共查询到19条相似文献,搜索用时 109 毫秒
1.
2.
复合调制信号由于其优异的性能,近几年成为许多学者的一个重要研究课题.基于对复合调制信号自相关函数特征的详细理论推导和分析,从高分辨率角度出发,研究了不同PSK调制对FSK/PSK信号分辨率的影响.在未引入旁瓣抑制网络情况下,获得了一种均匀二相编码与Barker码扩展序列组合的新型PSK调制方式,能较大地降低FSK/PSK信号的旁瓣.理论分析和计算机仿真表明:这种新型的复合调制方式可使旁瓣值达到-32.12 dB.这对通信系统、雷达以及信息安全等方面信号调制方式的选取有着重要的参考意义. 相似文献
3.
4.
5.
6.
7.
随机脉位调制脉冲串雷达信号的平均模糊函数 总被引:1,自引:0,他引:1
本文研究了随机脉位调脉冲串雷达信号。给出了该随机序列的模糊函数数学表达式,分析了调制数变化对结果的影响,结果表明适当选择其调制参数,其模糊函数可作到近似图订形。所以,这种信号是一种较佳的雷达信号。 相似文献
8.
TCM是一种将差错控制编码与调制有机结合的编码调制技术,在保持信息传输速率不变的前提下增加信号数量,以增加信号的冗余度来进行抗干扰编码,使系统的频带利用率和功率资源同时得到有效利用。先对TCM编码调制技术和直接序列扩频系统进行了研究,然后给出了一种基于TCM-8PSK的直扩系统的仿真模型,并分析了其在不同干扰信道下的性能。 相似文献
9.
一种基于混沌序列的随机离散频率编码信号 总被引:2,自引:0,他引:2
针对正交编码信号已有设计方法计算复杂、编码长度和数量受限等问题,该文利用混沌序列类随机、初值敏感,易产生和易使用的特点,提出应用混沌序列设计随机离散频率编码信号。在给出编码信号设计方案的基础上,详细推导此类信号的模糊函数,分析了其距离、多普勒分辨能力,讨论了信号的准正交特性,并比较了不同混沌序列对信号性能的影响。理论分析和仿真实验表明,结合混沌序列的频率编码信号具有优良的模糊函数、准正交性能,且信号产生容易,编码长度和数量可以任意设置,可以作为一类有潜力的雷达信号使用。 相似文献
10.
雷达通信一体化有利于提高设备硬件资源利用率和频谱利用率,改善频谱拥挤现象,成为近年来研究的热点.针对直接信息调制一体化信号旁瓣较高、扩频信息调制一体化信号带宽较大的缺点,提出了一种加权预处理一体化波形优化方法.分析了多符号正交频分复用雷达通信一体化信号的模糊函数及其相关函数对模糊函数的影响,利用鲸鱼优化算法选择加权系数来改善原始序列的自相关和互相关特性,进而优化模糊函数的峰值旁瓣比性能.仿真结果表明,所提的一体化波形设计方法带宽更小,同时峰值旁瓣比性能进一步得到优化,通信速率和误比特率性能满足通信需求,具有较好的雷达通信一体化性能. 相似文献
11.
一种具有LPI特性的雷达信号一新的FSK/PSK信号 总被引:2,自引:0,他引:2
探讨了一种由FSK信号和PSK信号组合而成的新的FSK/PSK雷达信号。理论分析了和计算机模拟了该类信号的模糊函数(图),距离分辨率、速度分辨率和低截获性能。分析表明了该类信号在高分辨和低截获方面的有效性。 相似文献
12.
Low probability of intercept (LPI) radar signal design is a very important issue on modern battlefield. Different phase coding technologies are used to modulate Costas frequency hop sequence, and five kinds of continuous wave radar signals including Costas, Costas_qbarker, Costas_frank16, Costas_px16 and Costas_zadoff-chu13 are proposed and designed in this paper. The target resolution and LPI performance of the Costas and Costas/PSK continuous wave radar signals are analysed and compared. The ambiguity function and power spectral densities (PSDs) of five different kinds of signals are also simulated and studied. The results show that the target resolution and LPI performance of proposed Costas/PSK signal are better than Costas signal. 相似文献
13.
14.
非线性随机共振系统能够有效利用噪声能量增强微弱周期信号,因此可用于强噪声背景下的微弱通信信号检测。本文提出基于人工鱼群算法的自适应随机共振方法处理相移键控(PSK)信号,分别从算法应用于参数估计、应用于提高带内信噪比、应用于降低检测信噪比门限三个角度分析本文算法对PSK信号检测带来性能上的提升,阐述了采样率在窄带PSK信号随机共振中的作用。对比谱线法,基于人工鱼群算法的自适应随机共振能够明显提升PSK信号参数估计性能,并且将参数估计信噪比门限降低3-6dB。此外,本文验证得到随机共振直接处理窄带周期信号没有实际提升效果。 相似文献
15.
An analysis of the spectra of digital signals is presented that includes Lundquist's and Glance's results for PSK signals as special cases while at the same time being much simpler than previous analyses. The signal is assumed to be modulated in phase and/or amplitude by a sequence of pulses that may have different shapes for different symbols. In addition, the pulse representing a given symbol may be affected by neighboring symbols, so that intersymbol interference in the modulating process is permitted. The results, nevertheless, take a simple form, and they are applied to two binary cases. 相似文献
16.
《Optical Fiber Technology》2013,19(5):514-517
This paper proposes an opto-electrical feed-forward circuit that reduces phase noise in binary PSK signals by averaging the noise. Random and independent phase noise is averaged over several bit slots by externally modulating a phase-fluctuating PSK signal with feed-forward signal obtained from signal processing of the outputs of delay interferometers. The simulation results demonstrate a reduction in the phase noise. 相似文献
17.
Liu Shuangping Wen Xiang Jin Liang 《电子科学学刊(英文版)》2007,24(5):600-606
Many monographs point out that differential encoding and decoding is necessary for ef- fectual information transmission against phase ambiguity while seldom discuss the reason why phase ambiguity will emerge inevitably.Available algorithms are specially designed for certain modulation scheme;these algorithms cannot satisfy the requirement of soft-defined radio,which perhaps demands a uniform algorithm for different modulations.This paper proposes a new opinion on phase ambiguity from the view of probability.This opinion believes that modulating symbol sequence can affect,at optimum sampling epoch,the modulated waveform as oscillating carrier has done,and so the stochastic sequence leads to phase ambiguity.Based on a general signal model,this paper also puts forward a novel universal algorithm,which is suitable for different signals,even some new ones,by configuring several parameters. 相似文献
18.