Blind Authentication via Pilot Signal Superposition
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Solution Overview
Problem
Existing wireless communication authentication technologies, such as Auth-SS, Auth-TDM, and Auth-SUP, face challenges in security, bandwidth usage, and performance degradation in time-varying fading channels, particularly in complex communication environments where channel estimation errors can occur and hostile users can exploit authentication information.
Innovation Solution
A physical layer blind authentication method and system based on belief propagation, where the authentication signal is superimposed on the pilot signal, allowing for blind known interference cancellation without affecting signal-to-noise ratio, and using a Tanner graph and prior probability density function to cancel the pilot signal, enabling authentication without channel estimation and extra bandwidth.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If the authentication signal is superimposed on the information signal (Auth-SUP), then extra bandwidth is not occupied, but the signal-to-noise ratio of the receiver is reduced and signal processing difficulty is higher
Solution Approach 1:
The patent introduces a pilot signal as an intermediary carrier to embed the authentication signal. Instead of directly superimposing the authentication signal on the information signal, the authentication signal is first modulated onto the pilot signal, which then serves as a mediator during transmission. This resolves the contradiction by maintaining bandwidth efficiency while protecting the information signal from degradation.
Solution Approach 2:
The patent segments the authentication process by separating the authentication signal from the information signal through the use of a pilot signal. The authentication signal is embedded in the pilot signal portion, allowing independent processing and extraction at the receiver, thus avoiding the need to process authentication and information signals together, which reduces signal processing difficulty and maintains SNR.
2Measurement precision
If channel parameter estimation and symbol recovery are performed to extract the authentication signal, then authentication can be achieved, but estimation errors occur in time-varying fading channels
Solution Approach 1:
The patent extracts the authentication signal directly from the pilot signal without requiring channel parameter estimation or symbol recovery processes. By using the pilot signal as a dedicated carrier for the authentication signal, the system eliminates the need for complex estimation procedures that are prone to errors in time-varying fading channels, thus resolving the contradiction between extraction accuracy and estimation reliability.
3Measurement precision
If a pilot signal is transmitted separately for channel estimation, then channel parameters can be recovered, but extra bandwidth is occupied and signal processing complexity increases
Solution Approach 1:
The patent makes the pilot signal multi-functional by using it both for channel estimation and for carrying the authentication signal. This eliminates the need for separate dedicated pilot signals and authentication signals, reducing bandwidth consumption and signal processing complexity while maintaining the ability to recover channel parameters accurately.
Data Source
AI summary
Provided is a physical layer blind authentication method for a time-varying fading channel based on belief propagation. The method includes that: a transmitter transmits a carrier signal to a wireless channel, the carrier signal includes an authentication signal, a pilot signal and an information signal, and the wireless channel is the time-varying fading channel; a receiver receives the carrier signal, and performs BKIC processing and differential signal processing on the carrier signal to obtain a target authentication signal, the receiver obtains a reference signal based on a key and the pilot signal, performs the differential signal processing on the reference signal to obtain a reference authentication signal, and calculates a correlation between the target authentication signal and the reference authentication signal to obtain a test statistic; and compares the test statistic with a prescribed threshold to determine whether the carrier signal is capable of passing authentication.