In this paper, we consider multiuser space-time block codes (STBCs) for 2 × 2 multiple–input multiple–output (MIMO) uplink transmissions. Using a truncated union–bound (UB) approximation, we propose design criteria of multiuser STBCs for quasi-static fading MIMO multiple access channels (MACs). Next, we demonstrate how, by combining the structure of algebraic perfect STBCs in [10], a family of ...

‎In wireless communication systems‎, ‎space-time codes are applied to encode data when multiple antennas are used in the receiver and transmitter‎. ‎The concept of diversity is very crucial in designing space-time codes‎. ‎In this paper‎, ‎using the equivalent definition of full diversity space-time codes‎, ‎we first characterize all real and complex $2times 2$ rate one linear dispersion space-...

Background: This study designed to determine and compare the prevalence of HSV-2 infection between two groups of women with high and low risk behaviors in Tehran. Materials and Methods: 362 women attending OB & GY clinics as low risk group and 156 prisoner and DIC (drop in Center) resident women in Tehran as high risk group, were enrolled in this cross sectional study. HSV-2 antibodies were tes...

Background and Aims: In this study we improved the purification of immunoglobulins from equine antiserum raised against the venom of 6 types of scorption species. Caprylic acid (octanoic acid), a fatty acid, was found to have no effect on the activity of the enzymes pepsin, which is used in antivenom purification to digest Fc fragment of immunoglobulins to obtain F(ab´)2. Materials and Methods...

We present some results about the parametric complexity for counting the number of truth assignments for two Conjunctive Forms (2CF’s), such problem is denoted as #2SAT. It is common to analyze the computational complexity for #2SAT regarding the number of variables or the number of clauses on the input formula F We consider here, the time complexity analysis for #2SAT based on a positive integ...

We consider the symmetric Darlington synthesis of a p × p rational symmetric Schur function S with the constraint that the extension is of size 2p × 2p and we investigate what happens when we impose that S and its extension have real coefficients. In this case, under the assumption that S is strictly contractive in at least one point of the imaginary axis, we determine the an upper bound for th...

When a train is traveling along the transition such as slab and ballasted track, dynamic behaviors of rail system and train are abruptly changed. In R&D project, the newly-developed precast slab track system and track transition between slab and ballasted track was planned to construct in 2006 on the newly-built Jeolla-line. Maintenance demand, settlement and component degradation were predicte...

iii Acknowledgments I want to thank my thesis advisor Jörg Rothe for all of his support during the past four years. In the first place, I am deeply grateful to him for giving me the chance to be part of his research team. Without his great efforts, I would never have had the chance to work in the scientific community. Many inspiring and valuable discussions with him initiated fruitful ideas tha...