Secure resource allocation in OFDMA-based cognitive radio networks with two-way relays

Abstract

In this paper, we consider a two-way cooperative communication framework to provide secure communications for secondary users within an Orthogonal Frequency-Division Multiple Access (OFDMA) based underlay cognitive network. By proposing a radio resource allocation problem with the aim of maximizing the secrecy sum-rate of secondary users and solving it, we show that deployment of relays is vital to achieve a non-zero secrecy sum rate. Also, impact of two-way relay in system performance improvement is clearly visible in comparison with one-way relay such that it can roughly double the resulting system secrecy sum-rate. The impact of different system parameters on the achievable secrecy sum rate for both one-way and two-way relay is also investigated and compared through simulations. Index Terms Physical (PHY) layer security, cognitive radio networks, Two-way communication, decode-and-forward relay

Limited Feedback Scheme for Device-to-Device Communications in 5G Cellular Networks with Reliability and Cellular Secrecy Outage Constraints

“…whereĈ D (m, n) is given by (6). Details on obtaining probability terms in (14) can be found in Appendix C.…”

“…With the above definitions and assumptions, the average transmission powers in (11) and (12), average transmission data rates in (13) and (14), and the outage probabilities in (7), (8), (9), and (10) should be manipulated to incorporate the effect of noisy feedback channel. Note that, choosing the transmit power level from a code book only depends on the corresponding channel region index which is feedbacked by the respective transmitter.…”

“…In this paper, we combine the last two approaches. More precisely, our objective is to maximize the average achievable data rate for D2D pair in the presence of cellular communication, i.e., (14), while it is required to maintain a minimum amount of the average achievable data rate of cellular link in the absence of D2D communication, i.e., (13), and the outage probability for cellular communication in the presence of D2D communication, i.e., (10), is kept below a predefined threshold. In this way, we take into account the performance of cellular communication both in the absence and presence of D2D communication.…”

“…Obtaining probability terms in ( 28) is similar to obtaining probability terms in (14) in Appendix C, and hence omitted.…”

“…To increase the security of wireless transmission, physical layer security has been developed based on information theoretic concepts [14]- [21]. From the physical layer point of view, the security is quantified by the secrecy rate which is defined as the difference of achievable rate between the legitimate receiver and the rate overheard by eavesdroppers [22].…”