{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,12]],"date-time":"2025-10-12T03:37:17Z","timestamp":1760240237783,"version":"build-2065373602"},"reference-count":45,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2019,4,22]],"date-time":"2019-04-22T00:00:00Z","timestamp":1555891200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["61471393","61771487"],"award-info":[{"award-number":["61471393","61771487"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Entropy"],"abstract":"<jats:p>Millimeter-wave (mmWave) communication is one of the key enabling technologies for fifth generation (5G) mobile networks. In this paper, we study the problem of secure communication in a mmWave wiretap network, where directional beamforming and link blockages are taken into account. For the secure transmission in the presence of spatially random eavesdroppers, an adaptive transmission scheme is adopted, for which sector secrecy guard zone and artificial noise (AN) are employed to enhance secrecy performance. When there exists no eavesdroppers within the sector secrecy guard zone, the transmitter only transmits information-bearing signal, and, conversely, AN along with information-bearing signal are transmitted. The closed-form expressions for secrecy outage probability (SOP), connection outage probability (COP) and secrecy throughput are derived under stochastic geometry. Then, we evaluate the effect of the sector secrecy guard zone and AN on the secrecy performance. Our results reveal that the application of the sector secrecy guard zone and AN can significantly improve the security of the system, and blockages also can be utilized to improve secrecy performance. An easy choice of transmit power and power allocation factor is provided for achieving higher secrecy throughput. Furthermore, increasing the density of eavesdroppers not always deteriorates the secrecy performance due to the use of the sector secrecy guard zone and AN.<\/jats:p>","DOI":"10.3390\/e21040427","type":"journal-article","created":{"date-parts":[[2019,4,22]],"date-time":"2019-04-22T11:02:53Z","timestamp":1555930973000},"page":"427","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["Secure Transmission in mmWave Wiretap Channels: On Sector Guard Zone and Blockages"],"prefix":"10.3390","volume":"21","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-1999-627X","authenticated-orcid":false,"given":"Yi","family":"Song","sequence":"first","affiliation":[{"name":"College of Communications Engineering, Army Engineering University of PLA, No. 88 Houbiaoying, Qinhuai District, Nanjing 210007, China"},{"name":"School of Physics and Electronic Electrical Engineering, Huaiyin Normal University, Huai\u2019an 223300, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Weiwei","family":"Yang","sequence":"additional","affiliation":[{"name":"College of Communications Engineering, Army Engineering University of PLA, No. 88 Houbiaoying, Qinhuai District, Nanjing 210007, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6510-6103","authenticated-orcid":false,"given":"Zhongwu","family":"Xiang","sequence":"additional","affiliation":[{"name":"College of Communications Engineering, Army Engineering University of PLA, No. 88 Houbiaoying, Qinhuai District, Nanjing 210007, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yiliang","family":"Liu","sequence":"additional","affiliation":[{"name":"Communications Research Center, Harbin Institute of Technology, Harbin 150001, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yueming","family":"Cai","sequence":"additional","affiliation":[{"name":"College of Communications Engineering, Army Engineering University of PLA, No. 88 Houbiaoying, Qinhuai District, Nanjing 210007, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2019,4,22]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"101","DOI":"10.1109\/MCOM.2011.5783993","article-title":"An Introduction to Millimeter-Wave Mobile Broadband Systems","volume":"49","author":"Pi","year":"2011","journal-title":"IEEE Commun. Mag."