Optimization of Code Rates in SISOME Wiretap Channels (original) (raw)

A Note on the Secrecy Capacity of the Multiple-Antenna Wiretap Channel

IEEE Transactions on Information Theory, 2000

The secrecy capacity of the multiple-antenna wiretap channel under the average total power constraint was recently characterized, independently, by Khisti and Wornell and Oggier and Hassibi using a Sato-like argument and matrix analysis tools. This paper presents an alternative characterization of the secrecy capacity of the multiple-antenna wiretap channel under a more general matrix constraint on the channel input using a channel-enhancement argument. This characterization is by nature information-theoretic and is directly built on the intuition regarding to the optimal transmission strategy in this communication scenario.

On the Secrecy Rate of Multi-Antenna Wiretap Channel under Finite-Alphabet Input

IEEE Communications Letters, 2011

This work investigates the effect of limiting source signals to finite-alphabet on the secrecy rate of a multi-antenna wiretap system. Existing works have characterized maximum achievable secrecy rate or secrecy capacity for single- and multi-antenna systems based on Gaussian source signals and secrecy code. Despite the impracticality of Gaussian source, its compact closed-form expression of mutual information motivated broad use of Gaussian input assumption. For practical consideration, we study the effect of finite discrete-constellation on instantaneous and ergodic secrecy rate of multiple-antenna wire-tap channels. Our results demonstrate substantial difference between systems involving finite-alphabet inputs and systems with Gaussian inputs. Results from Gaussian inputs serve as upper-bound of secrecy rate for practical systems with finite alphabet inputs.

A Note on the Secrecy Capacity of the Multi-antenna Wiretap Channel

Computing Research Repository, 2007

The secrecy capacity of the multi-antenna wiretap channel was recently characterized in- dependently by Khisti and Wornell (1) and Oggier and Hassibi (2) using a Sato-like argument and matrix analysis tools. This note presents an alternative characterization of the secrecy capacity of the multi-antenna wiretap channel using a channel enhancement argument. This characterization is by nature information rather than matrix

Optimal Transmission with Artificial Noise in MISOME Wiretap Channels

IEEE Transactions on Vehicular Technology, 2015

We investigate the optimal physical layer secure transmission with artificial noise in the wiretap channel with N antennas at the transmitter, a single antenna at the receiver, and M antennas at the eavesdropper. We analyze the performance and determine the optimal transmission parameters for two distinct schemes: (1) an on-off transmission scheme and (2) an adaptive transmission scheme. For the on-off transmission scheme where a channel-realization-independent secrecy rate is used for all transmission periods, we derive closed-form expressions for the secure transmission probability, the hybrid outage probability, and the effective secrecy throughput. For the adaptive transmission scheme where a channel-realizationdependent secrecy rate is used for each transmission period, we derive closed-form expressions for the secure transmission probability, the secrecy outage probability, and the effective secrecy throughput. Using these closed-form expressions, we determine the optimal power allocation between information signals and artificial noise signals for both schemes in order to maximize the secure transmission probability. We also determine the optimal secrecy rate for both schemes in order to maximize the effective secrecy throughput. We explicitly examine the impact of N and M on the optimal power allocation and the optimal secrecy rate. Finally, we demonstrate the performance gain of the adaptive transmission scheme over the on-off transmission scheme.

On Secrecy Rate Analysis of MIMO Wiretap Channels Driven by Finite-Alphabet Input

Computing Research Repository, 2011

This work investigates the effect of finite-alphabet source input on the secrecy rate of a multi-antenna wiretap system. Existing works have characterized maximum achievable secrecy rate or secrecy capacity for single and multiple antenna systems based on Gaussian source signals and secrecy code. Despite the impracticality of Gaussian sources, the compact closed-form expression of mutual information between linear channel Gaussian input and corresponding output has led to broad application of Gaussian input assumption in physical secrecy analysis. For practical considerations, we study the effect of finite discrete-constellation on the achievable secrecy rate of multiple-antenna wire-tap channels. Our proposed precoding scheme converts the multi-antenna system into a bank of parallel channels. Based on this precoding strategy, we propose a decentralized power allocation algorithm based on dual decomposition for maximizing the achievable secrecy rate. In addition, we analyze the achievable secrecy rate for finite-alphabet inputs in low and high SNR cases. Our results demonstrate substantial difference in secrecy rate between systems given finite-alphabet inputs and systems with Gaussian inputs.

