Gang Wu

• PhD
• Professor at University of Electronic Science and Technology of China

Artificial noise elimination (ANE) has arisen as a promising strategy to counteract artificial noise (AN) at the eavesdropper (Eve). However, conventional ANE schemes rely on the attainable channel state information (CSI) between the transmitter (Alice) and legitimate receiver (Bob), which may reduce the feasibility of ANE. To break the gridlock, w...

This letter proposes a novel orthogonal frequency division multiplexing (OFDM) waveform termed MDS-OFDM-IM, in which the subcarriers are divided into two distinct groups with specific functions: peak-to-average power ratio (PAPR) reduction and error detection. The PAPR reduction subcarriers employ a selective mapping (SLM) scheme without side infor...

In order to mitigate the distance reduction attack in Ultra-Wide Band (UWB) ranging, this paper proposes a secure ranging scheme based on a random time-hopping mechanism without redundant signaling overhead. Additionally, a secure ranging strategy is designed for backward compatibility with existing standards such as IEEE 802.15.4a/z, combined with...

Semantic communications can significantly improve transmission efficiency, especially in the low signal-to-noise (SNR) regime. However, two-way semantic communications still remain an unexplored topic, which is a critical issue in many machine communication scenarios. Simply extending existing semantic communication systems to the two-way situation...

A variety of ranging threats represented by Ghost Peak attack have raised concerns regarding the security performance of Ultra-Wide Band (UWB) systems with the finalization of the IEEE 802.15.4z standard. Based on channel reciprocity, this paper proposes a low complexity attack detection scheme that compares Channel Impulse Response (CIR) features...

In this paper, we present a novel and robust nonlinear precoding (NLP) design and detection structure specifically tailored for multiple-input multiple-output space division multiple access (MIMO-SDMA) systems toward 6G wireless. Our approach aims to effectively mitigate the impact of imperfect channel estimation by leveraging the channel fluctuati...

In this letter, based on outer loop link adaptation (OLLA), we propose an adaptive OLLA algorithm (AOLLA), which calculates the OLLA offset adapted to the current wireless channel environment in real-time by utilizing frequency statistics of packet error within the last observation window. AOLLA algorithm contains numerous parameters that require m...

In order to solve the problems of oxidation of the metal film coated on the outer surface of the photonic crystal fiber and the low sensitivity of the sensor, a side polishing temperature sensor based on surface plasmon resonance is proposed.the sensor is modelled with a metal coating on the side of the optical fiber of the sensor, using a temperat...

In order to detect the cancerization of the somatic cells early, a photonic crystal fiber (PCF) sensor with double gold nanowires based on surface plasmon resonance (SPR) is designed, whose air holes are arranged periodically and symmetrically, and two gold nanowires are embedded at the outer surface of the fiber as plasma material. The performance...

As a competitive technology for 6G, semantic communications can significantly improve transmission efficiency. However, many existing semantic communication systems require information feedback during the training coding process, resulting in a significant communication overhead. In this article, we consider a two-way semantic communication (TW-SC)...

Subwavelength gratings (SWGs) possess an excellent ability to manipulate the wavefronts of light waves. We investigated the beam tailoring mechanism of aperiodic SWGs in our current work, and a bifocal lens, a beam splitter, and a beam combiner based on transmission-type one-dimensional SWGs are presented and simulated here. By designing grating na...

This paper is focused on the multiuser implementation of fusion of radar and communication (RadCom) in internet-of-vehicles (IoV) scenarios. Traditional time-division multiple access (TDMA) technology degrades the velocity detection performance of orthogonal frequency-division multiplexing (OFDM)-based RadCom systems. We propose a new TDMA approach...

The ever-increasing demand for high data rates and high connection densities in the vehicle communication network, along with the widespread adoption of radio access over the Third Generation Partnership Project (3GPP) standard, has been a major driver for the research on cellular vehicle-to-everything (C-V2X) communication. Nevertheless, Wi-Fi and...

Intelligent wireless networks have long been expected to have self-configuration and self-optimization capabilities to adapt to various environments and demands. In this paper, we develop a novel distributed hierarchical deep reinforcement learning (DHDRL) framework with two-tier control networks in different timescales to optimize the long-term sp...

In this paper, we adopt a three-stage based uplink channel estimation protocol with reduced pilot overhead for an reconfigurable intelligent surface (RIS)-aided multi-user (MU) millimeter wave (mmWave) communication system, in which both the base station (BS) and the RIS are equipped with a uniform planar array (UPA). Specifically, in Stage I, the...

The ever-increasing demand for high data rates and high connection densities in the vehicle communication network, along with the widespread adoption of radio access over the Third Generation Partnership Project (3GPP) standard, has been a major driver of a large amount of research on cellular vehicle-to-everything (C-V2X) communication. Additional...

