27 research outputs found
Hybrid Beamforming for Large Antenna Arrays with Phase Shifter Selection
This paper proposes an asymptotically optimal hybrid beamforming solution for
large antenna arrays by exploiting the properties of the singular vectors of
the channel matrix. It is shown that the elements of the channel matrix with
Rayleigh fading follow a normal distribution when large antenna arrays are
employed. The proposed beamforming algorithm is effective in both sparse and
rich propagation environments, and is applicable for both point-to-point and
multiuser scenarios. In addition, a closed-form expression and a lower-bound
for the achievable rates are derived when analog and digital phase shifters are
employed. It is shown that the performance of the hybrid beamformers using
phase shifters with more than 2-bits resolution is comparable with analog phase
shifting. A novel phase shifter selection scheme that reduces the power
consumption at the phase shifter network is proposed when the wireless channel
is modeled by Rayleigh fading. Using this selection scheme, the spectral
efficiency can be increased as the power consumption in the phase shifter
network reduces. Compared to the scenario that all of the phase shifters are in
operation, the simulation results indicate that the spectral efficiency
increases when up to 50% of phase shifters are turned off.Comment: Accepted to Transactions on Wireless Communications, 201
Efficient implementation of filter bank multicarrier systems using circular fast convolution
In this paper, filter bank-based multicarrier systems using a fast convolution approach are investigated. We show that exploiting offset quadrature amplitude modulation enables us to perform FFT/IFFT-based convolution without overlapped processing, and the circular distortion can be discarded as a part of orthogonal interference terms. This property has two advantages. First, it leads to spectral efficiency enhancement in the system by removing the prototype filter transients. Second, the complexity of the system is significantly reduced as the result of using efficient FFT algorithms for convolution. The new scheme is compared with the conventional waveforms in terms of out-of-band radiation, orthogonality, spectral efficiency, and complexity. The performance of the receiver and the equalization methods are investigated and compared with other waveforms through simulations. Moreover, based on the time variant nature of the filter response of the proposed scheme, a pilot-based channel estimation technique with controlled transmit power is developed and analyzed through lower-bound derivations. The proposed transceiver is shown to be a competitive solution for future wireless networks
European H2020 Project WORTECS Wireless Mixed Reality Prototyping
This paper presents European collaborative project WORTECS objectives and reports on the development of several radio and optical wireless prototypes and a demonstrator targeting mixed reality (MR) application. The aim is to achieve a net throughput of up to Tbps in an indoor heterogeneous network for the MR use case, which seems to be a high throughput "killer application" beyond 5G. A special routing device is associated with the demonstrator to select the most suitable wireless access technology. Post introduction to the project, an overview of the demonstrator is presented with details of the current progress of the prototypes
5G-CLARITY: 5G-Advanced Private Networks Integrating 5GNR, WiFi, and LiFi
The future of the manufacturing industry highly
depends on digital systems that transform existing
production and monitoring systems into autonomous systems fulfilling stringent requirements in
terms of availability, reliability, security, low latency, and positioning with high accuracy. In order
to meet such requirements, private 5G networks
are considered as a key enabling technology. In
this article, we introduce the 5G-CLARITY system
that integrates 5GNR, WiFi, and LiFi access networks, and develops novel management enablers
to operate 5G-Advanced private networks.
We describe three core features of 5G-CLARITY, including a multi-connectivity framework, a
high-precision positioning server, and a management system to orchestrate private network slices.
These features are evaluated by means of packet-level simulations and an experimental testbed
demonstrating the ability of 5G-CLARITY to police
access network traffic, to achieve centimeter-level
positioning accuracy, and to provision private network slices in less than one minuteThis work is supported by the European Commission’s Horizon 2020 research and innovation
program under grant agreement No 871428,
5G-CLARITY project
Results analysis and validation - D5.3
Deliverable D5.3 del projecte OneFITPostprint (author’s final draft
Towards versatile access networks (Chapter 3)
Compared to its previous generations, the 5th generation (5G) cellular network features an additional type of densification, i.e., a large number of active antennas per access point (AP) can be deployed. This technique is known as massive multipleinput multiple-output (mMIMO) [1]. Meanwhile, multiple-input multiple-output (MIMO) evolution, e.g., in channel state information (CSI) enhancement, and also on the study of a larger number of orthogonal demodulation reference signal (DMRS) ports for MU-MIMO, was one of the Release 18 of 3rd generation partnership project (3GPP Rel-18) work item. This release (3GPP Rel-18) package approval, in the fourth quarter of 2021, marked the start of the 5G Advanced evolution in 3GPP. The other items in 3GPP Rel-18 are to study and add functionality in the areas of network energy savings, coverage, mobility support, multicast broadcast services, and positionin
Architecture landscape
The network architecture evolution journey will carry on in the years ahead, driving a large scale adoption of 5th Generation (5G) and 5G-Advanced use cases with significantly decreased deployment and operational costs, and enabling new and innovative use-case-driven solutions towards 6th Generation (6G) with higher economic and societal values. The goal of this chapter, thus, is to present the envisioned societal impact, use cases and the End-to-End (E2E) 6G architecture. The E2E 6G architecture includes summarization of the various technical enablers as well as the system and functional views of the architecture