459 research outputs found
Efficient Fast-Convolution-Based Waveform Processing for 5G Physical Layer
This paper investigates the application of fast-convolution (FC) filtering
schemes for flexible and effective waveform generation and processing in the
fifth generation (5G) systems. FC-based filtering is presented as a generic
multimode waveform processing engine while, following the progress of 5G new
radio standardization in the Third-Generation Partnership Project, the main
focus is on efficient generation and processing of subband-filtered cyclic
prefix orthogonal frequency-division multiplexing (CP-OFDM) signals. First, a
matrix model for analyzing FC filter processing responses is presented and used
for designing optimized multiplexing of filtered groups of CP-OFDM physical
resource blocks (PRBs) in a spectrally well-localized manner, i.e., with narrow
guardbands. Subband filtering is able to suppress interference leakage between
adjacent subbands, thus supporting independent waveform parametrization and
different numerologies for different groups of PRBs, as well as asynchronous
multiuser operation in uplink. These are central ingredients in the 5G waveform
developments, particularly at sub-6-GHz bands. The FC filter optimization
criterion is passband error vector magnitude minimization subject to a given
subband band-limitation constraint. Optimized designs with different guardband
widths, PRB group sizes, and essential design parameters are compared in terms
of interference levels and implementation complexity. Finally, extensive coded
5G radio link simulation results are presented to compare the proposed approach
with other subband-filtered CP-OFDM schemes and time-domain windowing methods,
considering cases with different numerologies or asynchronous transmissions in
adjacent subbands. Also the feasibility of using independent transmitter and
receiver processing for CP-OFDM spectrum control is demonstrated
CoMP Enhanced Subcarrier and Power Allocation for Multi-Numerology based 5G-NR Networks
With proliferation of fifth generation (5G) new radio (NR) technology, it is
expected to meet the requirement of diverse traffic demands. We have designed a
coordinated multi-point (CoMP) enhanced flexible multi-numerology (MN) for
5G-NR networks to improve the network performance in terms of throughput and
latency. We have proposed a CoMP enhanced joint subcarrier and power allocation
(CESP) scheme which aims at maximizing sum rate under the considerations of
transmit power limitation and guaranteed quality-of-service (QoS) including
throughput and latency restrictions. By employing difference of two concave
functions (D.C.) approximation and abstract Lagrangian duality method, we
theoretically transform the original non-convex nonlinear problem into a
solvable maximization problem. Moreover, the convergence of our proposed CESP
algorithm with D.C. approximation is analytically derived with proofs, and is
further validated via numerical results. Simulation results demonstrated that
our proposed CESP algorithm outperforms the conventional non-CoMP and single
numerology mechanisms along with other existing benchmarks in terms of lower
latency and higher throughput under the scenarios of uniform and edge users
Resource Optimization with Flexible Numerology and Frame Structure for Heterogeneous Services
We explore the potential of optimizing resource allocation with flexible
numerology in frequency domain and variable frame structure in time domain, in
presence of services with different types of requirements. We analyze the
computational complexity and propose a scalable optimization algorithm based on
searching in both the primal space and dual space that are complementary to
each other. Numerical results show significant advantages of adopting
flexibility in both time and frequency domains for capacity enhancement and
meeting the requirements of mission critical services.Comment: 4 page
Optimization of Mixed Numerology Profiles for 5G Wireless Communication Scenarios
The management of 5G resources is a demanding task, requiring proper planning of operating numerology indexes and spectrum allocation according to current traffic needs. In addition, any reconfigurations to adapt to the current traffic pattern should be minimized to reduce signaling overhead. In this article, the pre-planning of numerology profiles is proposed to address this problem, and a mathematical optimization model for their planning is developed. The idea is to explore requirements and impairments usually present in a given wireless communication scenario to build numerology profiles and then adopt one of the profiles according to the current users/traffic pattern. The model allows the optimization of mixed numerologies in future 5G systems under any wireless communication scenario, with specific service requirements and impairments, and under any traffic scenario. Results show that, depending on the granularity of the profiles, the proposed optimization model is able to provide satisfaction levels of 60–100%, whereas a non-optimized approach provides 40–65%, while minimizing the total number of numerology indexes in operation.Competitiveness and Internationalization Operational Programme (COMPETE 2020), the Regional Operational Program of the Algarve (2020), and Fundação para a Ciência e Tecnologia; i-Five:
Extensão do acesso de espectro dinâmico para rádio 5G, POCI-01-0145-FEDER-030500. This work
is also supported by Fundação para a ciência e Tecnologia within CEOT (Center for Electronic,
Optoelectronic and Telecommunications) and the UID/MULTI/00631/2020 projectinfo:eu-repo/semantics/publishedVersio
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