Fang Yang

• Ph.D
• Research Associate at Tsinghua University

Optical intelligent reflecting surface (OIRS) has attracted increasing attention due to its capability of overcoming signal blockages in visible light communication (VLC), an emerging technology for the next-generation advanced transceivers. However, current works on OIRS predominantly assume known channel state information (CSI), while its estimat...

In multi-cell downlink vehicular visible light communication (VLC) systems, vehicles at a cell edge experience lower achievable data rates compared with those at a cell center, primarily due to the weaker channel gain and inter-cell interference, leading to unfairness among vehicles. In this paper, a cooperative transmission approach is proposed fo...

Non-orthogonal multiple access (NOMA)-based visible light communication (VLC) is considered a promising technique for next generation high-speed wireless communications. The emerging optical intelligent reflecting surface (OIRS) offers significant benefits to the NOMA-based VLC, since it can mitigate signal blockage issues of VLC and improve its pe...

As transceiver elevation angles increase from small to large, existing ultraviolet (UV) non-line-of-sight (NLoS) models encounter two challenges: i) cannot estimate the channel characteristics of UV NLoS communication scenarios when there exists an obstacle in the overlap volume between the transmitter beam and the receiver field-of-view (FoV), and...

Unmanned aerial vehicles (UAVs) have gained significant attention due to their low cost and efficient deployment. Specifically, UAV-based communications hold promise to supplement the coverage limitations of terrestrial networks and achieve superior connectivity for the Internet of Things (IoT). Moreover, UAVs with visible light communication (VLC)...

Intelligent Transport Systems (ITS) are crucial for safety, efficiency, and reduced congestion in transportation. They require efficient, secure, high-speed communication. Radio Frequency (RF) technologies like Fifth Generation (5G), Beyond 5G (B5G), and Sixth Generation (6G) are promising, but spectrum scarcity mandates coexistence with Optical Wi...

Existing research on non-line-of-sight (NLoS) ultraviolet (UV) channel modeling mainly focuses on scenarios where the signal propagation process is not affected by any obstacle and the radiation intensity (RI) of the light source is uniformly distributed. To eliminate these restrictions, we propose a single-collision model for the NLoS UV channel i...

Existing studies on ultraviolet (UV) non-line-of-sight (NLoS) channel modeling primarily focus on scenarios without any obstacle, which makes them unsuitable for small transceiver elevation angles in most cases. To address this issue, a UV NLoS channel model incorporating an obstacle was investigated in this paper, where the impacts of atmospheric...

As transceiver elevation angles increase from small to large, existing ultraviolet (UV) non-line-of-sight (NLoS) models encounter two challenges: i) cannot estimate the channel characteristics of UV NLoS communication scenarios when there exists an obstacle in the overlap volume between the transmitter beam and the receiver field-of-view (FoV), and...

Intelligent reflecting surface (IRS) alters the wireless channel by dynamically adjusting the propagation of wireless signals, thereby having the ability to enhance communication performance. Due to its low power consumption, IRS is expected to play an important role in improving energy efficiency (EE). In this paper, both optical IRS (OIRS) and ra...

The existing works on ultraviolet (UV) channel modeling primarily focus on non-line-of-sight (NLoS) communication scenarios, where the UV transceiver does not need to be aligned and can communicate around obstacles. However, NLoS scenarios also face problems such as long channel delay spread and severe path loss, and consequently, these phenomena w...

The scheduling of the laser inter-satellite links (LISLs) can effectively decrease the energy consumption by deactivating idle LISLs and reduce the network latency by decreasing the average hop count through establishing appropriate dynamic LISLs, but is challenging in mega-constellations due to a large amount of satellites involved. In this paper,...

Unmanned aerial vehicles (UAVs) have gained significant attention in recent years due to their exceptional adaptability and maneuverability. This paper investigates the three-dimensional (3D) deployment of UAVs equipped with visible light communication (VLC) capabilities, aiming to maximize the sum data rate. To this end, the system model is establ...

Integrated sensing and communication (ISAC) is viewed as a crucial component of future mobile networks and has gained much interest in both academia and industry. Similar to the emergence of radio-frequency (RF) ISAC, the integration of free space optical communication and optical sensing yields optical ISAC (O-ISAC), which is regarded as a powerfu...

