Design and Performance Analysis of Wireless Communications using Non-Orthogonal Multiple Access (NOMA)

Student thesis: Doctoral Thesis

Abstract

The current and emerging wireless communication networks are anticipated to support the rising demand of high data-rate wireless applications and the rapidly growing number of users. Non-orthogonal multiple access (NOMA) is an efficient multiple access (MA) technique, which is considered as a promising scheme to provide an improved spectral efficiency with respect to orthogonal multiple access (OMA) techniques. Although NOMA is proven to be spectrally efficient, there are some challenges that should be taken into consideration in its design such as receiver complexity, error propagation, meticulous power control and resources allocation fairness. Therefore, this thesis presents a profound and structured performance analysis framework to determine the ability of NOMA systems to meet the requirements of the upcoming wireless networks. In particular, power-domain NOMA (PD-NOMA) is considered with the two widely used detection mechanisms, namely, successive interference cancellation detector (SICD) and joint multiuser detector (JMuD), where error-rate, spectral efficiency, analysis complexity, computational complexity and computational time are the evaluated performance metrics. The fairness and reliability of NOMA systems, in its detection process and resource allocation, are analyzed under varying operating conditions. The obtained analytical results demonstrate that the error-rate performance of all users in NOMA system is highly susceptible to users' ordering, power allocation (PA) and fading scenarios. Moreover, it is proven that the error-rate of the JMuD and SICD are identical, however, the processing time of the SICD is 51% more than the JMuD for several cases of interest which is critical for timesensitive applications. Furthermore, an adaptive bit loading algorithm for multicarriers NOMA (MC-NOMA) systems is proposed which can double the spectral efficiency for the same power efficiency at certain system settings in comparison with conventional bit loading based OMA schemes.
Date of AwardMay 2021
Original languageAmerican English

Keywords

  • Non-orthogonal multiple access (NOMA)
  • bit error rate (BER)
  • power allocation (PA)
  • joint multiuser detection
  • successive interference cancellation (SIC)
  • maximum likelihood detection (MLD)
  • fairness
  • spectral efficiency
  • computational efficiency
  • adaptive bit loading.

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