Full-Duplex Self-Interference Cancellation Using Adaptive Pre-Distortion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The challenge of implementing full-duplex communication systems is the difficulty in effectively removing self-interference signals, which limit the accuracy of signal recovery and system versatility due to interference from transmitted signals leaking into the receive link.
Innovation Solution
A full-duplex digital self-interference clear method using a self-adaptive algorithm to calculate a pre-distortion processing coefficient based on a preamble sequence, followed by pre-distortion processing and reconstruction to enhance interference cancellation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If full-duplex mode is adopted for simultaneous transmission and reception in the same frequency band, then data rate and spectrum efficiency are improved, but self-interference signals cause receiver saturation and reduce measurement precision
Solution Approach 1:
The patent applies pre-distortion processing before signal transmission to pre-compensate for self-interference. The pre-distortion coefficient is calculated in advance based on channel characteristics, and the transmit signal is pre-modified to counteract the expected self-interference, thereby preventing receiver saturation before it occurs
Solution Approach 2:
The patent implements an iterative feedback mechanism where the pre-distortion coefficient is initially calculated, applied to the signal, and then refined based on the actual self-interference measured at the receiver. This closed-loop feedback continuously improves the cancellation accuracy by adjusting the pre-distortion coefficient based on residual interference
2Measurement precision
If digital self-interference cancellation is performed to improve signal accuracy, then measurement precision is improved, but system complexity increases due to additional processing requirements
Solution Approach 1:
The patent replaces complex hardware-based self-interference cancellation mechanisms with digital signal processing algorithms. Instead of using additional analog components or complex RF circuitry, the solution uses software-based pre-distortion and digital cancellation algorithms that can be implemented in existing baseband processors
Solution Approach 2:
The patent transforms the self-interference cancellation problem into a parameter optimization problem by adjusting the pre-distortion coefficient. By changing this key parameter iteratively based on measured interference, the system achieves high cancellation accuracy without requiring complex structural modifications
Data Source
AI summary
The present disclosure provides a full-duplex digital self-interference clear method, including: before a signal is transmitted with a peer device in a full-duplex mode, performing a calculation by a self-adaptive algorithm to obtain a pre-distortion processing coefficient; under the condition that the signal is transmitted with the peer device in the full-duplex mode, performing pre-distortion processing on a first signal sent by the transmit link to the peer device according to the pre-distortion processing coefficient to obtain a second reconstructed interference signal; and performing self-interference clear according to the second reconstructed interference signal and a second interference signal of the receive link, with the second interference signal being a signal obtained through superimposition of an interference signal generated by the first signal in the receive link and a second signal received by the receive link from the peer device. The present disclosure further provides a full-duplex digital self-interference clear apparatus.