The realization of open-source-defined wireless networks in the telecommunication domain is accomplished through the fifth-generation network (5G). In contrast to its predecessors (3G and 4G), the 5G network can support a wide variety of heterogeneous use cases with challenging requirements from both the Internet and the Internet of Things (IoT). T...

Euclidean distance optimized antenna selection (EDAS) has been integrated with offset spatial modulation (OSM) for alleviating the effects of channel fading and increasing diversity gain, but the complexity of EDAS may become excessive upon increasing transmit antennas, particularly for the large-scale multiple-input multiple-output (MIMO) systems....

In this paper, we adopt a three-stage based uplink channel estimation protocol with reduced pilot overhead for an reconfigurable intelligent surface (RIS)-aided multi-user (MU) millimeter wave (mmWave) communication system, in which both the base station (BS) and the RIS are equipped with a uniform planar array (UPA). Specifically, in Stage I, the...

The unprecedented growth of the Internet of Things (IoT) has led to a huge amount of wireless resource consumption in a network. Due to limited wireless resources, a network can only guarantee the quality of service (QoS) of authenticated users rather than that of all users. By acknowledging this limitation, we realise that user authentication woul...

With affordable overhead on information exchange, energy-efficient beamforming has potential to achieve both low power consumption and high spectral efficiency. This paper formulates the problem of joint beamforming and power allocation for a multiple-input single-output (MISO) multi-cell network with local observations by taking the energy efficie...

In this paper, to obtain a higher information rate in the block fading channel, we propose an LDL-decomposition-based linear precoded faster-than-Nyquist (FTN) signaling with power allocation. We further propose an LDL-decomposition-based linear precoded FTN signaling with truncated power allocation (LDL-TPA-FTN) to extend the application range of...

Watermarking is a technique that provides ownership rights for shared data, and this technique can also help to transmit confidential information to realize secure communication. In this paper, we design a blind digital watermarking based on Discrete Wavelet Transform-Discrete Cosine Transform-Singular Value Decomposition (DWT-DCT-SVD) and optimize...

In this paper, a novel directional modulation with distributed receiver selection (DM-DRS) scheme is proposed for secure wireless communications. In DM-DRS, a particular subset of receivers is activated and part of the information bits are modulated by the index of the activation pattern, in addition to traditional digital modulation. Especially, t...

A wide-angle scanning circularly polarized (CP) antenna array based on a novel polarizer is proposed. The working mechanism is that the linear polarization (LP) substrate integrated waveguide (SIW) slot antenna array can be converted into CP antenna array through the proposed hybrid polarizer. Specifically, the proposed hybrid polarizer consists of...

A dual-band quad-polarized transmitarray (TA) is designed in a common aperture operating at 25.9/39.8 GHz. Using narrow strip patches as cells, the 25.9 GHz cells are arranged in the ±45° direction, and the 39.8 GHz cells are arranged in the 0/90° direction in the formed square gap of the 25.9 GHz cells to realize a compact design with four polariz...

A feeding network crossing method is proposed to form an N×N dual-polarized two-dimensional multibeam antenna array (2D-MBAA) with analog-digital hybrid beamforming, which solves the problem of needing additional connection structure between the dual-polarized antenna array and analog feeding network for large-scale antenna arrays. The main design...

A millimeter-wave (mm-wave) dual-polarization bidirectional multibeam array antenna based on substrate integrated waveguide (SIW) technology is presented in this article, which can generate 16 bidirectional radiation beams with two orthogonal linear polarizations. The proposed dual-polarization bidirectional multibeam array antenna, based on a new...

A Load Balancing Relay Algorithm (LBRA) is proposed in this letter to solve the unfair spectrum resource allocation problem in two-tier machine-type communications (MTC) uplink transmission. By adopting MTC devices (MTCDs)’s distribution, spectrum resources are dynamically allocated and reclustered for the link between MTCDs to cluster-head. Moreov...

In the massive machine-type communications (mMTC) scenario for Internet of Things (IoTs) applications, though a large number of devices are registered to an access point (AP), very few of them are active with uplink short packet transmission simultaneously, which requires novel design of protocols and receivers to enable efficient data transmission...

Massive machine-type communications (mMTC) is a crucial scenario to support booming Internet of Things (IoTs) applications. In mMTC, although a large number of devices are registered to an access point (AP), very few of them are active with uplink short packet transmission at the same time, which requires novel design of protocols and receivers to...

A Load Balancing Relay Algorithm (LBRA) was proposed to solve the unfair spectrum resource allocation in the traditional mobile MTC relay. In order to obtain reasonable use of spectrum resources, and a balanced MTC devices (MTCDs) distribution, spectrum resources are dynamically allocated by MTCDs regrouped on the MTCD to MTC gateway link. Moreover...

