Nonlinear Self-Interference Channel Estimation in Full Duplex Radio
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Solution Overview
Problem
Full Duplex Radio (FDR) systems face significant performance deterioration due to intra-device self-interference, which existing methods struggle to effectively cancel, especially when nonlinear components are involved, requiring complex calculations and resource-intensive processes.
Innovation Solution
A method and apparatus that utilize a sequence design and detection algorithm to estimate and cancel both linear and nonlinear self-interference components in FDR systems, employing a Zadoff-Chu sequence for channel estimation with lower complexity, allowing efficient self-interference cancellation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional methods are used to cancel self-interference in FDR systems, then linear self-interference can be removed, but nonlinear self-interference components remain and significantly deteriorate system performance
Solution Approach 1:
The patent segments the self-interference cancellation process into distinct linear and nonlinear components. The linear component is handled using conventional cancellation methods, while the nonlinear component is separately estimated and cancelled using polynomial-based nonlinear channel estimation, allowing each type of interference to be addressed with appropriate techniques
Solution Approach 2:
The patent performs preliminary action by estimating the nonlinear self-interference channel before the actual data reception and processing. The nonlinear channel characteristics are pre-characterized using training sequences, enabling the system to prepare cancellation filters in advance that account for nonlinear effects, thus improving overall cancellation effectiveness
2Measurement precision
If complex calculation methods are used to estimate nonlinear self-interference channel, then estimation accuracy improves, but computational complexity and resource consumption increase significantly
Solution Approach 1:
The patent changes the parameter representation of the nonlinear channel by using polynomial coefficients to model the nonlinear relationship. This parameterization transforms the complex nonlinear estimation problem into a more manageable form where the nonlinear channel can be represented by a finite set of polynomial coefficients that can be efficiently estimated and used for cancellation
Solution Approach 2:
The patent introduces an intermediary polynomial model that bridges the gap between the actual nonlinear channel and the cancellation process. This polynomial representation serves as an intermediate step that simplifies the estimation and application of nonlinear cancellation, reducing computational burden while maintaining accuracy
Data Source
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AI summary
A method for estimating a nonlinear self-interference channel in a wireless channel system, according to the present invention, can further comprise the steps of: applying a first sequence to a first symbol; applying, to a second symbol, a sequence of which a phase is shifted from that of the first sequence by π/2; and transmitting the first symbol and the second symbol.