We analytically obtain the exact fundamental limit of 4-level amplitude shifted keying formats (4ASK) with direct detection optically preamplified receivers. The optimum multilevel spacing and the corresponding decision thresholds, which depend both on the signal to noise ratio and optical bandwidth, are obtained numerically considering the Chi-squared distribution of each level. The quantum li...

The optimum time and space distribution of upper-air observations is considered in connection with the detection and prediction of instability lines-a mesoscale phenomenon. It is shown that the optimum spacing of observational stations is not only a function of the scale of the phenomena to be detected but of observational and analytical errors as well. When these errors are considered the opti...

We investigate the energy optimization (minimization) for amplified links. We show that using the using a well-established analytic nonlinear signal-to-noise ratio noise model that for a simple amplifier model there are very clear, fiber independent, amplifier gains which minimize the total energy requirement. With a generalized amplifier model we establish the spacing for the optimum power per...

A class of unified multicarrier DS-CDMA (MC DS-CDMA) schemes is defined and its performance is considered over multipath Nakagamim fading channels. The spacing between two adjacent subcarriers of the unified MC DS-CDMA scheme is a variable, allowing us to gain insight into the effects of the spacing on the bit error rate (BER) performance of MC DS-CDMA systems. This unified MC DS-CDMA scheme in...

A class of generalized multicarrier direct sequence code-division multiple-access (MC DS-CDMA) schemes is defined and its performance is considered over multipath Nakagamifading channels. The spacing between two adjacent subcarriers of the generalized MC DS-CDMA is a variable, allowing us to gain insight into the effects of the spacing on the bit error rate (BER) performance of MC DS-CDMA syste...

The effects of electrode spacing on the optical response of illuminated MESFETs are analyzed. The analysis targets various optical performance factors including terminal photocurrent peak value, peak-time and discharge time. Whereas photocurrent peak value increases nonlinearly with electrode spacing, it was found that increasing the electrode spacing has a profound effect on the ability of the...

W. Hofmann∗ a, G. Hermann a, A. Konopelko a, H. Krawczynski a, C. Köhler a, G. Pühlhofer a, F.A. Aharonian a, A.G. Akhperjanian b, M. Aye a, J.A. Barrio c,d, K. Bernlöhr a,h, J.J.G. Beteta d, H. Bojahr f, J.L. Contreras d, J. Cortina d, A. Daum a, T. Deckers e, J. Fernandez c,d, V. Fonseca d, J.C. Gonzalez d, G. Heinzelmann g, M. Hemberger a, A. Heusler a, M. Heß a, H. Hohl f, I. Holl c, D. Hor...