Terminal CSI Feedback Double Codebook Segmentation
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Solution Overview
Problem
In wireless communication systems, existing technologies face challenges in efficiently transmitting CSI feedback information, particularly in coordinating beamforming between base stations and terminals, due to differences in coherence times and the need for independent encoding of rank indication, channel quality information, and precoding matrix indicators.
Innovation Solution
A terminal is designed to generate and transmit CSI feedback information, including rank indication, beam index, and precoding matrix indicators, using a processor and radio frequency unit, with the ability to jointly or separately encode these components and utilize a double codebook structure for efficient beamforming, allowing for the transmission of indication information about reference signals to the base station.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If CSI feedback information including RI, CQI, and PMI are independently encoded and fed back at separate periods, then the coherence time requirements for each parameter are satisfied, but the feedback overhead and system complexity increase
Solution Approach 1:
The patent segments the CSI feedback information into two groups: RI and BI are fed back at a first periodicity, while CQI and PMI are fed back at a second periodicity. This segmentation allows each parameter group to be transmitted at appropriate intervals based on their coherence time requirements, resolving the contradiction between reliability and system complexity.
2Ease of operation
If the terminal transmits all CSI feedback information in a single feedback channel, then the feedback process is simplified, but the payload size exceeds the uplink coverage limit
Solution Approach 1:
The patent divides the CSI feedback information into multiple transmission groups with different periodicities. RI and BI are transmitted at a first periodicity while CQI and PMI are transmitted at a second periodicity. This segmentation ensures that each feedback transmission remains within uplink coverage limits while maintaining operational simplicity through structured periodic transmissions.
3Adaptability or versatility
If the terminal uses a double codebook structure for PMI to support vertical beamforming, then the beamforming capability is enhanced, but the processing complexity and encoding requirements increase
Solution Approach 1:
The patent implements a double codebook structure where PMI is divided into PMI1 and PMI2, corresponding to vertical and horizontal beamforming components. This segmentation enables the terminal to support advanced beamforming capabilities while managing processing complexity by organizing the codebook into distinct, manageable components that can be independently processed and fed back.
Data Source
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AI summary
Disclosed herein is a terminal including: receiving a precoded/beamformed CSI-RS from a base station, generating CSI feedback information including indicators such as RI, PTI, and BI (or CRI) and a first PMI and a second PMI that are elements of a double codebook, on the basis of the CSI-RS and transmits the CSI feedback information to the base station through an uplink subframe corresponding to predetermined feedback periodicity. Periodic CSI reporting using PUCCH according to the 3GPP TS 36.213 Release 13.