Single snapshot DOA estimation algorithm based on high-order power in LDACS

基于高阶幂的单快拍LDACS系统波达方向估计

CAAC Key Laboratory of Civil Aviation Wide Surveillance and Safety Operation Management & Control Technology, Civil Aviation University of China, Tianjin 300300, China

Received: 21 April 2023

Abstract

The L-band digital aeronautical communication system (LDACS) is one of the essential infrastructures for future aviation broadband communication. To address the problem of interference from adjacent high-power distance measuring equipment (DME) signals, a joint orthogonal projection interference suppression and single-snapshot sparse decomposition direction of arrival (DOA) estimation method is proposed. Firstly, the DME interference is suppressed by using the subspace projection, and then a pseudo-covariance matrix is constructed by using single-snapshot data. High-order power of the pseudo-covariance matrix is calculated, followed by singular value decomposition and sparse solution obtained using constraints to estimate the desired target. The proposed method in this paper reduces the impact of noise by utilizing high-order pseudo-covariance matrix, enabling accurate estimation of the DOA of OFDM signals with only a single snapshot. Simulation results show that the estimation accuracy by using ISS-HOP-L1-SVD algorithm is better than that via ISS-HOP-MUSIC algorithm. This method can effectively suppress DME interference and improve the performance of the OFDM receiver.

摘要

L波段数字航空通信系统(L band digital aeronautical communication system, LDACS)是未来航空宽带通信重要的基础设施之一, 针对LDACS信号容易受到相邻波道大功率测距仪(distance measuring equipment, DME)信号干扰的问题, 提出了联合正交投影干扰抑制与单快拍稀疏分解的波达方向(direction of arrival, DOA)估计方法。通过子空间投影抑制DME干扰, 然后使用单快拍数据构建伪协方差矩阵, 对伪协方差矩阵求高阶幂, 之后进行奇异值分解, 并利用约束条件求解稀疏解得到期望信号来向的估计值。所提方法使用高阶伪协方差矩阵降低了噪声影响, 仅用单快拍就可以准确估计LDACS信号的入射方向。仿真结果表明, 改进单快拍高级幂(improved single snapshot high order power, ISS-HOP)L1-SVD算法的估计精度优于ISS-HOP-MUSIC算法。该方法可以有效抑制DME干扰, 提高OFDM接收机性能。