Adaptive power permutation modulation: A novel transmission technique for increased spectral efficiency over fading channels


ÖZYURT S.

International Journal of Communication Systems, vol.37, no.3, 2024 (SCI-Expanded) identifier

  • Publication Type: Article / Article
  • Volume: 37 Issue: 3
  • Publication Date: 2024
  • Doi Number: 10.1002/dac.5667
  • Journal Name: International Journal of Communication Systems
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aerospace Database, Communication & Mass Media Index, Communication Abstracts, Compendex, INSPEC, Metadex, zbMATH, Civil Engineering Abstracts
  • Keywords: multiple-input multiple-output, orthogonal frequency division multiplexing, power allocation, power permutation, spectral efficiency
  • Ankara Yıldırım Beyazıt University Affiliated: Yes

Abstract

In this study, we propose a novel transmission technique for multiple-input multiple-output (MIMO) systems as a partial response to ever-growing demand for the increased spectral efficiency. The introduced scheme, called adaptive power permutation modulation (APPM), relies on the distinct power allocations on the conventionally modulated symbols to convey a certain number of additional information bits. Unlike the traditional power allocation strategies which generally aim to combat the channel fading and entail some form of channel state information (CSI) at the transmit side, APPM utilizes different power levels to convey additional information and does not necessitate any kind of CSI at the transmitter. The proposed approach is applied to two well-known MIMO configurations, Alamouti space-time block coding and zero-forcing beamforming, by embracing a general frequency-selective fading scenario under digital phase modulation. Both the modulation order and the power allocation levels on the modulated symbols are adaptively determined based on a set of additional information bits. It is shown that in addition to the conventionally modulated symbols, an extra sequence of (Formula presented.) bits can be conveyed without any significant additional complexity where (Formula presented.) equals the number of subcarriers. Also, it is demonstrated that considerable transmit power savings can be attained when compared with the standard schemes under a certain target spectral efficiency.