A Single Receive Channel DBF Method for Ultra-Wideband Radar

Liu Nan,Guo Kaisi,Zhang Linrang,Zhang Zhenghe

doi:10.1109/access.2019.2957493

Abstract

In this paper, we present a space code agility-based single receive channel digital beamforming (DBF) method for ultra-wideband radar. The proposed single channel DBF method outperforms the existing single channel DBF method with a space-time coded array architecture regarding both the angular and the range sidelobe levels by integrating multiple pulses modulated by irrelevant space codes. A frequency-domain equivalent DBF algorithm is also developed. This algorithm is immune to the mismatch between the sampling rate of the recorded signal and the space-time response function of the space-time coded array under ultra-wideband circumstances, in which cases the existing space-time coded array DBF methods will suffer. Moreover, the target motion over multiple pulse repetition intervals (PRIs) is taken into account in the development of the frequency-domain DBF algorithm. Therefore, performance degradation due to target motion is avoided. Numerical simulations verify the effectiveness of the proposed method.

Highlights

The digital beamforming (DBF) technique has been widely studied in the last few decades since it outperforms the analog beamforming technique in many aspects [1]
We present a space code agility-based single receive channel DBF method for ultra-wideband radar
Compared to the single-channel equivalent DBF (EDBF) of a circulating time-delay coded array, the range resolution of an ultra-wideband signal can be preserved through the proposed array architecture

Summary

INTRODUCTION

The digital beamforming (DBF) technique has been widely studied in the last few decades since it outperforms the analog beamforming technique in many aspects [1]. [12], another single receive channel DBF method was developed based on the circulating time-delay coded array (CTDCA) [13]–[15]. The range resolution can be preserved by further introducing space coding into the circulating time-delay coded array [16] Such a technique, which has been developed for transmit beamforming, can be utilized for single channel receive DBF. After coherently integrating the received signals of multiple PRIs, the relative sidelobe levels in both the range domain and the angular domain will be decreased compared to those in the existing single channel DBF methods with an STCA architecture. The signal model and low sidelobe principle of the space code agility-based space-time coded array (SCA-STCA) will be introduced, followed by the frequency-domain DBF algorithm.

PROBLEM FORMULATION

CONCLUSION