Distributed Antenna Propagation Delay Compensation
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Solution Overview
Problem
In distributed antenna systems, the multipath effect and timing drift issues caused by frequency reuse and handover in high-speed mobile communication systems lead to reduced data transmission efficiency and potential service shutdowns, particularly in rail communication systems where signal propagation delay variations affect channel quality and antenna synchronization.
Innovation Solution
A method and apparatus for controlling a distributed antenna system by estimating and compensating the propagation delay time of service antenna units to a target value, using a control module to select and switch remote antenna units based on delay compensation values, ensuring consistent timing difference between uplink and downlink signals and minimizing propagation delay variance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If the distributed antenna system extends the transmission range using longer fibers, then the extended range is improved, but the propagation delay time increases and the permitted extended range in pure air decreases
Solution Approach 1:
The system pre-calculates propagation delay values for all possible antenna combinations and stores them in a lookup table before actual communication occurs. When antenna switching is needed, the pre-computed delay values are immediately applied without real-time calculation, enabling fast switching while maintaining accurate timing compensation for the extended fiber transmission path.
Solution Approach 2:
The system dynamically switches between different remote antenna units based on mobile station position and signal conditions. By pre-computing and storing propagation delay characteristics for each antenna configuration, the system can rapidly adapt to changing conditions without the propagation delay becoming a limiting factor in the dynamic switching process.
2Reliability
If remote antenna units are switched to improve signal quality and reduce multipath effect, then receiving quality is improved, but timing drift occurs in the uplink signal
Solution Approach 1:
The base station pre-calculates the propagation delay values for all remote antenna units and stores them in advance. When a remote antenna unit needs to be switched, the corresponding pre-computed delay value is immediately retrieved and applied to compensate for the timing change, preventing uplink signal timing drift without affecting the reliability improvement from the antenna switching.
3Manufacturing precision
If additional fibers or electrical delay devices are added to compensate propagation delay, then timing synchronization is improved, but device complexity and cost increase
Solution Approach 1:
Instead of physically adding electrical delay devices or extending fiber length, the system creates a virtual copy of the delay compensation function through digital signal processing. The base station computes and applies delay values algorithmically, achieving precise timing synchronization without the physical complexity and cost of additional hardware components.
Solution Approach 2:
The patent replaces the mechanical/physical approach of using electrical delay devices and additional fibers with a digital/software-based propagation delay compensation method. By using computational algorithms to calculate and adjust timing, the system eliminates the need for complex physical hardware while achieving the same timing synchronization objective.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enhances data transmission efficiency by reducing multipath effects and timing drift, maintaining reliable communication services even at high speeds by ensuring consistent propagation delay across the system, thereby extending the transmission range without the need for additional fibers or complex electrical delay devices.
Implementation Method 1
Propagation delay time of a service antenna unit corresponding to the base station is estimated. The service antenna unit is turned on to perform signal transmission, and the propagation delay time of the service antenna unit is compensated to the target propagation delay value.
Data Source
AI summary
A method for controlling a distributed antenna system includes the following steps. A target propagation delay value is defined according to a transmit/receive transition gap. Propagation delay time of a service antenna unit corresponding to a base station is estimated. The service antenna unit is turned on to perform downlink signal transmission, and the propagation delay time of the service antenna unit is compensated to the target propagation delay value.