timation. Importantly, the author demonstrated
that the effect of pilot contamination can be
completely vanished under certain conditions
on the channel covariance. To reduce the com-
putational complexity of channel estimation,
[18] decomposed the space of the received
signals into three subspaces according to fac-
tor analysis, and an interference-free subspace
was created to obtain accurate channel esti-
mation. In [19], a joint pilot design and power
allocation strategy was considered to mitigate
pilot contamination and provide good service
in multi-cell massive MIMO system, which
can be used as a benchmark for pilot design
in ideal or non-ideal hardware scenarios. Due
to the high hardware complexity, linear pro-
cessing methods are widely used in massive
MIMO system [20]. In [21], a low-complexity
hybrid precoding method named phased-ZF
(PZF) was proposed to approach the perfor-
mance of the optimal linear precoding scheme
in massive MIMO systems. In [22], two inter-
ference-suppressed precoding methods were
proposed and significantly suppressed the
mutual interference between the users with
statistical and imperfect instantaneous channel
state information (CSI). Pilot-based channel
estimation can be avoided by utilizing statisti-
cal CSI.
author of [25] proposed an antenna selection
strategy based on the theory of rectangular
maximum volume submatrices. However, this
strategy is invalid if a square matrix with max-
imum-volume is not given.
A quantum-inspired
social emotional op-
timization (QSEO)
algorithm is proposed
to obtain the optimal
power control strategy
in massive MIMO up-
link networks.
Due to the growing demand of environ-
mental protection, energy efficiency (EE) and
spectral efficiency (SE) have become two
important concerns in massive MIMO net-
works [26-28]. Power allocation is an essential
technique to enhance the system performance
and promote energy conservation. To further
exploit the benefits of power allocation, more
and more works have been proposed for pow-
er allocation in massive MIMO networks [29-
32]. For maximizing the achievable uplink
rate in multi-cell massive MIMO systems, a
pilot power allocation strategy was proposed
in [29]. Considering pilot allocation, hardware
impairments and other system parameters, the
resource allocation problem for maximizing
SE in multi-cell massive MIMO system was
discussed in [30]. In [31], an approximate
power allocation scheme for maximizing EE
was proposed in massive MIMO networks.
The author considered power amplifier effi-
ciency, transmission power and circuit pow-
er. To ensure the QoS of the whole massive
MIMO system, minimum rate constraint of
the system was considered in [32]. The paper
developed a unified framework for EE op-
timization and proposed a power allocation
method based on fractional programming the-
ory. However, all schemes mentioned above
could not guarantee the QoS for each user and
the system simultaneously. Especially in more
complex conditions, it’s hard for mathematical
approximation to obtain the optimal solution.
With the dramatic increase of antenna quan-
tity, antenna selection is an effective technique
to decrease the operating cost and the number
of radio frequency chains in massive MIMO
networks. It’s impractical to obtain the opti-
mal antenna selection by exhaustive search
because of the high computational complexity.
Some researches on suboptimal antenna se-
lection methods are emerged in recent years
[23-25]. In [23], a successive removal strategy
for antenna selection was proposed. The suc-
cessive elimination strategy was performed
according to the received channel coefficients
from the previous users. Considering the trade-
off between the performance and computation-
al complexity, a mixed-integer programming
approach was proposed to jointly optimize
antenna selection and precoding scheme [24].
In order to maximize the channel capacity, the
1.1 Motivation and contributions
In this paper, we propose an effective anten-
na selection and power allocation strategy to
optimize the EE and SE in massive MIMO
uplink networks. To reduce the computation
complexity and satisfy the changing require-
ments of the practical system in real time, an
effective antenna selection strategy is designed
to select a group of antennas from the avail-
2
China Communications • April 2019
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