Spectral Efficient Non-orthogonal Radio Designs For Future Wireless Networks

  • Author / Creator
    Mohammadian, Amirhossein
  • The fifth-generation (5G) and beyond wireless networks aim to increase the current data rates to more than 10 Gbit/s. Thus, the spectrum crunch necessitates increasing spectral efficiency (SE). Key non-orthogonal technologies for this goal are (I) full-duplex wireless, (II) generalized frequency division multiplexing (GFDM), (III) cognitive radio. Non-orthogonal subcarriers instead of orthogonal subcarriers are the basis of GFDM. All these technologies exploit non-orthogonal designs in exchange for a favorable tradeoff between interference and improved SE. However, interference can also increase with radio frequency (RF) impairments. Thus, this research's primary goal is to investigate the interplay among non-orthogonal designs, SE improvement, and RF impairments. To this end, the SE improvement of cellular base stations (BS) with non-orthogonal signaling is investigated. Thus, a GFDM full-duplex BS transceiver with optimal filters is proposed to enhance the SE of both uplink and downlink transmissions. Moreover, the SE enhancement of secondary links in cognitive radios is studied. It is shown that the proposed GFDM-based full-duplex secondary links significantly improve the achievable SE in the presence of RF impairments and adjacent channel interference (ACI) constraints. However, it is also shown that RF impairments may negatively impact potential SE gains. Therefore, standard estimators and deep learning (DL) algorithms are proposed for RF impairment compensation in channel estimation and data detection for GFDM and multiple-input multiple-output (MIMO)-GFDM full-duplex systems. This thesis demonstrates that the non-orthogonal designs enhance the SE. Moreover, the RF impairments limit the SE gain, while the proposed compensation algorithms eliminate their impacts.

  • Subjects / Keywords
  • Graduation date
    Spring 2022
  • Type of Item
  • Degree
    Doctor of Philosophy
  • DOI
  • License
    This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.