A novel multiple access scheme based on spatial modulation MIMO

Abstract

Spatial modulation (SM) is a unique single-stream Multiple-Input Multiple-Output (MIMO) transmission technique. Unlike conventional MIMO schemes, SM activates a single transmit antenna at any time instance, and therefore completely avoids inter-channel interference in single user scenarios. When considering multiple users, precoding techniques can be applied to realise multi-user SM (MU-SM) and coordinate multi-user interference. The transmit antennas in MU-SM are divided into groups, and each group is dedicated to one user. This means that the management and selection of antennas are crucial with respect to capacity in MU-SM. Therefore, we propose a novel multiple access method in this paper, named spatial modulation multiple access (SMMA). Unlike in MU-SM where a fixed antenna arrangement is used, the concept of SMMA is to adaptively allocate the transmit antennas to multiple users. Results show that SMMA obtains a signal-to-noise ratio (SNR) gain of up to 6 dB over MU-SM. More importantly, the performance of SMMA degrades insignificantly as the number of users increases.

Handover-Aware Scheduling for Small- and Large-Scale VLC Networks

“…Another important aspect is the reliance on CSI accuracy for identifying the user location with respect to the APs, which necessitates making a trade-off between increasing the frequency of carrying out CSI estimation, and decreasing the pilot overhead used for channel estimation, depending on the channel variation rate. Future research directions include (i) consideration of usercentric and cell-free handover solutions [36]; (ii) the combined version of proposed scheduling solutions and physical-layer MA schemes such as the spatial modulation MA [37] to optimize resource utilization; (iii) modifying the proposed handover-aware scheduling with beamforming for improving the VLC network security; (iv) evaluation of the impact of errors in the uplink transmission with respect to the proposed handover-aware scheduling; and (v) experimental evaluation of the performance of the proposed solutions.…”

Blind Signal Reception in Downlink Generalized Spatial Modulation Multiuser MIMO System Based on Minimum Output Energy

“…The use of SM for downlink (DL) MU-MIMO transmission has also been investigated in [14]- [23]. In general, the SM DL MU-MIMO system can be categorized into two different schemes: The scheme considered in [14]- [18] termed as receive SM (RSM) employs zero-forcing (ZF) precoding aided SM technique at the base station transmitter (BSTx) to activate single receive antenna at each user terminal (UT). The second scheme considered in [19]- [21] termed as parallel SM (PSM) separates the BSTx antennas into K groups corresponding to K UTs.…”