Indian Institute of Technology Indore

About: Indian Institute of Technology Indore is a education organization based out in Indore, Madhya Pradesh, India. It is known for research contribution in the topics: Computer science & Chemistry. The organization has 1606 authors who have published 4803 publications receiving 66500 citations.

Secrecy Outage Analysis of Hybrid Satellite-Terrestrial Relay Networks with Opportunistic Relaying Schemes

Abstract: In this paper, we investigate the secrecy performance of a hybrid satellite-terrestrial relay network, where a satellite communicates with a terrestrial destination via multiple relays in the presence of eavesdropper. Particularly, to strengthen the system security against wiretapping attack, we present amplify-and-forward (AF) based optimal and partial relay selection schemes to minimize the secrecy outage probability (SOP). Hereby, the optimal scheme depends on both main and wiretapper links, while the partial scheme relies only on the legitimate terrestrial links. We derive the SOP expressions for both schemes by considering Shadowed-Rician fading for satellite channels and Nakagami-m fading for terrestrial channels. We further simplify these expressions at asymptotic high signal-to-noise ratio (SNR) and main-to-eavesdropper ratio (MER) regime to reveal useful insights on achievable diversity gains. Finally, the theoretical analysis is validated through Monte-Carlo simulations.

A Cooperation Scheme for User Fairness and Performance Enhancement in NOMA-HCN

Abstract: Rapid increase in number of cellular users and high demand for data has lead to the formation of multi-tier networks. Non-orthogonal multiple access (NOMA) has proved to be an efficient method to cater to the paradigm shift from 4G to 5G. This paper employs NOMA in an heterogeneous cellular network consisting of a macro base station (MBS) tier underlaid with femto base station (FBS) tier and device-to-device (D2D) tier, where NOMA is employed in FBS and D2D tier only. The congestion at the MBS tier is relieved by offloading macro users (MU) to the FBS tier. The offloaded MU are further supported by the D2D tier when the FBS tier fails to find a corresponding pairing user for the incoming offloaded MU. Since, absence of pairing user means outage for offloaded MU, D2D cooperation is employed, which decreases the rate outage probability by $86.87\%$ for the MU offloaded as cell edge user (CEU) in comparison to no cooperation. Also, a three times increase in ergodic rate and four times increase in sum ergodic rate for MU offloaded as CEU is achieved using cooperation from D2D tier. Verification of the results is done using Monte Carlo simulations.