OFDMA/SC-FDMA aided space-time shift keying for dispersive multi-user scenarios

Motivated by the recent concept of Space-Time Shift Keying (STSK) developed for achieving a flexible diversity versus multiplexing gain trade-off, we propose a novel Orthogonal Frequency Division Multiple Access (OFDMA)/Single Carrier Frequency Division Multiple Access (SC-FDMA) aided multi-user STSK scheme for frequency-selective channels. The proposed OFDMA/SC-FDMA STSK scheme is capable of providing an improved performance in dispersive channels, while supporting multiple users in a multiple antenna aided wireless system. Furthermore, the scheme has the inherent potential of benefitting from the low-complexity single-stream Maximum-likelihood (ML) detector. Both an uncoded and a sophisticated near-capacity coded OFDMA/SC-FDMA STSK scheme were studied and their performances were compared in multiuser wideband Multiple-Input Multiple-Output (MIMO) scenarios. Explicitly, OFDMA/SC-FDMA aided STSK exhibits an excellent performance even in the presence of channel impairments due to the frequency-selectivity of wideband channels and proves to be a beneficial choice for high capacity multi-user MIMO systems

Spatial Frequency Scheduling for Uplink SC-FDMA based Linearly Precoded LTE Multiuser MIMO Systems

This paper investigates the performance of the uplink single carrier (SC) frequency division multiple access (FDMA) based linearly precoded multiuser multiple input multiple output (MIMO) systems with frequency domain packet scheduling. A mathematical expression of the received signal to interference plus noise ratio (SINR) for the studied systems is derived and a utility function based spatial frequency packet scheduling algorithms is investigated. The schedulers are shown to be able to exploit the available multiuser diversity in time, frequency and spatial domains