College of Engineering and Computing
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Browsing College of Engineering and Computing by Subject "5G"
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Item Improving Physical Layer Group Key Generation Efficiency in 5G Wireless NetworksJiao, Long; Jiao, Long; Zeng, KaiIn this thesis, we investigate the scheme to improve the group secret key generation efficiency in 5G mmWave Massive MIMO networks by enhancing the efficiency of channel probing for group key generation. A new channel probing strategy for star-topology networks group key generation is proposed, which focuses on multiplexing of downlink probing signals to perform the downlink channel probing concurrently. The hybrid precoder has been considered in this scenario to mitigate the inter-group interference, which includes a analog precoder and baseband precoder. To further balance the group key rates, a genetic algorithm (GA) based power allocation algorithm is developed to allocate more power to the nodes with unfavorable channel conditions. What's more, we propose a scheme to estimate group key rates based on the maximum likelihood estimator (MLE) so that we can estimate the group key rates based on the probing samples. Various numerical results are provided including the group key rates and bits disagreement ratio (BDR). The numerical results show that the GA-based downlink channel probing scheme can increase the efficiency of channel probing and have higher group key rates compared with the existing channel probing schemes. When the SNR is 25dB, the key rates of GA-based power allocation scheme are 20% higher than the scheme with the conventional channel probing strategy.Item Security Through Frequency Diversity in The 5G NR StandardWeitz, Joshua D; Mark, BrianThis thesis explores the use of pseudo-random frequency hopping for added security in the 5G New Radio specification. Frequency hopping makes it more difficult for an attacker to intercept, detect, or jam a wireless connection in a 5G network. Current 5G resource allocation options are examined, and the state-of-the-art literature regarding Orthogonal Frequency Division Multiple Access (OFDMA) frequency hopping under various channel conditions is reviewed. Computer simulations were conducted to compare the throughput performance of the frequency hopping technique vs. static resource allocation. It is shown that under certain channel conditions and power allocation schemes, the aggregate user throughput under frequency hopping is within 95% of that of static allocation, although less under more realistic power allocations, while the probabilities of intercept and detection is significantly reduced.