scholarly journals MSE minimized joint transmission in coordinated multipoint systems with sparse feedback and constrained backhaul requirements

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Mohammad Bagher Nezafati ◽  
Mehrdad Taki ◽  
Tommy Svensson
Keyword(s):  
Base Stations ◽  
Channel State ◽  
Duplex System ◽  
Coordinated Multipoint ◽  
System A ◽  
Backhaul Link ◽  
Central Coordination ◽  
Value Decomposition ◽  
The Cost ◽  
Joint Transmission

AbstractIn a joint transmission coordinated multipoint (JT-CoMP) system, a shared spectrum is utilized by all neighbor cells. In the downlink, a group of base stations (BSs) coordinately transmit the users’ data to avoid serious interference at the users in the boundary of the cells, thus substantially improving area fairness. However, this comes at the cost of high feedback and backhaul load; In a frequency division duplex system, all users at the cell boundaries have to collect and send feedback of the downlink channel state information (CSI). In centralized JT-CoMP, although with capabilities for perfect coordination, a central coordination node have to send the computed precoding weights and corresponding data to all cells which can overwhelm the backhaul resources. In this paper, we design a JT-CoMP scheme, by which the sum of the mean square error (MSE) at the boundary users is minimized, while feedback and backhaul loads are constrained and the load is balanced between BSs. Our design is based on the singular value decomposition of CSI matrix and optimization of a binary link selection matrix to provide sparse feedback—constrained backhaul link. For comparison, we adopt the previously presented schemes for feedback and backhaul reduction in the physical layer. Extensive numerical evaluations show that the proposed scheme can reduce the MSE with at least $$25\%$$ 25 % , compared to the adopted and existing schemes.

scholarly journals MSE Minimized Joint Transmission in Coordinated MultiPoint Systems with Sparse Feedback and Constrained Backhaul Requirements

2020 ◽  
Author(s):  
Mohammad Bagher Nezafati ◽  
Mehrdad Taki ◽  
Tommy Svensson
Keyword(s):  
Base Stations ◽  
Channel State ◽  
Coordinated Multipoint ◽  
System A ◽  
Backhaul Link ◽  
Central Coordination ◽  
The Mean ◽  
Value Decomposition ◽  
The Cost ◽  
Joint Transmission

Abstract In a joint transmission coordinated multipoint (JT-CoMP) system, a shared spectrum is utilized by all neighbor cells. In the downlink, a group of base stations (BSs) coordinately transmit the users’ data to avoid serious interference at the users in the boundary of the cells, thus substantially improving area fairness. However, this comes at the cost of high feedback and backhaul load; In a frequency division duplex (FDD) system, all users at the cell boundaries have to collect and send feedback of the downlink channel state information (CSI). In centralized JT-CoMP, although with capabilities for perfect coordination, a central coordination node (CCN) have to send the computed precoding weights and corresponding data to all cells which can overwhelm the backhaul resources. In this paper, we design a JT-CoMP scheme, by which the sum of the mean square error (MSE) at the boundary users is minimized, while feedback and backhaul loads are constrained and the load is balanced between BSs. Our design is based on the singular value decomposition (SVD) of CSI matrix and optimization of a binary link selection matrix to provide sparse feedback - constrained backhaul link. For comparison, we adopt the previously presented schemes for feedback and backhaul reduction in the physical layer. Extensive numerical evaluations show that the proposed scheme can reduce the MSE with at least 25% , compared to the adopted and existing schemes.

scholarly journals MSE Minimized Joint Transmission in Coordinated MultiPoint Systems with Sparse Feedback and Constrained Backhaul Requirements

2021 ◽  
Author(s):  
Mohammad Bagher Nezafati ◽  
Mehrdad Taki ◽  
Tommy Svensson
Keyword(s):  
Base Stations ◽  
Channel State ◽  
Coordinated Multipoint ◽  
System A ◽  
Backhaul Link ◽  
Central Coordination ◽  
The Mean ◽  
Value Decomposition ◽  
The Cost ◽  
Joint Transmission

Abstract In a joint transmission coordinated multipoint (JT-CoMP) system, a shared spectrum is utilized by all neighbor cells. In the downlink, a group of base stations (BSs) coordinately transmit the users’ data to avoid serious interference at the users in the boundary of the cells, thus substantially improving area fairness. However, this comes at the cost of high feedback and backhaul load; In a frequency division duplex (FDD) system, all users at the cell boundaries have to collect and send feedback of the downlink channel state information (CSI). In centralized JT-CoMP, although with capabilities for perfect coordination, a central coordination node (CCN) have to send the computed precoding weights and corresponding data to all cells which can overwhelm the backhaul resources. In this paper, we design a JT-CoMP scheme, by which the sum of the mean square error (MSE) at the boundary users is minimized, while feedback and backhaul loads are constrained and the load is balanced between BSs. Our design is based on the singular value decomposition (SVD) of CSI matrix and optimization of a binary link selection matrix to provide sparse feedback -constrained backhaul link. For comparison, we adopt the previously presented schemes for feedback and backhaul reduction in the physical layer. Extensive numerical evaluations show that the proposed scheme can reduce the MSE with at least 25%, compared to the adopted and existing schemes.

