Adaptive CQI Feedback Granularity for Massive MIMO Overhead Reduction
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Solution Overview
Problem
In massive MIMO systems, the existing constant feedback granularity of channel quality indicators (CQIs) does not utilize the feature of reduced frequency selectivity, leading to increased system overheads due to unnecessary bit quantity usage.
Innovation Solution
Adaptive feedback granularity of CQIs is determined based on the antenna port quantity, allowing for larger subband sizes when the antenna port quantity is high, thereby reducing the bit quantity needed for feedback and optimizing system efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If constant feedback granularity is used for CQI, then feedback simplicity is maintained, but system overheads increase due to unnecessary bit quantity usage in massive MIMO systems
Solution Approach 1:
The patent applies dynamics by making the feedback granularity adaptive rather than fixed. The granularity changes based on the antenna port quantity, allowing the system to optimize feedback bit quantity dynamically. When antenna ports increase (massive MIMO), the granularity increases (larger subband size), reducing the number of CQI bits needed while maintaining accuracy where frequency selectivity is reduced.
Solution Approach 2:
The patent changes the parameter of feedback granularity based on the antenna port quantity. By establishing a correspondence between antenna port quantity and subband size (granularity), the system adapts the feedback parameters to match the channel characteristics. This parameter change allows reducing overhead in massive MIMO while maintaining appropriate feedback detail when needed.
2Reliability
If larger quantity of antennas is used, then diversity and array gain are improved, but frequency selectivity of channel quality decreases leading to increased feedback overhead
Solution Approach 1:
The patent applies local quality by making the feedback granularity different for different antenna port configurations. Instead of using a uniform granularity for all antenna quantities, the system applies locally optimized granularity values matched to specific antenna port ranges. This allows the feedback mechanism to adapt to the local channel characteristics created by different antenna quantities.
Solution Approach 2:
The patent changes the feedback granularity parameter based on the antenna port quantity parameter. By establishing that granularity increases with antenna port quantity, the system optimizes the feedback bit quantity to match the reduced frequency selectivity characteristic of massive MIMO systems, thereby reducing overhead while maintaining reliability.
3Ease of manufacture
If constant subband size is used for CQI feedback, then implementation simplicity is maintained, but bit quantity efficiency decreases when antenna port quantity is high
Solution Approach 1:
The patent transforms the static subband size into a dynamic parameter that adapts to antenna port quantity. The system determines subband size based on the configured antenna ports, creating a dynamic adjustment mechanism. This maintains implementation simplicity through a rule-based approach while significantly improving bit quantity efficiency in massive MIMO scenarios.
Solution Approach 2:
The patent changes the subband size parameter according to the antenna port quantity parameter. By establishing a direct relationship where subband size increases with antenna port quantity, the system optimizes feedback efficiency without complex algorithms, simply applying parameter changes based on the antenna configuration.
Data Source
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AI summary
Embodiments of the present invention provide a method for feeding back a channel quality indicator, and a method and an apparatus for sending resource scheduling information. An apparatus for feeding back a channel quality indicator includes: a determining module, configured to determine a feedback granularity of a CQI according to a system bandwidth, a CQI feedback mode, and antenna port quantity information specified by a network device; and a feedback module, configured to feed back the CQI to the network device according to the feedback granularity of the CQI. The method for feeding back a channel quality indicator, and the method and the apparatus for sending resource scheduling information provided in the embodiments of the present invention are used to reduce system overheads.