Massive MIMO Calibration System for Continuous Beamforming Quality
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Solution Overview
Problem
Massive MIMO antennas require continuous calibration to maintain beamforming quality due to temperature and aging effects, but conventional calibration methods can interfere with primary signals, causing communication disruptions or performance deterioration.
Innovation Solution
A calibration system using a reference signal generator and reference beamforming unit to create calibration signals that mimic operational signals, allowing for phase and amplitude adjustments to minimize interference, enabling continuous calibration during operation without affecting operational signals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If calibration signals are injected into signal paths during operation, then calibration can be performed continuously to maintain beamforming quality, but the calibration signals may overlay and interfere with primary operational signals
Solution Approach 1:
The patent extracts the calibration function from the primary signal path by using a separate calibration signal injection path. The calibration signals are injected through coupling elements that are isolated from the main operational signal flow, allowing calibration to occur without directly interfering with primary signals. This separation enables continuous calibration while maintaining operational signal integrity.
Solution Approach 2:
The patent introduces coupling elements as intermediary components between the calibration signal source and the receivers. These coupling elements act as mediators that inject calibration signals into the signal paths without directly disrupting the primary operational signals. The intermediaries enable the calibration process to occur concurrently with normal operation while minimizing harmful interactions.
2Duration of action of stationary object
If calibration is performed during normal operation, then continuous calibration is achieved to compensate for temperature and aging effects, but the calibration process may cause communication disruptions or performance deterioration
Solution Approach 1:
The patent enables continuous calibration during normal operation by injecting calibration signals concurrently with primary operational signals. The system maintains uninterrupted calibration activity to continuously compensate for temperature and aging effects, while the careful design of the calibration signal injection ensures that communication performance is not compromised. This allows the useful action of calibration to continue without interruption.
3Adaptability or versatility
If multiple transceivers are used in massive MIMO antennas, then beamforming capabilities are enhanced, but the number of signal paths increases drastically requiring more extensive calibration
Solution Approach 1:
The patent implements a universal calibration approach where a single calibration signal source serves all receivers in the massive MIMO system. The calibration signal is distributed through coupling elements to multiple signal paths simultaneously, enabling one calibration mechanism to handle multiple transceivers and their respective signal paths. This multi-functional calibration system reduces the complexity that would otherwise arise from needing separate calibration mechanisms for each signal path.
Data Source
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AI summary
The present invention provides a calibration system (100) for calibrating a number of receive signal paths, each comprising a receiver (151, 153, 155, 251, 253, 255), of an antenna system (250, 550), the calibration system (100) comprising a reference signal generator (101, 201) that is configured to generate a reference signal (102, 202), a reference beamforming unit (103, 203, 303) that is coupled to the reference signal generator (101,201) and that is configured to duplicate the reference signal (102, 202) into a calibration signal (104, 105, 106) for every one of the receive signal paths (151, 153,155,251,253,255) and to apply a beamforming with predetermined beamforming weights to the calibration signals (104,105,106) and to provide each one of the receive signal paths (151, 153, 155, 251, 253, 255) with the respectively beamformed calibration signal (104, 105, 106), and an estimation unit (110, 210) that is coupled to respective output interfaces of the receive signal paths (151, 153, 155, 251, 253, 255) and that is configured to determine amplitude deviations and/or phase deviations (111) of the receive signal paths (151, 153, 155, 251, 253, 255) based on output signals (107, 108, 109) provided by the receive signal paths (151, 153, 155, 251, 253, 255) via the respective output interfaces. In addition, the present invention provides a respective antenna system (250, 550) and a method for calibrating a number of receive signal paths (151, 153, 155, 251, 253, 255) of an antenna system (250, 550).