Before/after precoding massive MIMO systems for cloud radio access networks

Sangkyu Park, Chan Byoung Chae, Saewoong Bahk

Research output: Contribution to journalArticlepeer-review

15 Citations (Scopus)


In this paper, we investigate two types of in-phase and quadrature-phase (IQ) data transfer methods for cloud multiple-input multiple-output (MIMO) network operation. They are termed ¿after-precoding¿ and ¿before-precoding¿. We formulate a cloud massive MIMO operation problem that aims at selecting the best IQ data transfer method and transmission strategy (beamforming technique, the number of concurrently receiving users, the number of used antennas for transmission) to maximize the ergodic sum-rate under a limited capacity of the digital unit-radio unit link. Based on our proposed solution, the optimal numbers of users and antennas are simultaneously chosen. Numerical results confirm that the sum-rate gain is greater when adaptive ¿after/before-precoding¿ method is available than when only conventional ¿after-precoding¿ IQ-data transfer is available.

Original languageEnglish
Pages (from-to)398-406
Number of pages9
JournalJournal of Communications and Networks
Issue number4
Publication statusPublished - 2013

All Science Journal Classification (ASJC) codes

  • Information Systems
  • Computer Networks and Communications


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