MIMO Precoder Selection Using Slot-Based Channel Auto-Correlation
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Solution Overview
Problem
Inaccurate precoder design due to channel aging in MIMO communication systems, particularly in TDD-based systems, leads to degraded resource efficiency and network performance, as estimated channels from uplink sounding become outdated for downlink transmissions.
Innovation Solution
A method for precoder generation using slot-based channel temporal auto-correlation to select a precoder from a set of candidates based on historical channel estimates, without requiring channel estimation processing delay, by calculating temporal auto-correlation functions and selecting the precoder with the strongest correlation to the target slot.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If uplink sounding is used to obtain downlink channel estimates in TDD systems, then channel state information can be acquired, but channel aging causes the estimates to become outdated for downlink transmissions
Solution Approach 1:
The system performs preliminary channel estimation using uplink sounding references before downlink transmission occurs. By calculating temporal auto-correlation functions in advance and storing them for later use, the system prepares precoder candidates beforehand, reducing the processing delay when actual downlink transmission needs to occur.
Solution Approach 2:
The invention creates a copy of the channel estimation process by using temporal auto-correlation to generate virtual channel estimates for future time slots based on past measurements. This allows the system to use historical channel data to predict future channel states without requiring real-time measurements, effectively copying the estimation benefit to future transmissions.
2Productivity
If precoder is selected based on historical channel estimates, then processing delay is reduced, but channel aging degrades precoder accuracy
Solution Approach 1:
The system implements feedback by continuously monitoring channel conditions and updating temporal auto-correlation functions based on the most recent channel measurements. This feedback mechanism allows the system to adapt to changing channel conditions while still using historical data, maintaining precoder accuracy despite using delayed measurements.
Solution Approach 2:
The precoder selection system is made dynamic by allowing the temporal auto-correlation parameters and the set of precoder candidates to change based on current channel conditions. The system can adjust which historical estimates to use and how to weight them, optimizing the balance between using outdated information and maintaining accuracy.
Data Source
AI summary
Various embodiments of the present disclosure provide a method for precoder generation. The method which may be performed by a communication device comprises: estimating slot-based channel temporal auto-correlation according to a set of channel estimates of reference signals. In accordance with an exemplary embodiment, the method further comprises: selecting a precoder for a first slot from a set of precoder candidates according to the slot-based channel temporal auto-correlation. The set of precoder candidates may be calculated by using at least part of the set of the channel estimates of the reference signals.