scholarly journals On the Performance of UAV-Aided Content Caching in Small-Cell Networks with Joint Transmission

Electronics ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1040
Author(s):  
Menghan Wei ◽  
Youjia Chen ◽  
Ming Ding
Keyword(s):  
Transmission Rate ◽  
High Mobility ◽  
Limited Resource ◽  
Small Cell ◽  
Base Stations ◽  
Cell Content ◽  
Small Cell Networks ◽  
Content Caching ◽  
Cell Networks ◽  
Joint Transmission

Unmanned aerial vehicles (UAVs), featured by the high-mobility and high-quality propagation environment, have shown great potential in wireless communication applications. In this paper, a novel UAV-aided small-cell content caching network is proposed and analyzed, where joint transmission (JT) is considered in the dense small-cell networks and mobile UAVs are employed to shorten the serving distance. The system performance is evaluated in terms of the average cache hit probability and the ergodic transmission rate. From the analytical results, we find that (i) the proposed UAV-aided small-cell network shows superior caching performance and, even with a small density of UAVs the system’s cache hit probability, can be improved significantly; (ii) the content’s optimal caching probability to maximize the cache hit probability is proportional to the (K+1)-th root of its request probability, where K is the number of small-cell base stations that serve each user by JT; (iii) caching the most popular content in UAVs may lead to a low transmission rate due to the limited resource offered by the low-density UAVs. Simulation results are presented to validate the theoretical results and the performance gain achieved by the optimal caching strategy.

scholarly journals Transmission of wireless backhaul signal in a cellular system with small moving cells

2019 ◽  
Vol 2019 (1) ◽  
Author(s):  
Hyoung-Keon Kim ◽  
Yong-Suk Byun ◽  
Geon-Woong Jung ◽  
Yong-Hwan Lee
Keyword(s):  
Signal Transmission ◽  
Cellular Systems ◽  
Base Stations ◽  
Wireless Backhaul ◽  
Backhaul Link ◽  
Channel Information ◽  
Short And Long Term ◽  
Water Filling ◽  
Noise Ratio

Abstract Deployment of small moving cells (SMCs) has been considered in advanced cellular systems, where wireless backhaul links are required between base stations and SMCs. In this paper, we consider signal transmission by means of multiuser beamforming in the wireless backhaul link. We generate the beam weight in an eigen-direction of weighted combination of short- and long-term channel information of the backhaul link. The beam weight can maximize the average signal-to-leakage-plus-noise ratio (SLNR), while providing the transmission robust to SMC mobility. We analyze the performance of the proposed scheme in terms of the average signal-to-interference-plus-noise ratio (SINR) and optimize the transmit power by iterative water-filling. Finally, we verify the performance of the proposed scheme by computer simulation.

Cost-Effectiveness of Paving Fabrics Used to Control Reflective Cracking

2000 ◽  
Vol 1730 (1) ◽  
pp. 139-149 ◽  
Author(s):  
William G. Buttlar ◽  
Diyar Bozkurt ◽  
Barry J. Dempsey
Keyword(s):  
Life Cycle ◽  
Cost Effectiveness ◽  
Department Of Transportation ◽  
Reflective Cracking ◽  
Crack Control ◽  
Condition Rating ◽  
System A ◽  
Rigid Pavements ◽  
The Cost ◽  
And Control

The Illinois Department of Transportation (IDOT) spends $2 million annually on reflective crack control treatments; however, the cost-effectiveness of these treatments had not been reliably determined. A recent study evaluated the cost-effectiveness of IDOT reflective crack control System A, which consists of a nonwoven polypropylene paving fabric, placed either in strips longitudinally over lane-widening joints or over the entire pavement (area treatment). The study was limited to projects constructed originally as rigid pavements and subsequently rehabilitated with one or more bituminous overlays. Performance of 52 projects across Illinois was assessed through crack mapping and from distress and serviceability data in IDOT’s condition rating survey database. Comparisons of measured reflective cracking in treated and control sections revealed that System A retarded longitudinal reflective widening crack development, but it did not significantly retard transverse reflective cracking, which agrees with earlier studies. However, both strip and area applications of these fabric treatments appeared to improve overall pavement serviceability, and they were estimated to increase rehabilitation life spans by 1.1 and 3.6 years, respectively. Reduction in life-cycle costs was estimated to be 4.4 and 6.2 percent when placed in medium and large quantities, respectively, and to be at a break-even level for small quantities. However, life-cycle benefits were found to be statistically insignificant. Limited permeability testing of field cores taken on severely distressed transverse joints suggested that waterproofing benefits could exist even after crack reflection. This was consistent with the observation that, although serviceability was generally improved with area treatment, crack reflection was not retarded relative to untreated areas.

