Virtual multiple-input multiple-output (V-MIMO) technology promises significant performance enhancements to cellular systems in terms of spectral efficiency (SE) and energy efficiency (EE). How these two conflicting metrics scale up in large cellular V-MIMO networks is unclear. This paper studies the EE-SE trade-off of the uplink of a multi-user cellular V-MIMO system with decode-and-forward type protocols. We first express the trade-off in an implicit function and further derive closed-form formulas of the trade-off in low and high SE regimes. Unlike conventional MIMO systems, the EE-SE trade-off of the V-MIMO system is shown to be susceptible to many factors including protocol design (e.g., resource allocation) and scenario characteristics (e.g., user density). Focusing on the medium and high SE regimes, we propose a heuristic resource allocation algorithm to optimize the EE-SE trade-off. The fundamental performance limits of the optimized V-MIMO system are subsequently investigated and compared with conventional MIMO systems in different scenarios. Numerical results reveal a surprisingly chaotic behavior of V-MIMO systems when the user density scales up. Our analysis indicates that low frequency reuse factor, adaptive resource allocation, and user density control are critical to harness the full benefits of cellular V-MIMO systems.
Related Content
On the energy efficiency of base station cooperation under limited backhaul capacity
Recently, energy-efficient (EE) communications have received increasing interest specially in cellular networks. Promising techniques, such as multiple input multiple output (MIMO) and base station (BS) cooperation schemes, have been widely studied in the past to improve the spectral efficiency a...


Leakage-Aware Energy-Efficient Beamforming for Heterogeneous Multicell Multiuser Systems
Energy-efficient communications has attracted much interest in the research of 5G cellular systems. In this paper, we study energy-efficient coordinated beamforming design for heterogeneous multicell multiuser downlink systems. The considered problem is formulated as maximizing the weighted sum p...
— Invited Paper — Backscatter Communication and RFID: Coding, Energy, and MIMO Analysis
Radio Frequency IDentification (RFID) is intended to supplant legacy (optical) bar code scanning technology found in many logistic and retail applications. RFID is distinguished by inexpensive, low power and compact form factor tags, whose longevity and efficacy are predicated on using passive co...


Cognitive radio in 5G: a perspective on energy-spectral efficiency trade-off
A cognitive cellular network, which integrates conventional licensed cellular radio and cognitive radio into a holistic system, is a promising paradigm for the fifth generation mobile communication systems. Understanding the trade-off between energy efficiency, EE, and spectral efficiency, SE, in...
VLC: Beyond point-to-point communication
Due to the large growth of mobile communications over the past two decades, cellular systems have resorted to fuller and denser reuse of bandwidth to cope with the growing demand. On one hand, this approach raises the achievable system capacity. On the other hand, however, the increased interfere...

Spectral, energy and economic efficiency of relay-aided cellular networks
The authors investigate the relay-aided multicell multiple-input–multiple-output (MIMO) cellular network by comparing both the signal forwarding and interference forwarding relaying paradigms, each employing the adaptive MIMO relay scheme. The spectral, energy and economic efficiency value...
Tradeoff between energy-efficiency and spectral-efficiency by cooperative rate splitting
The trend of an increasing demand for a high-qualityuser experience, coupled with a shortage of radio resources, has necessitated more advanced wireless techniques to cooperatively achieve the required quality-of-experience enhancement. In this study, we investigate the critical problem of rate s...

Enhancing spectral-energy efficiency forLTE-advanced heterogeneous networks: a users social pattern perspective
The development of LTE-Advanced and beyond cellular networks is expected to offer considerably higher data rates than the existing 3G networks. Among the many potential technologies in LTE-Advanced systems, users?? characteristics and social behavior have been studied to improve the networks?? pe...
Traffic-aware two-dimensional dynamic network provisioning for energy-efficient cellular systems
Conventional peak-traffic-based provisioning of cellular mobile networks leads to a significant wastage of electrical energy. Therefore, we propose a novel traffic-aware two-dimensional dynamic network provisioning mechanism for enhancing the energy efficiency in orthogonal frequency division mul...

Device-to-device communications in cellular networks
Device-to-device communications enable two proximity users to transmit signal directly without going through the base station. It can increase network spectral efficiency and energy efficiency, reduce transmission delay, offload traffic for the BS, and alleviate congestion in the cellular core ne...