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Start Over Topic communication, networking and broadcast technologies Language undetermined Publisher ieee
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1. Constant Envelope Precoding and Non-Orthogonal Multiple Access for Massive MIMO Systems

Author

Tugrul Ozcan, Ayse Melda Yuksel Turgut, TOBB ETU, Faculty of Engineering, Department of Electrical & Electronics Engineering, TOBB ETÜ, Mühendislik Fakültesi, Elektrik ve Elektronik Mühendisliği Bölümü, and Turgut, Ayşe Melda Yüksel

Subjects
Independent and identically distributed random variables, Computer science, signal processing and analysis, engineering profession, 02 engineering and technology, Precoding, Sabit genlikli önkodlama, 5G mobile communication, massive MIMO, 0202 electrical engineering, electronic engineering, information engineering, Electronic engineering, Wireless, MUI, precoding, Rayleigh fading, business.industry, Transmitter, NOMA, dikgen olmayan çoklu erişim, 020206 networking & telecommunications, Communication, networking and broadcast technologies, wireless communication, energy states, CE precoding, Transmission (telecommunications), yoğun çok girdili çok çıktılı sistemler, business, çok kullanıcılı girişimi, tutorials, Communication channel
Abstract

28th Signal Processing and Communications Applications Conference, SIU (2020; Gaziantep, Turkey), Constant Envelope (CE) precoding is a transmission technique, which provides efficient power amplification and can be realised with a single radio frequency (RF) chain at the multi-antenna transmitter. In this paper, we study the multi-user massive MIMO broadcast channel with CE precoding and with non-orthogonal multiple access (NOMA). The motivation for this is to provide different multi-user interferance (MUI) energy levels to different users with different MUI requirements. Wepair users according to their channel conditions and examine the impact of the NOMA on MUI. Simulations for the independent and identically distributed Rayleigh fading channel show that different MUI energy levels is possible with NOMA under CE precoding., Sabit genlikli önkodlama, çok antenli ileticide tek bir radyo frekans zinciri kullanarak, etkili ve uygulanabilir güç yükseltimi sağlayan bir iletim tekniğidir. Bu bildiride, yoğun çok girdili çok çıktılı ve çok kullanıcıya iletim yapılan sistemlerde sabit genlikli önkodlama kullanımı incelenmektedir. Kullanıcılara iletim yapılırken dikgen olmayan çoklu erişim kullanılmaktadır. Bu yöntemle, farklı ihtiyaçlara sahip kullanıcılar için farklı girişim enerjisi seviyeleri sağlamak hedeflenmiştir. Kullanıcıların kanal durumları gözetilerek kullanıcı eşleştirme tekniği kullanılmış ve dikgen olmayan çoklu erişimin kullanıcılarda elde edilen girişim enerjisi üzerindeki etkisi incelenmiştir. Bağımsız ve eş dağılıma sahip Rayleigh sönümlü kanallar üzerinde yapılan benzetim sonuçlarına göre dikgen olmayan çoklu erişim kullanıldığında farklı seviyelerde çok kullanıcılı girişim ene

Published
2020

2. Analysis and design of complex impedance transforming marchand baluns

Author

Rasmus S. Michaelsen, Tom K. Johansen, and Kjeld M. Tamborg

Subjects
Engineering, Reactance, Impedance matching, Phase (waves), Capacitors, law.invention, Mathematical model, Balun, law, Microwave theory and techniques, Insertion loss, Electrical impedance, Monolithic microwave integrated circuit, Aerospace, Ports (Computers), Photonics and Electrooptics, business.industry, Electrical engineering, Impedance, Components, Circuits, Devices and Systems, Communication, Networking and Broadcast Technologies, Complex impedance transformation, Capacitor, Signal Processing and Analysis, Integrated circuit modeling, MMIC, business, Fields, Waves and Electromagnetics, Marchand balun
Abstract

A new type of Marchand balun is presented in this paper, which has the property of complex impedance transformation. To allow the Marchand balun to transform between arbitrary complex impedances, three reactances should be added to the circuit. A detailed analysis of the circuit gives the governing equations. To verify the theory, a design and electromagnetic simulation of a lumped element Marchand balun is made in a SiGe BiCMOS technology. The lumped element impementation is favorable because capacitors are placed where the additional reactances should be added. Thus it is possible to absorb a positive reactance by reducing a capacitor. At the design frequency of 10.5 GHz it matches 50Ω to 50 - j66Ω. It has an insertion loss of 5.1 dB, an input reflection of −20.8 dB, as well as phase and magnitude imbalance better than 0.2° and 0.12 dB, respectively.

Published
2014