5G NR Codebook Sub-Set Restriction for Interference Control

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

In the context of 5G New Radio (NR) communication, the existing Type II codebooks in Rel-15 are high in channel quantization precision but have high feedback overhead, and the transition to Rel-16 with low-overhead codebooks requires new methods to control beam directions and prevent interference.

Innovation Solution

The proposed solution involves determining codebook sub-set restriction indication information on the network side to restrict specific beam groups and coefficient sets, limiting amplitude and phase coefficients, and restricting base vector groups to prevent interference by controlling beam orientations.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If Type II codebook with linear combination for beams is used in Rel-15, then channel quantization precision is improved, but feedback overhead increases

Engineering Contradiction:

Improvechannel quantization precisionVSAvoidfeedback overhead

Core Design Contradiction:

Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent extracts and removes unnecessary feedback information by implementing codebook sub-set restriction. The base station indicates restricted beam groups and coefficient sets to the terminal, which then excludes certain beams and coefficients from feedback, thereby reducing feedback overhead while maintaining essential channel quantization precision

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The codebook is segmented into different beam groups and coefficient sets. By restricting specific segments (beam groups and coefficient sets) rather than the entire codebook, the system achieves selective reduction of feedback overhead while preserving channel quantization precision for non-restricted segments

Inventive Principle:

Principle #1Segmentation

2Object-affected harmful factors

If beam sub-set restriction is applied to control terminal feedback, then interference is prevented, but device complexity increases

Engineering Contradiction:

ImproveinterferenceVSAvoidcomputation complexity of terminal

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The base station performs preliminary action by indicating restricted beam groups and coefficient sets to the terminal before feedback transmission. This pre-configured restriction information guides the terminal to exclude certain beams and coefficients, preventing interference while simplifying terminal computation through predetermined constraints

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS11838084B2Codebook constraint and codebook parameter determination method and apparatus

Publication Date: 2023.12.05 DATANG MOBILE COMM EQUIP CO LTD

AI summary

Disclosed are a codebook constraint and codebook parameter determination method and apparatus, and same are used for preventing the generation of a beam with an orientation bringing about interference, and to prevent interference. The codebook constraint method includes determining codebook sub-set constraint indication information for indicating that one or more beam groups in a candidate combination beam set are constrained and coefficients in a first coefficient set corresponding to each beam of the beam groups are constrained, and sending the codebook sub-set constraint indication information to a terminal.