2 research outputs found
Generalized Spatial Modulation Aided MmWave MIMO with Sub-Connected Hybrid Precoding Scheme
Due to the high cost and low energy efficiency of the dedicated radio
frequency (RF) chains, the number of RF chains in a millimeter wave (mmWave)
multiple-input multiple-output (MIMO) system is usually limited from a
practical point of view. In this case, the maximum number of independent data
streams is also restricted by the number of RF chains, which consequently leads
to limiting the potentially attainable spatial multiplexing gain. In order to
address this issue, in this paper, a novel generalized spatial modulation
(GenSM) aided mmWave MIMO system is proposed, which enables the transmission of
an extra data stream via the index of the active antennas group and requires no
extra RF chain. Moreover, a two-step algorithm is also proposed to optimize the
hybrid precoder design with respect to spectral efficiency (SE) maximization.
Finally, numerical simulation results demonstrate the superior SE performance
achieved by the proposed scheme
Spatial Modulation for More Spatial Multiplexing: RF-Chain-Limited Generalized Spatial Modulation Aided MmWave MIMO with Hybrid Precoding
The application of hybrid precoding in millimeter wave (mmWave)
multiple-input multiple-output (MIMO) systems has been proved effective for
reducing the number of radio frequency (RF) chains. However, the maximum number
of independent data streams is conventionally restricted by the number of RF
chains, which leads to limiting the spatial multiplexing gain. To further
improve the achievable spectral efficiency (SE), in this paper we propose a
novel generalized spatial modulation (GenSM) aided mmWave MIMO system to convey
an extra data stream via the index of the active antennas group, while no extra
RF chain is required. Moreover, we also propose a hybrid analog and digital
precoding scheme for SE maximization. More specifically, a closed-form lower
bound is firstly derived to quantify the achievable SE of the proposed system.
By utilizing this lower bound as the cost function, a two-step algorithm is
proposed to optimize the hybrid precoder. The proposed algorithm not only
utilizes the concavity of the cost function over the digital power allocation
vector, but also invokes the convex relaxation to handle the
non-convex constraint imposed by analog precoding. Finally, the proposed scheme
is shown via simulations to outperform state-of-the-art mmWave MIMO schemes in
terms of achievable SE