TDD Repeater Time Synchronization to Prevent Signal Overlap
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Solution Overview
Problem
Repeater systems using the TDD scheme face oscillation issues due to signal coupling, leading to system instability and malfunction, which existing solutions attempt to address with expensive RF components and large, latency-prone interference cancellation systems.
Innovation Solution
An apparatus and method for time synchronization in repeaters, employing an upper and lower antenna, switches, a delay processor, and a synchronization controller to prevent signal overlap by compensating for time delays and controlling switching to ensure non-overlapping uplink and downlink intervals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If physical separation of antenna ports is implemented to prevent signal coupling, then oscillation is minimized, but device size increases and cost increases due to expensive RF components
Solution Approach 1:
The patent replaces the mechanical/physical separation approach (which requires large distance between antenna ports) with an electronic solution using a delay processor that introduces a time delay to the downlink signal. This electronic timing adjustment prevents signal coupling and oscillation without requiring physical separation, thereby reducing device size while maintaining reliability
Solution Approach 2:
The patent changes the timing parameter of the downlink signal by introducing a controlled time delay through the delay processor. This parameter change (time delay) prevents the downlink signal from coupling with the uplink signal, thereby preventing oscillation without requiring physical separation of antenna ports
2Reliability
If interference cancellation system (ICS) is added to minimize oscillation, then oscillation phenomenon is reduced, but latency increases, cost increases, and device size increases
Solution Approach 1:
The patent extracts and eliminates the complex ICS digital signal processing function from the system, replacing it with a simple delay processor that introduces a time delay to the downlink signal. This removal of the ICS function reduces latency, cost, and device size while still preventing oscillation through timing adjustment
Solution Approach 2:
The patent replaces the complex digital signal processing mechanism (ICS) with a simple time-delay mechanism. This substitution eliminates the need for complex algorithms and processing, thereby reducing latency while maintaining oscillation prevention effectiveness
3Reliability
If ICS function is added to repeater, then oscillation is minimized, but device complexity and cost increase significantly
Solution Approach 1:
The patent removes the complex ICS function from the repeater system and replaces it with a simple delay processor. This extraction of the unnecessary complex function reduces device complexity and cost while maintaining the essential oscillation prevention capability through timing adjustment
Solution Approach 2:
The patent replaces the expensive and complex ICS system with a simple, low-cost delay processor. This substitution uses a much simpler and cheaper component to achieve the same oscillation prevention goal, thereby reducing device complexity and cost
Data Source
AI summary
An apparatus for time synchronization of a repeater according to an embodiment of the present disclosure includes a downlink receiver and a downlink transmitter establishing a downlink path for delivering a downlink signal, an uplink receiver and an uplink transmitter establishing an uplink path for delivering an uplink signal, a switch including an upper switch and a lower switch and performing switching such that the downlink path is established in a downlink interval and the uplink path is established in an uplink interval, a delay processor compensating for a time delay of one of the downlink signal and the uplink signal, and a synchronization controller controlling the switching of the switch in synchronization with the time delay of the compensated signal so that the uplink interval and the downlink interval do not overlap.