In this paper, aiming at the emergency coverage for vehicular network, we consider the problem of resource allocation for unmanned-aerial-vehicle (UAV) enabled vehicular communications, where UAV work as a temporary cellular base station. Our objective is to maximize the sum achievable rate of vehicle-to-infrastructure (V2I) communications and ensu...

Heterogeneous cloud radio access network (H-CRAN) needs more elegant design to achieve higher energy efficiency and spectral efficiency than traditional cloud radio access networks. In this paper, we propose an energy-efficient resource allocation algorithm by taking into account the impact of arrival rates of various user traffic. Firstly, based o...

In this paper, an asynchronous sparse Bayesian learning (ASBL) algorithm based receiver for uplink (UL) grant-free transmission is proposed. The time-domain channel estimation is performed by the ASBL algorithm to obtain the channel impulse response (CIR) for each user. Then, the support vector machine (SVM) algorithm is adopted to classify the CIR...

Device-to-device (D2D) communications enabled dense heterogeneous networks (HetNets) with non-orthogonal multiple access (NOMA) are promising solutions to meet high-throughput requirement and support massive connectivity. In this paper, we propose a novel framework on D2D-enabled HetNets with NOMA, where small cells underlay the uplink spectrum of...

We study the decentralized caching scheme in a two-layer network, which includes a sever, multiple helpers, and multiple users. Basically, the proposed caching scheme consists of two phases, i.e, placement phase and delivery phase. In the placement phase, each helper/user randomly and independently selects contents from the server and stores them i...

In this paper, we study the resource allocation problem for a cooperative device-to-device (D2D)-enabled wireless caching network, where each user randomly caches popular contents to its memory and shares the contents with nearby users through D2D links. To enhance the throughput of spectrum sharing D2D links, which may be severely limited by the i...

Directional modulation (DM) refers to a class of efficient techniques for enhancing the physical layer security of wireless communications. However, conventional DM approaches cannot guarantee the transmission security when eavesdroppers are located close to the legitimate user. In this paper, to mitigate this problem, a new DM scheme with cooperat...

Heterogeneous cloud radio access network (H-CRAN) promises higher energy efficiency (EE) than the conventional cellular networks by centralizing the baseband signal processing into the baseband unit (BBU) pool hosted by cloud computing platforms. Because of the difference between H-CRAN and conventional cellular networks, existing energy-efficient...

In this paper, we focus on analysis of the preamble-based joint estimation for channel and laser-frequency offset (LFO) in coherent optical filter bank multicarrier systems with offset quadrature amplitude modulation (COFBMC/OQAM). In order to reduce the noise impact on the estimation accuracy, we proposed an estimation method based on inter-frame...

Spectrum efficiency is one of the key performance metrics in 5G communication networks. To enhance spectrum efficiency, advanced spectrum sharing techniques are normally used. In this article, we provide a survey of the recent development of advanced techniques for spectrum sharing. In particular, we elaborate cognitive radio, device-todevice commu...

We study a downlink non-orthogonal multiple access (NOMA) system with cooperative full-duplex relaying, where the near user in terms of the base station (BS) is enabled to act as a full-duplex relay for the far user. In particular, we first derive the outage probability and ergodic sum rate with closedform expressions when the power allocations at...

In cognitive radio networks, the channel gain between primary transceivers, namely, primary channel gain, is crucial for a cognitive transmitter (CT) to control the transmit power and achieve spectrum sharing. Conventionally, the primary channel gain is estimated in the primary system and thus unavailable at the CT. To deal with the issue, two esti...

Full-duplex (FD) allows the exchange of data between nodes on the same temporal and spectrum resources, however, it introduces self interference (SI) and additional network interference compared to half-duplex (HD). Power control in the FD networks, which is seldom studied in the literature, is promising to mitigate the interference and improve the...

This paper proposes a near-field communication (NFC) antenna solution for metal cover smartphone applications. In this NFC antenna solution, a narrow slot is initially loaded into the metal cover, and the position of this slot can be altered (with flexibility) according to the design of the smartphone’s external appearance. Next, an unconventional...

Full-duplex (FD) allows the exchange of data between nodes on the same temporal and spectrum resources, however, it introduces self interference (SI) and additional network interference compared to half-duplex (HD). Power control in the FD networks, which is seldom studied in the literature, is promising to mitigate the interference and improve the...

We study the coexistence problem in a two-tier heterogeneous network (HetNet) with cognitive small cells. In particular, we consider an underlay HetNet, where the cognitive small base station (C-SBS) is allowed to use the frequency band of the macro cell with an access probability (AP) as long as the C-SBS satisfies a preset interference probabilit...

In underlay heterogeneous networks (HetNets), the distance between a macro base station (MBS) and a macro user (MU) is crucial for a small-cell based station (SBS) to control the interference to the MU and achieve the coexistence. To obtain the distance between the MBS and the MU, the SBS needs a backhaul link from the macro system, such that the m...

