Full-Duplex Timing Alignment for Clutter Echo Interference
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Full-duplex wireless communication systems face challenges due to high levels of self-interference from clutter echoes, which reduce signal-to-interference and noise ratio (SINR) and lead to dropped communications, despite existing methods like beamforming not fully mitigating residual clutter interference.
Innovation Solution
Adjusting timing alignment between transmitted and received signals to ensure the clutter echo delay falls within an adjusted cyclic prefix length, combined with using different multiple access signatures to separate channel estimation, thereby reducing inter-symbol and inter-carrier interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If full-duplex mode communication is implemented, then spectral efficiency is improved, but self-interference from clutter echoes increases causing dropped communications
Solution Approach 1:
The system performs preliminary timing alignment adjustments before full-duplex communication begins. The base station calculates and applies timing offsets to ensure that clutter echoes from transmitted signals arrive during the cyclic prefix period of received signals, preventing interference with the actual data reception and maintaining communication reliability while enabling full-duplex operation.
Solution Approach 2:
The invention converts the harmful clutter echo interference into a beneficial situation by strategically positioning it within the cyclic prefix period. The timing alignment mechanism ensures that reflected signals that would normally interfere with reception instead occupy the guard interval, where they can be effectively isolated and do not degrade the signal-to-interference ratio during data symbol reception.
2Reliability
If timing adjustment is applied to align clutter echo within cyclic prefix, then SINR is improved, but device complexity increases
Solution Approach 1:
The base station utilizes its own transmitted signal as the reference for measuring clutter echo characteristics. By using the known transmitted waveform and comparing it with the received signal containing echoes, the system self-calibrates the timing offset without requiring external reference signals or additional infrastructure, thereby improving SINR while limiting complexity growth.
Solution Approach 2:
The system dynamically adjusts the timing offset parameter based on measured clutter echo characteristics. By changing the timing alignment parameter to match the dominant echo delay, the system achieves optimal SINR performance. The complexity is managed by focusing adjustments on a single critical parameter (timing offset) rather than reconfiguring multiple system parameters simultaneously.
Data Source
Figure 1
Figure 2
Figure 3A
AI summary
Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a base station may determine, for full-duplex mode communication on a first link and a second link, a timing adjustment to at least one of a first timing or a second timing, wherein the timing adjustment is to cause a delay between clutter reflection from a first signal and an occurrence of a second signal to occur during a cyclic prefix of the second signal; cause the timing adjustment to be applied to the at least one of the first timing or the second timing; and communicate in the full-duplex mode with a first node and a second node in accordance with the timing adjustment, wherein communicating includes transmitting the first signal to the first node and receiving the second signal from the second node. Numerous other aspects are provided.