Optical intelligent reflecting surface (OIRS) offers a new and effective approach to resolving the line-of-sight blockage issue in visible light communication (VLC) by enabling redirection of light to bypass obstacles, thereby dramatically enhancing indoor VLC coverage and reliability. This article provides a comprehensive overview of OIRS for VLC,...

The burgeoning technology of optical intelligent reflecting surfaces (OIRS) offers significant potential within the realm of visible light communication (VLC) systems. This is primarily attributed to the capability of OIRS to exploit reflected propagation paths, which in turn mitigates the inherent signal blockage challenges encountered in VLC. In...

Faced with growing demands for high-speed and reliable communication systems, optical intelligent reflecting surfaces (OIRS) have recently attracted a lot of interest in visible light communication (VLC). With potential applications in a variety of scenarios, including indoor wireless communications and the Internet of Things (IoT), OIRS is expecte...

The sixth-generation network is expected to achieve global coverage based on the space-air-ground integrated network, and the latest satellite network will play an important role in it. The introduction of inter-satellite links (ISLs) can significantly improve the throughput of the satellite network, and has recently received a lot of attention fro...

As one of the six usage scenarios of the sixth-generation (6G) mobile communication system, integrated sensing and communication (ISAC) is regarded as a key enabler for the future Internet-of-Everything (IoE). While numerous studies have been conducted in radio-frequency (RF)-ISAC, free space optical (FSO)-ISAC is also laying the foundation for the...

Optical intelligent reflecting surface (OIRS) is a promising technology in visible light communications (VLC), which can help VLC overcome the shortcoming of being susceptible to occlusion. It is shown that OIRS has many advantages for non-orthogonal multiple access (NOMA)-based VLC due to its ability to reconfigure optical wireless channels. In th...

Satellite-terrestrial communications based on mega low-Earth orbit (LEO) constellations enable extensive coverage and high data rates. However, the communication performance is significantly impacted by the non-uniform traffic distribution and the substantial interference caused by dense satellites. Therefore, in this paper, a multi-satellite coope...

Due to the wide and license-free bandwidth, visible light communication (VLC) functions as a potential technology to meet the exponentially expanding traffic demands in wireless communications. However, the sensitivity to obstacles and high path loss are the key issues that practical VLC systems must carefully deal with. In this paper, the utilizat...

Intelligent reflecting surface (IRS) is a promising technology for channel readjustment. In this paper, we investigate the simultaneous lightwave information and power transfer (SLIPT) technique deployed for the visible light communication (VLC) system, and implement SLIPT by adjusting the association between optical IRS (OIRS) and transceivers to...

Non-orthogonal multiple access (NOMA) is regarded as one of the primary enabling candidates for fifth-generation cellular systems. In this letter, we compare NOMA with orthogonal multiple access (OMA) for visible light communication (VLC) systems, and show that the relationship between NOMA and OMA in VLC is different from that in radio frequency (...

Compared with underwater acoustic communication, underwater wireless optical communication (UWOC) has the advantages of wide communication bandwidth, high transmission speed and strong directional transmission, which make it have broad application prospects. However, the absorption and scattering effects in underwater environments cause a UWOC syst...

With the capability of reconfiguring the wireless electromagnetic environment, intelligent reflecting surface (IRS) becomes a new paradigm for designing future wireless communication systems. In this paper, we consider optical IRS for improving the performance of visible light communication (VLC) under a multiple-input and multiple-output (MIMO) se...

With the explosive growth of the data traffic and the access number of intelligent devices, the wireless communication systems based on the radio frequency (RF) is suffering from the pressure of spectrum shortage and access congestion constantly, which can be alleviated with the help of visible light communication (VLC). However, due to the limitat...

As one of the key technologies of the intelligent transportation system (ITS), vehicle-to-everything (V2X) communications have received increasing attention. Because of the broad and unlicensed spectrum, free space optical (FSO) communications have become a potential technology for V2X communications. In this article, the implementation of FSO comm...

The future wireless network is expected to provide communication and sensing abilities simultaneously, and the optical spectrum brings a promising candidate for integrated sensing and communication. In this letter, an integrated sensing and communication scheme based on pulse sequence sensing and pulse position modulation is proposed for free space...

The integration of visible light communication (VLC) and radio frequency (RF) communication achieves complementary advantages of high data rates and wide coverage, while the power consumption should also be considered. In this letter, a genetic algorithm for cell zooming is proposed to realize high energy efficiency in hybrid VLC-RF cellular networ...

