5,285 research outputs found
Performance analysis of spatial modulation aided NOMA with full-duplex relay
A spatial modulation aided non-orthogonal multiple access with full-duplex relay (SM-NOMA-FDR) scheme is proposed for the coordinated direct and relay transmission in this paper. Specifically, the signal of the near user is mapped to an M-ary modulated symbol and the signal of the far user is mapped to an SM symbol. The base station first transmits signals to the near user and relay via SM-NOMA, and then the relay decodes and retransmits the signal of the far user. An SM-assisted FDR is used in this scheme to improve the spectral efficiency while reducing energy consumption and making full use of the antenna resources at the relay, since SM only activates one antenna in each transmission. We derive the ergodic capacity and bit error rate of the proposed scheme over independent Rayleigh fading channels. Numerical results validate the accuracy of the theoretical analysis and show the superior performance of the proposed SM-NOMA-FDR scheme
Performance Analysis of SSK-NOMA
In this paper, we consider the combination between two promising techniques:
space-shift keying (SSK) and non-orthogonal multiple access (NOMA) for future
radio access networks. We analyze the performance of SSK-NOMA networks and
provide a comprehensive analytical framework of SSK-NOMA regarding bit error
probability (BEP), ergodic capacity and outage probability. It is worth
pointing out all analysis also stand for conventional SIMO-NOMA networks. We
derive closed-form exact average BEP (ABEP) expressions when the number of
users in a resource block is equal to i.e., . Nevertheless, we analyze the
ABEP of users when the number of users is more than i.e., , and derive
bit-error-rate (BER) union bound since the error propagation due to iterative
successive interference canceler (SIC) makes the exact analysis intractable.
Then, we analyze the achievable rate of users and derive exact ergodic capacity
of the users so the ergodic sum rate of the system in closed-forms. Moreover,
we provide the average outage probability of the users exactly in the
closed-form. All derived expressions are validated via Monte Carlo simulations
and it is proved that SSK-NOMA outperforms conventional NOMA networks in terms
of all performance metrics (i.e., BER, sum rate, outage). Finally, the effect
of the power allocation (PA) on the performance of SSK-NOMA networks is
investigated and the optimum PA is discussed under BER and outage constraints
Optical Non-Orthogonal Multiple Access for Visible Light Communication
The proliferation of mobile Internet and connected devices, offering a
variety of services at different levels of performance, represents a major
challenge for the fifth generation wireless networks and beyond. This requires
a paradigm shift towards the development of key enabling techniques for the
next generation wireless networks. In this respect, visible light communication
(VLC) has recently emerged as a new communication paradigm that is capable of
providing ubiquitous connectivity by complementing radio frequency
communications. One of the main challenges of VLC systems, however, is the low
modulation bandwidth of the light-emitting-diodes, which is in the megahertz
range. This article presents a promising technology, referred to as "optical-
non-orthogonal multiple access (O-NOMA)", which is envisioned to address the
key challenges in the next generation of wireless networks. We provide a
detailed overview and analysis of the state-of-the-art integration of O-NOMA in
VLC networks. Furthermore, we provide insights on the potential opportunities
and challenges as well as some open research problems that are envisioned to
pave the way for the future design and implementation of O-NOMA in VLC systems
Detection for 5G-NOMA: An Online Adaptive Machine Learning Approach
Non-orthogonal multiple access (NOMA) has emerged as a promising radio access
technique for enabling the performance enhancements promised by the
fifth-generation (5G) networks in terms of connectivity, low latency, and high
spectrum efficiency. In the NOMA uplink, successive interference cancellation
(SIC) based detection with device clustering has been suggested. In the case of
multiple receive antennas, SIC can be combined with the minimum mean-squared
error (MMSE) beamforming. However, there exists a tradeoff between the NOMA
cluster size and the incurred SIC error. Larger clusters lead to larger errors
but they are desirable from the spectrum efficiency and connectivity point of
view. We propose a novel online learning based detection for the NOMA uplink.
In particular, we design an online adaptive filter in the sum space of linear
and Gaussian reproducing kernel Hilbert spaces (RKHSs). Such a sum space design
is robust against variations of a dynamic wireless network that can deteriorate
the performance of a purely nonlinear adaptive filter. We demonstrate by
simulations that the proposed method outperforms the MMSE-SIC based detection
for large cluster sizes.Comment: Accepted at ICC 201
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