同时同频全双工场景中的射频域自适应干扰抵消

考虑同时同频全双工无线收发信机的射频域自干扰抵消技术，现有研究多集中于利用手动方式调整自干扰估计信号的参数。针对这一问题，该文提出一种射频域的自适应干扰抵消算法。以正交、同相参考支路构成的自干扰估计结构为基础，利用梯度下降法搜索支路的最优权矢量，估计出自干扰信号，实现了射频域的自适应干扰抵消，并且给出了该算法的收敛性分析。分析与仿真表明，当迭代步长越大或统计时间越短时，算法的收敛速度越小。在100倍符号周期的统计时间，0.3的归一化步长，80 dB干信比以及0 dB信噪比的仿真条件下，该文提出的射频域自适应干扰抵消算法可以实现约100 dB的自干扰抑制。

Adaptive Self-interference Cancellation at RF Domain in Co-frequency Co-time Full Duplex Systems

In the context of the RF domain self-interference cancellation algorithms in the co-frequency and co-time full duplex system, the current research focuses mainly on the manually adjusting of self-interference parameters. To solve this problem, a RF domain adaptive self-interference cancellation is proposed. On the basis of the self-interference estimation construction within an in-phase and quadrature reference signal channels, the self-interference is reconstructed by searching the optimal weight vector with the method of gradient descending and cancelled at last. In addition, the convergence of the proposed algorithm is analyzed. The analysis and simulation show that the convergent speed is faster when the iterative step size is larger and the statistical time is shorter. The self-interference can decrease almost 100 dB adopting the RF domain adaptive self-interference cancellation algorithm proposed in this paper, when the statistical time is 100 symbol periods, the normalized iterative step is 0.3, the signal to noise ratio is 0 dB, and the interference to signal ratio is 80 dB.