Hierarchical Codebook Adaptation for 5G Beam Alignment

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Solution Overview

Problem

In 5G wireless systems, particularly in mmWave bands, high path loss leads to increased overhead in aligning beam directions for optimal signal transmission and reception, due to the need for narrow beams with high gain, which complicates beam alignment and increases processing time.

Innovation Solution

Adapting hierarchical codebooks by determining usage probabilities for codewords and rearranging their structure to prioritize higher usage probability nodes closer to the root node, facilitating faster beam alignment and selection for wireless communication.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If narrow beams with high gain are used to compensate for path loss in mmWave bands, then signal transmission quality is improved, but beam alignment overhead increases

Engineering Contradiction:
Improvesignal transmission qualityVSAvoidbeam alignment overhead
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The codebook is divided into multiple tiers with different beam widths. The first tier contains wide beams for initial search, while subsequent tiers contain progressively narrower beams for refined alignment. This segmentation allows the system to start with coarse beam selection and progressively narrow down, reducing the overall alignment overhead compared to using only narrow beams from the beginning.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces a hierarchical dimension to the codebook structure, organizing beams not just by their directional properties but also by their beam width characteristics across multiple tiers. This additional hierarchical dimension enables systematic exploration of beam options from broad to narrow, optimizing the alignment process.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Reliability

If narrow beams with high gain are used to compensate for path loss in mmWave bands, then signal transmission quality is improved, but processing time increases

Engineering Contradiction:
Improvesignal transmission qualityVSAvoidbeam alignment time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The hierarchical codebook structure performs preliminary beam selection using wide beams from the first tier before proceeding to narrower beams in subsequent tiers. This preliminary action of establishing a broad beam direction first significantly reduces the time required for subsequent fine-tuning alignment, as the coarse direction is already determined.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

By segmenting the beam alignment process into multiple stages corresponding to different codebook tiers, the system avoids the time-consuming process of exhaustively searching through all narrow beams simultaneously. Instead, it progresses systematically from wide to narrow beams, reducing total processing time.

Inventive Principle:
Principle #1Segmentation

3Speed

If a hierarchical codebook structure is adapted based on usage probabilities, then beam alignment speed is improved, but codebook structure complexity increases

Engineering Contradiction:
Improvebeam alignment speedVSAvoidcodebook structure complexity
Core Design Contradiction:
SpeedVSDevice complexity

Solution Approach 1:

The codebook structure is made dynamic by adapting it based on usage probabilities of different codewords. The system learns from actual communication conditions and adjusts the hierarchical structure to prioritize frequently used beams, making the codebook adaptive rather than static. This dynamic adaptation optimizes future beam alignment operations.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system incorporates feedback mechanisms where usage probabilities of codewords are tracked and used to reshape the hierarchical codebook structure. This feedback loop allows the codebook to evolve based on actual performance data, prioritizing paths that have proven effective in previous communications and reducing reliance on less effective beam configurations.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP3915200B1Design and adaptation of hierarchical codebooks
Publication Date: 2024.02.28 SAMSUNG ELECTRONICS CO LTD
  • EP3915200B1 patent drawingFigure 1
  • EP3915200B1 patent drawingFigure 2
  • EP3915200B1 patent drawingFigure 3

AI summary

The present disclosure relates to a communication method and system for converging a 5th-Generation (5G) communication system for supporting higher data rates beyond a 4th-Generation (4G) system with a technology for Internet of Things (IoT). The present disclosure may be applied to intelligent services based on the 5G communication technology and the IoT-related technology, such as smart home, smart building, smart city, smart car, connected car, health care, digital education, smart retail, security and safety services. An electronic device includes a memory and a processor configured to determine usage probabilities for codewords in the hierarchical codebook, change a structure of the hierarchical codebook based on the usage probabilities so that nodes associated with codewords having relatively higher usage probabilities are located closer to a root node than nodes associated with codewords having relatively lower usage probabilities, and select a codeword from the hierarchical codebook for use in wireless communication.