Loading...

Secure Transmission Strategies in Massive MIMO Systems in Presense of a Jammer

Soltani, Marziyeh | 2019

709 Viewed
  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 52411 (05)
  4. University: Sharif University of Technology
  5. Department: Electrical Engineering
  6. Advisor(s): Mirmohseni, Mahtab
  7. Abstract:
  8. Massive MIMO systems are systems, where the base station has many number of antenna so each user’s channel is orthogonal to one another.These systems have some valuable advantages such as reduction of energy needed for transmission and significant improvement in spectral efficiency, which makes them be suitable for next generation of wireless communication systems. Another advantage of Massive MIMO systems is inherent resistance against passive eavsdroppers due to having a directed power radiation in direction of the desired user. However another physical layer attack threat these systems: attacking in pilot phase then eavsdropping in downlink phase which must taken care of in physical layer. Because NOMA technology increases the system’s spectral efficiency by sending in one time-frequency resource and different in power domain, using NOMA and Massive MIMO systems has recently been noticed, where because of distributed nature of these systems, warranting security requires systematic solution. Therefore, in this thesis we investigate security in Massive MIMO systems with help of NOMA.in this thesis Massive MIMO NOMA systems are analyazed using stothastic geometry tools and system’s performance is considerd by calculating secrecy rate and outage probibility in three topologies. First we study security in presence of jammers in multi cell massive MIMO systems in which NOMA is used. Attackers try to eavsdroop during downlink phase by sending pilot sequenses the same as users in the channel estimating phase. Nodes are randomly located according to a PPP.we also calculate a lower bound on the secrecy ergodic rate and outage probibility for a desired pair of users. Then we study security in massive MIMO systems that use NOMA by help of relays in presence of eavsdropper and in two different system topologies. the difference of them is the location of nodes. we first assume that locations of nodes are fixed and random parameters of system are channel vectors.Then we assume that the location of relays are random according to FHPPP distribution in a disc with a fix radius and then we calculate a lower bound on the secrecy ergodic rate for a desired user
  9. Keywords:
  10. Massive Multiple-Input Multiple-Output Systems ; Non-Orthogonal Multiple Access ; Relay ; Security ; Adversary (Jammer) ; Stochastic Geometry ; Wiretapper

 Digital Object List

 Bookmark

...see more