Impacts of imperfect SIC and imperfect hardware in performance analysis on AF non-orthogonal multiple access network

Telecommunication Systems

https://doi.org/10.1007/s11235-019-00583-7

Impacts of imperfect SIC and imperfect hardware in performance

analysis on AF non-orthogonal multiple access network

Dinh-Thuan Do2 · Tu-Trinh Thi Nguyen1

© Springer Science+Business Media, LLC, part of Springer Nature 2019

Abstract

In normal non-orthogonal multiple access (NOMA) network, perfect successive interference cancellation (SIC) and perfect

hardware impairments are usually admitted at transceivers. However, imperfections of SIC and hardware exist in mathematical

analysis of practical system, and such imperfections provide guideline to deploy NOMA in practical circumstances effectively.

To overcome these disadvantages, this paper considers relaying NOMA as existence of hardware noise and interference of

imperfect SIC operation and hence degraded performance under related factors can be addressed. We examine the system

performance of the proposed system and develop a closed-form formulation of outage probabilities for each user. In high

signal to noise ratio regime, we consider the corresponding asymptotic outage probability to provide meaningful insights in

our proposed schemes. We also exhibit comparison study with other works related performance evaluation and with Decode

and Forward based NOMA as useful benchmark. To further examine system performance of the proposed scheme, we derive

formula and verify results in term of the throughput performance. Finally, numerical examples are performed to validate the

effectiveness of the proposed scheme as practical challenges are raised, and compare these performance considerations with

that in other system models with respect to outage behavior as varying related parameters.

Keywords Non-orthogonal multiple access · Hardware impairment · Outage probability · Amplify and forward

1 Introduction

Two requirements including high throughput and massive

connectivity are crucial challenge in conventional wireless

network. In such network, multiple users need be to served

simultaneously, and it can be addressed as introducing new

modern protocol in communication systems. As emerging

multiple access technique, non-orthogonal multiple-access

(NOMA) is introduced as methodology to recycle the physi￾cal resources with respect to temporal and spectral diversities

[1]. Wireless system employing NOMA architecture which

allows the same frequency/time-slot can be distributed to

B Dinh-Thuan Do

[email protected]

Tu-Trinh Thi Nguyen

[email protected]

1 Faculty of Electronics Technology, Industrial University of

Ho Chi Minh City, Ho Chi Minh City, Vietnam

2 Wireless Communications Research Group, Faculty of

Electrical and Electronics Engineering, Ton Duc Thang

University, Ho Chi Minh City, Vietnam

dissimilar users and permits different channel gains to

serve users in the same cell. This promising principle has

attracted a large amount of research works in both academic

and industry communities [2–5]. To meet significant trend

in deployment of 5G wireless network, the superimposed

transmission scheme for multiuser scenario with two-stage

scheme was introduced for cooperative NOMA [6]. In addi￾tion, to improve spectral efficiency, a device-to-device (D2D)

assisted cooperative relaying system is employed together

with using NOMA in 5G wireless communications [7]. In

these NOMA networks, power allocation factors make cru￾cial impact on performance gap among NOMA users, and

such problemn of optimal power allocation configuration is

investigated in in a cooperative relaying system using NOMA

[8]. Furthermore in NOMA, advanced non-linear detectors

can be implemented by considering power domain multiplex￾ing signal. In particular, the NOMA users who possessing

superior channel conditions can be implemented with succes￾sive interference cancellation (SIC) to eliminate the signals

intended for other users before deciphering their own signal.

With regard to system performance analysis, outage proba￾bility in NOMA and effective coverage area of the relaying

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