Mugen Peng

Beijing University of Posts and Telecommunications | BUPT · Department of Communication Engineering

The fundamental performance of IRS-aided communication/sensing has been extensively studied, demonstrating the benefits of IRS in improving communication rate or sensing accuracy, while that of IRS-aided integrated sensing and communication (ISAC) and the impacts of IRS on the communication-sensing tradeoff are far from being well understood. In th...

Sensing is considered a native capability of the sixth-generation (6G) mobile communication systems, inspiring a variety of research endeavors with regard to integrated sensing and communication (ISAC) waveforms. The orthogonal time frequency space (OTFS) is a promising modulation technique for high-mobility ISAC applications. OTFS accommodates the...

The guard interval, termed as cyclic prefix (CP) or zero-padding (ZP), is utilized to mitigate multipath interference in orthogonal frequency division multiplexing (OFDM) systems but at the expense of spectral efficiency. Symbol cyclic shift equalization (SCSE) is our previous proposal to address multipath propagation in CP-free OFDM systems. Howev...

Terahertz (THz) communications, with their substantial bandwidth, are essential for meeting the ultra-high data rate demands of emerging high-mobility scenarios such as vehicular-to-everything (V2X) networks. In these contexts, beamwidth adaptation has been explored to address the problem that high-mobility targets frequently move out of the narrow...

Mega low earth orbit (LEO) satellite constellation is promising in achieving global coverage with high capacity. However, forwarding packets in mega constellation faces long end-to-end delay caused by multi-hop routing and highcomplexity routing table construction, which will detrimentally impair the network transmission efficiency. To overcome thi...

Communication-sensing integration represents an up-and-coming area of research, enabling wireless networks to simultaneously perform communication and sensing tasks. However, in urban cellular networks, the blockage of buildings results in a complex signal propagation environment, affecting the performance analysis of integrated sensing and communi...

This letter investigates interference resulting from the overlap of coverage zones in multi-cell integrated sensing and communication (ISAC) scenarios. To mitigate this challenge, we formulate an optimization problem and leverage semidefinite relaxation (SDR) techniques to suppress inter-cell interference between communication and sensing. Building...

Recently, reconfigurable intelligent surface (RIS) has gained growing research interests in sensing fields. While extensive efforts have been devoted to designing RIS space beamforming for improving sensing accuracy, the potential of RIS in improving sensing resolution has so far not been fully dug. In this paper, we investigate the fundamental per...

Ensuring secure access to cellular networks is of paramount importance, in which system information (SI) protection plays a crucial role at the initial access stage. While the 3rd generation partnership project (3GPP) released many standardizations to enhance SI protection for preventing users from false base station (FBS) attacks, most of them are...

Integrated sensing and communication (ISAC) has been envisioned as one of the key features of the sixthgeneration wireless networks. However, the coverage and sensingcommunication performance are limited due to the uncontrollable environments, especially when operating in the high-frequency bands. To address this issue, we utilize the benefits of i...

Low earth orbit (LEO) satellite communication networks have been considered as promising solutions to providing high data rate and seamless coverage, where satellite beam management plays a key role. However, due to the limitation of beam resource, dynamic network topology, beam spectrum reuse, time-varying traffic arrival and service continuity re...

Traditional optical positioning techniques employing visible light signals or infrared light signals require line-of-sight links between transmitters and receivers. The wireless positioning techniques using ultraviolet (UV) signals can enjoy both non-line-of-sight (NLOS) positioning ability and immunity to electromagnetic jamming. In this work, we...

Ultra-dense networks (UDNs) are considered to be a key technology that can meet the growing rate requirements caused by the explosion of user equipments (UEs) in the Internet of Things (IoT) applications. The dense deployment of small-cell base stations (SBSs) facilitates the reuse of spectrum resources but also leads to significant interference am...

The spectrum shift from the sub-6G band to the high-frequency band has posed an ever-increasing demand on the paradigm shift from narrowband beamforming to wideband beamforming. Despite recent research efforts, the problem of wideband beamforming design is particularly challenging in reconfigurable intelligent surface (RIS)-assisted systems, due to...