scholarly journals Using Bluetooth to Implement a Pervasive Indoor Positioning System with Minimal Requirements at the Application Level

2012 ◽  
Vol 8 (1) ◽  
pp. 73-82 ◽  
Author(s):  
Mario Muñoz-Organero ◽  
Pedro J. Muñoz-Merino ◽  
Carlos Delgado Kloos
Keyword(s):  
Base Stations ◽  
Estimation Accuracy ◽  
Signal Quality ◽  
Positioning System ◽  
Reference Base ◽  
Related Data ◽  
Triangulation Method ◽  
Cellular Signal ◽  
The Cost ◽  
Indoor Positioning System

Different systems have been proposed to estimate the position of a mobile device using Bluetooth based on metrics such as the Radio Signal Strength Indicator (RSSI), the received Bit Error Rate (BER) or the Cellular Signal Quality (CSQ). These systems try to improve the estimation accuracy of the basic and straightforward triangulation method among discovered BT reference base stations at the cost of requiring that the positioning application has access to low level hardware related data (provided by the Host Controller Interface) and obtaining information which is in many cases hardware, and therefore device, dependent. In this paper we design, simulate, implement and validate a Bluetooth positioning system that only requires the ability to handle SDP service records at the application level, achieving mean errors around 1 to 3 meters, improving the basic triangulation method among discovered BT reference base stations.

An Active Low Cost Mesh Networking Indoor Tracking System

2014 ◽  
Vol 6 (1) ◽  
pp. 45-79 ◽  
Author(s):  
Sean Carlin ◽  
Kevin Curran
Keyword(s):  
Tracking System ◽  
Low Cost ◽  
Cost Effective ◽  
Limiting Factors ◽  
Unique Contribution ◽  
Scalable Vector Graphics ◽  
Web Technologies ◽  
Working Environments ◽  
System A ◽  
The Cost

Indoor radio frequency tracking systems are generally quite expensive and can vary in accuracy due to interference, equipment quality or other environmental factors. Due to these limiting factors of the technology, many businesses today find it hard to justify investing in RFID tracking technologies to improve the safety, efficiency and security of their working environments. The aim of this project was to provide a budget RFID tracking system that was capable of tracking a person or object through an indoor environment. To minimize the cost of the RFID tracking system, the components of the system were built from existing electronic equipment and hardware. The software was also written to minimize licensing and support fees allowing a cost effective budget RFID tracking system to be developed. The tracking system consists of a tag, reader nodes and a PC reader which utilize synapse RF 100 engines with python scripts embedded on to the chips. The tracking system software operates through a web portal utilizing web technologies such as HTML, JavaScript and PHP to allow the tags location to be represented on a two dimensional map using scalable vector graphics. During development of the system a new trilateration algorithm was developed and used convert the signals received from the tag to a virtual position on the map correlating to the actual physical position of the tag. A unique contribution of this system is the low cost of building which we estimate as less than £200 UK sterling for a five node system.

scholarly journals Optimizing a Secure Two-Way Network with Non-Linear SWIPT, Channel Uncertainty, and a Hidden Eavesdropper

Electronics ◽  
2020 ◽  
Vol 9 (8) ◽  
pp. 1222
Author(s):  
Pham Viet Tuan ◽  
Pham Ngoc Son ◽  
Tran Trung Duy ◽  
Sang Quang Nguyen ◽  
Van Quang Binh Ngo ◽  
...  
Keyword(s):  
Base Stations ◽  
Artificial Noise ◽  
Power Splitting ◽  
Transmission Power ◽  
Channel State ◽  
Downlink Beamforming ◽  
Non Linear ◽  
Channel Information ◽  
Downlink Channels

In this paper, the optimization of downlink beamforming vectors, uplink transmission power, and power-splitting factors is investigated for a secure two-way SWIPT network in the presence of a hidden eavesdropper and non-linear energy harvesting circuits over both perfect and imperfect channels. The eavesdropper is inactive, so its channel information is not available at the base stations (BSs). The purpose of artificial noise is to create downlink interference with the hidden eavesdropper as much as possible, while satisfying the quality of service for two-way communications. For perfect downlink channels, the semidefinite relaxation (SDR) technique is exploited, and the optimal matrices are proven to satisfy rank-1 conditions, thus providing the optimal beamforming vectors. For imperfect downlink channel state information, we propose an iterative algorithm with a penalty function to obtain the approximate rank-1 matrices. On uplink, we attain the optimal transmission power for users receiving maximum ratio transmission beamforming at the BSs. Eventually, the numerical experiments show the superiority of the proposed scheme, compared to a conventional scheme, in terms of signal-to-interference-plus-noise ratio at the eavesdropper.

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