Self-Interference Cancellation Using Truncated Detection Windows
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Solution Overview
Problem
In wireless communication systems, especially in full-duplex mode, self-interference signals significantly degrade the receive signal, and existing methods for self-interference cancellation face challenges due to inter-symbol interference and timing misalignment during channel estimation.
Innovation Solution
A method and apparatus for self-interference cancellation that involves truncating signals based on a detection window shorter than the symbol length, using a comb-structured reference signal for channel estimation, and reconstructing the self-interference signal for cancellation, with the detection window position determined by the timing of the receive signal to minimize inter-symbol interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If full-duplex mode is used to increase spectral efficiency, then data transmission rate is improved, but self-interference signal significantly degrades receive signal quality
Solution Approach 1:
The patent converts the harmful self-interference signal into a useful channel estimation resource by using the received self-interference signal to estimate the self-interference channel characteristics. This estimated channel information is then used to reconstruct and subtract the self-interference signal, transforming the original harmful interference into a beneficial tool for signal cleaning and full-duplex operation.
2Object-affected harmful factors
If traditional self-interference cancellation method is used, then self-interference is reduced, but inter-symbol interference and timing misalignment cause estimation inaccuracy
Solution Approach 1:
The patent applies preliminary action by performing channel estimation before signal reconstruction and cancellation. The self-interference channel is estimated in advance using the received signal and comb-structured reference signals, allowing the system to prepare the necessary channel information before executing the actual self-interference subtraction, thereby avoiding timing misalignment issues during the cancellation process.
Solution Approach 2:
The patent segments the self-interference signal processing into distinct stages: reference signal reception, channel estimation, signal reconstruction, and cancellation. By dividing the complex self-interference cancellation process into separate manageable steps, the system can address timing alignment issues at specific stages and improve overall estimation accuracy.
3Measurement precision
If detection window length is increased to capture complete signal, then channel estimation is improved, but processing time and computational complexity increase
Solution Approach 1:
The patent applies local quality by using comb-structured reference signals that are distributed sparsely in the frequency domain rather than requiring continuous signal capture. This sparse frequency-domain sampling allows the system to achieve accurate channel estimation with a shorter detection window, as the comb structure provides sufficient channel characteristics at key frequency points without requiring the full symbol duration for processing.
Data Source
AI summary
The present disclosure provides a method and an apparatus for self-interference cancellation, a terminal and a base station are disclosed. The method includes truncating a signal based on a detection window, where the signal comprises a receive signal and a self-interference signal which is associated with a transmit signal, and a length of the detection window is less than a symbol length, performing self-interference channel estimation to obtain an estimation of a self-interference channel, based on the truncated signal and a first reference signal which is carried by the transmit signal and used for self-interference channel estimation, where the first reference signal has a comb structure in frequency domain, and performing self-interference cancellation based on the transmit signal and the estimation of the self-interference channel. The method can reduce the influence on the accuracy of self-interference channel estimation due to inter-symbol interference caused by timing misalignment. And, the present disclosure provides a method and device for transmitting a first physical signal in a wireless communication system, the method including: mapping a sequence of each antenna port for the first physical signal to a same plurality of subcarriers on same one or more OFDM symbols based on a frequency-domain mapping pattern of the first physical signal; and transmitting the first physical signal.