A dual-polarized hybrid eight-antenna array operating in the 2.6-GHz band (2550-2650 MHz) for 5G communication multi-input multi-output (MIMO) operation in the smartphone is presented. The proposed hybrid antenna array elements are symmetrically placed along the long edges of the smartphone, and they are composed of two different four-antenna array...

In an underlay cognitive radio network, the crosschannel gain from a cognitive transmitter (CT) to a primary receiver (PR) is crucial for spectrum sharing. By exploiting the relaying capability of the CT, we propose a proactive estimation scheme for the cross-channel gain. Specifically, the CT proactively acts as a full-duplex amplify-and-forward (...

In this paper, we introduce and investigate a design concept for a polyatomic photonic crystal ring resonator (PCRR). In contrast to conventional sensors, this PCRR comprises two different branching waveguides (WG), which are all oriented in the same lattice direction, but with different optical propagation properties due to the binary nature of th...

Conventionally, fast frequency hopping (FFH) is regarded as a non-coherent system, which has inevitable shortcomings in low spectral efficiency. To achieve a high spectral efficiency while maintaining a favourable bit error ratio (BER) performance in FFH systems, in this study, the authors extend their previously proposed subset-based coherent FFH...

The decentralized caching is studied in two-layer networks, where users request contents through intermediate nodes (helpers) from a file server. By placing contents randomly and independently in each node and carefully designing the data delivery, the correlations of the pre-stored contents across layers can be utilized to reduce the transmission...

In cognitive radio networks, the channel gain between primary transceivers is crucial for a cognitive transmitter (CT) to control the transmit power and achieve the coexistence. To obtain the channel gain, a backhaul between the primary system and the CT is needed. However, the backhaul is usually unavailable in practice. To deal with this issue, t...

A dual-loop antenna for hepta-band wireless wide area network (WWAN)/long term evolution (LTE) narrow-frame full metal-rimmed smartphone application is proposed and studied. Compared with recent reported works, the main advantage of this design is the ability to achieve narrow-frame (smaller ground clearance) with unbroken metal-rim (or full metal-...

The previous work on interference alignment for multiple-input-multiple-output (MIMO) two-way X relay channel assumes perfect channel state information at the transmitter (CSIT), which is reasonable in slow fading channel. However, in fast fading scenario, this assumption is impractical. In this paper, assuming that each node has delayed CSIT, we s...

In this letter, we present a design framework for fixed-point implementation of the log-domain message passing algorithm (Log-MPA) for sparse code multiple access signals, and make a detailed comparative analysis on the complexity of Log-MPA and traditional MPA. We also investigate the impact of the number of massage-passing iterations within the L...

We investigate the energy efficiency (EE) in cognitive radio networks, where cognitive users are allowed to access a licensed frequency band opportunistically, provided that the licensed band is vacant. In particular, we study the impact of imperfect spectrum sensing and formulate the average EE maximization problem in fading channels as a joint op...

A reconfigurable narrow-frame coupled-loop antenna capable of providing hepta-band long term evolution/wireless wide area network (LTE/WWAN) for metal-rimmed smartphone applications is proposed. The ground clearance of this proposed antenna is only 7 × 70 mm2 which is promising for narrow-frame smartphone applications. Moreover, this proposed anten...

Under the assumption that each node has delayed channel state information at transmitter (D-CSIT), this letter studies the achievable degrees of freedom (DOF) for K-user multiple-input-multiple-output (MIMO) Y channel in frequency division duplex (FDD) systems, where each user exchanges messages with other K-1 users simultaneously via an intermedia...

With the rapid development of information technology, massive MIMO is becoming attractive for the fifth generation (5G) communication because of its outstanding performance in both spectral efficiency (SE) and energy efficiency (EE). Recently, many algorithms have been proposed to improve the EE while achieving high SE in massive MIMO systems. In p...

This paper presents a substrate integrated waveguide (SIW) multibeam slot array operating at ∼ 30 GHz for future 5G mobile terminal applications. The multibeam forming network is realized with a Butler matrix that is composed of hybrid couplers, crossovers, and phase shifters (135° and 0°). The crossovers are formed with two cascaded hybrid coupler...

A hybrid antenna is proposed for future 4G/5G multiple input multiple output (MIMO) applications. The proposed antenna is composed of two antenna modules, namely, 4G antenna module and 5G antenna module. The 4G antenna module is a two -antenna array capable of covering the GSM850/900/1800/1900, UMTS2100, and LTE2300/2500 operating bands, while the...

Control data separation architecture (CDSA) is a more efficient architecture to overcome the overhead issue than the conventional cellular networks, especially for the huge bursty traffic like Internet of Things, and over-the-top (OTT) content service. In this paper, we study the optimization issue of network energy efficiency of the CDSA-based het...