RF Link Calibration Using Digital Attenuators for DAS Startup
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Solution Overview
Problem
The installation of distributed antenna systems is hindered by manual gain adjustments due to hardware differences and varying optical fiber lengths, requiring significant human resources and time for debugging.
Innovation Solution
An automatic calibration method for radio frequency links using digital ATT modules to adjust signal power levels, with successive approximation methods to compensate for line loss and provide error prompts, facilitating efficient deployment and maintenance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If manual gain adjustment is performed to compensate for hardware differences and optical fiber length variations, then the RF link power balance can be achieved, but significant human resources and debugging time are consumed
Solution Approach 1:
The system performs preliminary automatic calibration during the installation process to pre-establish the RF link power balance. The calibration module automatically measures and adjusts gain parameters before the system goes into service, eliminating the need for time-consuming manual debugging later. This preliminary automatic adjustment resolves the contradiction by achieving power balance without consuming significant debugging time.
Solution Approach 2:
The calibration module enables the system to self-calibrate automatically by measuring actual RF link parameters and adjusting gain settings without human intervention. The system performs self-diagnosis and self-adjustment to compensate for hardware differences and optical fiber length variations, thereby achieving power balance while minimizing the need for manual debugging resources and time.
2Manufacturing precision
If manual gain adjustment is performed to account for hardware differences and optical fiber length variations, then the RF link power balance can be achieved, but significant human resources are required
Solution Approach 1:
The calibration module enables the system to self-calibrate automatically by measuring actual RF link parameters and adjusting gain settings without human intervention. The system performs self-diagnosis and self-adjustment to compensate for hardware differences and optical fiber length variations, thereby achieving power balance while minimizing the need for manual debugging resources and time.
Solution Approach 2:
The system replaces manual mechanical adjustment operations with automated electronic calibration. The calibration module uses electronic measurement and control to automatically adjust RF link parameters, substituting the mechanical manual debugging process with an automated electronic system that requires minimal human resources and simplifies operation.
3Area of stationary object
If multiple levels of devices (PBMU-NEU-IRU) are installed with varying optical fiber lengths, then system coverage can be extended, but different links have different line loss making debugging difficult
Solution Approach 1:
The system performs preliminary automatic calibration during the installation process to pre-establish the RF link power balance. The calibration module automatically measures and adjusts gain parameters before the system goes into service, eliminating the need for time-consuming manual debugging later. This preliminary automatic adjustment resolves the contradiction by achieving power balance without consuming significant debugging time.
Solution Approach 2:
The calibration module implements a feedback mechanism that automatically measures the actual RF link parameters including line loss from varying optical fiber lengths, and uses this feedback information to adjust gain settings accordingly. This closed-loop feedback system compensates for the different line losses in multi-level device configurations, achieving power balance while simplifying the debugging process.
Data Source
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AI summary
The present disclosure relates to a calibration method for a radio frequency link including: generating, by a signal source module, a first signal with a predetermined frequency in a near-end device, adjusting, by a first digital ATT module, the first signal to generate a second signal with a first predetermined power level, and adjusting, by a second digital ATT module of a first optical module in the near-end device, the second signal to cause an input signal or an output signal of the first optical module to have a second predetermined power level, the first optical module being connected to the signal source module via an optical fiber. Further, the present disclosure relates to a calibration method in a relay device of such as a network expansion unit and in a far-end device. With the help of the above-mentioned calibration method, the distributed antenna system can be intelligently started up.