Intelligent reflecting surface (IRS) has the potential to enhance sensing performance, due to its capability of reshaping the echo signals. Different from the existing literature, which has commonly focused on IRS beamforming optimization, in this paper, we pay special attention to designing effective signal processing approaches to extract sensing...

Integrated sensing and communication (ISAC) has been recognized as a key enabler and feature of future wireless networks. In the existing works analyzing the performances of ISAC, discrete-time systems were commonly assumed, which, however, overlooked the impacts of temporal, spectral, and spatial properties. To address this issue, we establish a u...

In order to provide voice services with full coverage and high disaster tolerance, satellite communication-based voice solutions utilizing private protocols were proposed, which however cannot be integrated with existing terrestrial voice solutions specified by the 3rd Generation Partnership Project. To overcome this issue, we propose two voice sol...

None-line-of-sight (NLOS) ultraviolet (UV) communication has attracted increasing attention in recent years. The atmospheric turbulence will deteriorate the performance of NLOS UV communications. Existing works on the turbulent model of NLOS UV single-scattering channels only considered the narrow beam cases. In this letter, we propose a turbulent...

In this paper, an unmanned aerial vehicle (UAV)-mobile edge computing (MEC) network is considered, where cellular-connected UAVs can either handle the computing tasks locally or offload to base stations. Considering the emerging computation-intensive and delay-sensitive applications, how to strike a balance between energy and delay, is one of the k...

Modeling of multiple-scattering channels in atmospheric turbulence is essential for the performance analysis of long-distance non-line-of-sight (NLOS) ultraviolet (UV) communications. Existing works on the turbulent channel modeling for NLOS UV communications either ignored the turbulence-induced scattering effect or erroneously estimated the turbu...

Multi-beam low earth orbit (LEO) satellites are emerging as key components in beyond 5G and 6G to provide global coverage and high data rate. To fully unleash the potential of LEO satellite communication, resource management plays a key role. However, the uneven distribution of users, the coupling of multi-dimensional resources, complex inter-beam...

This letter presents a novel multicarrier waveform scheme for high Doppler communications, referred to as frequency-Doppler (FD) division multiplexing (FDDM). The FDDM enables the conversion of the time-varying channel representation in the time-frequency (TF) domain to a static FD domain channel composed of independent Doppler taps. Distinguished...

Introducing blockchain into Federated Learning (FL) to build a trusted edge computing environment for transmission and learning has attracted widespread attention as a new decentralized learning pattern. However, traditional consensus mechanisms and architectures of blockchain systems face significant challenges in handling large-scale FL tasks, es...

With gigahertz-level bandwidth, terahertz (THz) holds promise for achieving exceptionally high transmission rates in prospective sixth-generation (6G) communications. However, considerable loss poses an obstacle to THz communication. To compensate for this, massive multiple-input-multiple-output (MIMO) based beamforming is utilized to promote direc...

In this chapter, angle information acquisition for location sensing in the RIS-enabled ISAC system is addressed. In Sect. 3.1, the introduction is first provided. Then, Sect. 3.2 proposes an RIS-aided AoA estimation method for single-user localization. Then, Sect. 3.3 extends the single-user case to the multi-user case, where simultaneous multi-use...

In this chapter, sensing-assisted beamforming in the RIS-enabled ISAC system is studied. In Sect. 5.1, the introduction is first provided. In Sect. 5.2, we study sensing-assisted beamforming in the single-user case and then extend it to the multi-user case in Sect. 5.3. Finally, Sect. 5.4 summarizes this chapter.

In this chapter, delay-Doppler information acquisition in the RIS-enabled ISAC system is studied. In Sect. 4.1, the introduction is first provided. In Sect. 4.2, we introduce the system model of the RIS-enabled OFDM ISAC system. Section 4.3 presents the coarse-grained sensing via Delay-Doppler estimation, while Sect. 4.4 introduces the fine-grained...

In this section, we discuss future trends and open issues of RIS-enabled ISAC from four aspects, namely, new information theory and practical measurement, air interface technologies, signal processing technologies, and hardware design and practical deployments.

