CSI Feedback Method for Planar Antenna Arrays
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Solution Overview
Problem
In wireless communications, particularly in LTE systems with large-scale planar antenna arrays, the complexity and overhead of channel state information (CSI) measurement and feedback increase significantly, leading to inefficient use of uplink channel resources, with no prior art providing effective solutions for reducing these overheads.
Innovation Solution
The method involves differentiating between horizontal and vertical direction channel changes, allowing for separate and optimized feedback modes in the frequency or time domain, reducing the number of antenna ports to be measured and feedback, and using specific feedback granularities and cycles for channel state information, such as precoding matrix indicators and channel quality indicators, to minimize overhead.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the antenna scale is extended to large-scale planar arrays (16, 32, 64 antennas) to improve transmission performance, then spatial multiplexing capability and transmission rates are improved, but CSI measurement and feedback complexity increases significantly
Solution Approach 1:
The patent segments the 2D planar antenna array into multiple 1D antenna groups (e.g., dividing a 4x4 array into four 1x4 groups). Each group is measured and reported independently, reducing the overall feedback complexity. The UE reports CSI for each 1D group separately rather than treating the entire 2D array as a single complex measurement task.
Solution Approach 2:
The patent transforms the 2D planar antenna array measurement problem into multiple 1D antenna group measurements. By changing from a two-dimensional measurement approach to multiple one-dimensional measurements, the complexity is reduced while maintaining the ability to capture the channel characteristics of the larger array.
2Loss of information
If traditional CSI feedback methods are applied to large-scale planar arrays, then complete channel state information can be obtained, but uplink channel resource overhead becomes excessive
Solution Approach 1:
The patent extracts only the essential CSI components from each 1D antenna group (such as PMI and CQI for each group) rather than reporting complete CSI for all antennas. This selective extraction reduces the amount of uplink resources required while maintaining sufficient information for effective precoding and scheduling decisions.
Solution Approach 2:
Instead of measuring and reporting CSI for all antennas in the large-scale array, the patent uses partial measurement by selecting representative 1D antenna groups. This partial action approach provides sufficient channel state information for system operation without the excessive overhead of complete array measurement.
Data Source
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AI summary
The present invention relates to the field of mobile communications technologies, and in particular, to a feedback method and apparatus of channel state information. The method includes: acquiring, by user equipment, first channel state information based on a first channel state information measurement resource that is configured by a base station and that corresponds to a first antenna port representing a horizontal dimension; and acquiring, based on a second channel state information measurement resource, which is configured by the base station, of a second antenna port representing a vertical dimension, second channel state information; and feeding back channel state information to the base station, which includes: feeding back the first channel state information to the base station according to a first feedback mode, and feeding back the second channel state information to the base station according to a second feedback mode, where the second feedback mode is different from the first feedback mode; or feeding back third channel state information according to a third feedback mode, where the third channel state information is obtained by the user equipment and based on the first channel state information and the second channel state information.