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一种AM调幅—2FSK调频通信系统的研究 被引量:4
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作者 何婕 何小海 +1 位作者 滕奇志 罗代升 《信息与电子工程》 2004年第1期21-25,共5页
介绍了AM(standard amplitude modulation)和2FSK(binary frequency-shift keying)的基本原理,提出了把二者结合起来的双重调制技术用于同时进行语音和数据的无线传输。在接收端用AM接收机解调AM语音信号,用内加的MC3362解调FM数据信号... 介绍了AM(standard amplitude modulation)和2FSK(binary frequency-shift keying)的基本原理,提出了把二者结合起来的双重调制技术用于同时进行语音和数据的无线传输。在接收端用AM接收机解调AM语音信号,用内加的MC3362解调FM数据信号,达到了二媒体同时通信的目的。 展开更多
关键词 AM调幅 2FSK 调频通信 标准调幅 二进制频移键控 双重调制技术 数据传输
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调频通信射频功放模块的实现途径
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作者 胡四章 胥陆军 《移动通信》 北大核心 1995年第5期27-30,共4页
本文介绍了一种超短波调幅航空通信电台发射机用的放大器的性能指标,并从总体上论述了其实现途径。
关键词 调频通信 射频功率放大器 模块 发射机
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基于NFM-BOK波形的低检测概率通信技术 被引量:1
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作者 孙志国 沙钰彭 宁晓燕 《系统工程与电子技术》 EI CSCD 北大核心 2023年第12期4030-4039,共10页
针对以直接序列扩频(direct sequence spread spectrum,DSSS)和切普扩频(chirp spread spectrum,CSS)为代表,现有低检测概率(low probability of detection,LPD)通信波形变换域聚敛特征明显、影响LPD性能的问题,以满足误码率(bit error ... 针对以直接序列扩频(direct sequence spread spectrum,DSSS)和切普扩频(chirp spread spectrum,CSS)为代表,现有低检测概率(low probability of detection,LPD)通信波形变换域聚敛特征明显、影响LPD性能的问题,以满足误码率(bit error rate,BER)需求的信噪比下通信波形变化域聚敛特征最小化为目标,提出一种新型LPD通信方法——以噪声调频(noise frequency modulation,NFM)为波形基、以二进制正交键控(binary orthogonal keying,BOK)为信息载荷方式的NFM-BOK通信技术。以直接序列——二进制相移键控(direct sequence-binary phase shift keying,DS-BPSK)为对比对象,在给出NFM-BOK通信技术方案的基础上,着重研究了所提NFM-BOK的BER性能、功率谱域和循环相关域内的聚敛特征。理论分析和仿真结果表明:相较于DS-BPSK,NFM-BOK通信系统的抗噪性能相近,相同BER对应的信噪比下的功率谱域和循环相关域内的聚敛特征显著降低。 展开更多
关键词 低检测概率 噪声调频通信 功率谱检测 循环谱检测 聚敛系数
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弱信号下的调频数据通信
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作者 黄超 周绮丽 《移动通信》 1998年第3期21-23,共3页
本文介绍了针对较弱信号时FM接收机鉴频器输出脉冲噪声的特点,采用二次调制、话音子带编码、分集接收等综合措施,在信号低于接收机灵敏度时进行可靠的数据通信,为山区无线数据通信提供一种可行的方法。
关键词 子带编码 分集接收 调频通信 数据通信
全文增补中
变容管调相式间接调频及频偏扩展
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作者 刘祖刚 曾梅香 《高等函授学报(自然科学版)》 1999年第6期9-12,共4页
关键词 间接调频 频偏扩展 调频通信 变容管相电路
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1.2GHz 2瓦直接锁相调频发射机
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作者 张溥 廖向东 《微波与卫星通信》 1995年第3期32-34,共3页
本文介绍了1.2GHz2瓦直接锁相调频发射机的。作原理、电路组成和设计方法。
关键词 锁相 发射机 调频发射机 调频通信
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短波战术跳频通信系统的技术现状和发展 被引量:1
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作者 李海明 《科技与生活》 2010年第18期25-25,共1页
随着世界经济的发展,通信技术已经成为世界各国不断开拓研发的行业,目前,西方发达国家从全球战略的高度出发,不断深入对短波战术调频通信技术的研究,战术无线通信系统得到快速发展。与此同时,为完善军事力量,我国在短波通信技术... 随着世界经济的发展,通信技术已经成为世界各国不断开拓研发的行业,目前,西方发达国家从全球战略的高度出发,不断深入对短波战术调频通信技术的研究,战术无线通信系统得到快速发展。与此同时,为完善军事力量,我国在短波通信技术上也取得重大突破。介绍国外短波通信的发展动态以及我国的发展现状。 展开更多
关键词 短波 调频通信技术 战术使用
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边带抑制式低载频调频通讯系统初探
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作者 荆丙礼 王永民 《空军电讯工程学院学报》 1995年第2期51-55,共5页
为了改进有广播和通讯系统的不足,本文初步探讨了边带抑制式窄调频通讯系统方案,并对边频恢复做了数学推证。
关键词 低载频 边带抑制 调频通信系统 通信系统
全文增补中
基于无线通信的灾害环境参数模拟系统
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作者 陈迪 李孝揆 《陕西煤炭》 2013年第5期27-28,48,共3页
介绍了基于无线通信的培训演练系统用灾害环境参数模拟系统的设计,并对灾害环境参数模拟系统的硬件和软件设计,进行了简要叙述和分析。
关键词 训练系统 环境参数模拟 调频通信 灾害处置
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脉冲调频
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作者 黄贯光 《电信科学》 1959年第9期28-29,共2页
由于调频通信或广播系統的抗干扰性强,保真度大,它的应用已經相当广泛,但是,一般采用电抗管的直接調频方式或是从調相间接获得调频的方式,往往不能滿足近代通信和广播的技术要求,因此又发展了脉冲調频的方法。这一方法。
关键词 脉冲调频 调频通信 正脉冲 抗干扰性 技术要求 窄脉冲 脉冲产生 脉冲放大器 脉冲波 脉位
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Performance analysis of graph-based scheduling for device-to-device communications overlaying cellular networks
