  Non-Orthogonal Multiple Access (NOMA) is a popular solution for supporting a
high number of users and along with significant bandwidth in 5G cellular
communication. By using a technique called cooperative relaying, the same data
is sent to all the users, and one user can relay data to the other. In order to
provide enough power for the users, energy harvesting techniques have been
introduced with Simultaneous Wireless Information and Power Transfer (SWIPT)
coming to prominence in recent times. In this paper, analysis has been made
comparing two different power allocation schemes in NOMA, Fixed Power
allocation Scheme (FPS) and Dynamic Power allocation Scheme (DPS). The
comparisons were made in terms of their performance and characteristics while
undergoing SWIPT. It has been found that by using DPS, an almost 25% increase
in peak spectral efficiency can be obtained compared to FPS. However, DPS
suffers from a higher outage probability as the increase of power causes the
signal bandwidth to drop below the target rate a significant number of times.
Based on the detailed results, conclusions were drawn as to which power
allocation coefficient scheme would be used in real-time and non-real time
communication standards, respectively. The results suggest that for real-time
communication, FPS is more suitable while for non-real-time communication, DPS
appears to work better than FPS.
