针对混沌序列单一调频或调相波形存在波形复杂度低,限制了混沌信号可预测的概率、雷达的截获概率和抗干扰性能的问题,提出了基于混沌序列将频率和相位联合调制用于波形设计的方法。首先,对雷达信号进行混沌频率编码,即将一个脉冲分成一...针对混沌序列单一调频或调相波形存在波形复杂度低,限制了混沌信号可预测的概率、雷达的截获概率和抗干扰性能的问题,提出了基于混沌序列将频率和相位联合调制用于波形设计的方法。首先,对雷达信号进行混沌频率编码,即将一个脉冲分成一系列子脉冲,对不同子脉冲进行不同的频率调制。同时,在每个频率编码子脉冲内对波形的每个周期使用随机产生的初始相位。仿真结果表明,联合调频调相混沌雷达信号的自相关旁瓣峰值最大值达到-24.71 d B,相比调频混沌信号或调相混沌信号,其相关性性能有所提高。实验结果表明,联合调频调相混沌雷达波形结合调相和调频的优点,既具有调相信号的功率谱平坦的特性,又具有调频信号抗噪声干扰特性,为非常理想的探测信号。展开更多
针对宽带正交低截获概率(low probability of intercept,LPI)雷达波形簇设计,利用频率编码捷变和调频斜率捷变的复合波形编码技术,在波形正交约束的基础上构造了一种复合频率编码的非线性代价目标函数,提出了基于频率编码捷变或调频斜...针对宽带正交低截获概率(low probability of intercept,LPI)雷达波形簇设计,利用频率编码捷变和调频斜率捷变的复合波形编码技术,在波形正交约束的基础上构造了一种复合频率编码的非线性代价目标函数,提出了基于频率编码捷变或调频斜率捷变的复合波形簇优化设计方法。利用模式搜索算法获得了具有良好自相关和互相关旁瓣特性的宽带正交LPI波形簇。仿真结果表明,所设计的波形能够获得低自相关旁瓣和低互相关旁瓣,可为LPI雷达发射波形与多输入多输出雷达波形的设计提供参考。展开更多
In many classic Ultra Wide Band communication systems, only Gaussian and monocycle pulses associate to PPM modulation are used. In this paper, an original communication system based on orthogonal functions and the Bip...In many classic Ultra Wide Band communication systems, only Gaussian and monocycle pulses associate to PPM modulation are used. In this paper, an original communication system based on orthogonal functions and the Bipolar PPM modulation is proposed. This system allows good performances in terms of Bit Error Rate (BER) and high data rate. This study concerns new applications, such as Vehicle to Vehicle (V2V) and Vehicle to Infrastructure (V2I) communication systems or a wireless link between computers. These applications need high reliability to transmit security-related information and high data rate to exchange multimedia data. With the emergence of the orthogonal wave-forms, the performances of the UWB communication system will be more interesting in terms of BER and data rate. In this paper, two kinds of improvement are proposed. The first improvement permits us to decrease the Bit Error Rate using the original waveforms. The second allows improving the data rate via novel modulation method. The last parameter study, in this paper, concerns the problem of synchronization between the different users. We will study the performances of the proposed system in multiusers environment in synchronous and asynchronous cases. In the first stage, the theoretical and simulation results will be presented for the proposed system. The simulation results obtained by comparing the classic UWB system and the proposed system show that our solution gives good performances in terms of BER and data rate. The theoretical results of BER values will be given for our proposed solution. In the second stage, we will compute BER values for different jitter effects. Theses studies report theoretical and simulation performances evaluation in the case of two展开更多
文摘针对混沌序列单一调频或调相波形存在波形复杂度低,限制了混沌信号可预测的概率、雷达的截获概率和抗干扰性能的问题,提出了基于混沌序列将频率和相位联合调制用于波形设计的方法。首先,对雷达信号进行混沌频率编码,即将一个脉冲分成一系列子脉冲,对不同子脉冲进行不同的频率调制。同时,在每个频率编码子脉冲内对波形的每个周期使用随机产生的初始相位。仿真结果表明,联合调频调相混沌雷达信号的自相关旁瓣峰值最大值达到-24.71 d B,相比调频混沌信号或调相混沌信号,其相关性性能有所提高。实验结果表明,联合调频调相混沌雷达波形结合调相和调频的优点,既具有调相信号的功率谱平坦的特性,又具有调频信号抗噪声干扰特性,为非常理想的探测信号。
文摘针对宽带正交低截获概率(low probability of intercept,LPI)雷达波形簇设计,利用频率编码捷变和调频斜率捷变的复合波形编码技术,在波形正交约束的基础上构造了一种复合频率编码的非线性代价目标函数,提出了基于频率编码捷变或调频斜率捷变的复合波形簇优化设计方法。利用模式搜索算法获得了具有良好自相关和互相关旁瓣特性的宽带正交LPI波形簇。仿真结果表明,所设计的波形能够获得低自相关旁瓣和低互相关旁瓣,可为LPI雷达发射波形与多输入多输出雷达波形的设计提供参考。
文摘In many classic Ultra Wide Band communication systems, only Gaussian and monocycle pulses associate to PPM modulation are used. In this paper, an original communication system based on orthogonal functions and the Bipolar PPM modulation is proposed. This system allows good performances in terms of Bit Error Rate (BER) and high data rate. This study concerns new applications, such as Vehicle to Vehicle (V2V) and Vehicle to Infrastructure (V2I) communication systems or a wireless link between computers. These applications need high reliability to transmit security-related information and high data rate to exchange multimedia data. With the emergence of the orthogonal wave-forms, the performances of the UWB communication system will be more interesting in terms of BER and data rate. In this paper, two kinds of improvement are proposed. The first improvement permits us to decrease the Bit Error Rate using the original waveforms. The second allows improving the data rate via novel modulation method. The last parameter study, in this paper, concerns the problem of synchronization between the different users. We will study the performances of the proposed system in multiusers environment in synchronous and asynchronous cases. In the first stage, the theoretical and simulation results will be presented for the proposed system. The simulation results obtained by comparing the classic UWB system and the proposed system show that our solution gives good performances in terms of BER and data rate. The theoretical results of BER values will be given for our proposed solution. In the second stage, we will compute BER values for different jitter effects. Theses studies report theoretical and simulation performances evaluation in the case of two
