95 research outputs found
A Survey of Downlink Non-orthogonal Multiple Access for 5G Wireless Communication Networks
Accepted by ZTE CommunicationsAccepted by ZTE CommunicationsAccepted by ZTE CommunicationsAccepted by ZTE CommunicationsAccepted by ZTE CommunicationsNon-orthogonal multiple access (NOMA) has been recognized as a promising multiple access technique for the next generation cellular communication networks. In this paper, we first discuss a simple NOMA model with two users served by a single-carrier simultaneously to illustrate its basic principles. Then, a more general model with multicarrier serving an arbitrary number of users on each subcarrier is also discussed. An overview of existing works on performance analysis, resource allocation, and multiple-input multiple-output NOMA are summarized and discussed. Furthermore, we discuss the key features of NOMA and its potential research challenges
Dynamic Non-Orthogonal Multiple Access (NOMA) and Orthogonal Multiple Access (OMA) in 5G Wireless Networks
In this paper, facilitated via the flexible software defined structure of the
radio access units in 5G, we propose a novel dynamic multiple access technology
selection among orthogonal multiple access (OMA) and non-orthogonal multiple
access (NOMA) techniques for each subcarrier. For this setup, we formulate a
joint resource allocation problem where a new set of access technology
selection parameters along with power and subcarrier are allocated for each
user based on each user's channel state information. Here, we define a novel
utility function taking into account the rate and costs of access technologies.
This cost reflects both the complexity of performing successive interference
cancellation and the complexity incurred to guarantee a desired bit error rate.
This utility function can inherently demonstrate the trade-off between OMA and
NOMA. Due to non-convexity of our proposed resource allocation problem, we
resort to successive convex approximation where a two-step iterative algorithm
is applied in which a problem of the first step, called access technology
selection, is transformed into a linear integer programming problem, and the
nonconvex problem of the second step, referred to power allocation problem, is
solved via the difference-of-convex-functions (DC) programming. Moreover, the
closed-form solution for power allocation in the second step is derived. For
diverse network performance criteria such as rate, simulation results show that
the proposed new dynamic access technology selection outperforms
single-technology OMA or NOMA multiple access solutions.Comment: 28 pages, 6 figure
Dynamic non-orthogonal multiple access (NOMA) and orthogonal multiple access (OMA) in 5G wireless networks
In this paper, a novel dynamic multiple access
technology selection among orthogonal multiple access (OMA)
and non-orthogonal multiple access (NOMA) techniques is proposed. For this setup, a joint resource allocation problem is
formulated in which a new set of access technology selection
parameters along with power and subcarrier are allocated for
each user based on each user’s channel state information. Here,
a novel utility function is defined to take into account the
rate and costs of access technologies. This cost reflects both
the complexity of performing successive interference cancellation
and the complexity incurred to guarantee a desired bit error
rate. This utility function can inherently capture the tradeoff
between OMA and NOMA. Due to non-convexity of the proposed
resource allocation problem, a successive convex approximation
is developed in which a two-step iterative algorithm is applied. In
the first step, called access technology selection, the problem is
transformed into a linear integer programming problem, and
then, in the second step, a nonconvex problem, referred to
power allocation problem, is solved via the difference-of-convexfunctions (DC) programming. Moreover, the closed-form solution
for power allocation in the second step is derived. For diverse
network performance criteria such as rate, simulation results
show that the proposed new dynamic access technology selection
outperforms single-technology OMA or NOMA multiple access
solutions
PERFORMANCE OF UPLINK-NOMA WITH USER PAIRING AND DATA RATE-BASED POWER SCHEME
This paper analyzes a performance of uplink power-domain non-orthogonal multiple access (NOMA) system with 2K users in which a resource allocation is taken into consideration. Since the power allocation and user pairing are tightly intertwined, they are considered as a hybrid issue. Accordingly, High-High/High-Low user pairing process precedes date rate-based power allocation. Derived closed-form expressions for the outage probabilities and the sum data rate for uplink power-domain NOMA system over a composite Fisher-Snedecor (F) fading channel are used for an extensive performance evaluation. The impact of different fading/shadowing channel conditions, various users’ positions and their number on the performance metrics is examined. Presented results have high level of generality since the F fading model provides accurate characterization of the multipath/shadowing conditions in numerous communication scenarios of interest
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