In this chapter, we present the theoretical framework for performance evaluation of RIS-enabled NO-ISAC systems. Section 2.1 provides the introduction. Section 2.2 introduces the system model. Section 2.3 presents the theoretical framework for performance evaluation, while Sect. 2.4 provides the beamforming design based on the proposed performance...

In this chapter, we first introduce the basics of ISAC and RIS, and discuss the motivations of RIS-enabled ISAC in 6G. Then, we present the potential application scenarios of RIS-enabled ISAC and provide its fundamentals, including the RIS response model, the signal model, as well as the channel model. Finally, research on RIS-enabled ISAC is revie...

This chapter focuses on the beamforming design for simultaneous communication and sensing enhancement in the RIS-enabled ISAC system. In Sect. 6.1, the introduction is first provided. Section 6.2 studies narrowband beamforming design in device-based scenarios, while Sect. 6.3 studies wideband beamforming design in device-free scenarios. Finally, Se...

Integrated sensing and communication (ISAC) technology stands as a pivotal enabler for the sixth-generation mobile communication systems (6G) to enable high data rate communication while ensuring accurate target sensing. Orthogonal time-frequency space (OTFS) modulation has emerged as a promising candidate for ISAC, owing to its remarkable performa...

In this paper, we consider an unmanned aerial vehicle (UAV)-enabled mobile edge computing (MEC) network, where multiple UAVs with caching and computation functionalities are deployed to satisfy the heterogeneous content and service requests from the user equipments (UEs). In order to comprehensively characterize the capability of our considered net...

With the burgeoning demand for data-intensive services, satellite-terrestrial networks (STNs) face increasing backhaul link congestion, deteriorating user quality of service (QoS), and escalating power consumption. Cache-aided STNs are acknowledged as a promising paradigm for accelerating content delivery to users and alleviating the load of backha...

Analog over-the-air (A-OTA) computing is an effective approach to achieving distributed learning among multiple end-user devices within a bandwidth-constrained spectrum. In this paradigm, users’ intermediate parameters, such as gradients, are modulated onto a set of common waveforms and concurrently transmitted to the parameter server. Benefiting f...

The sixth generation of wireless communications technologies (6G) will be characterized by intelligence and con cise ness. Intelligent techniques consume a huge amount of computing resources and require additional network elements in the network architecture. This will no doubt increase network complexity and propose challenges for ultra-low-lat...

The spectrum shift from sub-6G bands to high-frequency bands has posed an ever-increasing demand on the paradigm shift from narrowband beamforming to wideband beamforming. Despite recent research efforts, the problem of wideband beamforming design is particularly challenging in reconfigurable intelligent surface (RIS)-assisted systems, due to that...

To achieve ubiquitous wireless connectivity, low earth orbit (LEO) satellite networks have drawn much attention. However, effective beam management is challenging due to time-varying cell load, high dynamic network topology, and complex interference situations. In this paper, under inter-satellite handover frequency and satellite-terrestrial/inter-...

The forthcoming sixth generation (6G) mobile communication system aims to advance technologies that span and integrate computation and communications. Computing power networks (CPNs) and virtualized radio access networks (vRANs) are regarded as two fundamental techniques to achieve this integration. Network functions of virtualized next-generation...

The fifth generation (5 G) networks have changed the world we live in, and device-to-device (D2D) communications are expected to further enhance 5 G by enabling direct communication between two adjacent user equipments (UEs) without bypassing the next generation Node B. However, direct D2D communications are insufficient for establishing high-quali...

Direction-of-arrival (DoA) estimation holds significant importance in both communication and sensing. Spectrum peak search in DoA estimation requires careful selection of the search step size. While a large step size can result in the loss of angular information, known as the fence effect; a very small step size can have a detrimental impact on rea...

The full-duplex optical communications can be achieved simply by separating the transmitting link and the receiving link in the space. However, it is challenging to achieve the non-line-of-sight (NLOS) full-duplex ultraviolet (UV) communication due to the serious self-interference caused by the strong multiple scattering effects of UV signals. To e...

Reconfigurable intelligent surface (RIS) has shown its great potential in facilitating device-based integrated sensing and communication (ISAC), where sensing and communication tasks are mostly conducted on different time-frequency resources. While the more challenging scenarios of simultaneous sensing and communication (SSC) have so far drawn litt...

