An Introduction to Adaptive QAM Modulation Schemes for Known and Predicted Channels

2007 ◽  
Vol 95 (12) ◽  
pp. 2322-2336 ◽  
Author(s):  
Arne Svensson
2021 ◽  
Vol 107 ◽  
pp. 194-200
Author(s):  
Theman Ibrahim Jirnadu ◽  
Adeyemi Abel Ajibesin ◽  
Ahmed T. Ishaq

Although, most researchers focus on some of the key components of good digital wireless communications which are the Bit Error Rate (BER) versus Signal to Noise Ratio (SNR) of modulation schemes. Energy consumption optimization is necessary for enhancing the performance of a wireless communication system as it offers numerous advantages to the system and the users. Therefore, this research focuses on analyzing the efficiency in the performance of the various QAM Modulation Schemes (4QAM, 16QAM, 32QAM & 64QAM) as they travel over noise/fading channels with the quest to obtain an energy-efficient scheme which will enhance system performance in terms of system runtime and quality of service. The efficiency of any given process, operation, or device is rated per the energy it consumes in carrying out an activity per unit output. Hence, the objective of this research work is to study and analyze comparatively the efficiency of these modulation schemes and to conclude with the most efficient scheme over the various channels. The evaluation of the Bit Error Rate (BER) versus energy per bit to noise spectral density (EbNo) for each communication scenario was carried out in MATLAB.


2021 ◽  
Vol 17 (4) ◽  
pp. 358-365
Author(s):  
Joel E. Cordeiro Jr ◽  
Marcelo S. Alencar ◽  
Marina V. Yashina ◽  
Alexander G. Tatashev

2014 ◽  
Vol 530-531 ◽  
pp. 729-733
Author(s):  
Xue Yi Zhang ◽  
Shuang Le Zhao

This paper gives a theoretical basis principle and structure of OFDM. The O-OFDM has three parts including transmitter, receiver and fiber. The main and key component is IFFT and FFT block. And then a basic direct detection optical-OFDM system (DO-OFDM) is designed and simulated by the software Optisystem. The performance of the system is viewed by the visualizer of the software compared to the RZ, OFDM and QAM modulation system. The result shows that the OFDM system is better than conventional serial modulation schemes like RZ, QAM.


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