Abstract
This work focuses on exploiting the constructive interference among
different users’ data waveforms to introduce new coding and decoding
techniques, which are specifically designed for non-orthogonal multiple
access (NOMA) systems. In this paper, a structured coding scheme is
devised. In essence, the proposed technique focuses on finding a
relationship between the sent users’ data waveforms and then uses this
relationship in the decoding process at the receiving destination. It is
worth pointing out that the proposed coding and decoding techniques
exhibit better performance and reduced the complexity compared with the
conventional uncoded NOMA. The complexity order evaluation shows that
the proposed scheme attains a reduction in the required number of the
floating point operations (FLOPs) of 5N and 6N at the second and third
users, respectively, compared with that of the uncoded NOMA. Moreover,
we have derived a closed-form expression for the bit-error rate (BER),
which is verified using the Monte Carlo simulation. To demonstrate the
practicality of the proposed system, the obtained results are compared
with those of the uncoded and convolutional coding NOMA systems.
Finally, the performance of the proposed system outperformed
conventional systems by an average of 5 dB in the case of two users and
an average of 15 dB in the case of three users in the same work
environment.