A complementary coded code-division multiple-access (CC-CDMA) system is built on the direct sequence (DS) spread spectrum technique, which can suppress multipath interferences and multiple-access interferences due to the ideal correlation property of complementary codes (CCs). However, the DS spread spectrum technique will cause poor bandwidth effi...

Spatial diversity receptions are usually employed to improve the performance of scattering based optical communication (SOC) systems. Existing works on the diversity receptions for SOC systems ignored the detecting properties of the photomultiplier tube (PMT) receivers. In this paper, we focus on single-input multiple-output (SIMO) SOC systems usin...

Ultraviolet (UV) communication is a promising technology for future vehicle communication systems due to its inherent advantages including the non-line-of-sight ability, low background noise, and high local security. Full-duplex relayassisted UV communications can achieve longer communication distances and higher efficiency of time-frequency utiliz...

Reconfigurable intelligent surface (RIS) has shown its great potential in facilitating device-based integrated sensing and communication (ISAC), where sensing and communication tasks are mostly conducted on different time-frequency resources. While the more challenging scenarios of simultaneous sensing and communication (SSC) have so far drawn litt...

The intelligent reflecting surface (IRS) aided integrated sensing and communication (ISAC) is a promising technique in mmWave systems. However, most of the existing works on IRS-aided ISAC assume the availability of channel state information (CSI) along with high-overhead channel estimation. Besides, none has taken the impact of the echo interferen...

Radar, serving as a sensing technology, is anticipated to be integrated into the sixth-generation (6G) mobile communication system to facilitate high-precision sensing functions, potentially inciting spectrum competition between radar and wireless communication systems. To address this challenge, this study explores a code domain method for mitigat...

Orthogonal time frequency space (OTFS) is considered a promising modulation technology for integrated sensing and communication (ISAC) systems, which is robust against Doppler effects in time-frequency doubly-selective channels. However, limited by the communication bandwidth and frame duration, the fractional delay and Doppler problem in OTFS-ISAC...

Federated learning is a promising technique to implement network intelligence for the sixth generation (6G) communication systems. However, the collected data in wireless networks is non-independent and identically distributed (non-IID), which leads to severe deterioration of model performance. Although various enhanced schemes are proposed, it is...

The strong scattering effects of ultraviolet (UV) signals in the atmosphere enables the non-line-of-sight (NLOS) ability of UV communications, but introduces large time dispersion of the channel impulse response (CIR), which inevitably results in serious inter-symbol interferences (ISIs). Because a larger transmitting rate can introduce a larger IS...

The unprecedented increase in wireless data traffic has motivated the development of terahertz communications (THzCom) over the years. Since THzCom would suffer from performance degradation and even link outage in mobile scenarios, the integrated sensing and communications (ISAC) are promised to settle the mobility challenges by extracting informat...

Low earth orbit (LEO) satellite communication based on 3GPP standard is seen as a promising solution to rolling out communication services in areas without terrestrial base stations. However, due to the fast movement of satellites and large beam footprint size, the existing 5G timing advance (TA) estimation mechanism cannot be directly applied when...

Unmanned aerial vehicle (UAV)-enabled network has been regarded as a promising component of the sixth generation (6G) wireless network to provide flexible and on-demand services. In the UAV-enabled networks, due to the user mobility and the dynamic channel characteristics, it is difficult to obtain the accurate location information and channel stat...

Software-defined satellite-terrestrial integrated networks (SDSTNs) are seen as a promising paradigm for achieving high resource flexibility and global communication coverage. However, low latency service provisioning is still challenging due to the fast variation of network topology and limited onboard resource at low earth orbit satellites. To ad...

Ultraviolet (UV) communication is a promising technology for civilian and military secure communication systems due to non-line-of-sight transmission, low background noise, and high local security. The full-duplex relay assisted UV communications can achieve longer communication distances and higher efficiency of time-frequency utilization compared...

Satellite communication with beam hopping is a promising approach to meeting wide-area user traffic demands under on-board resource limitation. However, there is currently a lack of theoretical models that characterize the impact of beam hopping on user uplink transmission performance. In this paper, two simplified beam hopping modes for satellite...

