Adaptive modulation is a powerful technique to improve the energy efficiency and increases the data rate over a fading channel. The ground station transmitter and the satellite receiver adapt the modulation scheme and the transmitter power to the state of the channel. In this paper, we study adaptive multi-level quadrature amplitude modulation (M-QAM) schemes for LEO satellite over a Rayleigh f...

A (k, n;w) multi-receiver multi-message authentication code allows a transmitter to broadcast up to w − 1 different authenticated messages to n receivers in such a way that (1) not only an opponent but also any up to k − 1 receivers cannot cheat any other receivers, and (2) all the receivers can independently verify the authenticity of the messages. Obana and Kurosawa (Designs, Codes and Crypto...

We propose a downlink multiple-input multiple-output multi-carrier code division multiple access system with adaptive beamforming algorithm for smart antennas. The algorithm used in this paper is based on the least mean square, with pilot channel estimation and the zero forcing equalizer in the receiver, requiring reference signal and no knowledge channel. multi-carrier code division multiple a...

Quantum key distribution (QKD) is the best candidate for securing communications against attackers, who may in future exploit quantum-enhanced computational powers to break classical encryption. As such, new challenges are arising from our need large-scale deployment of QKD systems. In a realistic scenario, transmitting and receiving devices different vendors should be able communicate with eac...

In this paper, we have implemented Radar Transmitter-Receiver. Direct Sequence Spread Spectrum BPSK is chosen as modulation method because of its numerous advantages like accuracy of ranging, sensitivity, targetseparation, accuracy of power-estimation, interference suppression, etc. We have employed this scheme using MATLAB Simulink which is a software package for modelling, simulating, and ana...

Signal optimization is affected during radio links between a transmitter and a receiver located in adjacent material media with differing optical densities. The optimization is carried out via the automated control theory method. The radio signal obtained after the optimization is coordinated with the two media's electrical characteristics simultaneously; and this enables low power and small an...

This work deals with the analysis of a multisensor radar system in the context of maritime border control scenario. The system is composed by a receiver that exploits the signal emitted by two non co-operative transmitters of opportunity: a UMTS base station and a FM radio station. An algorithm for selecting the transmitter for the tracking of a radar target is proposed. This algorithm can prov...

Detection of slow moving targets using a moving pulsed Doppler radar system has been a problem of great interest for quite some time [1]. One distinguishes between monostatic (MS) configurations, where the radar transmitter and receiver are colocated and bistatic (BS) configurations, where they are physically separated and have separated motions. In either case, a train of coherent pulses is tr...

In this paper we present an analytic filtered-backpropagation inversion method for radar imaging when the transmitters and receivers are moving along independent flight paths. The flight paths are arbitrary, but assumed known. We assume a singlescattering model for the radar data, and we assume that the ground topography is known. We assume, in addition, that the receiver can correctly associat...