Joint carrier frequency and DOA estimation using a modified ULA based MWC discrete compressed sampling receiver

摘要

The uniform linear array (ULA) based modulated wideband converter discrete compressed sampling (CS) receiver is a recently introduced sub-Nyquist sampling scheme for effective acquisition of the carrier frequency (CF) and direction-of-arrival (DOA) of the received radar signal. However, the ULA based system needs to correct the phase differences of the CS data in order to estimate DOA, which would cause a low DOA estimation performance. In this study, the authors propose a modified ULA based system to improve the DOA estimation performance, where another similar branch is added in each antenna to construct the proposed symmetry system. First, the received signal is mixed to basebands. Then, the mixed signals are low-pass filtered and down-sampled to get the CS data. Second, the two branches of the CS data received in one antenna can be utilised to estimate CF. The CS data received in the added branches can be used to estimate DOA without correcting the phase differences. Finally, simulations illustrate the validity of the proposed modified ULA based system and show the proposed system outperforms the ULA based system in DOA estimation when signal-to-noise ratio is more than -10dB and the number of snapshots is more than 20.