36 research outputs found
Convolutional neural network-based hybrid beamforming design based on energy efficiency for mmWave M-MIMO systems
Get PDFMillimeter-wave (mmWave) massive multiple-input multiple-output (M- MIMO) technology brings significant improvements in data transmission rates for communication systems. A key to the design of mmWave M-MIMO systems is beamforming techniques, which focus signals toward specific directions but rely on expensive, energy-intensive radio frequency (RF) chains. To address this issue, hybrid beamformers (HB) have been introduced as a partial solution, and deep learning (DL) has proven effective for HB design. However, previous works utilizing machine learning (ML) networks have primarily focused on the spectral efficiency (SE) metric for constructing HB. In this paper, we present a convolutional neural network (CNN) architecture whose loss function is defined to maximize energy efficiency (EE) directly. The network jointly learns analog and digital beamformers by evaluating EE (throughput per total power, including phase shifters, switches, digital-to-analog converters (DACs), and RF chains) and selecting the configuration that yields the highest EE. The CNN takes a channel matrix as input and outputs RF and baseband beamformer matrices. Simulation results validate the effectiveness of the proposed M-MIMO EE scheme, achieving significant EE improvements by optimizing hybrid precoding and reducing RF chain usage
Synthese de reseaux non periodiques d'antennes microruban a loi d'alimentation uniforme ou predeterminee
No full textCNRS T Bordereau / INIST-CNRS - Institut de l'Information Scientifique et TechniqueSIGLEFRFranc
ALTERNATIVE LOW-COMPLEXITY APPROACHES FOR PAPR REDUCTION IN FBMC-OQAM SYSTEMS
Get PDFRecently, the Filter Bank Multi-Carrier with Offset-QAM modulation (FBMC-OQAM) system proved to be a strong candidate wave that can replace the conventional OFDM (Orthogonal Frequency Division Multiplexing) through several properties in future mobile generations (5G and 5G+). However, it faces a significant issue, which is high Peak-to-Average-Power-Ratio (PAPR) as all advanced waveforms. Many researchers have proposed either hybrid or non-hybrid techniques adapted to the FBMC-OQAM structure to minimize the PAPR parameter. Nevertheless, all of these techniques suffer from high complexity, which is a significant challenge in practical implementations. Therefore, in this paper, we propose two alternative low-complexity approaches, TD and TC, to effectively mitigate the PAPR problem in FBMC-OQAM systems. Both proposed hybrid schemes achieve superior PAPR performance compared to the conventional TR and very competitive results in comparison to the existing literature algorithms while requiring less computational complexity
Cooperative Multiagents Detection and Beamforming with Spherical Array Sensors
Get PDFDigital Information Processing and Communications,
Communications in Computer and Information Science, ISSN :1865-0929, Volume 189, pp 460-469, July 7-9, 2011.In this paper multi-agents systems are presented as a new design paradigm that allows an efficient use of multiprocessor architectures and distributed systems architectures currently widely available and preferred. Moreover, in our case, multiagent systems will bring the concepts of artificial intelligence, collaboration principles, autonomy, proactive behavior and communications possibility. Adopting a multiagent approach on spherical array sensors for both sources detection and spatial filtering will provide several issues: simultaneous several signals acquisition, effective spatial filttering, optimal performance under the imposed environment circumstances and prompt reaction and treatment
Analytical bound for the CCDF of Crest Factor in NC-OFDM Systems
Get PDFNon-contiguous orthogonal frequency division multiplexing (NC-OFDM) is a promising framework for wireless communication systems due to OFDM characteristics like the spectral bandwidth efficiency, robustness to frequency selective fading channels, etc. However, it has been widely known that multicarrier signals generated by OFDM technique exhibit a large peak to average power ration (PAPR), one of the main impediment that has limited the applicability of OFDM systems. Several approaches are employed in literature to derive the PAPR distribution and thus try to reduce it in OFDM context, as Central limit theorem and modern extreme value theory. In new contexts like NC OFDM systems when flexible access to spectrum is done with non contiguous portions, the PAPR distribution remains generally unknown, and it is necessary to describe it, since this is one of the key design parameters. In this correspondence, we develop the PAPR bound expression in NC-OFDM context
A Comparative Study of Aspect-Oriented and Object-Oriented Implementations: Pervasive System Use Case
No full text