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"366","DOI":"10.1109\/JPROC.2014.2299397","article-title":"Millimeter Wave Cellular Wireless Networks: Potentials and Challenges","volume":"102","author":"Rangan","year":"2014","journal-title":"Proc. IEEE"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"2059","DOI":"10.1109\/TVT.2016.2578943","article-title":"Millimeter-Wave Secrecy Beamforming Designs for Two-Way Amplify-and-Forward MIMO Relaying Networks","volume":"66","author":"Gong","year":"2017","journal-title":"IEEE Trans. Veh. Technol."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"70","DOI":"10.1109\/MCOM.2014.6894455","article-title":"Coverage and Capacity of Millimeter-Wave Cellular Networks","volume":"52","author":"Bai","year":"2014","journal-title":"IEEE Commun. Mag."},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Bai, T., and Heath, R.W. (2013, January 3\u20135). Coverage Analysis for Millimeter Wave Cellular Networks with Blockage Effects. Proceedings of the 2013 IEEE Global Conference on Signal and Information Processing, Austin, TX, USA.","DOI":"10.1109\/GlobalSIP.2013.6736994"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"32681","DOI":"10.1109\/ACCESS.2019.2898180","article-title":"Secure On-Off Transmission in MmWave Systems with Randomly Distributed Eavesdroppers","volume":"7","author":"Yang","year":"2019","journal-title":"IEEE Access"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"347","DOI":"10.1109\/COMST.2016.2598968","article-title":"Physical Layer Security for Next Generation Wireless Networks: Theories, Technologies, and Challenges","volume":"19","author":"Liu","year":"2017","journal-title":"IEEECommun. Surv. Tutor."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Xiang, Z., Yang, W., Pan, G., Cai, Y., and Song, Y. (2019). Physical Layer Security in Cognitive Radio Inspired NOMA Network. IEEE J. Sel. Top. Signal Process., 1\u201314.","DOI":"10.1109\/JSTSP.2019.2902103"},{"key":"ref_9","first-page":"2035","article-title":"Secrecy Outage Analysis of Buffer-Aided Cooperative MIMO Relaying Systems","volume":"67","author":"Tang","year":"2018","journal-title":"IEEE Trans. Veh. Technol."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"212","DOI":"10.1109\/TIFS.2018.2848630","article-title":"Energy-Constrained SWIPT Networks: Enhancing Physical Layer Security With FD Self-Jamming","volume":"14","author":"Tang","year":"2019","journal-title":"IEEE Trans. Inf. Forensics Secur."},{"key":"ref_11","doi-asserted-by":"crossref","unstructured":"Jameel, F., Wyne, S., Kaddoum, G., and Duong, T.Q. (2018). A Comprehensive Survey on Cooperative Relaying and Jamming Strategies for Physical Layer Security. IEEE Commun. Surv. Tuts.","DOI":"10.1109\/COMST.2018.2865607"},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"3088","DOI":"10.1109\/TIT.2010.2048445","article-title":"Secure Transmission with Multiple Antennas II: The MIMOME Wiretap Channel","volume":"56","author":"Khisti","year":"2010","journal-title":"IEEE Trans. Inf. Theory"},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"1817","DOI":"10.1109\/TIFS.2018.2885286","article-title":"Secure Transmissions in Wireless Information and Power Transfer Millimeter Wave Ultra-dense Networks","volume":"14","author":"Sun","year":"2019","journal-title":"IEEE Trans. Inf. Forensics Secur."},{"key":"ref_14","doi-asserted-by":"crossref","unstructured":"Xiang, Z., Yang, W., Pan, G., Cai, Y., and Sun, X. (2019). Secure Transmission in Non-Orthogonal Multiple Access Networks with an Untrusted Relay. IEEE Commun. Lett. (Early Access).","DOI":"10.1109\/LWC.2019.2899309"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"1771","DOI":"10.1109\/TCOMM.2015.2419634","article-title":"Artificial Noise: Transmission Optimization in Multi-Input Single-Output Wiretap Channels","volume":"63","author":"Yang","year":"2015","journal-title":"IEEE Trans. Commun."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"1628","DOI":"10.1109\/LCOMM.2012.081612.121344","article-title":"Secure Communication via Sending Artificial Noise by the Receiver: Outage Secrecy Capacity\/Region Analysis","volume":"16","author":"Li","year":"2012","journal-title":"IEEE Commun. Lett."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"487","DOI":"10.1109\/LSP.2013.2252898","article-title":"PHY Layer Security Based on Protected Zone and Artificial Noise","volume":"20","author":"Mclernon","year":"2013","journal-title":"IEEE Signal Process. Lett."