Artificial Noise: Transmission Optimization in Multi-Input Single-Output Wiretap Channels

IEEE Transactions on Communications

We analyze and optimize the secrecy performance of artificial noise (AN) in multi-input single-output wiretap channels with multiple antennas at the transmitter and a single antenna at the receiver and the eavesdropper. We consider two transmission schemes: 1) an on-off transmission scheme with a constant secrecy rate for all transmission periods, and 2) an adaptive transmission scheme with a varying secrecy rate during each transmission period. For the on-off transmission scheme, an easy-to-compute expression is derived for the hybrid outage probability, which allows us to evaluate the transmission outage probability and the secrecy outage probability. For the adaptive transmission scheme where transmission outage does not occur, we derive a closed-form expression for the secrecy outage probability. Using these expressions, we determine the optimal power allocation between the information signal and the AN signal and also determine the optimal secrecy rate such that the effective s...

Secure Transmission With Multiple Antennas I: The MISOME Wiretap Channel

—The role of multiple antennas for secure communication is investigated within the framework of Wyner's wiretap channel. We characterize the secrecy capacity in terms of generalized eigenvalues when the sender and eavesdropper have multiple antennas, the intended receiver has a single antenna, and the channel matrices are fixed and known to all the terminals, and show that a beamforming strategy is capacity-achieving. In addition , we study a masked beamforming scheme that radiates power isotropically in all directions and show that it attains near-optimal performance in the high SNR regime. Insights into the scaling behavior of the capacity in the large antenna regime as well as extensions to ergodic fading channels are also provided.

How to attain the ordinary channel capacity securely in wiretap channels

2005

It is known that a message can be transmitted safely against any wiretapper via a noisy channel without a secret key if the coding rate is less than the so-called secrecy capacity CS, which is usually smaller than the channel capacity C. In order to remove the loss C − CS, we propose a multiplex coding scheme with plural independent messages. In this paper, it is shown that the proposed multiplex coding scheme can attain the channel capacity as the total rate of the plural messages and the perfect secrecy for each message. The coding theorem is proved by extending Hayashi's proof, in which the coding of the channel resolvability is applied to the wiretap channel.

Fundamental properties of on-off transmission scheme for wiretap channels

2015 International Conference on Wireless Communications & Signal Processing (WCSP), 2015

This work reveals some fundamental properties of an on-off transmission (OOT) scheme, in which a transmitter sends signals occasionally as per the capacity of the main channel in order to achieve physical layer security. To this end, we first identify the widely used hybrid secrecy outage probability as a function of the transmission probability and the conditional secrecy outage probability of the OOT scheme. This indicates, for the first time, that the hybrid secrecy outage probability can be achieved by the OOT scheme. We then derive a lower bound on the conditional secrecy outage probability of the OOT scheme in case of transmission, which is solely determined by the average signal-to-noise ratios (SNRs) of the main channel and eavesdropper's channel. Finally, we re-investigate the OOT scheme within an absolutely completely passive eavesdropping scenario, in which even the average SNR of the eavesdropper's channel is not required. Specifically, we derive an easy-evaluated expression for the average conditional secrecy outage probability of the OOT scheme by adopting an annulus threat model.

The Two-Way Wiretap Channel: Achievable Regions and Experimental Results

2010

This work considers the two-way wiretap channel in which two legitimate users, Alice and Bob, wish to exchange messages securely in the presence of a passive eavesdropper Eve. In the full-duplex scenario, where each node can transmit and receive simultaneously, we obtain new achievable secrecy rate regions based on the idea of allowing the two users to jointly optimize their channel prefixing distributions and binning codebooks in addition to key sharing.