The photovoltaic properties of In-doped CdTe(p) thin film homojunction structure have been investigated, specially the effect of the series resistance on the short-circuit current at low and high light intensities has been discussed in detail. A simulation of the fabricated device is achieved successfully using the PSPICE computer program. Mathematical derivations are implemented in order to interpret the results. It is found that the deteriorative effect of the series resistance on the short circuit current versus light intensity characteristics increases with increasing the light intensity. A new factor has been suggested to measure how the series resistance affects the solar cell behavior at low and high light intensities.

The scarcity of available radio spectrum presently limits the extension of modern multimedia systems. This paper presents a theoretical investigation into the possibility of using a frequency overlay of a narrowband Code Division Multiple Access (CDMA) System and a Time Division Multiple Access (TDMA) System to provide a greater spectral efficiency. This paper shows that under certain conditions the two systems can operate in the same frequency band and in the same area with a considerable improvement in the overall capacity of the whole system.