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1617","DOI":"10.1109\/TIFS.2014.2341453","article-title":"Enhanced Secrecy in Stochastic Wireless Networks: Artificial Noise With Secrecy Protected Zone","volume":"9","author":"Chae","year":"2014","journal-title":"IEEE Trans. Inf. Forensics Secur."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"373","DOI":"10.1109\/TIFS.2015.2500178","article-title":"Secure Transmission Design for Cognitive Radio Networks With Poisson Distributed Eavesdroppers","volume":"11","author":"Xu","year":"2016","journal-title":"IEEE Trans. Inf. Forensics Secur."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"3231","DOI":"10.1109\/TCOMM.2013.061013.120459","article-title":"Antenna Subset Modulation for Secure Millimeter-wave Wireless Communication","volume":"61","author":"Valliappan","year":"2013","journal-title":"IEEE Trans. Commun."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"20","DOI":"10.1109\/MCOM.2015.7081071","article-title":"Safeguarding 5G Wireless Communication Networks Using Physical Layer Security","volume":"53","author":"Yang","year":"2015","journal-title":"IEEE Commun. Mag."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"6664","DOI":"10.1109\/TWC.2015.2457921","article-title":"Directional Cell Discovery in Millimeter Wave Cellular Networks","volume":"14","author":"Barati","year":"2015","journal-title":"IEEE Trans. Wirel. Commun."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"3507","DOI":"10.1109\/TCOMM.2016.2587287","article-title":"An Analysis on Secure Communication in Millimeter\/Micro-Wave Hybrid Networks","volume":"64","author":"Vuppala","year":"2016","journal-title":"IEEE Trans. Commun."},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Wang, L., Elkashlan, M., Duong, T.Q., and Heath, R.W. (2014, January 22\u201325). Secure Communication in Cellular Networks: The Benefits of Millimeter Wave Mobile Bbroadband. Proceedings of the 2014 IEEE 15th International Workshop on Signal Processing Advances in Wireless Communications (SPAWC), Toronto, ON, Canada.","DOI":"10.1109\/SPAWC.2014.6941328"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"5569","DOI":"10.1109\/TWC.2016.2562010","article-title":"Physical Layer Security in Millimeter Wave Cellular Networks","volume":"15","author":"Wang","year":"2016","journal-title":"IEEE Trans. Wirel. Commun."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"3205","DOI":"10.1109\/TWC.2017.2676087","article-title":"Secure Communications in Millimeter Wave Ad Hoc Networks","volume":"16","author":"Zhu","year":"2017","journal-title":"IEEE Trans. Wirel. Commun."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"2114","DOI":"10.1109\/TCOMM.2017.2672661","article-title":"Secure Transmissions in Millimeter Wave Systems","volume":"65","author":"Ju","year":"2017","journal-title":"IEEE Trans. Commun."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"1802","DOI":"10.1109\/TIFS.2013.2279842","article-title":"Enhancing Secrecywith Multi-Antenna Transmission in Wireless Ad Hoc Networks","volume":"8","author":"Zhang","year":"2013","journal-title":"IEEE Trans. Inf. Forensics Secur."},{"key":"ref_29","first-page":"403","article-title":"Modeling and Analyzing Millimeter Wave Cellular Systems","volume":"65","author":"Andrews","year":"2017","journal-title":"IEEE Trans. Commun."},{"key":"ref_30","doi-asserted-by":"crossref","unstructured":"Song, Y., Yang, W., Xiang, Z., and Cai, Y. (2018, January 18\u201320). Secure Transmission Design of Millimeter-Wave Wiretap Channel with Guard Zone and Artificial Noise. Proceedings of the 2018 International Conference on Wireless Communications and Signal Processing (WCSP 2018), Hangzhou, China.","DOI":"10.1109\/WCSP.2018.8555904"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"1239","DOI":"10.1109\/JSAC.2014.2328173","article-title":"Joint Spatial Division and Multiplexing for mm-Wave Channels","volume":"32","author":"Adhikary","year":"2014","journal-title":"IEEE J. Sel. Areas Commun."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"1100","DOI":"10.1109\/TWC.2014.2364267","article-title":"Coverage and Rate Analysis for Millimeter Wave Cellular Networks","volume":"14","author":"Bai","year":"2015","journal-title":"IEEE Trans. Wirel. Commun."