Massive but few active MIMO

Dushyantha A. Basnayaka, Marco Di Renzo, Harald Haas

Research output: Contribution to journalArticlepeer-review


In this paper, an emerging wireless communication concept, which is termed as spatial modulation (SM) for largescale multiple-input-multiple-output (MIMO), is considered. The results show that from the information-theoretic perspective, SM achieves capacity comparable to the open-loop MIMO capacity, although a subset of transmit antennas is activated in every channel use because both the channel coefficients and the input symbols carry information in SM. As a result, SM compensates the loss of information capacity due to a subset of antennas being activated by modulating information in the antenna index; therefore, the total information rate remains high. In particular, an upper bound for the capacity of SM is derived in closed form, and it is shown analytically that this upper bound is almost certainly achievable in the massive MIMO regime. Moreover, it is shown that the upper bound is achievable with no channel state information at the transmitter (CSIT) but with channel distribution information (CDI) at the transmitter (CDIT). The optimum transmission strategy should adapt the channel input distribution to fading using CDI such as the K factor in Rician fading or the shape parameter m in Nakagami-m fading.

Original languageEnglish
Article number7298445
Pages (from-to)6861-6877
Number of pages17
JournalIEEE Transactions on Vehicular Technology
Issue number9
Early online date14 Oct 2015
Publication statusPublished - 1 Sep 2016


  • Capacity
  • Channel distribution information (CDI)
  • Channel state information (CSI)
  • Channel state information at the transmitter (CSIT)
  • Massive multiple-input multiple-output (MIMO)
  • Spatial modulation (SM)


Dive into the research topics of 'Massive but few active MIMO'. Together they form a unique fingerprint.

Cite this