Optical Repeater Timing Alignment for Multi-Band TDD Switching
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Solution Overview
Problem
Optical repeater systems deployed in mobile communication networks face issues with unsynchronized uplink/downlink (UL/DL) switching timing across different frequency bands, leading to non-compliance with 3GPP regulations and increased circuit complexity when multiple systems are expanded.
Innovation Solution
The system employs a primary master station and secondary master stations to detect and adjust UL/DL switching timing differences using intra- and inter-master timing comparators, cable delay compensators, and monitoring units to synchronize timing across multiple slave stations and master units.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If an optical repeater system is deployed to expand communication coverage, then the communication area is expanded, but the UL/DL switching timing becomes unsynchronized across multiple remote units
Solution Approach 1:
The master unit acts as an intermediary between the base station and multiple remote units. It receives the timing adjustment amount from the base station and distributes it to all remote units, ensuring synchronized UL/DL switching timing across the expanded communication area while maintaining timing coordination.
Solution Approach 2:
The system divides the communication network into a master unit and multiple remote units. The master unit handles timing coordination functions, while remote units focus on radio signal transmission, allowing timing synchronization to be managed centrally while expanding coverage through distributed remote units.
2Area of stationary object
If multiple optical repeater systems are introduced to cover a common area, then the communication coverage is enhanced, but the circuit complexity increases due to interconnections between master units
Solution Approach 1:
Multiple master units are merged into a single timing coordination domain by having them all synchronize to the same base station timing signals. This eliminates the need for complex inter-master unit connections, as each master unit independently derives timing from the base station, reducing overall circuit complexity while maintaining coverage.
Solution Approach 2:
Each master unit independently obtains timing synchronization information from the base station and autonomously coordinates its remote units. This self-service approach eliminates the need for centralized timing distribution infrastructure between master units, simplifying the overall system architecture.
3Productivity
If carrier aggregation is implemented across frequency bands, then communication speed is improved, but the UL/DL switching timing difference exceeds 3GPP regulations
Solution Approach 1:
The base station measures the actual UL/DL switching timing difference at the RF output points of remote units and feeds back a timing adjustment amount to the master unit. The master unit then adjusts the timing of remote units based on this feedback, ensuring the timing difference remains within 3GPP regulatory limits while enabling carrier aggregation.
Solution Approach 2:
The system dynamically adjusts the timing parameter (UL/DL switching timing) of remote units based on measured conditions. By changing the timing parameter in response to actual system performance, the system maintains regulatory compliance while optimizing carrier aggregation performance for improved communication speed.
Data Source
AI summary
According to one embodiment, an optical repeater system is provided with a master station including: an inter-master timing comparator that detects delay adjustment amounts respectively corresponding to a plurality of TDD transceivers, based on a switching timing detected by a TDD timing detector and information acquired by a cable delay compensator, and that transmits the delay adjustment amounts to the master station; and a TDD timing delay adjustor that delays signals from the TDD transceivers, using the delay adjustment amounts. The optical repeater system is provided with another master station including: a TDD timing detector that detects switching timings between downlink and uplink for the plurality of TDD transceivers; an intra-master station timing comparator that transmits information on the switching timings between downlink and uplink for the plurality of TDD transceivers; and a TDD timing delay adjustor that delays signals from the TDD transceivers, using the delay adjustment amounts.