共查询到20条相似文献,搜索用时 93 毫秒
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本文研究并设计实现了一种用于浅海水声信道多速率通信的无线/水声通信(racom)浮标,介绍了其水声通信和无线通信技术方案和工程设计与实现。本文设计的浮标综合了水声通信、DSP信号处理和无线电通信等技术,也可以用作水声通信/传感网络中的无线/水声通信(racom)网关节点。海上试验验证了本浮标总体设计方案的可行性。海上试验中,浮标无线通信距离达到15.2 km,误码率不大于10 6;除2 kbps速率外,浮标各种速率的水声通信数据传输误码率都小于1%,最大通信作用距离达到9.6 km;同时,试验也验证了浮标与水下运动平台之间的通信功能。 相似文献
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We study the equalization of the channel for chaotic communication systems.A channel equalizer is designed and realized by a modified recurrent neural network for eliminating channel distortions.The results from computer simulations demonstrate the effectiveness of the equalizer as applied to a chaotic communication system. 相似文献
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设计了工作在太赫兹频段的无线通信系统,基带部分采用16QAM调制体制,射频部分采用混频器实现两级上下变频,功放部分采用固态功率放大+电真空器件放大级联的功率放大技术,实现了0.14 THz频段W量级的功率输出。接收端采用全固态常温接收技术,接收机等效噪声温度为1100 K,接收灵敏度达到-57 dBm。采用两个增益50 dBi的卡塞格伦天线,在成都市双流区与新津县之间开展了距离21 km的无线通信试验,单路实时通信速率达到5 Gbps,误码率低于10-6。并成功同时实时传输了两路符合HD-SDI标准的无压缩高清视频数据流,每一路的标准有效速率达到1.485 Gbps。 相似文献
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X. -M. Xiu L. Dong Y. -J. Gao F. Chi 《Journal of Experimental and Theoretical Physics》2007,105(6):1132-1135
A theoretical scheme of a multiparty-controlled quantum secure direct communication is proposed. The supervisor prepares a
communication network with Einstein-Podolsky-Rosen pairs and auxiliary particles. After passing a security test of the communication
network, a supervisor tells the users the network is secure and they can communicate. If the controllers allow the communicators
to communicate, the controllers should perform measurements and inform the communicators of the outcomes. The communicators
then begin to communicate after they perform a security test of the quantum channel and verify that it is secure. The recipient
can decrypt the secret message in a classical message from the sender depending on the protocol. Any two users in the network
can communicate through the above processes under the control of the supervisor and the controllers.
The text was submitted by the authors in English. 相似文献
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We present a general technique for hiding a classical bit in multipartite quantum states. The hidden bit, encoded in the choice of one of two possible density operators, cannot be recovered by local operations and classical communication without quantum communication. The scheme remains secure if quantum communication is allowed between certain partners, and can be designed for any choice of quantum communication patterns to be secure, but to allow near perfect recovery for all other patterns. No entanglement is needed since the hiding states can be chosen to be separable. A single ebit of prior entanglement is not sufficient to break the scheme. 相似文献
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Quantum secure direct communication with Greenberger-Horne-Zeilinger-type state (GHZ state) over noisy channels 下载免费PDF全文
We propose a quantum error-rejection scheme for direct communication with three-qubit quantum codes based on the direct communication of secret messages without any secret key shared in advance. Given the symmetric and independent errors of the transmitted qubits, our scheme can tolerate a bit of error rate up to 33.1%, thus the protocol is deterministically secure against any eavesdropping attack even in a noisy channel. 相似文献
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Xiao-Ming Xiu Hai-Kuan Dong Li Dong Ya-Jun Gao Feng Chi 《Optics Communications》2009,282(12):2457-2459
A deterministic secure quantum communication scheme using entanglement swapping is proposed. The sender prepares four-particle genuine entangled states and sends two particles in each state to the receiver and remains the rest particles. If the quantum channel is secure, they begin to communicate. After their four-particle projective measurements, the receiver can obtain the secret information according to his measurement outcomes and classical information from the sender. Using entanglement swapping, there are no particles carrying secret information to be transmitted. 相似文献
