that the slave base station uses more symbols for physical downlink shared channel (PDSCH) signal transmission compared with configuring a multicast/broadcast single frequency network (MBSFN) sub-frame, thereby effectively making the best use of radio resources.