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Analog optics [1], commonly termed microwave photonics [2], is a decades-old field that offers well-cited advantages over analog and digital electronics. The two most important features in most, if not all, deployable use cases are low propagation loss in fiber and wide bandwidth. Indeed, the massive fiber telecommunications industry was born from simultaneous utilization of these two advantages over...
In this paper, we propose a novel mixed-signal cancellation circuit for LTE carrier aggregation receivers targeting modulated spur interference. This circuit senses interference via an auxiliary analog path, and generates a reference signal for the adaptive digital cancellation. To evaluate the performance of the proposed technique, a demonstrator, realized in 28 nm LP CMOS, is shown with a cancellation...
RF self-interference cancellation for Full-Duplex communication with a microwave photonic technique is proposed and demonstrated experimentally. It is based on an integrated dual-parallel Mach-Zehnder modulator (DP-MZM), where the sub-MZMs (MZM1 and MZM2) are biased at the quadrature point and the minimum point, respectively. It avoids the optical interference at the combining Y branch waveguide....
Hybrid precoding provides a compromise between the system performance and the implementation complexity in millimeter wave (mmWave) systems, while cloud radio access network (C-RAN) is a green network composed of central baseband unit (BBU), distributed low-cost remote radio heads (RRHs) and low-latency fronthaul links connecting BBU and RRHs. This paper jointly optimizes the user scheduling and hybrid...
This paper investigates a large-scale cognitive radio network with primary users (PUs) and secondary users (SUs) spatially and randomly distributed. All the PUs need to harvest wireless energy from their associated access points (APs) before transmitting information. To combat the low efficiency of wireless power transfer caused by the severe path-loss, we propose to apply an energy cooperation zone...
In this paper, a non-orthogonal multiple access cognitive radio network with simultaneous wireless information and power transfer is studied under a practical non-linear energy harvesting model. A multi-objective optimization problem(MOOP) is formulated to maximize the harvesting power of each energy harvesting receiver. This problem is non-convex and challenging to be solved. The weighted Tchebycheff...
Microring weight banks enable reconfiguration in analog photonic networks and multi-channel RF front-ends. We demonstrate 2-ring weight banks and show that they are tolerant to fabrication and thermal effects. Weights consisting of two microrings can potentially increase channel capacity by a factor of 2.72-fold.
In this paper, we propose hybrid beamforming scheme for multi-user transmission in millimeter wave (mmWave) communications. The sum rate maximization problem considering limited feedback is formulated and solved by the joint scheduling and hybrid beamforming algorithm with two-stage channel state information (CSI) feedback framework. In the proposed scheme, the base station (BS) first narrows down...
With the explosive growth of mobile data demand, exploiting millimeter wave (mmWave) frequency band is regarded as a promising solution in the fifth-generation (5G) cellular networks. In each generation of cellular networks, cell planning (CP) is the primary stage before deployment. However, due to mmWave's characteristics being different from traditional microwave at relatively low frequency, CP...
In order to satisfy rate requirement in the enhanced mobile broadband (eMBB) application group, wireless technologies as Air Interfaces (AI) are widely studied, including non-orthogonal multiple access (NOMA) and massive multiple-input multiple-output (mMIMO). In this paper, we propose a Minorization-Maximization (MM) based hybrid precoding scheme in NOMA-mMIMO system. Firstly, we introduce a user...
Cognitive radio network (CRN) is regarded as an emerging technology for better spectrum efficiency where unlicensed secondary users (SUs) sense RF spectrum to find idle channels and access them opportunistically without causing any harmful interference to licensed primary users (PUs). However, RF spectrum sensing and sharing along with reconfigurable capabilities of SUs bring severe security vulnerabilities...
In this paper, we study the electrical performance of a flip-chip ball grid array package assembled with a alloy steel stiffener on top. The metal plate on the chip package could create the cavity resonance at sensitive frequency bands, thus introducing couplings and interferences among high speed digital signals and analog or radio frequency signals. It affects the signal transmission, such as impedance...
A multi-fidelity simulation-based workflow is presented as an efficient means of achieving interference-free design for electronic devices. By using desensitization, or “desense”, as the primary figure of merit, this work flow is achieved in three stages: 1) Identification of high-risk sources of radiation from the printed circuit board (PCB) using signal integrity (SI) simulation models that already...
With an abundance of wireless devices saturating daily life, the ability of devices to coexist among other devices is of increasing interest. While standards are starting to incorporate coexistence measurements, the robustness of coexistence measurement methods is still an area of active research. To demonstrate the robustness of the multiple test methods, a series of measurements needs to be conducted...
The RTCA DO-260B document has stimulated since a few years ago the adoption of novel algorithms to improve the ability of receivers to detect and decode ADS-B signals, with particular emphasis on preamble detection, declaration of bit state and confidence level, detection and correction of errors. Motivated by an industry-driven project, this paper reports on performance analysis of a set of enhanced...
5G network is visualized to simplify the burden on current cellular infrastructure by offering significantly higher data rates through increased channel bandwidth. 5G communication system is expected toexploit spectrum band at millimeter wave (mmWave)frequencies. But the mobile communication at these mmWave spectrum band is far more complex than the current frequencies that are being used around the...
In this paper, big Radio Frequency (RF) data assisted optimization is considered for future wireless networks employing cognitive radio technology with machine learning capability. A cognitive radio network (CRN) with multiple Secondary Users (SUs) may coexist with other wireless systems such as Small Cells (SC) and Radar systems, both Primary Users (PUs) with different level of priorities. Traditional...
This paper targets empirical voice and video quality assessment in mobile networks and presents fundamental QoS testing methods in correlation to RF indicators. The paper focuses on the most critical performance parameters for real-time services (e.g. voice) such as call drop vs. poor coverage in UMTS. The empirical study was based on a clearly defined drive test scenario with predetermined routes...
This work investigates the downlink resource allocation (RA) problem in orthogonal frequency division multiplexing (OFDM)-based cognitive radio networks. The objective of this work is to develop a fair RA-algorithm that maximizes the capacity of secondary users (SUs) and in the same time limits the interference caused to the primary users. The fairness condition is formulated as a minimal data condition...
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