融入纠错编码的认知无线电物理层安全认证研究
发布时间：2018-10-17 14:07
【摘要】：认知无线电技术,是为了解决无线频谱资源短缺以及通信标准的多样化等问题提出的有效方案。在认知无线电网络系统中,主用户的优先级别最高,次用户只有在主用户未占用信道的空闲时段可以以某种“机会”的方式暂时取代主用户利用频谱空洞在信道中传输数据。当主用户需要重新使用信道时,次用户必须马上撤出,因此攻击者常常模仿主用户信号非法占用信道。为了解决主用户攻击的问题,需要在用户接入信道前对用户身份进行认证。现代无线通信系统中,若在上层通信网络中对信号进行认证需要对信号进行复杂的解析操作,效率低、速率慢且没有必要,而物理层认证技术很好的解决了这一问题。它利用Hash函数的单向性来有效解决主用户认证问题,同时通过物理层低速率传输实现认证的隐藏传输,最大限度降低对合法用户的干扰,保证通信双方是其所声称的身份,防止非法用户的接入与访问。本文主要研究了认知无线电物理层安全认证中嵌入认证标签的两种方法:寄生调制方法与寄生纠错编码方法(ECC)。本论文的主要研究工作和创新如下:(1)首先研究了认知无线电物理层安全认证中的调制方案。从信道纠错编码的角度探讨认知无线电寄生认证信道的容量。通过推导认证信道的对数似然比,给出了其简化计算方式,分析与仿真结果表明:简化计算与严格计算结果相仿,因而认证信道可等效为二元输入的加性高斯白噪声(BI-AWGN)信道;(2)在调制方案中,基于对数似然比的简化形式,通过置信度传播迭代译码,考察了融入LDPC纠错机制的认证信道实际传输性能。仿真结果表明:简化译码的结果与理想BI-AWGN的译码性能无法区分。研究结论:认知无线电寄生认证信道可严格等效为BI-AWGN信道,因而可采用BI-AWGN信道设计的纠错编码来有效逼近寄生认证信道的传输极限。(3)研究了认知无线电物理层安全认证中的编码方案,首先对认证标签进行编码,再嵌入同样经过信道编码的信息中;并对比了RS编码与LDPC编码两种编码方式在不同的信道上传输的误码率性能,分析结果表明:采用LDPC编码比RS编码性能更为优越。(4)从误码率性能与认证标签传输速率关系角度出发,分析比较了寄生调制与寄生编码这两种方案性能的优劣。本文分析结果表明:在同等误码率与信噪比的条件下,寄生调制方案标签传输所需的时间要远远低于寄生编码方案标签传输所需的时间,由此可以得出寄生调制方案要优于寄生纠错编码方案的结论。
[Abstract]:Cognitive radio technology is an effective solution to the shortage of wireless spectrum resources and the diversification of communication standards. In cognitive radio networks, primary users have the highest priority, and secondary users can temporarily replace primary users by using spectral holes to transmit data in the channel only in the idle time when the primary user does not occupy the channel. When the primary user needs to reuse the channel, the secondary user must withdraw immediately, so the attacker often imitates the primary user signal to illegally occupy the channel. In order to solve the problem of primary user attack, it is necessary to authenticate the user's identity before the user accesses the channel. In modern wireless communication system, if the signal is authenticated in the upper layer communication network, the signal needs complex parsing operation, which is inefficient, slow and unnecessary, and the physical layer authentication technology solves this problem very well. It makes use of the unidirectionality of Hash function to solve the problem of primary user authentication effectively. At the same time, it realizes the hidden transmission of authentication through physical layer low rate transmission, reduces the interference to legitimate users to the maximum extent, and ensures that both sides of communication are their claimed identities. Prevent illegal user access and access. This paper mainly studies two methods of embedding authentication tags in physical layer security authentication of cognitive radio: parasitic modulation method and parasitic error correction coding method (ECC). The main work and innovations of this thesis are as follows: (1) the modulation scheme in the physical layer security authentication of cognitive radio is studied firstly. The capacity of parasitic authentication channel of cognitive radio is discussed from the point of view of channel error correction coding. By deducing the logarithmic likelihood ratio of authentication channel, the simplified calculation method is given. The results of analysis and simulation show that the simplified calculation is similar to the rigorous calculation. Therefore, the authentication channel can be equivalent to an additive Gao Si white noise (BI-AWGN) channel with binary input. (2) in the modulation scheme, iterative decoding is propagated by confidence based on the simplified form of log-likelihood ratio. The actual transmission performance of authentication channel with LDPC error correction mechanism is investigated. The simulation results show that the simplified decoding results can not be distinguished from the decoding performance of ideal BI-AWGN. Conclusion: the parasitic authentication channel of cognitive radio can be strictly equivalent to BI-AWGN channel. Therefore, the error-correcting coding designed by BI-AWGN channel can be used to effectively approximate the transmission limit of parasitic authentication channel. (3) the coding scheme in the physical layer of cognitive radio authentication is studied. Firstly, the authentication label is coded. Then we embed the same channel coded information, and compared the BER performance of RS coding and LDPC coding on different channels. The analysis results show that the performance of LDPC coding is better than that of RS coding. (4) the performance of parasitic modulation scheme and parasitic coding scheme are analyzed and compared from the point of view of the relationship between bit error rate (BER) performance and the transmission rate of authentication tag. The results show that under the same BER and SNR, the time required for tag transmission of parasitic modulation scheme is much lower than that for tag transmission in parasitic coding scheme. It is concluded that the parasitic modulation scheme is superior to the parasitic error correction coding scheme.
