  In this paper, we investigate the energy-efficient resource allocation
problem in an uplink non-orthogonal multiple access (NOMA) millimeter wave
system, where the fully-connected-based sparse radio frequency chain antenna
structure is applied at the base station (BS). To relieve the pilot overhead
for channel estimation, we propose a codebook-based analog beam design scheme,
which only requires to obtain the equivalent channel gain. On this basis, users
belonging to the same analog beam are served via NOMA. Meanwhile, an advanced
NOMA decoding scheme is proposed by exploiting the global information available
at the BS. Under predefined minimum rate and maximum transmit power constraints
for each user, we formulate a max-min user energy efficiency (EE) optimization
problem by jointly optimizing the detection matrix at the BS and transmit power
at the users. We first transform the original fractional objective function
into a subtractive one. Then, we propose a two-loop iterative algorithm to
solve the reformulated problem. Specifically, the inner loop updates the
detection matrix and transmit power iteratively, while the outer loop adopts
the bisection method. Meanwhile, to decrease the complexity of the inner loop,
we propose a zero-forcing (ZF)-based iterative algorithm, where the detection
matrix is designed via the ZF technique. Finally, simulation results show that
the proposed schemes obtain a better performance in terms of spectral
efficiency and EE than the conventional schemes