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We present an (n,n) threshold quantum secret sharing scheme of secure direct communication using Greenberger-Horne-Zeilinger state and teleportation.After ensuring the security of the quantum channel,the sender encodes the secret message directly on a sequence of particle states and transmits it to the receivers by teleportation.The receivers can recover the secret message by combining their measurement results with the sender's result.If a perfect quantum channel is used,our scheme is completely secure because the transmitting particle sequence does not carry the secret message.We also show our scheme is secure for noise quantum channel. 相似文献
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我们提出了一个控制的量子隐形传态方案。在这方案中,发送方Alice 在监督者Charlie的控制下以他们分享的三粒子纠缠态作为量子通道将二能级粒子未知态的量子信息忠实的传给了遥远的接受方Bob。我们还提出了借助此传态的控制的量子安全直接通信方案。在保证量子通道安全的情况下, Alice直接将秘密信息编码在粒子态序列上,并在Charlie控制下用此传态方法传给Bob。Bob可通过测量他的量子位读出编码信息。由于没有带秘密信息的量子位在Alice 和Bob之间传送,只要量子通道安全, 这种通信不会泄露给窃听者任何信息, 是绝对安全的。这个方案的的特征是双方通信需得到第三方的许可。 相似文献
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We propose a novel protocol for quantum secure direct communication with cluster states. In this protocol, the two legitimate users, Alice and Bob, can directly transmit the secret messages by using the Bell-basis measurement and Z-basis measurement, respectively, in classical communication. Since our quantum secure direct communication protocol is based on the cluster state, it is easily processed by a one-way quantum computer. 相似文献
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Chuan-Jia Shan Ji-Bing Liu Tao Chen Tang-Kun Liu Yan-Xia Huang Hong Li 《International Journal of Theoretical Physics》2010,49(2):334-342
In this paper, we proposed an experimentally feasible new scheme for controlled quantum secure direct communication in cavity
quantum electrodynamics without apparent joint Bell-state measurement. According to the results measured by the sender and
the controller, the receiver can obtain different secret messages in a deterministic way using GHZ state as the quantum channel
with unit successful probability if controller cooperates with it. In the communication processes, with the assistance of
a strong classical driving field, the interactions between atoms and a single-mode nonresonant cavity substitute the generalized
joint Bell-basis measurements. So this scheme only need separate measurements. In addition, the scheme is insensitive to the
cavity decay and the thermal field. The discussion of the scheme indicates that it is simple and realizable with present technology. 相似文献
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Based on the famous quantum secure direct communication protocol (i.e., the Boström-Felbinger protocol) [Phys. Rev. Lett. 89 (2002) 187902] and its improvements, we propose a scheme of multiparty quantum secret sharing of classical messages (QSSCM), in which no subset of all the classical message receivers is sufficient to extract the sender’s secret classical messages but all the parties cooperate together. Then we take advantage of this multiparty QSSCM scheme to establish a scheme of multiparty secret sharing of quantum information (SSQI), in which the unknown quantum state in the sender’s qubit can be reconstructed in one receiver’s qubit if and only if all the quantum information receivers collaborate together. 相似文献
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量子保密通信包括量子密钥分发、量子安全直接通信和量子秘密共享等主要形式.在量子密钥分发和秘密共享中,传输的是随机数而不是信息,要再经过一次经典通信才能完成信息的传输.在量子信道直接传输信息的量子通信形式是量子安全直接通信.基于量子隐形传态的量子通信(简称量子隐形传态通信)是否属于量子安全直接通信尚需解释.构造了一个量子隐形传态通信方案,给出了具体的操作步骤.与一般的量子隐形传态不同,量子隐形传态通信所传输的量子态是计算基矢态,大大简化了贝尔基测量和单粒子操作.分析结果表明,量子隐形传态通信等价于包含了全用型量子密钥分发和经典通信的复合过程,不是量子安全直接通信,其传输受到中间介质和距离的影响,所以不比量子密钥分发更有优势.将该方案与量子密钥分发、量子安全直接通信和经典一次性便笺密码方案进行对比,通过几个通信参数的比较给出各个方案的特点,还特别讨论了各方案在空间量子通信方面的特点. 相似文献