The paper concerns with the study of the modulation diversity in PSK scheme due to rotation of the signal constellation along with bit interleaving. We derive here the expressions for the Symbol Error Probability (SEP) of rotated BPSK and QPSK modulations over frequency non-selective slowly fading Nakagami-q channels. Numerical results based on moment generating function (MGF) are obtained and ...

The design of space–time codes to achieve full spatial diversity over fading channels has largely been addressed by handcrafting example codes using computer search methods and only for small numbers of antennas. The lack of more general designs is in part due to the fact that the diversity advantage of a code is the minimum rank among the complex baseband differences between modulated codeword...

Differential transmit diversity which can be detected noncoherently is an attractive alternative to coherent space-time block codes since channel estimation is more difficult in multi-antenna systems than in single antenna systems. We focus on differential space-time block codes from orthogonal designs which derive the transmit symbols from an M -PSK constellation in order to fulfill the requir...

In wireless sensor networks, the key deployment problem has received little attention, whereas it is in fact fundamental, heavily involving crucial (scarce) resources of ad-hoc networks, such as memory and energy availability. In this paper, we first briefly survey the state-of-the art of key deployment strategies that are amenable to ad-hoc network. Then we proposed two possible methods and we...