78 research outputs found
Full-Duplex Cloud Radio Access Network: Stochastic Design and Analysis
Full-duplex (FD) has emerged as a disruptive communications paradigm for
enhancing the achievable spectral efficiency (SE), thanks to the recent major
breakthroughs in self-interference (SI) mitigation. The FD versus half-duplex
(HD) SE gain, in cellular networks, is however largely limited by the
mutual-interference (MI) between the downlink (DL) and the uplink (UL). A
potential remedy for tackling the MI bottleneck is through cooperative
communications. This paper provides a stochastic design and analysis of FD
enabled cloud radio access network (C-RAN) under the Poisson point process
(PPP)-based abstraction model of multi-antenna radio units (RUs) and user
equipments (UEs). We consider different disjoint and user-centric approaches
towards the formation of finite clusters in the C-RAN. Contrary to most
existing studies, we explicitly take into consideration non-isotropic fading
channel conditions and finite-capacity fronthaul links. Accordingly,
upper-bound expressions for the C-RAN DL and UL SEs, involving the statistics
of all intended and interfering signals, are derived. The performance of the FD
C-RAN is investigated through the proposed theoretical framework and
Monte-Carlo (MC) simulations. The results indicate that significant FD versus
HD C-RAN SE gains can be achieved, particularly in the presence of
sufficient-capacity fronthaul links and advanced interference cancellation
capabilities
Understanding the Computational Requirements of Virtualized Baseband Units using a Programmable Cloud Radio Access Network Testbed
Cloud Radio Access Network (C-RAN) is emerging as a transformative
architecture for the next generation of mobile cellular networks. In C-RAN, the
Baseband Unit (BBU) is decoupled from the Base Station (BS) and consolidated in
a centralized processing center. While the potential benefits of C-RAN have
been studied extensively from the theoretical perspective, there are only a few
works that address the system implementation issues and characterize the
computational requirements of the virtualized BBU. In this paper, a
programmable C-RAN testbed is presented where the BBU is virtualized using the
OpenAirInterface (OAI) software platform, and the eNodeB and User Equipment
(UEs) are implemented using USRP boards. Extensive experiments have been
performed in a FDD downlink LTE emulation system to characterize the
performance and computing resource consumption of the BBU under various
conditions. It is shown that the processing time and CPU utilization of the BBU
increase with the channel resources and with the Modulation and Coding Scheme
(MCS) index, and that the CPU utilization percentage can be well approximated
as a linear increasing function of the maximum downlink data rate. These
results provide real-world insights into the characteristics of the BBU in
terms of computing resource and power consumption, which may serve as inputs
for the design of efficient resource-provisioning and allocation strategies in
C-RAN systems.Comment: In Proceedings of the IEEE International Conference on Autonomic
Computing (ICAC), July 201
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