Designing multi-user MIMO for energy efficiency: When is massive MIMO the answer?
2014 (English)In: IEEE Wireless Communications and Networking Conference, WCNC, 2014, 242-247 p.Conference paper (Refereed)
Assume that a multi-user multiple-input multiple-output (MIMO) communication system must be designed to cover a given area with maximal energy efficiency (bits/Joule). What are the optimal values for the number of antennas, active users, and transmit power? By using a new model that describes how these three parameters affect the total energy efficiency of the system, this work provides closed-form expressions for their optimal values and interactions. In sharp contrast to common belief, the transmit power is found to increase (not decrease) with the number of antennas. This implies that energy efficient systems can operate at high signal-to-noise ratio (SNR) regimes in which the use of interference-suppressing precoding schemes is essential. Numerical results show that the maximal energy efficiency is achieved by a massive MIMO setup wherein hundreds of antennas are deployed to serve relatively many users using interference-suppressing regularized zero-forcing precoding.
Place, publisher, year, edition, pages
2014. 242-247 p.
Antennas, Communication channels (information theory), MIMO systems, Optimal systems, Signal to noise ratio, Wireless telecommunication systems, Closed-form expression, Energy efficient systems, High signalto-noise ratios (SNR), Multi user multiple input multiple outputs, Multi-user MIMO, Numerical results, Precoding scheme, Three parameters, Energy efficiency
IdentifiersURN: urn:nbn:se:kth:diva-168366DOI: 10.1109/WCNC.2014.6951974ScopusID: 2-s2.0-84912091959ISBN: 9781479930838OAI: oai:DiVA.org:kth-168366DiVA: diva2:816083
2014 IEEE Wireless Communications and Networking Conference, WCNC 2014; Istanbul; Turkey; 6 April 2014 through 9 April 2014
QC 201506022015-06-022015-06-022015-06-02Bibliographically approved