A precoding scheme for physical layer security of multiple-input single-output (MISO) wiretap channel with spatial correlation is designed. Quality-of-service (QoS) of the link is defined in terms of upper bounds on a...
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A precoding scheme for physical layer security of multiple-input single-output (MISO) wiretap channel with spatial correlation is designed. Quality-of-service (QoS) of the link is defined in terms of upper bounds on average symbol error rate function at Bob (legitimate user) and Eve (illegitimate user). Specifically, two problems are considered. First, a precodermatrix is designed to minimise the average transmitted power subject to QoS requirements at Bob and Eve. Next, we propose two algorithms to minimize QoS of illegitimate party for a given reliability level, depending on whether main user link has no correlation or is fully correlated. Our result for uncorrelated case demonstrate that by increasing the allocated power, main user can increase secrecy level up to an optimum point above which both legitimate and illegitimate receivers experience adequate QoS in their links. In fully correlated case, the problem is identified as an instance of concave minimisation over a polytope, and optimum power allocation is obtained via the widely known vertex enumeration algorithm. In both cases, our simulations validate the analysis significantly. The results confirm that linear precoding is able to trade average power against minimum achievable Eve performance.
This paper focuses on precoder optimization of a spatially multiplexed multiple-input multiple-output (MIMO) system with noncoherent reception in a correlated Rayleigh fading environment. We consider a Kronecker produ...
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This paper focuses on precoder optimization of a spatially multiplexed multiple-input multiple-output (MIMO) system with noncoherent reception in a correlated Rayleigh fading environment. We consider a Kronecker product model for the channel correlation with a transmit equicorrelation matrix and a receive correlation matrix which is diagonal. The transmit symbol vector, in which the symbols are taken from two binary constellations {0, 1} and {1, -r} (with 0 = r < 1), is premultiplied by a diagonal precodermatrix with positive precoder parameters. As the average signal-to-noise ratio per diversity branch becomes large, the symbol vector error probability (SVEP) tends to reach saturation. We minimize this saturation value with respect to the precoder parameters and the constellation parameter r. It is found from computation that the optimalprecoder parameters are approximately in geometric progression for both constellations. By observing the patterns in optimal values obtained from computation, we simplify the optimization problem. This simplification reduces the computational effort required to solve the complex minimization problem without affecting the SVEP significantly. Furthermore, in the case of the constellation {1, -r}, it is found from computation that as the number of transmit antennas increases, the optimal value of r decreases.
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