Intelligent reflecting surface (IRS) is a novel technology that provides new research perspectives for wireless communications due to its capability of redesigning the wireless electromagnetic environment. In this letter, we investigate the OIRS-aided VLC system employing the power-domain non-orthogonal multiple access (NOMA), where the achievable...

The rapid development of mobile communication services in recent years has resulted in a scarcity of spectrum resources. This paper addresses the problem of multi-dimensional resource allocation in cognitive radio systems. Deep reinforcement learning (DRL) combines deep learning and reinforcement learning to enable agents to solve complex problems....

Although the multi-antenna or so-called multiple-input multiple-output (MIMO) transmission has been the enabling technology for the past generations of radio-frequency (RF)-based wireless communication systems, its application to the visible light communication (VLC) still faces a critical challenge as the MIMO spatial multiplexing gain can be hard...

Generative adversarial network (GAN) has attracted wide attention because of its remarkable ability to learn highdimensional and complex data distributions based on game theory and machine learning. In this paper, we focus on the role that GANs play in wireless communications, which has been well researched and developed in recent years. With the g...

Although the multi-antenna or so-called multiple-input multiple-output (MIMO) transmission is an enabling technology for past generations of wireless communication systems, its application to visible light communication (VLC) still faces a critical challenge due to the strong spatial correlation of VLC channels, which makes it difficult to achieve...

The promising visible light communication (VLC) technology, which performs superior for Internet of Things (IoT) networks, can alleviate the spectrum congestion of current radio frequency communications. To overcome the drawbacks of VLC such as blockages and high path loss, we propose a multiple-input single-output (MISO) VLC system equipped with o...

Integrated sensing and communication (ISAC) is a crucial component of future wireless networks, with optical ISAC regarded as a promising complement to its radio-frequency counterpart. In this letter, an ISAC scheme combining linear frequency modulation (LFM) and continuous phase modulation (CPM) is proposed for free space optics. The generalized i...

Radio frequency (RF) technology is widely adopted in indoor wireless communications due to its attractive benefits such as low cost and easy deployment. However, this technology also faces certain challenges such as spectrum scarcity and security concerns. In this article, ultraviolet (UV) communication is introduced to tackle these issues thanks t...

In response to the shortcomings existing in radio frequency vehicular communications, vehicular visible light communication (VVLC) provides a viable alternative. However, the fluctuation of optical intensity induced by atmospheric turbulence (AT) adversely affects the communication performance of VVLC. In this letter, multi-input multi-output (MIMO...

Laser inter-satellite links (LISLs) have greatly extended communication distance between satellites, allowing for establishment of dynamic links to reduce communication delay. However, a closed-loop control is required for LISL, which causes high energy consumption. Proper scheduling of dynamic LISLs can effectively reduce energy consumption and co...

Visible light communication (VLC) is one of the candidates to realize data rates of up to tera-bps in indoor scenarios, and is a popular topic in Internet of Things (IoT) applications. However, the receiving performance of the VLC channel is affected by relative locations of transceivers directly, while the uniform illumination is also required whe...

As a high-speed, large-capacity underwater communication technology, underwater wireless optical communication (UWOC) has broad development prospects. However, accurately characterizing the underwater optical channel for various underwater conditions is still a challenging task due to light absorption and scattering, which may limit further researc...

Unmanned aerial vehicle (UAV) swarm communication has received increasing attention thanks to its intriguing advantages, such as low costs, high mobility, and deployment convenience. However, this technology is also facing certain new challenges, e.g., RF spectrum scarcity, interference, and network connectivity. To this end, ultraviolet (UV) commu...

Radio signal recognition has a wide application in future communication systems and the vehicular communication, whose core is the extraction of signal features such as electromagnetic fingerprints. With the rapid development of artificial intelligence technology, deep learning has made amazing breakthroughs in image recognition, speech recognition...

Intelligent lighting has attracted lots of research interests to investigate all the possible schemes to support this need as human has spent more and more time indoor. Semiconductor-based illumination network is an ideal bearer to carry on this mission. In this paper, we propose the concept of Internet of Light (IoL) and define its key functionali...

