Implementation of QAM Modulation Demodulation Based on Simulink

Simulink-based Simulation of Quadrature Amplitude Modulation (QAM) System

Adaptive modulation system is one of the key techniques in building a broadband mobile communication network because of increasing shortage of wireless communication channels. Quadrature amplitude modulation (QAM) has been widely used in adaptive modulation because of its efficiency in power and bandwidth. To better understand the QAM system, a Simulink-based simulation system is designed. In t...

Study of Blind Demodulation Algorithm based on Sequential Detection of Unknown Constellation QAM

In this paper, we propose a novel on-line blind demodulation algorithm for Quadrature Amplitude Modulation (QAM). The proposed approach can demodulate QAM signal without constellation knowledge, and reach the theoretical optimal performance under the constraint of sequential detection. Numerical simulations are provided to validate the analytical results. Results show that when iterations are l...

Performance Comparison of Rayleigh and Rician Fading Channels In QAM Modulation Scheme Using Simulink Environment

Iterative Demodulation and Decoding of Coded Non-Square QAM

It is shown that a non-square ( N S ) 2'"+'-ary quadrature amplitude modulation (QAM) can be decomposed into a single-parity-check (SPC) block encoder and a memoryless modulator in such a way that the inherent block encoder has a recursive nature. When concatenated with a forward-error-correcting (FEC) code, iterative demodulation and decoding of the FEC code and the inherent SPC code of NS-2'"...

Synchronous Demodulation of Coherent 16-QAM with Feedforward Carrier Recovery

Coherent optical transmission allows for improved bandwidth utilization and impairment compensation of existing optical fiber links and is a key for future communication systems with transmission rates of 112 Gb/s and above. In recent years quadrature phase shift keying (QPSK) was the preferred modulation format because of its robustness on long-haul links [1]–[3]. However, for metropolitan are...