  The various requirements in terms of data rates and latency in beyond 5G and
6G networks have motivated the integration of a variety of communications
schemes and technologies to meet these requirements in such networks. Among
these schemes are Terahertz (THz) communications, cooperative non-orthogonal
multiple-access (NOMA)-enabled schemes, and mobile edge computing (MEC). THz
communications offer abundant bandwidth for high-data-rate short-distance
applications and NOMA-enabled schemes are promising schemes to realize the
target spectral efficiencies and low latency requirements in future networks,
while MEC would allow distributed processing and data offloading for the
emerging applications in these networks. In this paper, an energy-efficient
scheme of multi-user NOMA-assisted cooperative THz single-input multiple-output
(SIMO) MEC systems is proposed to allow the uplink transmission of offloaded
data from the far cell-edge users to the more computing resources in the base
station (BS) through the cell-center users. To reinforce the performance of the
proposed scheme, two optimization problems are formulated and solved, namely,
the first problem minimizes the total users' energy consumption while the
second problem maximizes the total users' computation energy efficiency (CEE)
for the proposed scheme. In both problems, the NOMA user pairing, the BS
receive beamforming, the transmission time allocation, and the NOMA
transmission power allocation coefficients are optimized, while taking into
account the full-offloading requirements of each user as well as the predefined
latency constraint of the system. The obtained results reveal new insights into
the performance and design of multi-user NOMA-assisted cooperative THz-SIMO MEC
systems.
