FIGURE 3 - available via license: Creative Commons Attribution 4.0 International
Content may be subject to copyright.
Comparison between the baseline and RIS-assisted models when λ RIS λ BS . Squares indicate RISs. In RIS-assisted model, each RIS has its own coverage area since the UE communicates with the nearest RIS.
Source publication
The use of millimeter-wave (mmWave) bandwidth is one key enabler to achieve the high data rates in the fifth-generation (5G) cellular systems. However, mmWave signals suffer from significant path loss due to high directivity and sensitivity to blockages, limiting its adoption within small-scale deployments. To enhance the coverage of mmWave communi...
Context in source publication
Similar publications
This paper brings the concept of wireless edge caching (WEC) to the realm of integrated access and backhaul (IAB) networks. Traditionally, both access and backhaul are allocated fixed spectrum. However, when WEC is applied to the IAB nodes to pre-fetch some popular files, the backhaul traffic can be drastically reduced. Accordingly, an analytical f...
A novel stochastic geometry framework is proposed in this paper to study the downlink coverage performance in a millimeter wave (mmWave) cellular network by jointly considering the polar coordinates of the Base Stations (BSs) with respect to the typical user located at the origin. Specifically, both the Euclidean and the angular distances of the BS...
The aim of this work is to propose a dual band millimeter wave (mmwave) MIMO antenna
system for 5G technology. In addition, the arrangement of the antenna elements in an array should be in such a manner that without using the traditional decoupling structures and/or techniques, a reasonable isolation level must be achieved. To demonstrate this, a s...
5G and beyond (B5G) networks are moving towards the higher end of the millimeter-wave (mmWave) spectrum (i.e., from 25 GHz to 100 GHz) to support integrated communications and ranging (ICAR) services in next-generation factory deployments. The ICAR services in factory deployments require extreme bandwidth/capacity and large ranging coverage, which...
In this paper, we model the aggregate interference power in directional beamforming mobile networks. The work considers the random waypoint model to describe the mobility of the nodes and adopts directional beamforming for communication. The major contribution of this paper is the statistical characterization of the aggregate interference caused by...
Citations
... MIMO system was considered in [87], and the problem of rank improvement to enhance the channel capacity was studied. Furthermore, by properly optimizing the phase shifts of the RIS elements, the coverage area of the wireless network can be expanded in RIS-assisted communication systems [88][89][90]. Moreover, in [91][92][93] ...
Keywords: Advanced MIMO Techniques, Wireless Communications, Sparase Layered MIMO Systems, RIS-assisted Spatial Modulation, Quadrature Spatial Modulation, Generalized Spatial Modulation, Performance Analysis, Joint MGF of Ordered Eigenvalues, Probability Analysis, Wireless Communications.
... RIS, also known as passive large intelligent surface (LIS) [11] or intelligent reflecting surface (IRS) [12], has been envisaged to realize the so-called smart radio environment [13] that has become part of the system design parameters. It has been used to transform the channel for achieving multifarious tasks in various scenarios [14]- [24]. To enhance the coverage in mmWave systems, [14] and [15] introduced RIS to alleviate the significant path loss and severe blockage, respectively. ...
... It has been used to transform the channel for achieving multifarious tasks in various scenarios [14]- [24]. To enhance the coverage in mmWave systems, [14] and [15] introduced RIS to alleviate the significant path loss and severe blockage, respectively. In [16] and [17], RISs were used for beamforming and broadcasting, and the corresponding large-scale fading models were provided together with measurement verifications. ...
In strong line-of-sight millimeter-wave (mmWave) wireless systems, the rank-deficient channel severely hampers spatial multiplexing. To address this inherent deficiency, multiple reconfigurable-intelligent-surfaces (RISs) are introduced in this study to customize the wireless channel. Utilizing the RIS to reshape electromagnetic waves, we theoretically show that a favorable channel with an arbitrary tunable rank and a minimized truncated condition number can be established by elaborately designing the placement and reflection matrix of RISs. Different from existing works on multi-RISs, the number of elements needed for each RIS to combat the path loss and the limited phase control is also considered. On the basis of the proposed channel customization, a joint transmitter-RISs-receiver (Tx-RISs-Rx) design under a hybrid mmWave system is investigated to maximize the spectral efficiency. Using the proposed scheme, the optimal singular value decomposition-based hybrid beamforming at the Tx and Rx can be obtained without matrix decomposition for the digital and analog beamforming. The bottoms of the sub-channel mode in the water-filling algorithm, which are conventionally uncontrollable, are proven to be independently adjustable by RISs. Moreover, the transmit power required for realizing multi-stream transmission is derived. Numerical results are presented to verify our theoretical analysis and exhibit substantial gains over systems without RISs.
