Hailing Yang¹, Suoping Li^1,2,*, Duo Peng²

CMC-Computers, Materials & Continua, Vol.79, No.3, pp. 5273-5294, 2024, DOI:10.32604/cmc.2024.050869 - 20 June 2024

Abstract To address the problems of network congestion and spectrum resources shortage in multi-user large-scale scenarios, this paper proposes a twice random access OFDMA-NOMA-RA protocol combining the advantages of orthogonal frequency division multiple access (OFDMA) and non-orthogonal multiple access (NOMA). The idea of this protocol is that OFMDA is used to divide the entire frequency field into multiple orthogonal resource units (RUs), and NOMA is used on each RU to enable more users to access the channel and improve spectrum efficiency. Based on the protocol designed in this paper, in the case of imperfect successive interference… More >

Hong Zhu¹, Lisha Gao¹, Lei Wei¹, Guangchang Yang^2,*, Sujie Shao²

CMC-Computers, Materials & Continua, Vol.75, No.3, pp. 5501-5519, 2023, DOI:10.32604/cmc.2023.035759 - 29 April 2023

Abstract As the scale of power networks has expanded, the demand for multi-service transmission has gradually increased. The emergence of WiFi6 has improved the transmission efficiency and resource utilization of wireless networks. However, it still cannot cope with situations such as wireless access point (AP) failure. To solve this problem, this paper combines orthogonal frequency division multiple access (OFDMA) technology and dynamic channel optimization technology to design a fault-tolerant WiFi6 dynamic resource optimization method for achieving high quality wireless services in a wirelessly covered network even when an AP fails. First, under the premise of AP… More >

Omar Abdulghafoor¹, Musbah Shaat², Ibraheem Shayea³, Ahmad Hamood¹, Abdelzahir Abdelmaboud⁴, Ashraf Osman Ibrahim⁵, Fadhil Mukhlif^6,*, Herish Badal¹, Norafida Ithnin⁶, Ali Khadim Lwas⁷

CMC-Computers, Materials & Continua, Vol.75, No.2, pp. 3045-3064, 2023, DOI:10.32604/cmc.2023.033888 - 31 March 2023

Abstract The computational complexity of resource allocation processes, in cognitive radio networks (CRNs), is a major issue to be managed. Furthermore, the complicated solution of the optimal algorithm for handling resource allocation in CRNs makes it unsuitable to adopt in real-world applications where both cognitive users, CRs, and primary users, PUs, exist in the identical geographical area. Hence, this work offers a primarily price-based power algorithm to reduce computational complexity in uplink scenarios while limiting interference to PUs to allowable threshold. Hence, this paper, compared to other frameworks proposed in the literature, proposes a two-step approach… More >

C. Thiruvengadam^1,*, M. Palanivelan²

Intelligent Automation & Soft Computing, Vol.36, No.3, pp. 2803-2818, 2023, DOI:10.32604/iasc.2023.030493 - 15 March 2023

Abstract There are numerous goals in next-generation cellular networks (5G), which is expected to be available soon. They want to increase data rates, reduce end-to-end latencies, and improve end-user service quality. Modern networks need to change because there has been a significant rise in the number of base stations required to meet these needs and put the operators’ low-cost constraints to the test. Because it can withstand interference from other wireless networks, and Adaptive Complex Multicarrier Modulation (ACMM) system is being looked at as a possible choice for the 5th Generation (5G) of wireless networks. Many… More >

Attia Irum¹, Abdul Muiz Fayyaz¹, Sara Ayub², Mudassar Raza³, Majed Alhaisoni⁴, Muhammad Attique Khan⁵, Abdullah Alqahtani⁶, Heebum Kim⁷, Byeong-Gwon Kang^7,*

Computer Systems Science and Engineering, Vol.46, No.1, pp. 1265-1276, 2023, DOI:10.32604/csse.2023.032861 - 20 January 2023

Abstract An effective communication application necessitates the cancellation of Impulsive Noise (IN) from Orthogonal Frequency Division Multiplexing (OFDM), which is widely used for wireless applications due to its higher data rate and greater spectral efficiency. The OFDM system is typically corrupted by Impulsive Noise, which is an unwanted short-duration pulse with random amplitude and duration. Impulsive noise is created by humans and has non-Gaussian characteristics, causing problems in communication systems such as high capacity loss and poor error rate performance. Several techniques have been introduced in the literature to solve this type of problem, but they… More >

