Elsaid Md. Abdelrahim^1,2, Mona Alduailij³, Mai Alduailij³, Romany F. Mansour^4,*, Osama A. Ghoneim⁵

Computer Systems Science and Engineering, Vol.47, No.2, pp. 1493-1505, 2023, DOI:10.32604/csse.2023.037976

Abstract Massive multiple-input multiple-output (MIMO) systems that use the millimeter-wave (mm-wave) band have a higher frequency and more antennas, which leads to significant path loss, high power consumption, and server interference. Due to these issues, the spectrum efficiency is significantly reduced, making spectral efficiency improvement an important research topic for 5G communication. Together with communication in the terahertz (THz) bands, mmWave communication is currently a component of the 5G standards and is seen as a solution to the commercial bandwidth shortage. The quantity of continuous, mostly untapped bandwidth in the 30–300 GHz band has presented a rare opportunity to boost the capacity… More >

Imran Khan¹, Fahd N. Al-Wesabi², Marwa Obayya³, Anwer Mustafa Hilal⁴, Manar Ahmed Hamza⁴, Mohammed Rizwanullah⁴, Fahad Ahmed Al-Zahrani⁵, Hirofumi Amano⁶, Samih M. Mostafa^7,*

CMC-Computers, Materials & Continua, Vol.71, No.1, pp. 697-715, 2022, DOI:10.32604/cmc.2022.021847

Abstract With the rapid development of wireless communication technology, the spectrum resources are increasingly strained which needs optimal solutions. Cognitive radio (CR) is one of the key technologies to solve this problem. Spectrum sensing not only includes the precise detection of the communication signal of the primary user (PU), but also the precise identification of its modulation type, which can then determine the a priori information such as the PU’ service category, so as to use this information to make the cognitive user (CU) aware to discover and use the idle spectrum more effectively, and improve the spectrum utilization. Spectrum sensing… More >

Xiaohong Ji¹, Junjun Du¹, Guoqing Jia^1,*, Weidong Fang^2,3

Intelligent Automation & Soft Computing, Vol.27, No.1, pp. 221-231, 2021, DOI:10.32604/iasc.2021.013145

Abstract Sparse code multiple access (SCMA) is a new non-orthogonal multiple access scheme suitable for 5G communication, which can effectively improve spectrum efficiency and support massive connections. Multiple users in the SCMA system realize the sharing of the same time-frequency resources by mapping data into codewords of a special code book (Code Book, CB). A typical SCMA system increases the spectrum utilization to 150%. In order to further improve the system spectrum utilization and increase the number of user connections, this paper proposes an uplink SCMA codebook reuse transmission and reception scheme (CB-Reuse-SCMA), which reuse a codebook to multiple users. The… More >