共查询到19条相似文献,搜索用时 62 毫秒
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为了分析多进制正交幅度调制(MQAM)映射方式、小波滤波器长度和小波包树结构对小波包跳频通信系统(WPM-FH)的影响,首先利用多进制幅移键控(MASK)和MQAM之间的关系,推导了MQAM-WPM-FH系统在加性高斯白噪声(AWGN)信道中的误码率理论公式,分析了不同小波滤波器长度和小波包树结构对WPM-FH系统的影响。理论分析和仿真结果表明,与正交频分复用跳频(OFDM-FH)系统相比,MQAM-WPM-FH系统具有较高频带利用率和较好的性能;在给定带宽下,通过增大MQAM数据映射中的星座点数M和小波滤波器长度L,可以有效降低多址干扰(MAI)对系统的干扰;AWGN信道下,不同的小波包树结构对跳频系统的性能影响较小,但小波包调制结构的多样性可以提高系统的安全性。 相似文献
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介绍了美军联合战术信息分发系统(Joint Tactical Information Distribution System,JTIDS)的特征及其主要技术。运用Simulink建立系统的链路仿真平台,在高斯白噪声干扰方式下进行了抗干扰性能仿真,对误码率进行了较深入的分析。给出了具体的仿真模型,并对模型中的每个模块进行了较为详细的说明,最后给出了仿真结果。 相似文献
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针对跳时超宽带(TH-UWB)和直接序列超宽带(DS-UWB)在加性高斯白噪声干扰下(AWGN)的误码率性能进行了分析,并对超宽带信号脉冲位置调制(PPM)和脉冲幅度调制(PAM)的误码率做了比较。通过理论分析和软件仿真,结果说明在加性高斯白噪声干扰下,对于TH-UWB调制和DS-UWB调制,PAM的误码率性能都优于PPM,并在此基础上给出了几种方法来提高超宽带脉冲信号抗加性高斯白噪声的能力。 相似文献
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QAM调制由于高频谱效率得到了广泛应用,但由于QAM信号的功率峰均比较高,功率放大器的非线性会导致解调性能的下降。针对功放非线性对QAM解调性能的影响,传统方法采用仿真实验的方法来获得,而文中推导了高斯信道下功率放大器的非线性对QAM解调误码率影响的闭合表达式,可求出非线性功放在不同静态工作点对应的误码率。仿真结果验证了理论分析的正确性。 相似文献
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本文利用蒙特卡罗方法原理仿真验证了通信系统在采用GMSK、QPSK的调制方式下,受高斯白噪声信道影响的误码率;进一步阐明了蒙特卡罗方法的原理与其在通信系统中的应用;通过仿真可以得到蒙特卡罗方法与理论推算的结果基本一致.说明可以利用该方法分析验证通信系统的设计. 相似文献
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π/4-DQPSK调制解调硬件实现中的误码率分析 总被引:2,自引:1,他引:1
介绍了全数字π/4差分四相移相键控的(DQPSK)调制解调电路原理,应用最新提出的1bit解调算法成功实现解调,该算法大大简化了解调部分的数据处理。分析了新的1bit解调算法理论误码率,比传统的8位π/4—DQPSK差1.5dB。当信噪比不低于15dB时,该算法误码率可达10^-7,仍是一有效解调方法。在Xilinx ise5.2开发环境下用VHDL语言实现调制解调,RTL仿真结果有误码存在,分析发现实现过程中将1kHz时钟用做2^10(1024)进行分频引起了频率误差,对该误差带来的误码进行仿真分析,同时提出改进的方案,即分频设计时让计数器在0~2″-x之间循环计数,通过仿真证明该方案达到了预期的减小误码率的效果。 相似文献
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基于Turbo码的大气无线光通信系统特性分析 总被引:13,自引:5,他引:13
提出并分析了基于Turbo码的大气无线光通信系统 ,针对大气无线光通信中的各种衰减和噪声分别进行了分析 ,通过仿真得出了特性曲线。比较了基于Turbo码的大气无线光通信系统与未编码大气无线光通信系统 ,发现Turbo码技术能够很好地补偿和克服各种衰减和噪声 ,提高了系统的抗干扰能力 ,使系统的性能得到了很大的提高。 相似文献
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针对脉冲超宽带通信技术采用的调制方式,对其的误比特率性能进行理论分析。结论指出,对于脉冲超宽带常用的两种调制方式PAM和PPM,PAM的误比特性能具有3dB增益;且充分利用FCC功率限制之下的能量是提升超宽带无线通信误比特性能的关键。 相似文献
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The bit error rate (BER) performance for high-speed personal communication service in tunnels with and without traffic is investigated. The impulse responses of tunnels for any transmitter–receiver location are computed by shooting and bouncing ray/image techniques. By using the impulse responses of these multipath channels, the BER performance of BPSK (binary phase shift keying) system with phase and timing recovery circuits are calculated. Numerical results have shown that the multipath effect by the vehicles in the tunnel is an important factor for BER performance. In addition, the effect of space diversity techniques and decision feedback equalizer on mitigating the multipath fading is also investigated.Chien-Hung Chen was born in Kaohsiung, Taiwan, Republic of China, on 8 March 1971. He received the MSEE degree from Tamkang University in 1999. He is studying for Ph.D. degree in the Department of Electrical Engineering, Tamkang University. His current research interests include indoor wireless communications and numerical techniques in electromagnetics.Chien-Ching Chiu was born in Taoyuan, Taiwan, Republic of China, on 23 January 1963. He received the BSCE degree from National Chiao Tung University, Hsinchu, Taiwan, in 1985 and MSEE and PhD degrees from National Taiwan University, Taipei, Taiwan, in 1987 and 1991, respectively. From 1987 to1989, he served in the ROC Army Force as a communication officer. In 1992 he joined the faculty of the Department of Electrical Engineering, Tamkang University, where he is now an Professor. He was a visiting scholar at the MIT and University of Illinois, Urbana from 1998 to 1999. His current research interests include microwave imaging, numerical techniques in electromagnetics and indoor wireless communications.Shi-Cheng Hung received the MSEE degree from Tamkang University in 1998. He is now a RF engineer. His current research interests include indoor wireless communications and numerical techniques in electromagnetics.Chien-Hung Lin received the MSEE degree from Tamkang University in 2001. He is now a RF engineer. His current research interests include indoor wireless communications and numerical techniques in electromagnetics. 相似文献
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