Suma Sekhar^1,*, Sakuntala S. Pillai², S. Santhosh Kumar³

Intelligent Automation & Soft Computing, Vol.35, No.3, pp. 3187-3197, 2023, DOI:10.32604/iasc.2023.028702 - 17 August 2022

Abstract Worldwide Interoperability for Microwave Access (WiMAX) trusts Multiple Input Multiple Output-Orthogonal Frequency Division Multiplexing (MIMO-OFDM) combination for the deployment of physical layer functions and for connecting the medium access control to the wireless media. Even though Orthogonal Frequency Division Multiplexing (OFDM) facilitates reliable digital broadband transmission in the fading wireless channels, the presence of synchronization errors in the form of Carrier Frequency Offset (CFO) and Time Offset (TO) adversely affect the performance of OFDM based physical layers. The objective of this work is to improve the accuracy of the frequency and the time offset estimation More >

M. Prabhu^1,*, B. Muthu Kumar²

Intelligent Automation & Soft Computing, Vol.35, No.2, pp. 2513-2525, 2023, DOI:10.32604/iasc.2023.027823 - 19 July 2022

Abstract Orthogonal Frequency-Division Multiplexing (OFDM) is the form of a digital system and a way of encoding digital data across multiple frequency components that are used in telecommunication services. Carrier Frequency Offset (CFO) inaccuracy is a major disadvantage of OFDM. This paper proposed a feasible and elegant fuzzy-based resource allocation technique, that overcomes the constraints of the CFO. The suggested Fuzzy linear CFO estimation (FL-CFO) not only estimates the CFO with increased precision but also allocates resources effectively, and achieves maximum utilization of dynamic resources. The suggested FL-CFO error estimation algorithm in OFDM systems employing 1-bit… More >

Xiukai Ruan¹, Shahid Iqbal Awan^2,*

Journal on Internet of Things, Vol.4, No.4, pp. 215-225, 2022, DOI:10.32604/jiot.2022.038270 - 18 July 2023

Abstract A SCMA ACO-OFDM downlink visible light communication (VLC) system is proposed. Six users share four spectrum resources, four of which are 4 primary color LED lights. ACO-OFDM technology is used to convert the user’s sparse codebook mapped signal into a positive real value signal that can be carried on the light wave, which can realize high-speed parallel communication. Simulation verifies the feasibility of the system. At the same time, the channel model of visible light communication is constructed, and the signal-to-noise ratio(SNR) and channel gain of the visible light channel are systematically analyzed. Finally, the More >

Rajneesh Pareek¹, Karthikeyan Rajagopal², Himanshu Sharma¹, Nidhi Gour¹, Arun Kumar³, Sami Althahabi⁴, Haya Mesfer Alshahrani⁵, Mohamed Mousa⁶, Manar Ahmed Hamza^7,*

CMC-Computers, Materials & Continua, Vol.73, No.1, pp. 1637-1648, 2022, DOI:10.32604/cmc.2022.029563 - 18 May 2022

Abstract Multi and single carrier waveforms are utilized in cellular systems for high-speed data transmission. In The Fifth Generation (5G) system, several waveform techniques based on multi carrier waveforms are proposed. However, the Peak to Average Power Ratio (PAPR) is seen as one of the significant concerns in advanced waveforms as it degrades the efficiency of the framework. The proposed article documents the study, progress, and implementation of PAPR reduction algorithms for the 5G radio framework. We compare the PAPR algorithm performance for advanced and conventional waveforms. The simulation results reveal that the advanced Partial Transmission More >

Ramesh Ramamoorthy¹, Himanshu Sharma², A. Akilandeswari³, Nidhi Gour², Arun Kumar^4,*, Mehedi Masud⁵

Computer Systems Science and Engineering, Vol.43, No.3, pp. 1207-1217, 2022, DOI:10.32604/csse.2022.024749 - 09 May 2022

Abstract Spectrum sensing is one of the major concerns in reaching an efficient Quality of service (QOS) in the advanced mobile communication system. The advanced engineering sciences such as 5G, device 2 device communications (D2D), Internet of things (IoT), MIMO require a large spectrum for better service. Orthogonal frequency division multiplexing (OFDM) is not a choice in advanced radio due to the Cyclic Prefix (CP), wastage of the spectrum, and so on. Hence, it is important to explore the spectral efficient advanced waveform techniques and combine a cognitive radio (CR) with the 5G waveform to sense… More >