... Based on the analysis of signal-to-interference ratio (SIR), Ref. [14] verified the effectiveness of deploying RISs to improve the SIR coverage of millimeter wave networks from both theoretical analysis and simulation experiments. However, given that millimeter wave networks are non-interference limited [15], the impact of noise on system performance cannot be ignored. ...
... However, given that millimeter wave networks are non-interference limited [15], the impact of noise on system performance cannot be ignored. In addition, ref. [14] only considers Rayleigh fading in order to simplify the analysis. Refs. ...
Reconfigurable intelligent surface (RIS) is emerging as a promising technology to achieve coverage enhancement. This paper develops a tractable analytical framework based on stochastic geometry for performance analysis of RIS-assisted millimeter wave networks. Based on the framework, a two-step cell association criterion is proposed, and the analytical expressions of the user association probability and the coverage probability in general scenarios are derived. In addition, the closed-form expressions of the two performance metrics in special cases are also provided. The simulation results verify the accuracy of the theoretically derived analytical expressions, and reveal the superiority of deploying RISs in millimeter wave networks and the effectiveness of the proposed cell association scheme to improve coverage. Furthermore, the effects of the RIS parameters and the BS density on coverage performance are also investigated.
... In the SG-based mmWave network context, several studies consider IRSs in their network models for coverage analysis [18]- [24]. Authors in [18] assume a downlink communication between the TUE and BSs through the direct link or the indirect link. ...
... In the SG-based mmWave network context, several studies consider IRSs in their network models for coverage analysis [18]- [24]. Authors in [18] assume a downlink communication between the TUE and BSs through the direct link or the indirect link. With Rayleigh small scale fading and productdistance model for the PL law of the indirect link, they derive the signal-to-interference ratio (SIR) coverage probability, where interference from only the LoS BSs are considered. ...
p>Intelligent reflecting surfaces (IRSs) have become a popular topic in recent years for their great potential for controlling the radio link environment of wireless networks. With this controlled environment, the coverage can be increased. This paper examines the coverage analysis of IRS-aided networks, considering both two-dimensional buildings and the product-distance path loss model for the first time. Leveraging the tools from stochastic geometry, the locations of base stations (BSs), buildings, and IRSs are modeled with a homogeneous Poisson point process (PPP). A Gamma approximation for the distribution of the nearest line-of-sight (LoS)-neighbor distance is proposed, leading to a closed-form expression for the distribution of the product-distance. Feasible BSs are defined as BSs which are reachable via an IRS deployed on a specific facade of a building, and the ratio of feasible BSs is derived. Simulations are performed, which confirm the proposed analytical methods. In the numerical results, it is observed that the IRSs can introduce up to a 45\% coverage boost, and the effect of the IRS length on the coverage probability is limited beyond 1.2 meters at 60 GHz.</p
... Recently a number of researchers attempted to employ RIS to improve the coverage area of WiGig communications. In particular, researchers in [12] leveraged stochastic geometry to analyze the possible coverage improvement via RIS-enhanced WiGig communications. The work in [13] investigated WiGig communications with random blockers utilizing multiple RIS panel structures. ...
... This paper [13] proposes a RIS-aided AirComp method for WDA in mmWave communication networks, jointly optimizing the receive beamforming vector, transmit scalars, and phase-shift matrix of the RIS. This work [14] proposes deploying RISs to enhance mmWave coverage in 5G networks, with closedform expressions for peak reflection power and downlink SIR coverage derived using stochastic geometry. ...
... In the SG-based mmWave network context, several studies consider IRSs in their network models for coverage analysis [18]- [24]. Authors in [18] assume a downlink communication between the TUE and BSs through the direct link or the indirect link. ...
... In the SG-based mmWave network context, several studies consider IRSs in their network models for coverage analysis [18]- [24]. Authors in [18] assume a downlink communication between the TUE and BSs through the direct link or the indirect link. With Rayleigh small scale fading and productdistance model for the PL law of the indirect link, they derive the signal-to-interference ratio (SIR) coverage probability, where interference from only the LoS BSs are considered. ...
p>Intelligent reflecting surfaces (IRSs) have become a popular topic in recent years for their great potential for controlling the radio link environment of wireless networks. With this controlled environment, the coverage can be increased. This paper examines the coverage analysis of IRS-aided networks, considering both two-dimensional buildings and the product-distance path loss model for the first time. Leveraging the tools from stochastic geometry, the locations of base stations (BSs), buildings, and IRSs are modeled with a homogeneous Poisson point process (PPP). A Gamma approximation for the distribution of the nearest line-of-sight (LoS)-neighbor distance is proposed, leading to a closed-form expression for the distribution of the product-distance. Feasible BSs are defined as BSs which are reachable via an IRS deployed on a specific facade of a building, and the ratio of feasible BSs is derived. Simulations are performed, which confirm the proposed analytical methods. In the numerical results, it is observed that the IRSs can introduce up to a 45\% coverage boost, and the effect of the IRS length on the coverage probability is limited beyond 1.2 meters at 60 GHz.</p
... [17] modeled the line Boolean blockages model to analyze the direct case and the reflection case. Subsequently, it is assumed that the received signal's direct and reflected paths might be independent from a receive diversity perspective [18]. Based on the approximation of statistical analysis, the direct and reflected paths can be roughly regarded as independent [19], [20]. ...
