关键词: 压缩采样, 均匀线阵, 调制宽带转换器, 载频估计, 波达方向估计, 阵列信号处理

Abstract:

In view of the problems that the traditional Nyquist sampling generates huge data volume and the existing array compressed sampling systems have complex structures and large reconstruction operations, this paper proposes an array reception system based on an improved modulated wideband converter(MWC) of uniform linear array, which can directly perform carrier frequency and direction of arrival(DOA) estimation on the compressive sampling(CS) data of the received signal without reconstruction. The proposed system sets multiple MWC branches after the first antenna, and selects the periodic cyclic shift pseudo-random sequence as the mixing function, so that there is a fixed phase difference between the compressed sampled values of adjacent branches, and the subband index estimation can be obtained from the phase difference. The baseband frequency is estimated by FFT(Fast Fourier Transform) spectral line interpolation method, and the carrier frequency estimation of the received signal can be obtained when the two estimated values are combined. The rest of the array antennas are set as a single channel MWC structure, and the mixing function of each channel is the same as that in the first MWC branch of the first array antenna, which avoids the need for phase compensation and the resulting error in DOA estimation. The high-resolution multiple signal classification(MUSIC) algorithm can be directly used to complete DOA estimation on the CS data obtained from the first branch and other array antennas. The experimental simulation results show that the proposed system can estimate the carrier frequency and DOA parameters of the target from the compressed sampling data.

Key words: compressed sampling, uniform linear array, modulation broadband converter, carrier frequency estimation, direction of arrival estimation, array signal processing