Secure On-Off Transmission Design With Channel Estimation Errors

Abstract

Physical layer security has recently been regarded as an emerging technique to complement and improve the communication security in future wireless networks. The current research and development in physical layer security is often based on the ideal assumption of perfect channel knowledge or the capability of variable-rate transmissions. In this work, we study the secure transmission design in more practical scenarios by considering channel estimation errors at the receiver and investigating both fixed-rate and variable-rate transmissions. Assuming quasi-static fading channels, we design secure onoff transmission schemes to maximize the throughput subject to a constraint on secrecy outage probability. For systems with given and fixed encoding rates, we show how the optimal onoff transmission thresholds and the achievable throughput vary with the amount of knowledge on the eavesdropper's channel. In particular, our design covers the interesting case where the eavesdropper also uses the pilots sent from the transmitter to obtain imperfect channel estimation. An interesting observation is that using too much pilot power can harm the throughput of secure transmission if both the legitimate receiver and the eavesdropper have channel estimation errors, while the secure transmission always benefits from increasing pilot power when only the legitimate receiver has channel estimation errors but not the eavesdropper. When the encoding rates are controllable parameters to design, we further derive both a non-adaptive and an adaptive rate transmission schemes by jointly optimizing the encoding rates and the on-off transmission thresholds to maximize the throughput of secure transmissions.Index Terms-Physical layer security, channel estimation error, on-off transmission, secrecy outage probability.

Covert Communication in Fading Channels under Channel Uncertainty

“…Here, I n represents an n × n identity matrix. Considering channel uncertainty, the channel coefficient h ak is given by [10,11] h ak =ĥ ak +h ak ,…”

QoS-Aware Enhanced-Security for TDMA Transmissions from Buffered Source Nodes

“…New closed-form expressions for the transmission probability, the connection outage probability, the secrecy outage probability, and the reliable and secure transmission probability were derived to characterize the achievable system's performance. The authors of [19] investigated the secure transmission design in practical scenarios by considering channel estimation errors at the legitimate receiver and investigating both fixed-and variable-rate transmissions.…”

On the Design of Secure Non-Orthogonal Multiple Access Systems

“…In the seminal work [12], Wyner introduced the wiretap channel as a framework for physical layer security, where a transmitter wants to send confidential messages to a legitimate receiver in the presence of an external eavesdropper. Following Wyner's wiretap channel, the wireless physical layer security against external eavesdroppers has been extensively studied in recent years, e.g., [13]- [15] from an information-theoretic perspective on the performance analysis and [16]- [18] from a signal-processing perspective on the system design. It is worth mentioning that there is another research direction on physical layer security, which does not focus on the secrecy issue against external eavesdroppers.…”

“…Obtain P o = [P o 1 , · · · , P o K ] according to (16); 7: if (17), (18), and In the case of two users, we obtain the closed-form expressions for the solutions to the problem (23), which are summarized in the following Proposition 3. It is worth mentioning that the scenario of two users to perform NOMA jointly is of practical interest.…”