Cooperative positioning with multiple low earth orbit (LEO) satellites is promising in providing location-based services and enhancing satellite-terrestrial communication. However, positioning accuracy is greatly affected by inter-beam interference and satellite-terrestrial topology geometry. To select the best combination of satellites from visibl...

Unmanned aerial vehicle (UAV)-assisted edge caching has been attracting significant attention, due to the potential of UAVs in delivering prompt content services to users. One of the key issues in UAV-assisted edge caching networks is the unpredictable user requests, which requires dynamic update of cache placement. Moreover, the timescale differen...

Terahertz (THz) wideband ultra-massive multiple-input multiple-output (UM-MIMO) systems are critical for the upcoming 6G. The far- and near-field regions always coexist as the hybrid-field regions in the THz wideband UM-MIMO systems, but the existing hybrid-field estimation schemes can not perform well for the wideband channel without prior knowled...

To support massive connections of Internet of things (IoT) devices, backscatter communication has been proposed as a promising technique. However, its transmission reliability cannot be guaranteed due to the lack of error protection. To solve this problem, the optimization design of backscatter communications with retransmissions is studied in this...

Virtual reality (VR) is an emerging technology reshaping interactive experience and can be widely applied in gaming, operation training, and so on. Despite its great potentials, most existing VR solutions suffer from low mobility support, high latency, quick battery drain, as well as high cost of user devices. To overcome these issues, a mobile VR...

As a promising paradigm towards the sixth generation mobile communication, integrated satellite-terrestrial networks (ISTN) can greatly extend network coverage and reduce the dependence on terrestrial infrastructure. Despite the charming potentials of ISTN, many challenges are still unsolved, in terms of architectures, air-interface protocol enhanc...

Channel state information (CSI) based sensing approaches have unique advantages for fine-grained motion sensing. However, due to the mismatch between the sensing position and detection probability, mapping motion-sensing precision to optimal detection zones is an involved problem. In this letter, we propose a general CSI-based motion detection mode...

Satellite Internet technology has evolved significantly over the past few years. Low Earth orbit (LEO) satellite communication technology and its applications have received growing interest in the field of global communication, due to their advantages of faster speed, lower latency, higher throughput, etc. GalaxySpace’s first satellite (YINHE-1) ha...

Satellite-Terrestrial integrated Networks (STNs) have been advocated by both academia and industry as a promising network paradigm to achieve service continuity and ubiquity. However, STNs suffer from problems including poor flexibility of network architecture, low adaptability to dynamic environments, the lack of network intelligence, and low reso...

Terahertz (THz) joint radar-communication (T-JRC) has been envisioned as a method to overcome the challenges in THz communications. Recent works mainly emphasize the tradeoffs between radar estimations and data communications, unable to characterize the mutual benefit relationship as a key feature of T-JRC system. In this work, a comprehensive perf...

The timely sharing of raw sensing information in the vehicular networks (VNETs) is essential to safety. In order to improve the freshness of sensing information, joint scheduling of multi-dimensional resources such as communication and computation is required. However, the complex relevance among multi-dimensional resources is still unclear, and it...

The benefits of intelligent reflecting surfaces (IRS) assisted massive multiple-input multiple-output systems are based on the accurate acquisition of channel state information but at the cost of the high pilot overhead. In this work, the sparse structure in angular domain is revealed, and then the uplink cascaded channel estimation is converted in...

To satisfy the low-latency requirements of emerging computation-intensive vehicular services, offloading these services to edge or cloud servers has been recognized as an effective solution. However, the limited resources of edge servers and the faraway distance of cloud servers restrict their performance gain. In this article, an end-edge-cloud co...

In the past decade, blockchain has shown a promising vision to build trust without any powerful third party in a secure, decentralized and scalable manner. However, due to the wide application and future development from cryptocurrency to the Internet of things, blockchain is an extremely complex system enabling integration with mathematics, comput...

In this paper, we leverage the benefits of unmanned aerial vehicle (UAV)-enabled wireless networks in providing high link qualities and on-demand services to achieve low-latency mobile virtual reality content delivery. Taking the limited energy storage at the UAVs into consideration, we formulate an average latency minimization problem, subject to...

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