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作者 杜鹏 张源 《Journal of Southeast University(English Edition)》 EI CAS 2016年第3期272-277,共6页
The performance of the graph-based scheduling for device-to-device communications overlaying cellular networks is studied. The graph-based scheduling consists of two stages, the frequency assignment stage and the time... The performance of the graph-based scheduling for device-to-device communications overlaying cellular networks is studied. The graph-based scheduling consists of two stages, the frequency assignment stage and the time slot scheduling stage. For such scheduling, a theoretical method to analyze the average spectrum efficiency of the D2D subsystem is proposed. The method consists of three steps. First, the frequency assignment stage is analyzed and the approximate formula of the average number of the D2D links which are assigned the same frequency is derived. Secondly, the time slot scheduling stage is analyzed and the approximate formula of the average probability of a D2D link being scheduled in a time slot is derived. Thirdly, the average spectrum efficiency of the D2D subsystem is analyzed and the corresponding approximate formula is derived. Analysis results show that the average spectrum efficiency of the D2D subsystem is approximately inversely linearly proportional to the second- order origin moment of the normalized broadcast radius of D2D links. Simulation results show that the proposed method can correctly predict the average spectrum efficiency of the D2D subsystem. 展开更多
关键词 CELLULAR device-to-device (D2D) communication GRAPH SCHEDULING spectrum efficiency
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无线比例遥控系统
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作者 李勇 《计算机测量与控制》 CSCD 2002年第4期258-259,266,共3页
介绍一种实用的、无线遥控方式的、线性遥控系统。文章阐明了它是一个理论上严密的线性控制系统。不用A/D、D/A、MCU等成本较高的系统组成,用它可节约线缆成本。
关键词 无线比例遥控系统 比例编码 比例遥控 调频通信
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一种多址差分跳频系统
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作者 赵松(译) 曾锦祥(校) 《电信技术研究》 2005年第12期45-50,共6页
军用通信系统要求波形在遭遇干扰信号时具有灵活性(比如抗干扰(AJ)),对非预期接收机具有低检测概率(LPD),对敌对接收机具有低截获概率(LPI),并且还能使多个授权用户通信流畅。当前的扩频通信技术,如标准的跳频(FH)和直接... 军用通信系统要求波形在遭遇干扰信号时具有灵活性(比如抗干扰(AJ)),对非预期接收机具有低检测概率(LPD),对敌对接收机具有低截获概率(LPI),并且还能使多个授权用户通信流畅。当前的扩频通信技术,如标准的跳频(FH)和直接序列扩频(DSSS)在同时具有AJ、LPD和LPI性能要求的情况下,实现起来并非易事。新近提出的多址差分跳频通信系统与现用的扩频技术相比具有更好的AJ和LPD性能。此外,该方法还能容易地实现有效检测并解译自组织网络中的多个(干扰)用户。初步分析和仿真结果表明性能已得到改善。 展开更多
关键词 多址差分调频 调频通信 DFH
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A novel M-ary modulation technique based on optimal chirp signal design
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作者 孟繁宇 Gu Xuemai Guo Qing 《High Technology Letters》 EI CAS 2012年第4期357-363,共7页
A novel M-ary chirp modulation technique based on an optimal chirp signal design is proposed in this paper to offer higher data rate for an indoor wireless chirp spread spectrum communication system. Both linear chirp... A novel M-ary chirp modulation technique based on an optimal chirp signal design is proposed in this paper to offer higher data rate for an indoor wireless chirp spread spectrum communication system. Both linear chirp signals and combined chirp signals are used in this system to reduce the effect of the cross correlation, and simplify the complexity of the system. The optimal scheme of de- signing both linear chirp signals and combined chirp signals is discussed to minimize the value of the cross correlation and obtain a better system performance. Simulation results show that, compared with the binary orthogonal chirp modulation technique, the M-ary chirp modulation technique based on an optimal chirp signal set has a higher data rate with a reasonable bit-error rate (BER) perform- ance under both additive white gaussian noise (AWGN) channel and indoor wireless channel. 展开更多