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"11654","DOI":"10.1109\/TVT.2018.2872884","article-title":"Secrecy Analysis of Random MIMO Wireless Networks Over \u03b1-\u03bc Fading Channels","volume":"67","author":"Kong","year":"2018","journal-title":"IEEE Trans. Veh. Technol."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"1139","DOI":"10.1109\/TCOMM.2017.2776944","article-title":"On the Physical Layer Security Analysis of Hybrid Millimeter Wave Networks","volume":"66","author":"Vuppala","year":"2018","journal-title":"IEEE Trans. Commun."},{"key":"ref_35","first-page":"4463","article-title":"Coverage in Heterogeneous Downlink Millimeter Wave Cellular Networks","volume":"65","author":"Turgut","year":"2017","journal-title":"IEEE Trans. Commun."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"2706","DOI":"10.1109\/JSAC.2016.2605901","article-title":"On the Secure Spectral-Energy Efficiency Tradeoff in Random Cognitive Radio Networks","volume":"34","author":"Xu","year":"2016","journal-title":"IEEE J. Sel. Areas Commun."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"1575","DOI":"10.1109\/TIT.2009.2013043","article-title":"On the Throughput of Secure Hybrid-ARQ Protocols for Gaussian Block-fading Channels","volume":"55","author":"Tang","year":"2009","journal-title":"IEEE Trans. Inf. Theory"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"6913","DOI":"10.1109\/TWC.2016.2593445","article-title":"On Secrecy Metrics for Physical Layer Security Over Quasi-Static Fading Channels","volume":"15","author":"He","year":"2016","journal-title":"IEEE Trans. Wirel. Commun."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"9577","DOI":"10.1109\/TVT.2017.2703159","article-title":"Artificial noise injection for securing single-antenna systems","volume":"66","author":"He","year":"2017","journal-title":"IEEE Trans. Veh. Technol."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"2717","DOI":"10.1109\/TCOMM.2013.050713.120730","article-title":"Power allocation and time-domain artificial noise design for wiretap OFDM with discrete inputs","volume":"12","author":"Qin","year":"2013","journal-title":"IEEE Trans. Wirel. Commun."},{"key":"ref_41","doi-asserted-by":"crossref","unstructured":"Akitaya, T., Asano, S., and Saba, T. (2014, January 10\u201314). Time-domain artificial noise generation technique using time-domain and frequency-domain processing for physical layer security in MIMO-OFDM systems. Proceedings of the 2014 IEEE International Conference on Communications Workshops (ICC), Sydney, NSW, Australia.","DOI":"10.1109\/ICCW.2014.6881299"},{"key":"ref_42","unstructured":"Gradshteyn, I.S., and Ryzhik, I.M. (2007). Table of Integrals, Series, and Products, Academic Press. [7th ed.]."},{"key":"ref_43","doi-asserted-by":"crossref","unstructured":"Baccelli, F., and Baszczyszyn, B. (2009). Stochastic Geometry and Wireless Networks, Volume II: Applications, Now Publishers Inc.","DOI":"10.1561\/9781601982674"},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"1029","DOI":"10.1109\/JSAC.2009.090902","article-title":"Stochastic Geometry and Random Graphs for the Analysis and Design of Wireless Networks","volume":"27","author":"Haenggi","year":"2009","journal-title":"IEEE J. Sel. Areas Commun."},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"2388","DOI":"10.1109\/ACCESS.2015.2486778","article-title":"Indoor Office Wideband Millimeter-wave Propagation Measurements and Channel Models at 28 and 73 GHz for Ultra-Dense 5G Wireless Networks","volume":"3","author":"MacCartney","year":"2015","journal-title":"IEEE Access"}],"container-title":["Entropy"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1099-4300\/21\/4\/427\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T12:46:20Z","timestamp":1760186780000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1099-4300\/21\/4\/427"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2019,4,22]]},"references-count":45,"journal-issue":{"issue":"4","published-online":{"date-parts":[[2019,4]]}},"alternative-id":["e21040427"],"URL":"https:\/\/doi.org\/10.3390\/e21040427","relation":{},"ISSN":["1099-4300"],"issn-type":[{"type":"electronic","value":"1099-4300"}],"subject":[],"published":{"date-parts":[[2019,4,22]]}}}