184 research outputs found
Power saving and optimal hybrid precoding in millimeter wave massive MIMO systems for 5G
The proliferation of wireless services emerging from use cases offifth-generation(5G) technology is posing many challenges on cellular communicationinfrastructure. They demand to connect a massive number of devices withenhanced data rates. The massive multiple-input multiple-output (MIMO)technology at millimeter-wave (mmWave) in combination with hybrid precodingemerges as a concrete tool to address the requirements of 5G networkdevelopments. But Massive MIMO systems consume significant power fornetwork operations. Hence the prior role is to improve the energy efficiency byreducing the power consumption. This paper presents the power optimizationmodels for massive MIMO systems considering perfect channel state information(CSI) and imperfect CSI. Further, this work proposes an optimal hybrid precodingsolution named extended simultaneous orthogonal matchingpursuit (ESOMP).Simulation results reveal that a constant sum-rate can be achieved in massiveMIMO systems while significantly reducing the power consumption. Theproposed extended SOMPhybrid precoder performsclose to the conventionaldigital beamforming method. Further, modulation schemes compatible withmassive MIMO systems are outlined and their bit error rate (BER) performance isinvestigate
Near-field Hybrid Beamforming for Terahertz-band Integrated Sensing and Communications
Terahertz (THz) band communications and integrated sensing and communications
(ISAC) are two main facets of the sixth generation wireless networks. In order
to compensate the severe attenuation, the THz wireless systems employ large
arrays, wherein the near-field beam-squint severely degrades the beamforming
accuracy. Contrary to prior works that examine only either narrowband ISAC
beamforming or far-field models, we introduce an alternating optimization
technique for hybrid beamforming design in near-field THz-ISAC scenario. We
also propose an efficient approach to compensate near-field beam-squint via
baseband beamformers. Via numerical simulations, we show that the proposed
approach achieves satisfactory spectral efficiency performance while accurately
estimating the near-field beamformers and mitigating the beam-squint without
additional hardware components.Comment: Accepted Paper in 2023 IEEE Global Communications Conference
(GLOBECOM), Kuala Lumpur, Malaysia, 202
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