关键词 M-ary modulation chirp spread spectrum combined chirp signal indoor wirelesschannel
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High Sensitivity Acquisition Algorithm for DSSS Signal with Data Modulation 被引量:3
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作者 SHEN Yuyao WANG Yongqing +1 位作者 CHEN Jingyao WU Siliang 《China Communications》 SCIE CSCD 2015年第4期76-85,共10页
In direct sequence spread spectrum communication both for satelliteto-ground and inter-satellite links, the system constrains due to radio frequency spectral occupation, channel data throughput and link performances i... In direct sequence spread spectrum communication both for satelliteto-ground and inter-satellite links, the system constrains due to radio frequency spectral occupation, channel data throughput and link performances in terms of data channel coding which might result in a signal structure where the symbol duration is shorter than the pseudo code period. This can generate some difficulties in the DSSS signal acquisition due to the polarity inversion caused by the data modulation. To eliminate the influence due to polarity inversion, this paper proposes a novel acquisition algorithm based on the simultaneous search of the code phase, data phase and Doppler frequency. In the proposed algorithm the data phase is predicted and the correlation period for the coherent integration can be set equal to the symbol duration. Then non-coherent accumulation over different symbol is implemented in order to enhance the acquisition algorithm sensitivity; the interval of non-coherent accumulation is the least common multiple between the symbol duration and the pseudo code period. The algorithm proposed can largely minimize the SNR loss caused by data polarity inversion and enhance acquisition performance without a noticeable increase in hardware complexity. Theoretical analysis, simulation and measured results verify the validity of the algorithm. 展开更多
关键词 DSSS signal acquisition dataphase prediction data polarity inversion segment search high sensitivity
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An ultraviolet laser communication system using frequency-shift keying modulation scheme
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作者 彭帝永 施军 +4 位作者 彭光辉 肖沙里 徐山河 王珊 刘锋 《Optoelectronics Letters》 EI 2015年第1期65-68,共4页
A communication system based on an ultraviolet(UV) laser at 266 nm is presented to improve the communication distance. The pulse frequency-shift keying(FSK) modulation scheme is studied and improved in order to reduce... A communication system based on an ultraviolet(UV) laser at 266 nm is presented to improve the communication distance. The pulse frequency-shift keying(FSK) modulation scheme is studied and improved in order to reduce the bit error rate(BER), and is put into practice on a field programmable gate array(FPGA). The mathematical models of the modulation and demodulation are established. A test platform is set up to measure the energy density and pulse response under different distances and receiver elevation angles. It is shown that the omnibearing communication can be realized, and the bit rate is limited to 12.5 Mbit/s. The BER is estimated to be less than 10-7 at distance of 300 m in line-of-sight(LOS) communication model and to be less than 10-6 at distance of 80 m in non-line-of-sight(NLOS) communication model. 展开更多
关键词 diaphragm silica potentially modulus trough preferred Fabry fabrication length fringe
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