Spatial degrees of freedom exploration and analog beamforming designs for signature spatial modulation

Yuwen Cao, Tomoaki Ohtsuki

Research output: Contribution to journalArticlepeer-review

1 Citation (Scopus)


In this paper, we focus on developing efficient multi-configuration selection mechanisms by exploiting the spatial degrees of freedom (DoF), and leveraging the simple design benefits of spatial modulation (SM). Notably, the SM technique, as well as its variants, faces the following critical challenges: (i) the performance degradation and difficulty in improving the system performance for higher-level QAM constellations, and (ii) the vast complexity cost in precoder designs particularly for the increasing system dimension and amplitude-phase modulation (APM) constellation dimension. Given this situation, we first investigate two independent modulation domains, i.e., the original signal- and spatial-constellations. By exploiting the analog shift weighting and the virtual spatial signature technologies, we introduce the signature spatial modulation (SSM) concept, which is capable of guaranteing superior trade-offs among spectral- and cost-efficiencies, and system bit error rate (BER) performance. Besides, we develop an analog beamforming for SSM by solving the introduced unconstrained Lagrange dual function minimization problem. Numerical results manifest the performance gain brought by our developed analog beamforming for SSM.

Original languageEnglish
Pages (from-to)934-941
Number of pages8
JournalIEICE Transactions on Communications
Issue number8
Publication statusPublished - 2021


  • Analog beamforming
  • Analog shift weighting
  • Signal- and spatial-constellations
  • Signature spatial modulation (SSM)
  • Spatial degrees of freedom (DoF)

ASJC Scopus subject areas

  • Software
  • Computer Networks and Communications
  • Electrical and Electronic Engineering


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