Multi-Resolution Beamforming Codebooks for Millimeter-Wave MIMO Systems

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Conventional beamforming techniques in wireless communication, such as Eigen-beamforming, require complex matrix calculations and feedback of channel state information, which can be computationally intensive and inefficient, especially in millimeter-wave communications.

Innovation Solution

The implementation of methods and apparatuses that optimize beamforming by selecting and updating beamforming and combining vectors to maximize signal-quality parameters like ESNR, using multi-resolution beamforming and beam codebooks, which reduce computational complexity and processing latency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional beamforming techniques (e.g., Eigen-beamforming) are used to achieve optimal beamforming performance, then signal quality is improved, but computational complexity and processing time increase significantly

Engineering Contradiction:
Improvebeamforming optimalityVSAvoidcomputational complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent segments the codebook into multiple subsets, each corresponding to different channel conditions or antenna configurations. This allows the system to select from pre-computed beamforming vectors rather than performing full matrix calculations, reducing computational complexity while maintaining optimality for each segment.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent pre-computes and stores beamforming vectors in codebooks during system initialization or offline phases. These pre-computed vectors are stored for later retrieval based on channel conditions, eliminating the need for real-time matrix calculations and significantly reducing processing time during actual beamforming operations.

Inventive Principle:
Principle #10Preliminary action

2Reliability

If conventional beamforming techniques are used to achieve optimal beamforming performance, then signal quality is improved, but processing latency increases

Engineering Contradiction:
Improvebeamforming optimalityVSAvoidprocessing latency
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent pre-computes beamforming vectors and stores them in codebooks before actual communication occurs. During real-time operation, the system only needs to retrieve pre-computed vectors based on current channel conditions, dramatically reducing processing latency compared to performing full eigen-decomposition or matrix calculations in real-time.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent creates a codebook that contains copies of pre-computed beamforming vectors for various channel conditions. Instead of recalculating vectors during operation, the system copies and uses the appropriate pre-computed vector from the codebook, eliminating calculation time while maintaining optimality.

Inventive Principle:
Principle #26Copying

3Measurement precision

If full channel state information feedback is used to achieve accurate beamforming, then beamforming accuracy is improved, but feedback overhead and system complexity increase

Engineering Contradiction:
Improvechannel state information accuracyVSAvoidfeedback overhead
Core Design Contradiction:
Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent extracts only the essential information needed for beamforming (channel quality indicators or preferred beam indices) from the full channel state information. Instead of feeding back complete channel matrices, the system extracts and transmits only the critical parameters required to select appropriate pre-computed beamforming vectors, significantly reducing feedback overhead.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces codebooks as an intermediary between the channel and the beamforming process. The codebooks serve as a lookup table that maps channel conditions to optimal beamforming vectors, allowing the system to achieve accurate beamforming without transmitting detailed channel state information, thus reducing feedback requirements.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP2255504B1Multi-resolution beamforming based on codebooks in MIMO systems
Publication Date: 2017.06.21 QUALCOMM INC
  • EP2255504B1 patent drawingFigure 1
  • EP2255504B1 patent drawingFigure 2
  • EP2255504B1 patent drawingFigure 3

AI summary

Transmission and reception beamforming coefficients are calculated on the basis of training signals and a set of codebooks.