Though visible light communication (VLC) is a significant supplement to current communication technologies, disadvantages such as the sensitivity to obstacles limit its development and commercialization. As a revolutionizing technology, intelligent reflecting surface (IRS) offers an ability to reconfigure the wireless environment dynamically and pa...

This letter investigates physical layer security in intelligent reflecting surface (IRS)-aided VL communication (VLC). Under the point source assumption, we first elaborate the system model in the scenario with multiple legitimate users and one eavesdropper, where the secrecy rate maximization problem is transformed into an assignment problem by ob...

With the capability of reconfiguring the wireless electromagnetic environment, intelligent reflecting surface (IRS) is a new paradigm for designing future wireless communication systems. In this paper, we consider optical IRS for improving the performance of visible light communication (VLC) under a multiple-input and multiple-output (MIMO) setting...

Power line communication (PLC) is an important interconnection technology for the smart grid, but the robustness of PLC transmission is faced with a great challenge due to strong non-Gaussian noise and interference. In this paper, a narrowband interference (NBI) resistant preamble is designed, and an effective timing and frequency synchronization m...

Wearable technologies provide a non-invasive way to monitor user's activity, identity, and health in real-time, which have attracted tremendous interests from both academia and industry. Due to constraints in form factor and power consumption, the sensing capabilities and functionalities of the wearables are usually limited by the available sensors...

Ultraviolet (UV) technology plays an important role in the fields of sterilization, disinfection, and short-range wireless optical communications. In this Letter, a theoretical model to determine the UV radiation intensity (UVRI) on human skin is put forward based on the Monte Carlo method, where the UV wavelength ranges from 200 to 300 nm. Meanwhi...

The further demand for data traffic growth makes the conventional radio frequency (RF) wireless network face ever increasing challenges such as spectrum shortage and access congestion. Visible light communication (VLC) is envisioned as a promising candidate for wireless communication in the future, but it also has limitations like limited coverage...

The ubiquitous deployment and restricted consumption are the requirements restricting the development of Internet of Things. Thus, a promising technology named Internet of Lamps (IoL) is discussed in this paper to address these challenges. Compared with other communication networks, the remarkable advantage of IoL is that it can make full use of th...

This letter investigates physical layer security in intelligent reflecting surface (IRS)-aided visible light communication (VLC). Under the point source assumption, we first elaborate the system model in the scenario with multiple legitimate users and one eavesdropper, where the secrecy rate maximization problem is transformed into an assignment pr...

In order to obtain favorable communication performance, impulsive noise needs to be suppressed which is a major interference in scenarios such as broadcasting system and power line communication. In this paper, a time-domain impulsive noise suppression method is combined with deep learning, whose parameters are calculated by neural networks. The pa...

To satisfy the explosive growing traffic demands in wireless communications, visible light communication (VLC) performs as a promising technology due to its broad and license-free bandwidth. However, practical VLC systems usually confront challenges, such as blockage and high path loss. Different from traditional VLC techniques, intelligent reflect...

The most significant challenge of underwater optical wireless communication (UOWC) system is to overcome its limited coverage. To expand the achievable communication range, we investigate the performance of the dual-hop UOWC system with simultaneous lightwave information and power transfer (SLIPT). The time splitting (TS) method is adopted for wire...

italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Digital terrestrial television broadcasting (DTTB), the most fundamental infrastructure for audio/video transmission networks, can support multimedia information services, targeting lots of audiences within a wide area in an efficient way. The advanced...

Existing studies of the ultraviolet (UV) channel mainly focus on non-line-of-sight (NLOS) scenarios, while line-of-sight (LOS) scenarios are generally neglected since obstacles sometimes block them. To fill this gap, a UV diffused-LOS channel model in the presence of an obstacle is proposed for the first time, to the best of our knowledge. For easy...

Spectrum sensing for the Digital Television Terrestrial Multimedia Broadcasting (DTMB) system is considered in this paper. A novel method, which contains a preprocessing method of partition and averaging, a convolutional neural network (CNN) and a threshold chosen scheme, is proposed to solve this problem. In the spectrum sensing process, the recei...

With the promotion of the solid-state lighting industry, visible light communication (VLC) has attracted increasing interests these years. However, the blockage problems in VLC due to the nanoscale wavelength of the visible light are severe. In this letter, a VLC system deployed with the intelligent reflecting surface (IRS) is modeled under the poi...

