Array Antenna Calibration Using Reference Antenna
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Solution Overview
Problem
Conventional array antenna devices in communication systems face challenges in efficiently performing calibration operations, especially in sub-array based structures and fully digital systems, where calibration does not enhance direct communication performance and requires complex RF networks, making it difficult to apply calibration operations effectively.
Innovation Solution
The proposed solution involves an apparatus and method for controlling an array antenna device that can operate in multiple modes, including a calibration mode, using a reference antenna to perform simultaneous data communication and on-line calibration without impacting data communication, and supporting sub-array based structures by determining the need for calibration operations and transitioning between normal, interference control, and calibration modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If calibration operation is performed using additional antenna in conventional array antenna device, then calibration accuracy is improved, but device complexity increases due to fully digital system structure requiring N+1 RF chains
Solution Approach 1:
The reference antenna is designed to serve multiple functions: it acts as a calibration reference for phase difference measurement and simultaneously functions as a normal array antenna for data transmission and reception. This eliminates the need for a separate additional antenna dedicated solely to calibration, thereby reducing device complexity while maintaining calibration accuracy.
Solution Approach 2:
The patent extracts the calibration reference function from a dedicated additional antenna and integrates it into one of the existing array antennas (the reference antenna). This extraction allows the system to perform calibration operations using the reference antenna's signal, eliminating the need for the extra hardware component while preserving the calibration capability.
2Measurement precision
If calibration operation is performed in conventional array antenna device, then phase difference measurement is improved, but data communication is interrupted during calibration process
Solution Approach 1:
The system performs calibration operations periodically at predetermined intervals rather than continuously or before each data transmission. This periodic calibration approach allows data communication to proceed uninterrupted between calibration cycles, maintaining both measurement precision and communication productivity.
Solution Approach 2:
The reference antenna continuously transmits reference signals that serve dual purposes: enabling ongoing phase difference measurement for calibration and simultaneously functioning as valid data transmission signals. This continuity allows calibration and data communication to occur simultaneously without interruption to productive operations.
3Device complexity
If sub-array based structure is used in array antenna device, then device complexity is reduced, but calibration operation cannot be effectively applied
Solution Approach 1:
The array antenna is divided into multiple sub-arrays, with each sub-array containing a reference antenna that performs calibration for its respective sub-array. This segmentation allows calibration operations to be effectively applied to each sub-array independently, maintaining calibration reliability while preserving the complexity-reducing benefits of the sub-array structure.
Data Source
AI summary
One or more embodiments provide a method for controlling array antenna device in a base station (BS) in a communication system. The method includes determining whether to perform a calibration operation for BSs while operating in one of a normal mode and an interference control mode. The method also includes transiting from the one of the normal mode and the interference control mode to a calibration mode based on the determining result of whether to perform the calibration operation for the BSs. A reference antenna among antennas included in the array antenna device is used in all of the normal mode, the interference control mode, and the calibration mode.