1,555 research outputs found
Outdoor to Indoor Penetration Loss at 28 GHz for Fixed Wireless Access
This paper present the results from a 28 GHz channel sounding campaign
performed to investigate the effects of outdoor to indoor penetration on the
wireless propagation channel characteristics for an urban microcell in a fixed
wireless access scenario. The measurements are performed with a real-time
channel sounder, which can measure path loss up to 169 dB, and equipped with
phased array antennas that allows electrical beam steering for directionally
resolved measurements in dynamic environments. Thanks to the short measurement
time and the excellent phase stability of the system, we obtain both
directional and omnidirectional channel power delay profiles without any delay
uncertainty. For outdoor and indoor receiver locations, we compare path loss,
delay spreads and angular spreads obtained for two different types of
buildings
Millimeter-wave Evolution for 5G Cellular Networks
Triggered by the explosion of mobile traffic, 5G (5th Generation) cellular
network requires evolution to increase the system rate 1000 times higher than
the current systems in 10 years. Motivated by this common problem, there are
several studies to integrate mm-wave access into current cellular networks as
multi-band heterogeneous networks to exploit the ultra-wideband aspect of the
mm-wave band. The authors of this paper have proposed comprehensive
architecture of cellular networks with mm-wave access, where mm-wave small cell
basestations and a conventional macro basestation are connected to
Centralized-RAN (C-RAN) to effectively operate the system by enabling power
efficient seamless handover as well as centralized resource control including
dynamic cell structuring to match the limited coverage of mm-wave access with
high traffic user locations via user-plane/control-plane splitting. In this
paper, to prove the effectiveness of the proposed 5G cellular networks with
mm-wave access, system level simulation is conducted by introducing an expected
future traffic model, a measurement based mm-wave propagation model, and a
centralized cell association algorithm by exploiting the C-RAN architecture.
The numerical results show the effectiveness of the proposed network to realize
1000 times higher system rate than the current network in 10 years which is not
achieved by the small cells using commonly considered 3.5 GHz band.
Furthermore, the paper also gives latest status of mm-wave devices and
regulations to show the feasibility of using mm-wave in the 5G systems.Comment: 17 pages, 12 figures, accepted to be published in IEICE Transactions
on Communications. (Mar. 2015
Design of a Practical and Compact mm-Wave MIMO System with Optimized Capacity and Phased Arrays
In this paper we evaluate the feasibility of short range outdoor mm-wave MIMO links in the 70 GHz portion of the E-band (71–76 GHz). We use phased arrays in order to strongly reduce the impact of the multipath components, thus making the channel mainly line-of-sight (LOS). We design the array using a simple patch as a single element and simulate the performances for a 200 m link and a MIMO system with equal element spacing at the transmitter and the receiver. Each node of the MIMO system consists of a uniform rectangular array (URA) where the single element is a patch antenna, in order to achieve higher gains and narrow beams. Such configuration is much more compact compared to the antennas currently employed for the same bandwidth. We optimize the interelement distances at the transmitter and the receiver and evaluate the capacity achievable with different array sizes. The results show that, for the proposed link budget, capacity up to 29 bit/s/Hz is achievable at a range of 200 m, with practical dimensions. We also show that the beamforming capabilities make the design much more flexible than the single reflector antenna systems. In the last part of the paper, we verify that our antenna can also operate in rainy conditions and longer ranges
Dual-polarized 28-GHz air-filled SIW phased antenna array for next-generation cellular systems
A high-performance dual-polarized eight-element air-filled substrate-integrated-waveguide (AFSIW) cavity-backed patch antenna array is presented. The antenna operates in the [26.5-29.5] GHz band and provides a stable high data-rate wireless communication link between end-user terminals and access points in next-generation cellular systems. Its topology is carefully selected to maximize the performance of the array. In addition, by combining the AFSIW technology with a new antenna architecture, a low-profile, low-cost, stable, and high-performance array design is guaranteed. A prototype was fabricated and validated, demonstrating a wide active impedance bandwidth over ±35 o scanning range and low-cross polarization level within the entire frequency band
- …