Beamforming Training for Secure Wireless Communication

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Solution Overview

Problem

In wireless communication systems, especially in the 60 GHz frequency spectrum, existing technologies face challenges in preventing eavesdropping due to the broadcast nature of wireless signals, which allows potential eavesdroppers to intercept information intended for legitimate receivers, as conventional encryption methods are vulnerable to interception at the physical layer.

Innovation Solution

The implementation of communication devices and methods that utilize PHY layer spatial diversity and multi-array antenna configurations, along with beamforming techniques, to select and use trained antenna beam combinations that minimize the probability of eavesdropping by exploiting spatial properties such as position and orientation, thereby enhancing security and reducing the eavesdropping probability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional encryption methods are used at upper layers, then information security is improved, but the system becomes vulnerable to physical layer interception and brute force decryption

Engineering Contradiction:
Improveinformation securityVSAvoidvulnerability to interception
Core Design Contradiction:
ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces conventional cryptographic approaches (software-based upper layer encryption) with a physics-based physical layer security mechanism. By using spatial diversity and beamforming, the system creates a physical barrier to eavesdropping where the signal is intentionally degraded for any receiver not at the precise intended location, eliminating vulnerability to brute force decryption

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the fundamental parameter of signal transmission by introducing spatial selectivity through beamforming. The transmit signal parameters are dynamically adjusted based on the legitimate receiver's position, creating a spatially selective channel that provides high signal quality only to the intended recipient while degrading the signal for potential eavesdroppers

Inventive Principle:
Principle #35Parameter changes

2Reliability

If beamforming techniques are implemented to minimize eavesdropping probability, then security is improved, but device complexity increases due to multi-array antenna configurations

Engineering Contradiction:
ImprovesecurityVSAvoidantenna configuration complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent segments the communication system into multiple independent antenna arrays, each capable of forming its own beams. This segmentation allows the complex beamforming task to be distributed across multiple simpler antenna subsystems, where each array independently contributes to the overall spatial selectivity without requiring a single overly complex antenna structure

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent makes the antenna arrays universal by designing them to perform multiple functions: they simultaneously provide spatial diversity for security, enable beamforming for signal focusing, and support channel estimation. This multi-functionality reduces overall system complexity by eliminating the need for separate dedicated components for each function

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Object-affected harmful factors

If spatial diversity is exploited to prevent eavesdropping, then the probability of successful eavesdropping is reduced, but the system requires precise position and orientation information

Engineering Contradiction:
Improveeavesdropping probabilityVSAvoidposition and orientation accuracy
Core Design Contradiction:
Object-affected harmful factorsVSMeasurement precision

Solution Approach 1:

The patent performs preliminary beamforming training to establish the spatial relationship between transmitter and receiver before actual data transmission. This preliminary action includes channel estimation and beam alignment that captures the spatial characteristics in advance, allowing the system to use this pre-acquired spatial information for secure communication without requiring continuous high-precision position tracking during data transmission

Inventive Principle:
Principle #10Preliminary action

4Reliability

If PHY layer security is implemented using beamforming, then eavesdropping is prevented, but the handshake procedure becomes more complex

Engineering Contradiction:
Improvecommunication securityVSAvoidhandshake procedure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the security establishment process with the existing beamforming training procedure. The spatial channel characteristics required for security are obtained as a byproduct of the necessary beam alignment training, eliminating the need for separate security setup procedures and reducing overall handshake complexity

Inventive Principle:
Principle #5Merging (Combining)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This approach effectively minimizes the probability of eavesdropping by ensuring that only the intended receiver can decode the complete message, as the eavesdropper cannot be in the same position to receive the superposition of sub-streams, thus enhancing the secrecy rate and security of wireless communication.

Implementation Method 1

beamforming circuitry configured to perform beamforming and to control the antenna circuitry in a beamforming training phase to transmit and/or receive RF signals using one or more selected directive beams

Methodology Applied
Scientific EffectBeamforming:

Implementation Method 2

an antenna circuitry configured to transmit and receive RF signals

Methodology Applied
Scientific EffectElectromagnetic radiation:

Data Source

PatentEP4011053B1Communication devices and methods for secure communication
Publication Date: 2023.08.30 SONY GROUP CORP
  • EP4011053B1 patent drawingFigure 1~2
  • EP4011053B1 patent drawingFigure 3~4B
  • EP4011053B1 patent drawingFigure 5A~7

AI summary

A first communication device for use in a wireless communication system to communicate with a second communication device comprises circuitry configured to perform beamforming training with the second communication device to train a plurality of antenna beam combinations of antenna beams used by the first and second communication devices for transmitting and/or receiving signals, select one or more of the trained antenna beam combinations according to a security criterion that is directed to reducing the probability that a third communication device can eavesdrop on the communication between the first communication device and the second communication device, and communicate with the second communication device using the selected one or more antenna beam combinations.