719 research outputs found
Spectral Efficiency of MIMO Millimeter-Wave Links with Single-Carrier Modulation for 5G Networks
Future wireless networks will extensively rely upon bandwidths centered on
carrier frequencies larger than 10GHz. Indeed, recent research has shown that,
despite the large path-loss, millimeter wave (mmWave) frequencies can be
successfully exploited to transmit very large data-rates over short distances
to slowly moving users. Due to hardware complexity and cost constraints,
single-carrier modulation schemes, as opposed to the popular multi-carrier
schemes, are being considered for use at mmWave frequencies. This paper
presents preliminary studies on the achievable spectral efficiency on a
wireless MIMO link operating at mmWave in a typical 5G scenario. Two different
single-carrier modem schemes are considered, i.e. a traditional modulation
scheme with linear equalization at the receiver, and a single-carrier
modulation with cyclic prefix, frequency-domain equalization and FFT-based
processing at the receiver. Our results show that the former achieves a larger
spectral efficiency than the latter. Results also confirm that the spectral
efficiency increases with the dimension of the antenna array, as well as that
performance gets severely degraded when the link length exceeds 100 meters and
the transmit power falls below 0dBW. Nonetheless, mmWave appear to be very
suited for providing very large data-rates over short distances.Comment: 8 pages, 8 figures, to appear in Proc. 20th International ITG
Workshop on Smart Antennas (WSA2016
MmWave Massive MIMO Based Wireless Backhaul for 5G Ultra-Dense Network
Ultra-dense network (UDN) has been considered as a promising candidate for
future 5G network to meet the explosive data demand. To realize UDN, a
reliable, Gigahertz bandwidth, and cost-effective backhaul connecting
ultra-dense small-cell base stations (BSs) and macro-cell BS is prerequisite.
Millimeter-wave (mmWave) can provide the potential Gbps traffic for wireless
backhaul. Moreover, mmWave can be easily integrated with massive MIMO for the
improved link reliability. In this article, we discuss the feasibility of
mmWave massive MIMO based wireless backhaul for 5G UDN, and the benefits and
challenges are also addressed. Especially, we propose a digitally-controlled
phase-shifter network (DPSN) based hybrid precoding/combining scheme for mmWave
massive MIMO, whereby the low-rank property of mmWave massive MIMO channel
matrix is leveraged to reduce the required cost and complexity of transceiver
with a negligible performance loss. One key feature of the proposed scheme is
that the macro-cell BS can simultaneously support multiple small-cell BSs with
multiple streams for each smallcell BS, which is essentially different from
conventional hybrid precoding/combining schemes typically limited to
single-user MIMO with multiple streams or multi-user MIMO with single stream
for each user. Based on the proposed scheme, we further explore the fundamental
issues of developing mmWave massive MIMO for wireless backhaul, and the
associated challenges, insight, and prospect to enable the mmWave massive MIMO
based wireless backhaul for 5G UDN are discussed.Comment: This paper has been accepted by IEEE Wireless Communications
Magazine. This paper is related to 5G, ultra-dense network (UDN), millimeter
waves (mmWave) fronthaul/backhaul, massive MIMO, sparsity/low-rank property
of mmWave massive MIMO channels, sparse channel estimation, compressive
sensing (CS), hybrid digital/analog precoding/combining, and hybrid
beamforming. http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=730653
- …