... System model signal transmission [3], [5], [8], [24], [25] (2), (18) Application signal statistics [3], [22], [24], [25] (25), (26) cover probability/ASE/AEE [3]- [12], [24], [25], [29] variable. Define diag[a 1 , a 2 , · · · , a n ] by a diagonal matrix whose main diagonal elements are a 1 , a 2 , · · · , a n in order. ...
With the fast development of reconfigurable intelligent surface (RIS), the network topology becomes more complex and varied, which makes the network design and analysis extremely challenging. Most of the current works adopt the binary system stochastic geometric, missing the coupling relationships between the direct and reflected paths caused by RISs. In this paper, we first define the typical triangle which consists of a base station (BS), a RIS and a user equipment (UE) as the basic ternary network unit in a RIS-assisted ultra-dense network (UDN). In addition, we extend the Campbell's theorem to the ternary system and present the ternary probability generating functional (PGFL) of the stochastic geometry. Based on the ternary stochastic geometry theory, we derive and analyze the coverage probability, area spectral efficiency (ASE), area energy efficiency (AEE) and energy coverage efficiency (ECE) of the RIS-assisted UDN system. Simulation results show that the RISs can improve the system performances, especially for the UE who has a high signal to interference plus noise ratio (SINR), as if the introduced RIS brings in Matthew effect. This phenomenon of RIS is appealing for guiding the design of complex networks.
... In addition, the advantages of lowdimensional, flexible, and compact allow the IRS to be seamlessly integrated into existing wireless systems [9]- [11]. In particular, both the low hardware cost and the passive nature of an IRS facilitate sustainable development of practical wireless networks and thus it has been exploited for various applications, such as coverage extension [12]- [14], mobile-edge computing [15]- [17], integrated sensing and communication systems [18]- [20], multi-cell systems [21]- [23], etc. However, the above works have primarily focused on the capability of an IRS to either increase the received signal strength or mitigate the intra-/inter-cell interference at the receiver [24]. ...
Compared with traditional half-duplex wireless systems, the application of emerging full-duplex (FD) technology can potentially double the system capacity theoretically. However, conventional techniques for suppressing self-interference (SI) adopted in FD systems require exceedingly high power consumption and expensive hardware. In this paper, we consider employing an intelligent reflecting surface (IRS) in the proximity of an FD base station (BS) to mitigate SI for simultaneously receiving data from uplink users and transmitting information to downlink users. The objective considered is to maximize the weighted sum-rate of the system by jointly optimizing the IRS phase shifts, the BS transmit beamformers, and the transmit power of the uplink users. To visualize the role of the IRS in SI cancellation by isolating other interference, we first study a simple scenario with one downlink user and one uplink user. To address the formulated non-convex problem, a low-complexity algorithm based on successive convex approximation is proposed. For the more general case considering multiple downlink and uplink users, an efficient alternating optimization algorithm based on element-wise optimization is proposed. Numerical results demonstrate that the FD system with the proposed schemes can achieve a larger gain over the half-duplex system, and the IRS is able to achieve a balance between suppressing SI and providing beamforming gain.
... In [17], the cell coverage is maximized by optimizing the RIS orientation and horizontal distance. Te RISassisted channel model is presented in [18], and the principle of phase-shift adjustment at RIS beamforming is applied to enhance the coverage in desired regions [19]. Te RIS can be programmed to discrete adjustment of the refection phase [20], which provides an opportunity for the introduction of various artifcial intelligence methods. ...
As one of the most important radio communication scenarios in vertical industry, the high-speed railway (HSR) station is facing the challenge of coverage optimization due to its complex structure. Regarding the wireless network planning and optimization of HSR stations as a part of the customized network, this paper makes an analysis on the 5G-R channel in the HSR station scenario. Channel characteristics, including path loss, power ratio (PR), and angular spread (AS), are extracted on the basis of ray tracing (RT). Multipath components can also be distinguished based on RT. In order to achieve a better performance, the reconfigurable intelligent surface (RIS) technology is adopted to the network deployment. Moreover, machine learning (ML) is used to locate the best direction of the beam. The analysis results show that the received power in RIS-assisted channels is significantly promoted. Our research can provide a deep understanding to the 5G-R channel in station scenario and a well reference for the design and optimization of the customized network.
