基于MR-MWC系统的载频与DOA联合估计

Joint Estimation of Carrier Frequency and DOA Based on the MR-MWC System

针对传统奈奎斯特采样会产生庞大的数据量以及现有的阵列压缩采样系统存在结构复杂、重构运算量大等问题,本文提出了一种基于均匀线型阵列的改进型调制宽带转换器(Modulated Wideband Converter,MWC)的阵列接收系统,无需重构即可直接对接收信号的压缩采样数据进行载频与波达方向(Direction Of Arrival,DOA)估计.所提系统在MWC测频支路中采用周期性循环移位伪随机序列作为混频函数以求得子带索引估计,采用基于快速傅里叶变换(Fast Fourier Transform,FFT)谱线插值法进行基带频率估计,且将MWC测向分支中混频函数设置为相同的伪随机序列,便可直接利用高分辨率的多重信号分类(MUltiple SIgnal Classification,MUSIC)算法对组合压缩采样数据完成DOA估计.实验仿真结果证明了所提系统能较好地从压缩采样数据中完成对目标的载频与DOA参数估计.

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 ar-ray reception system based on an improved modulated wideband converter(MWC)of uniform linear array,which can direct-ly perform carrier frequency and direction of arrival(DOA)estimation on the compressive sampling(CS)data of the re-ceived 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 differ-ence.The baseband frequency is estimated by FFT(Fast Fourier Transform)spectral line interpolation method,and the carri-er 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 es-timation.The high-resolution multiple signal classification(MUSIC)algorithm can be directly used to complete DOA esti-mation 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.