적응형 모노펄스 빔포밍 기반 다중 표적 고해상도 각도 추정 및 추적 알고리즘 = Adaptive Monopulse Beamforming based High Resolution Multi-Target Angle Estimation and Tracking Algorithm

다국어 초록 (Multilingual Abstract)

With the rapid proliferation of Unmanned Aerial Vehicles (UAVs) and the advancement of radar-based surveillance and reconnaissance systems, there is a growing demand for high resolution multi-target angle estimation and stable tracking algorithms. Understandably in practical scenarios, it is more common to encounter multiple targets located within a narrow angular sector rather than an ideal single-target case. In such situations, conventional single-target monopulse beamforming and classical Direction-of-Arrival (DoA) algorithms such as MUSIC and ESPRIT, which rely on eigen- decomposition of covariance matrices, suffer from either performance degradation or high computational complexity for real-time embedded applications. In Chapter 2, single-target monopulse beamforming is designed for an Frequency-Modulated Continuous Wave (FMCW) radar with a vertical uniform linear array. Classical sum and difference beams are modeled, and convex optimization (CVX) is used to improve boresight linearity, sidelobe levels, and sensitivity. Simulations confirm accurate angle estimation for single-target cases and reveal limitations when multiple targets or strong multipath are present. Chapter 3 extends this framework to adaptive multi-target monopulse beamforming. A common weight vector based formulation is used to control boresight slope, sidelobes, and nulls toward interference directions, and an iterative nulling algorithm based on orthogonal projection is introduced to reduce complexity. The proposed method improves angular resolution and tracking stability for closely spaced targets compared with conventional single-target based designs. Chapter 4 applies the monopulse beamforming concept to a mmWave Wireless Power Transfer (WPT) system. In a multi-stage beam search structure, monopulse beamforming based beam patterns are used to refine beam direction and local power distribution, enabling faster and more reliable beam alignment when the receiver position is unknown or time-varying. This illustrates that monopulse techniques developed for radar can also enhance power transfer efficiency and robustness in WPT applications. This research develops a unified set of techniques that span single-target monopulse design, adaptive multi-target monopulse beamforming, and WPT- oriented beam control. These results provide a practical framework for high- resolution angle estimation and robust tracking in realistic multi-target with low computational complexity.

목차 (Table of Contents)

• Ⅰ. 서론 1
• Ⅱ. 단일 표적 기반 모노펄스 빔포밍 기법 3
• 2.1 서론 3
• 2.2 시스템 모델 4
• 2.3 기존의 모노펄스 빔포밍 기법 5
• 2.4 CVX 기반 모노펄스 빔포밍 기법 7
• 2.5 시뮬레이션 결과 및 한계 8
• 2.5.1 MSE 비교 9
• 2.5.2 단일 표적 기반 모노펄스 빔포밍 기법이 갖는 한계 10
• Ⅲ. 적응형 다중 표적 기반 모노펄스 빔포밍 기법 11
• 3.1 서론 11
• 3.2 시스템 모델 13
• 3.3 제안하는 다중 표적 모노펄스 빔포밍 기법 15
• 3.3.1 반복적 convex 최적화를 이용한 적응형 모노펄스 빔포밍 기법 16
• 3.3.2 직교 투영 기반 저복잡도 모노펄스 빔포밍 기법 21
• 3.4 시뮬레이션 결과 27
• 3.4.1 시뮬레이션 환경 및 파라미터 설정 28
• 3.4.2 제안하는 두 기법의 수렴 여부 확인 29
• 3.4.3 다중 표적 각도 추정 성능 비교 29
• 3.4.4 제안하는 기법들 간 각도 분해능 비교 32
• 3.4.5 Algorithm 1과 Algorithm 2의 계산 복잡도 비교 33
• 3.5 결론 34
• Ⅳ. 모노펄스 빔포밍 기법을 이용한 무선 전력 전송 시스템 35
• 4.1 서론 35
• 4.2 무선 전력 전송 시스템 36
• 4.3 모노펄스 빔포밍 기반 다단계 빔 패턴 설계 38
• 4.3.1 방위각 탐지 절차 38
• 4.3.2 고각 탐지 절차 40
• 4.4 결론 42
• Ⅴ. 결론 44
• 참고 문헌 46
• 감사의 글 48