  One of focuses in green communication studies is the energy efficiency (EE)
of massive multiple-input multiple-output (MIMO) systems. Although the massive
MIMO technology can improve the spectral efficiency (SE) of cellular networks
by configuring a large number of antennas at base stations (BSs), the energy
consumption of radio frequency (RF) chains increases dramatically. The
increment of energy consumption is caused by the increase of RF chain number to
match the antenna number in massive MIMO communication systems. To overcome
this problem, a generalized spatial modulation (GSM) solution is presented to
simultaneously reduce the number of RF chains and maintain the SE of massive
MIMO communication systems. A EE model is proposed to estimate the transmission
and computation power of massive MIMO communication systems with GSM.
Simulation results demonstrate that the EE of massive MIMO communication
systems with GSM outperforms the massive MIMO communication systems without
GSM. Besides, the computation power consumed by massive MIMO communication
systems with GSM is effectively reduced.
