Outage Probability Analysis of Multiuser MISO Systems Exploiting Joint Spatial Diversity and Multiuser Diversity with Outdated Feedback

Abstract

In this paper, the outage performance of multiuser multiple-input single-output (MISO) systems exploiting joint spatial and multiuser diversities is investigated for Rayleigh fading channels with outdated feedback. First, we derive closed-form exact outage probabilities for the joint diversity schemes that combine user scheduling with different spatial diversity techniques, including: 1) transmit maximum-ratio combining (TMRC); 2) transmit antenna selection (TAS); and 3) orthogonal space-time block coding (OSTBC). Then the asymptotic outage probabilities are analyzed to gain more insights into the effect of feedback delay. It is observed that with outdated feedback, the asymptotic diversity order of the multiuser OSTBC (M-OSTBC) scheme is equal to the number of transmit antennas at the base station, while that of the multiuser TMRC (M-TMRC) and the multiuser TAS (M-TAS) schemes reduce to one. Further by comparing the asymptotic outage probabilities, it is found that the M-TMRC scheme outperforms the M-TAS scheme, and the M-OSTBC scheme can perform best in the outage regime of practical interest when the feedback delay is large. Theoretical analysis is verified by simulation results.

On the outage probability of a multiuser TAS/MRC system with outdated feedback

“…This process is rather involved and the detailed derivation has been presented in [13], in which P (L, α, β, Z, Q) is shown to be calculated in a closed-form as…”

Achievable Sum Rate Analysis of ZF Receivers in 3D MIMO Systems

“…= G HΩ (2) where ∈ H ℂ N K × denotes the small-scale fading and the elements of H are assumed to be identically and independently distributed (i.i.d.) with zero mean and unit variance; Ω is a K K × diagonal matrix, which captures the large-scale fading including distance-dependent path-loss, log-normal shadowing fading, and antenna gain between the base station and the K users.…”