Channel Calibration via Grouped Sets and Inter-Set Compensation
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Solution Overview
Problem
In large-scale multiple-input multiple-output (MIMO) systems, the existing channel calibration methods, particularly wired calibration, become impractical due to increased complexity and cost, and wireless calibration faces accuracy issues as the scale of array elements grows, leading to a dynamic problem that affects calibration precision.
Innovation Solution
The method involves grouping multiple channels into smaller channel sets, determining compensation values to ensure consistent frequency responses within each set, and using inter-set compensation to maintain uniformity across all channels, thereby meeting signal-to-noise ratio (SNR) requirements and improving calibration accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If wired calibration is used in large-scale MIMO systems, then calibration can be performed, but device complexity and cost increase significantly
Solution Approach 1:
The patent replaces the mechanical wired calibration system (coupling disks, cables, combiners) with an electromagnetic field-based wireless calibration system. The base station transmits calibration signals wirelessly to terminal devices, which measure and feed back channel state information, eliminating the need for physical coupling devices and their associated complexity.
2Device complexity
If wireless calibration is used in large-scale arrays, then device complexity is reduced, but calibration accuracy deteriorates due to dynamic problems
Solution Approach 1:
The patent segments the large-scale antenna array into multiple antenna groups, each calibrated independently. By dividing the array into smaller subsets, the dynamic problems affecting overall array calibration are localized and managed more effectively, improving measurement precision while maintaining the simplicity of wireless calibration.
Solution Approach 2:
The patent performs calibration on partial arrays (antenna groups) rather than requiring complete calibration of the entire large-scale array simultaneously. This partial action approach allows for more accurate calibration measurements by reducing the complexity of the measurement scenario, while still achieving sufficient overall system performance.
3Measurement precision
If the number of antennas is increased to improve spatial resolution, then beam precision improves, but channel calibration becomes more difficult
Solution Approach 1:
The patent introduces terminal devices as intermediaries in the calibration process. These terminal devices receive calibration signals from the base station's antenna groups, measure the channel state information, and feed back the measurements. This intermediary approach enables calibration of large-scale arrays by distributing the measurement function across multiple terminal devices rather than requiring direct measurement at the base station.
Data Source
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AI summary
This application provides a channel calibration method and a network device, where the method includes: obtaining at least two channel sets, where the at least two channel sets are obtained by grouping a plurality of to-be-calibrated channels, each of the at least two channel sets includes a reference channel and at least one to-be-calibrated channel, and a first channel set and a second channel set that are in the at least two channel sets have an intersection set, where the intersection set includes a common channel; determining a compensation value of each to-be-calibrated channel in each of the channel sets; determining an inter-set compensation value between the first channel set and the second channel set; and calibrating the plurality of channels based on the inter-set compensation value and the compensation value of each to-be-calibrated channel in each of the channel sets. In embodiments of this application, frequency responses of all channels can be kept consistent, thereby improving calibration accuracy.