Abstract Signal conversion plays an important role in many applications such as communication, sensing, and imaging. Realizing signal between optical microwave frequencies is a crucial step to construct hybrid communication systems that combine both wireless technologies achieve better features, which are highly desirable the future communications. However, process typically requires complicated relay perform multiple operations, will consume additional hardware/time/energy resources. Here,...

Existing indoor positioning methods for visible-light communication systems require large database, powerful signal processing units, additional sensors, such as gyroscopes, or the receiver placed toward a certain angle. These assumptions limit applications of in low-cost scenarios. In this paper, we propose novel framework based on angle differences arrival (ADOA) 3-D coordinate systems, which can be used receivers with image sensors photodiodes. The proposed ADOA does not to and no sensor...

A monolithic multicomponent system is proposed and implemented on a III-nitride-on-silicon platform, whereby two multiple-quantum-well diodes (MQW-diodes) are interconnected by suspended waveguide. Both MQW-diodes have an identical low-In-content InGaN/Al0.10Ga0.90N MQW structure produced the same fabrication process flow. When appropriately biased, both operate under simultaneous emission-detection mode function as transmitter receiver at time, forming in-plane full-duplex light...

Since optical links are easily blocked by obstacles in the environment, they have been considered difficult to directly perform wireless communications. However, reconfigurable intelligent surfaces (RISs), as a new type of digital coding meta-materials, can significantly improve coverage communication establishing links. We propose controllable multi-branch system based on RISs. By setting up multiple RISs artificial channels built performance and reduce outage probability. In this paper, we...

It is difficult for free space optical communication to be applied in mobile due the obstruction of obstacles environment, which expected solved by reconfigurable intelligent surface technology. The a new type digital coding meta-materials, can reflect, compute and program electromagnetic waves real time. We purpose controllable multi-branch wireless system based on By setting up multiple artificial channels are built improve performance reduce outage probability. Three factors affecting...

Traditional visible light positioning (VLP) systems estimate receivers' coordinates based on the assumption that light-emitting diode (LED) are known accurately, which is not always practical. Even with accurate laser range finders, structural changes of buildings due to temperature, humidity, and material aging might affect LED unpredictably. Besides, when number LEDs increases, it time-consuming build a database coordinates. In this paper, we propose novel system exploiting two optical...

Programmable metasurfaces enable real-time control of electromagnetic waves in a digital coding manner, which are suitable for implementing time-domain with strong harmonic manipulation capabilities. However, the usually realized by adopting wired electrical method, is effective and robust, but there still some limitations. Here, we propose light-controllable metasurface consisting full-polarization dynamic high-speed photoelectric detection circuit, from microwave reflection spectra...

Abstract Programmable metasurfaces have brought significant advance to electromagnetic (EM) and related fields, making it easier more efficient manipulate the EM waves realize higher tuning flexibility range. However, how achieve independent control of each unit programmable metasurface in a low‐overhead wireless manner remains challenge. Here, laser‐programmable microwave is proposed constructed, which can be controlled remotely by laser intensity real time. The key design an ultra‐compact...

Radio and optical signals are two different carriers with their own distinctive features, efficient conversion is pivotal to achieve better performance wider applications in information transmission. Unlike the conventional radio‐over‐fiber system based on fiber circuit technologies, herein a laser‐to‐microwave wireless transmission scheme proposed by dual‐band time‐domain optoelectronic metasurface. By integrating high‐speed positive‐intrinsic‐negative diodes meticulously designed...

ABSTRACT The robustness against timing offsets of filter bank multi‐carrier (FBMC) is appealing for grant‐free massive access scenarios that mainly adopt asynchronous transmissions. In this work, we propose a compressed sensing based algorithm joint active user detection as well offset and channel estimation in uplink communication under the combination FBMC systems, which critical subsequent decoding or other processes at receiver. part on generalized approximate massage passing (GAMP). are...

Angle-of-arrival (AOA) estimator is the core device in visible light positioning (VLP) systems with AOA algorithms. However, existing estimators suffer from high computational complexity, narrow field-of-view (FOV), low accuracy, or power consumption. In this work, we propose a novel based on an array of tilted complementary photodiodes (CPDs), where estimator's FOV can be $2\pi$ rad, and estimation only requires solution linear equation set. The orientations CPDs are optimized respect to...

Most existing visible light positioning (VLP) systems assume vertically placed receivers, or estimate the receiver rotations through gyroscopes. Although several recent VLP can deal with arbitrary tilting of without additional sensors, frequency, algorithm efficiency and stability are still to be improved. In this work, we propose a novel rotation estimation based on eigenvalue decomposition covariance matrix direction vectors. Four more light-emitting diodes (LEDs) serve as anchors three...

In this paper, an indoor visible light communication (VLC) system with the input-dependent noise is considered. system, main caused by Gaussian noise, however, a variance depending on current input signal strength. presence of theoretical expression bit error rate (BER) for VLC using on-off keying derived. Based derived BER, optimization problem formulated to improve BER performance tilting receiver plane. The proposed proven be convex problem, which can efficiently solved specialized solver...

Optimal relay placement is studied for free-space optical multihop communication with link obstacles and infeasible regions. An optimal scheme proposed to achieve the lowest outage probability, enable links bypass of various geometric shapes, place nodes in specified available When number large, searching space can grow exponentially, thus, a grouping optimization technique reduce time. We numerically demonstrate that provide suboptimal solutions close solutions, but average time linearly...

Prior asymptotic performance analyses are based on the series expansion of moment-generating function (MGF) or probability density (PDF) channel coefficients. However, these techniques fail for lognormal fading channels because Taylor PDF a random variable is zero at origin and MGF does not have an explicit form. Although model has been widely applied in wireless communications free-space optical communications, few analytical tools available to provide elegant expressions correlated...

Free-space optical communication using ON-OFF keying (OOK) and source information transformation is proposed. It shown that the allows proposed system to detect OOK signal without requiring knowledge of instantaneous channel state probability density function (pdf) turbulence model. Analytical expressions are derived for pdf detection threshold, an upper bound obtained on average bit error rate (BER). Numerical studies show can achieve comparable performance idealized adaptive system, with a...

This paper investigates estimation of direction arrivals (DOAs) and time (TOAs) for a multi-user orthogonal frequency-division multiplexing (OFDM) system that is equipped with large-scale arrays interfered by carrier frequency offsets (CFOs). We propose novel scheme joint TOA DOA CFO compensation taking advantages receive antenna arrays. The pilot designed to balance the length performance. proposed lower complexity. After analyzing resolution estimation, we find criterion choose an...

Photon-electron interactions are essential for many areas such as energy conversion, signal processing, and emerging quantum science. However, the current demonstrations typically targeted to fiber on-chip applications lack of study in wave space. Here, we introduce a concept optoelectronic metasurface that is capable realizing direct efficient optical–microwave free The realized via hybrid integration microwave resonant meta-structures with photoresponsive material. As proof concept,...

The InGaN/GaN multiple-quantum-well (MQW) diode has selectable functionalities with emission and detection in the visible region due to MQW-based p-n junction structure, which is employed achieve on-chip optocoupling. Here, we propose fabricate a suspended MQW on an III-nitride-on-silicon platform by combination of silicon removal III-nitride backside etching. Spatial simultaneous light-emitting light-detecting functionality, detected light comes from external source, experimentally...