Journal ArticleDOI
Making smart use of excess antennas: Massive MIMO, small cells, and TDD
TLDR
It is suggested that time division duplexing (TDD) could be a key enabler for a new heterogeneous network architecture with the potential to provide ubiquitous coverage and unprecedented spectral area efficiencies.Abstract:
In this paper, we present a vision beyond the conventional Long Term Evolution Fourth Generation (LTE-4G) evolution path and suggest that time division duplexing (TDD) could be a key enabler for a new heterogeneous network architecture with the potential to provide ubiquitous coverage and unprecedented spectral area efficiencies. This architecture is based on a cochannel deployment of macro base stations (BSs) with very large antenna arrays and a secondary tier of small cells (SCs) with a few antennas each. Both tiers employ a TDD protocol in a synchronized fashion. The resulting channel reciprocity enables not only the estimation of large-dimensional channels at the BSs, but also an implicit coordination between both tiers without the need to exchange user data or channel state information (CSI) over the backhaul. In particular, during the uplink (UL), the BSs and SCs can locally estimate the dominant interference sub-space. This knowledge can be leveraged for downlink (DL) precoding to reduce intra- and inter-tier interference. In other words, the BSs and SCs “sacrifice” some of their degrees of freedom for interference rejection. Our simulation results demonstrate that the proposed architecture and precoding scheme can achieve a very attractive rate region compared to several baseline scenarios. For example, with 100 antennas at each BS and four antennas at each SC, we observe an aggregate area throughput of 7.63 Gb/s/km2 (DL) and 8.93 Gb/s/km2 (UL) on a 20 MHz band shared by about 100 mobile devices.read more
Citations
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Dissertation
Interference analysis and mitigation for heterogeneous cellular networks
Gutierrez Estevez,David Manuel +1 more
Proceedings ArticleDOI
Capacity and energy management in massive mimo and heterogeneous small cell networks
M. Bala Krishna,Puneet Bansal +1 more
TL;DR: The capacity and energy management techniques in M-MIMO and HSCN are discussed and the performance of H SCN is enhanced by using the methods such as resource allocation, user association, offloading, scheduling services in hotspots, mmWave and SDN.
Journal ArticleDOI
Deep Unfolded Extended Conjugate Gradient Method for Massive MIMO Processing with Application to Reciprocity Calibration
TL;DR: Deep unfolding the standard iterative conjugate gradient (CG) algorithm to solve a linear system of equations is considered wherein a scalar parameter is substituted by a matrix-parameter to augment the degrees of freedom per layer.
Journal ArticleDOI
Mobile Device Association and Resource Allocation in HCNs With Mobile Edge Computing and Caching
TL;DR: In this paper , a joint MD association and resource allocation is performed to minimize the total delay of mobile devices in heterogeneous cellular networks (HCNs) under the resource partitioning and resource constraints.
Book ChapterDOI
Greedy Matching-Based Pilot Allocation in Massive MIMO Systems
TL;DR: In this paper, a greedy matching-based pilot allocation (GMPA) algorithm is proposed to mitigate the impact of pilot contamination in heterogeneous cellular networks, which transforms the pilot allocation problem into matching optimization problem through matching theory.
References
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Journal ArticleDOI
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Journal ArticleDOI
On Limits of Wireless Communications in a Fading Environment when UsingMultiple Antennas
G. J. Foschini,M. J. Gans +1 more
TL;DR: In this article, the authors examined the performance of using multi-element array (MEA) technology to improve the bit-rate of digital wireless communications and showed that with high probability extraordinary capacity is available.
Journal ArticleDOI
Noncooperative Cellular Wireless with Unlimited Numbers of Base Station Antennas
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Journal ArticleDOI
Scaling Up MIMO: Opportunities and Challenges with Very Large Arrays
Fredrik Rusek,Daniel Persson,Buon Kiong Lau,Erik G. Larsson,Thomas L. Marzetta,Fredrik Tufvesson +5 more
TL;DR: The gains in multiuser systems are even more impressive, because such systems offer the possibility to transmit simultaneously to several users and the flexibility to select what users to schedule for reception at any given point in time.