Massive MIMO Beam Selection via Coarse-Fine Scanning

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Solution Overview

Problem

The narrow beam traverse scanning method in Massive MIMO systems consumes a long time and results in large overheads due to the need to scan a whole spatial channel using a narrow beam, limiting system efficiency.

Innovation Solution

A method where a network side device sends downlink sounding signals using wider beams to determine an approximate spatial area, then uses narrower beams to determine a communication beam, reducing channel scanning time and overheads by focusing on a smaller coverage area.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If narrow beam traverse scanning method is used to determine communication beam, then beam accuracy is improved, but channel scanning time increases and overheads increase

Engineering Contradiction:
Improvebeam accuracyVSAvoidchannel scanning time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent segments the beam determination process into two distinct phases: a coarse scanning phase using wide beams to cover the entire spatial channel, and a fine scanning phase using narrow beams to precisely determine the communication beam within a reduced spatial area. This segmentation allows the system to first quickly locate the approximate direction of user equipment using wide beams, then focus narrow beam scanning only on the identified spatial region, thereby maintaining high beam accuracy while significantly reducing the overall scanning time and overheads compared to exhaustive narrow beam traversal.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent performs preliminary coarse scanning using wide beams before executing the fine scanning with narrow beams. By first identifying the approximate spatial area containing user equipment through wide beam traversal, the system prepares the groundwork for subsequent precise beam determination. This preliminary action eliminates the need to perform narrow beam scanning across the entire spatial channel, thus reducing scanning time and overheads while preserving measurement precision in the final beam selection.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If narrow beam traverse scanning method is used to determine communication beam, then beam accuracy is improved, but system overheads increase

Engineering Contradiction:
Improvebeam accuracyVSAvoidoverheads
Core Design Contradiction:
Measurement precisionVSQuantity of substance

Solution Approach 1:

The patent segments the beam determination process into two distinct phases: a coarse scanning phase using wide beams to cover the entire spatial channel, and a fine scanning phase using narrow beams to precisely determine the communication beam within a reduced spatial area. This segmentation allows the system to first quickly locate the approximate direction of user equipment using wide beams, then focus narrow beam scanning only on the identified spatial region, thereby maintaining high beam accuracy while significantly reducing the overall scanning time and overheads compared to exhaustive narrow beam traversal.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Instead of performing complete narrow beam traversal across the entire spatial channel, the patent applies partial action by conducting narrow beam scanning only within the reduced spatial area identified during the coarse scanning phase. This partial scanning approach is sufficient to achieve accurate beam determination since the coarse phase has already eliminated most of the spatial search space, thereby reducing overheads while maintaining the necessary measurement precision.

Inventive Principle:
Principle #16Partial or excessive action

Data Source

PatentEP3349367B1Method of determining communication beam, and corresponding device
Publication Date: 2020.02.26 HUAWEI TECH CO LTD
  • EP3349367B1 patent drawingFigure 1
  • EP3349367B1 patent drawingFigure 2
  • EP3349367B1 patent drawingFigure 3a~3d

AI summary

The present invention discloses a communication beam determining method and a corresponding apparatus, so as to resolve a prior-art problem that when a narrow beam traverse scanning method is used to determine a communication beam, a long time is consumed and large overheads are caused. The method includes: respectively sending, by a network side device, downlink sounding signals by using M beams with a first width, where main lobe directions of any two of the M beams with the first width are different, and M is not less than 2; receiving, by the network side device, sounding results returned by user equipment UE, and determining N beams with a second width based on the sounding results, where the second width is less than the first width, a coverage area of a set of the N beams with the second width is smaller than a coverage area of a set of the M beams with the first width, and N is not less than 2; and respectively sending, by the network side device, downlink scanning signals by using the N beams with the second width, and determining, based on scanning results returned by the UE, a first beam for data transmission with the UE.