【学位授予单位】：南京邮电大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN925
本文编号：2276912
[Abstract]:Cognitive radio technology is an effective solution to the shortage of wireless spectrum resources and the diversification of communication standards. In cognitive radio networks, primary users have the highest priority, and secondary users can temporarily replace primary users by using spectral holes to transmit data in the channel only in the idle time when the primary user does not occupy the channel. When the primary user needs to reuse the channel, the secondary user must withdraw immediately, so the attacker often imitates the primary user signal to illegally occupy the channel. In order to solve the problem of primary user attack, it is necessary to authenticate the user's identity before the user accesses the channel. In modern wireless communication system, if the signal is authenticated in the upper layer communication network, the signal needs complex parsing operation, which is inefficient, slow and unnecessary, and the physical layer authentication technology solves this problem very well. It makes use of the unidirectionality of Hash function to solve the problem of primary user authentication effectively. At the same time, it realizes the hidden transmission of authentication through physical layer low rate transmission, reduces the interference to legitimate users to the maximum extent, and ensures that both sides of communication are their claimed identities. Prevent illegal user access and access. This paper mainly studies two methods of embedding authentication tags in physical layer security authentication of cognitive radio: parasitic modulation method and parasitic error correction coding method (ECC). The main work and innovations of this thesis are as follows: (1) the modulation scheme in the physical layer security authentication of cognitive radio is studied firstly. The capacity of parasitic authentication channel of cognitive radio is discussed from the point of view of channel error correction coding. By deducing the logarithmic likelihood ratio of authentication channel, the simplified calculation method is given. The results of analysis and simulation show that the simplified calculation is similar to the rigorous calculation. Therefore, the authentication channel can be equivalent to an additive Gao Si white noise (BI-AWGN) channel with binary input. (2) in the modulation scheme, iterative decoding is propagated by confidence based on the simplified form of log-likelihood ratio. The actual transmission performance of authentication channel with LDPC error correction mechanism is investigated. The simulation results show that the simplified decoding results can not be distinguished from the decoding performance of ideal BI-AWGN. Conclusion: the parasitic authentication channel of cognitive radio can be strictly equivalent to BI-AWGN channel. Therefore, the error-correcting coding designed by BI-AWGN channel can be used to effectively approximate the transmission limit of parasitic authentication channel. (3) the coding scheme in the physical layer of cognitive radio authentication is studied. Firstly, the authentication label is coded. Then we embed the same channel coded information, and compared the BER performance of RS coding and LDPC coding on different channels. The analysis results show that the performance of LDPC coding is better than that of RS coding. (4) the performance of parasitic modulation scheme and parasitic coding scheme are analyzed and compared from the point of view of the relationship between bit error rate (BER) performance and the transmission rate of authentication tag. The results show that under the same BER and SNR, the time required for tag transmission of parasitic modulation scheme is much lower than that for tag transmission in parasitic coding scheme. It is concluded that the parasitic modulation scheme is superior to the parasitic error correction coding scheme.
【学位授予单位】：南京邮电大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN925
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