The propagation of information by electromagnetic waves suffers different types of interference, according to the characteristics of the environment. The 5G system relies on adaptive modulation and coding techniques to better suit the channel and maximize effective data exchange between the user equipment and the network. Practical studies on the behaviour of the system under different environmental conditions, subject to attenuation processes such as fading, are important to understand and improve the 5G efficiency. This work has analysed the effect of the MCS (Modulation and Coding Scheme) variation on throughput for channel degraded by the multipath fading effect in a mobile communication. The analysis was carried out showing that the decision algorithms in terms of MCS switching to maintain adequate data rates according to the requirement (QoS) is an important factor. Considering both 64 QAM and 256 QAM, the throughput degradation effect was more evident in higher-order modulations due to the higher probability of bit error in the symbol constellation. This study can be a key for understanding and developing robust MCS switcher for 5G and beyond communications.