电讯技术
電訊技術
전신기술
Telecommunication Engineering
2015年
10期
1124-1129
,共6页
天波超视距雷达%小孔径圆阵%目标探测%正交频分非线性调频信号%峰值旁瓣抑制%凸优化
天波超視距雷達%小孔徑圓陣%目標探測%正交頻分非線性調頻信號%峰值徬瓣抑製%凸優化
천파초시거뢰체%소공경원진%목표탐측%정교빈분비선성조빈신호%봉치방판억제%철우화
skywave over-the-horizon radar%small aperture array%target detection%OFD-NLFM signal%peak sidelobe suppression%convex optimization
针对小孔径超视距目标探测时阵列孔径减小空域滤波性能下降的问题,提出了一种正交频分非线性调频( OFD-NLFM)的发射波形设计方法. 首先以正切调频函数为频率函数对发射信号进行建模,详细说明了影响脉压性能的正切函数时间副瓣电平控制因子的选择方法,重点提出一种基于凸优化的脉压信号峰值旁瓣抑制算法,建立了脉压输出噪声功率最小的优化模型并进行求解. 仿真表明,提出的正交频分非线性调频信号具有较好的正交性,采用凸优化加权算法后脉压主瓣宽度比传统线性调频信号降低约1/3,峰值旁瓣为-31. 22 dB,旁瓣电平平均值小于-100 dB,具备更低的抗噪声和干扰性能,从波形设计和脉压处理角度改善了空域滤波性能的不足.
針對小孔徑超視距目標探測時陣列孔徑減小空域濾波性能下降的問題,提齣瞭一種正交頻分非線性調頻( OFD-NLFM)的髮射波形設計方法. 首先以正切調頻函數為頻率函數對髮射信號進行建模,詳細說明瞭影響脈壓性能的正切函數時間副瓣電平控製因子的選擇方法,重點提齣一種基于凸優化的脈壓信號峰值徬瓣抑製算法,建立瞭脈壓輸齣譟聲功率最小的優化模型併進行求解. 倣真錶明,提齣的正交頻分非線性調頻信號具有較好的正交性,採用凸優化加權算法後脈壓主瓣寬度比傳統線性調頻信號降低約1/3,峰值徬瓣為-31. 22 dB,徬瓣電平平均值小于-100 dB,具備更低的抗譟聲和榦擾性能,從波形設計和脈壓處理角度改善瞭空域濾波性能的不足.
침대소공경초시거목표탐측시진렬공경감소공역려파성능하강적문제,제출료일충정교빈분비선성조빈( OFD-NLFM)적발사파형설계방법. 수선이정절조빈함수위빈솔함수대발사신호진행건모,상세설명료영향맥압성능적정절함수시간부판전평공제인자적선택방법,중점제출일충기우철우화적맥압신호봉치방판억제산법,건립료맥압수출조성공솔최소적우화모형병진행구해. 방진표명,제출적정교빈분비선성조빈신호구유교호적정교성,채용철우화가권산법후맥압주판관도비전통선성조빈신호강저약1/3,봉치방판위-31. 22 dB,방판전평평균치소우-100 dB,구비경저적항조성화간우성능,종파형설계화맥압처리각도개선료공역려파성능적불족.
Since the performance of the array spatial filtering is depressed by using the small aperture ar-ray,the waveform design of orthogonal frequency division-nonlinear frequency modulation(OFD-NLFM) is used to overcome the declining performance. With the aid of the signal model based on the tangent fre-quency modulation function,the selection method for the parameter of time sidelobe level control is ana-lyzed. In order to suppress range sidelobe,the convex optimization based on minimized noise power is pro-posed. The simulation shows that OFD-NLFM signal has fine orthogonality and the mainlobe of the pulse compression is 1/3 narrower than that of the linear frequency modulation( LFM) signal. The peak sidelobe level is -31. 22 dB and the average of pulse compression is less than-100 dB. According to the result,the capability of noise and interference cancelation of the OFD-NLFM signal is better,which improves the spa-tial filtering performance.
