FD-MIMO Channel State Feedback Overhead Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In Full Dimension MIMO (FD-MIMO) wireless communication systems, the existing channel state information (CSI) transmission methods lead to excessive uplink overhead, reducing system throughput due to increased resource allocation for reference signals, which in turn decreases data transmission capacity.
Innovation Solution
The method involves transmitting CSI-RSs in multiple dimensions using horizontal and vertical CSI-RSs, allowing the UE to measure channel state information using a reduced number of CSI-RS ports, thereby optimizing resource allocation and reducing overhead.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If existing CSI transmission methods are used in FD-MIMO systems, then channel state measurement accuracy is improved, but uplink overhead increases excessively
Solution Approach 1:
The patent segments the channel state information feedback into two parts: wideband CQI/PMI feedback and subband CQI feedback. This segmentation allows the system to transmit essential channel state information while reducing the overall feedback overhead, directly addressing the contradiction between measurement accuracy and uplink overhead.
Solution Approach 2:
The patent extracts and transmits only the most critical channel state information parameters (CQI and PMI) at wideband level, while deriving subband CQI through differential encoding. This extraction approach maintains measurement accuracy by preserving key parameters while removing redundant information to reduce uplink overhead.
2Measurement precision
If more resources are allocated for reference signals, then channel state information quality is improved, but data transmission capacity decreases
Solution Approach 1:
The patent applies partial action by transmitting wideband CQI and PMI for all antenna ports while transmitting subband CQI only for selected antenna ports or using differential encoding. This partial feedback approach maintains sufficient channel state information quality for MIMO scheduling while reducing the resources needed for reference signals, thereby preserving data transmission capacity.
3Productivity
If full dimension MIMO with 32 or more transmission antennas is deployed, then system throughput is improved, but feedback overhead increases
Solution Approach 1:
The patent introduces a new dimension in feedback organization by separating wideband and subband feedback, and further separating antenna port groups. This dimensional organization allows efficient handling of feedback from 32 or more antennas by structuring the feedback in a hierarchical manner that reduces overall overhead while maintaining the ability to support high system throughput through FD-MIMO.
Data Source
AI summary
A method and system are provided for a terminal to measure channel quality and transmit channel state information to a base station in a wireless mobile communication system operating in a multi-carrier-based multiple access scheme such as Orthogonal Frequency Division Multiple Access (OFDMA). The feedback information transmission method of a terminal in a mobile communication system includes receiving configuration information corresponding to at least two reference signals from a base station, receiving, at the terminal, feedback configuration information for measuring the at least two reference signals and generating feedback information based on a measurement result, receiving, at the terminal, the at least two reference signals, and transmitting, by the terminal, the feedback information at timings indicated in the feedback configuration information.