Underwater wireless optical communication (UWOC) has attracted considerable attention as a technology with high data rates and low time delays. However, the light scattering in water spreads beam pulse temporally, thereby resulting in time-varying underwater optical channels with inter-symbol interference (ISI) especially when the data rate is very...

Wearable technologies provide a non-invasive way to monitor user's activity, identity, and health in real-time, which have attracted tremendous interests from both academia and industry. Due to constraints in form factor and power consumption, the sensing capabilities and functionalities of the wearables are usually limited by the available sensors...

To tackle the sub-optimization problem of the conventional block structure communication systems, recently, a novel concept named end-to-end communication system that can optimize the whole system jointly has been proposed. A channel autoencoder (AE) is one of the methods, which regards the wireless communication system as an AE along with a channe...

Underwater wireless optical communication (UWOC) has great potential to provide higher data rates and lower time delay communication compared to radio frequency and acoustic counterparts. However, UWOC systems with wide bandwidths are subject to photon absorption and scattering, which result in severe energy loss for optical beams and inter-symbol...

In this paper, a flexible non-orthogonal multiple access (NOMA) based optical orthogonal frequency division multiplexing (OFDM) modulation scheme, called non-orthogonal hybrid optical OFDM (NOHO-OFDM), is proposed to increase the achievable data rate of the visible light communication system with high efficiency. In addition, a receiver with iterat...

Facing the worldwide explosive growth of the wireless devices, the future wireless network is required to provide seamless access for the users with diverse quality of service (QoS) requirements. In this paper, a novel multiple access scheme based on the principle of multi-domain index modulation is proposed to address the downlink multiple access...

Modern society demands a new kind of ultra-high-speed ground transportation, which can be achieved by evacuated tube transportation (ETT). However, conventional radio frequency communication is faced with serious Doppler spread and frequent handovers in such ultra-high-speed environments. Thus, in this article, a novel wireless communication system...

In this paper, the rate optimization problem in a relaying visible light communication system with simultaneous lightwave information and power transfer (SLIPT) is investigated, where the power splitting (PS) transmission strategy is adopted. The expressions of the transmission rate and energy harvesting at the target node are derived, based on whi...

Visible light communication has received great attention as the superior candidate for radio frequency communication in indoor scenarios, but research on how the location of light-emitting diode lamps affects the achievable rate is rare. In this Letter, the lamp location is optimized with the Adam algorithm for maximization of the average achievabl...

Clean water free of bacteria is a precious resource in areas where no centralized water facilities are available. Conventional chlorine disinfection is limited by chemical transportation, storage, and the production of carcinogenic by-products. Here, a smartphone-powered disinfection system is developed for point-of-use (POU) bacterial inactivation...

In this paper, a deep learning-based detection scheme is proposed for the visible light communication (VLC) systems using generalized spatial modulation (GenSM). In the proposed detection scheme, a deep neural network consisting of several neural layers is applied to detect the received signals. By integrating the signal processing modules of the c...

As the most popularly utilized broadcasting network, digital terrestrial television broadcasting (DTTB) can provide multimedia information coverage for the broad audience in a very efficient way because of its characteristic of wide-range coverage and mobile reception ability. After promulgating the first generation DTTB standard, digital terrestri...

When the generalized spatial modulation (GSM) is applied to visible light communication (VLC), radio frequency (RF) technologies, such as constellation designs, should be modified for the ergodic VLC channel, which is different from that in typical RF environments. In this paper, constellations of amplitude-phase modulation (APM) symbols are optimi...

Visible light communication (VLC) is a secure, low-cost and high-rate communication method. On-off keying (OOK) is one of the modulation schemes of VLC, turning each light either on or off to generate binary signals. Recently, deep learning (DL) technologies have made a series of breakthroughs for dimming in VLC system. This task is actually quite...

In this letter, a convolutional neural network-based detection framework is proposed for the wireless communication systems using orthogonal frequency-division multiplexing with index modulation (OFDM-IM). In the proposed framework, the received symbols are transformed to polar coordinates to help the neural network detect the indices of the activa...

Mutual interference is a crucial issue for the visible light communication (VLC) systems to be addressed, including both co-channel interference (CCI) and inter-carrier interference (ICI). In this paper, to solve the CCI problem, a novel optical attocell network is introduced, which can be regarded as a hybrid network based on both single frequency...