3 research outputs found
Joint In-Band Backhauling and Interference Mitigation in 5G Heterogeneous Networks
In this paper, we study the problem of joint inband backhauling and
interference mitigation in 5G heterogeneous networks (HetNets) in which a
massive multiple-input multipleoutput (MIMO) macro cell base station equipped
with a large number of antennas, overlaid with self-backhauled small cells is
assumed. This problem is cast as a network utility maximization subject to
wireless backhaul constraints. Due to the non-tractability of the problem, we
first resort to random matrix theory to get a closed-form expression of the
achievable rate and transmit power in the asymptotic regime, i.e., as the
number of antennas and users grows large. Subsequently, leveraging the
framework of stochastic optimization, the problem is decoupled into dynamic
scheduling of macro cell users and backhaul provisioning of small cells as a
function of interference and backhaul links. Via simulations, we evaluate the
performance gains of our proposed framework under different network
architectures and low/high frequency bands. Our proposed HetNet method achieves
the achievable average UE throughput of 1.7 Gbps as well as ensures 1 Gbps
cell-edge UE throughput when serving 200 UEs per km2 at 28 GHz with 1 GHz
bandwidth. In ultra-dense network, the UE throughput at 28 GHz achieves 62x
gain as compared to 2.4 GHz.Comment: 22th European Wireless Conference, 2016, Best Paper Awar
User-Centric Joint Access-Backhaul Design for Full-Duplex Self-Backhauled Wireless Networks
Full-duplex self-backhauling is promising to provide cost-effective and
flexible backhaul connectivity for ultra-dense wireless networks, but also
poses a great challenge to resource management between the access and backhaul
links. In this paper, we propose a user-centric joint access-backhaul
transmission framework for full-duplex self-backhauled wireless networks. In
the access link, user-centric clustering is adopted so that each user is
cooperatively served by multiple small base stations (SBSs). In the backhaul
link, user-centric multicast transmission is proposed so that each user's
message is treated as a common message and multicast to its serving SBS
cluster. We first formulate an optimization problem to maximize the network
weighted sum rate through joint access-backhaul beamforming and SBS clustering
when global channel state information (CSI) is available. This problem is
efficiently solved via the successive lower-bound maximization approach with a
novel approximate objective function and the iterative link removal technique.
We then extend the study to the stochastic joint access-backhaul beamforming
optimization with partial CSI. Simulation results demonstrate the effectiveness
of the proposed algorithms for both full CSI and partial CSI scenarios. They
also show that the transmission design with partial CSI can greatly reduce the
CSI overhead with little performance degradation.Comment: to appear in IEEE Trans. on Communication
Wireless Backhaul in 5G and Beyond: Issues, Challenges and Opportunities
With the introduction of new technologies such as Unmanned Aerial Vehicle
(UAV), High Altitude Platform Station (HAPS), Millimeter Wave (mmWave)
frequencies, Massive Multiple-Input Multiple-Output (mMIMO), and beamforming,
wireless backhaul is expected to be an integral part of the 5G networks. While
this concept is nothing new, it was shortcoming in terms of performance
compared to the fiber backhauling. However, with these new technologies, fiber
is no longer the foremost technology for backhauling. With the projected
densification of networks, wireless backhaul has become mandatory to use. There
are still challenges to be tackled if wireless backhaul is to be used
efficiently. Resource allocation, deployment, scheduling, power management and
energy efficiency are some of these problems. Wireless backhaul also acts as an
enabler for new technologies and improves some of the existing ones
significantly. To name a few, rural connectivity, satellite communication, and
mobile edge computing are some concepts for which wireless backhauling acts as
an enabler. Small cell usage with wireless backhaul presents different security
challenges. Governing bodies of cellular networks have standardization efforts
going on especially for the Integrated Acces-Backhaul (IAB) concept, and this
is briefly mentioned. Finally, wireless backhaul is also projected to be an
important part of the beyond 5G networks, and newly developed concepts such as
cell-free networking, ultra-massive MIMO, and extremely dense network show this
trend as well. In this survey, we present the aforementioned issues,
challenges, opportunities, and applications of wireless backhaul in 5G, while
briefly mentioning concepts related to wireless backhaul beyond 5G alongside
with security and standardization issues