中文摘要：

针对传统天波超视距雷达接收阵列孔径大的问题，提出一种基于小孔径的超视距目标探测方法。分析了阵列孔径减小后信号接收与处理的性能损失，在此基础上采用正交频分复用线性调频信号，从发射信号设计方面提升系统性能。首先对信号进行建模，重点提出一种基于凸优化的脉压信号峰值旁瓣抑制算法，建立了优化模型并进行求解。仿真表明，采用正交频分复用线性调频信号可以提升距离分辨率，采用凸优化的算法后脉压峰值旁瓣为-26．28dB，旁瓣电平平均值小于～50dB，距离门内和距离门外噪声／干扰的抑制能力得到提升，改善了小孔径超视距目标探测的处理性能。

英文摘要：

The method of over-the-horizon detection based on the small aperture array is used to overcome the quite large aperture of the traditional OTHR. Since the performance of signal processing is depressed by using the small aperture array,this paper presents an orthogonal frequency division multiplexing linear frequency modulation（OFDM-LFM ） waveform design method. With the aid of the signal model, the range resolution of the coherence-synthetic is analyzed. In order to suppress range side-lobe, the convex optimization is proposed. The simulation shows that OFDM-LFM signal can improve the performance of the range resolution. The peak side-lobe level is --26.28 dB and the average of pulse compression is less than --50 dB. According to the result, the capability of noise and interference cancelation are increased, and the target detection performance is improved too.