Frequency Selective Precoded CSI-RS Port Selection

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Solution Overview

Problem

Current wireless communication systems, particularly in 5G NR, face challenges in efficiently managing channel state information (CSI) reference signals (CSI-RS) due to limitations in port selection and precoding methods, leading to increased overhead and complexity in CSI reporting and processing.

Innovation Solution

The implementation of a method where a UE receives and reports CSI based on a frequency selective precoded CSI-RS pattern, with different CSI-RS ports transmitted on distinct resource blocks, allowing for reduced reporting overhead and complexity through port selection and linear combination coefficients.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of information

If traditional CSI-RS port selection and precoding methods are used, then channel state information can be obtained, but the reporting overhead and processing complexity increase

Engineering Contradiction:

ImproveCSI reporting overheadVSAvoidCSI processing complexity

Core Design Contradiction:

Loss of informationVSDevice complexity

Solution Approach 1:

The patent segments the CSI-RS ports into different groups, where each group is associated with specific resource blocks. This segmentation allows the UE to report CSI only for selected port groups rather than all ports, reducing the CSI reporting overhead and processing complexity while maintaining essential channel state information.

Inventive Principle:

Principle #1Segmentation

2Measurement precision

If more CSI-RS ports are used for frequency selective precoding, then channel state information accuracy improves, but the number of coefficients for CSI payload increases

Engineering Contradiction:

Improvechannel state information accuracyVSAvoidnumber of coefficients

Core Design Contradiction:

Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent extracts and reports only the necessary linear combination coefficients for selected CSI-RS port groups rather than coefficients for all ports. This extraction approach maintains channel state information accuracy for the selected ports while reducing the total number of coefficients that need to be reported in the CSI payload.

Inventive Principle:

Principle #2Taking out (Extraction)

3Reliability

If frequency selective precoded CSI-RS is implemented with multiple ports, then channel state information quality improves, but the overhead of CSI-RS transmission increases

Engineering Contradiction:

Improvechannel state information qualityVSAvoidCSI-RS transmission overhead

Core Design Contradiction:

ReliabilityVSLoss of substance

Solution Approach 1:

The patent applies local quality by associating different CSI-RS port groups with specific resource blocks and allowing selective reporting based on local channel conditions. This enables the system to maintain high channel state information quality where needed while reducing transmission overhead in other frequency regions by not reporting CSI for all ports everywhere.

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS20230261831A1Port-selection codebook with frequency selective precoded CSI-rs

Publication Date: 2023.08.17 QUALCOMM INC

AI summary

A configuration to configure a UE to receive a plurality of CSI-RS ports where different ports may be transmitted on different sets of RBs within the frequency band of the CSI-RS. The apparatus receives CSI-RS through a plurality of CSI-RS ports, wherein different CSI-RS ports of the plurality of CSI-RS ports are transmitted on a different set of RBs. The apparatus reports at least one CSI based on a CSI-RS pattern.