Experimental investigation has been carried out to study the effect og gamma ray radiations on silicon solar cells. The measured experimental data are compared with the theoretical results obtained by computer simulation programs before and after radiation. P-N junction silicon cell samples were used for the study showing degradation behavior for the output power and the short circuit current with less effect on the open circuit voltage as the radiation doses increases. Enhanced series resistance was added to the solar cell model due to deformation of I –V characteristics resulting from gamma ray radiations. Wide spread spectrum of doses were employed to study the effect of the radiation on the crystal deformation and damages on different parameters of solar cells. Study reveals an improvement in the output power and short circuit current due to post annealing effect of gamma ray radiations. The conclusion consist of suggestions to protect the solar cells in space satellites.
W. ABUGHRES, M. EL-MURADI, H. EL-FITOURI(9-1992)

Multiple Input Multiple Output (MIMO) systems with limited Radio Frequency (RF) chains play a pivotal role in the Fifth Generation (5G) of wireless networks. However, the transmitter of Generalized Spatial Modulation MIMO (GSM-MIMO) systems that characterized by a single RF chain and multiple active antennas is capable of reducing both the energy consumption and the transmitter cost. In this paper, combining GSM-MIMO systems with the fully digital Geometric Mean Decomposition (GMD)-based precoding scheme and Analog Beamforming (ABF) into Hybrid Beamforming (HBF) regime is presented for Millimeter-wave (mmWave) massive MIMO systems which is a key enabler for 5G networks. In addition, applying the norm-based user selection algorithm in GSM-MIMO scheme with GMD-based hybrid precoding is proposed, and referred to as Multiuser Steered GSM-MIMO (MUS-GSM-MIMO) scheme. Simulation results demonstrate that the proposed schemes are capable of achieving considerable performance gains over the conventional GSM-MIMO schemes, while avoiding the overwhelming costs of multiple RF chains. Therefore, the proposed schemes are very efficient and highly suitable for large-scale and 5G wireless networks.
Taissir Y. Elganimi, Amani A. Aturki(9-2020)

AbstractThis paper examines the process of sending an image over wireless mobile Channels with errors while maintaining bandwidth, transmission speed and image quality. With the tremendous development in networks, new wireless channels have been opened that threaten the security of data transmitted through networks and communication channels, and from this emerged Encryption techniques to increase the security of the transmitted data, and since the digital image compression algorithm is a process to reassemble the parts of the image so that it takes less space, but this increases the impact of the error extension in sending compressed digital images and greatly reduces the quality of the received image. This prompts us in this paper to study the performance of HQAM technology for the purpose of transmitting image data over wireless communication channels containing errors. In this paper, image quality performance has been evaluated by the BER, SNR, PSNR, SSIM, and Correlation evaluation criteria. The simulated results show that there is an improvement in the image quality received using the proposed technique.
wael saleh mohamed abughres, , , Ashrf Alzrouk Almagdob1, Ahmed B. Abdurrhman, Ibrahim A.Nasir, (9-2020)