Interference Avoidance

Our demo aims at proving the concept of a recent proposed interference management scheme that reduces the inter-cell interference in downlink without complex coordination, known as non-classic interference alignment (IA) scheme. We assume a case where one main Base Station (BS) needs to serve three users equipments (UE) while another BS is causing interference. The primary goal is to construct the alignment scheme ; i.e. each UE estimates the main and interfered channel coefficients, calculates the optimal interference free directions dropped by the interfering BS and feeds them back to the main BS which in turn applies a scheduling to select the best free inter-cell interference directions. Once the scheme is build, we are able to measure the total capacity of the downlink interference channel. We run the scheme in CorteXlab ; a controlled hardware facility located in Lyon, France with remotely programmable radios and multi-node processing capabilities, and we illustrate the achiev...

Underactuated Cable-Driven Parallel Robots (UACDPRs) typically rely on relative internal sensors to estimate the end-effector (EE) state. Therefore, at startup, the reference values of the quantities measured by these sensors are unknown, and so is the initial pose of the EE. The problem of determining the reference values of the internal sensors is called initial-pose self-calibration. The latter is often formulated as an overdetermined system of nonlinear equations and solved using nonlinear weighted least-squares methods, minimizing the error between modeled and measured variables, and its effectiveness is highly influenced by the choice of measurement configurations, as well as the motion planning and control strategy used to reach them. This work presents two practical data acquisition methods for initial-pose self-calibration of UACDPRs, aiming to reduce the overall time required by the procedure and enhance process automation. The first method is slower but richer in data, as it relies on equilibrium poses and, therefore, can leverage cable-tension data, whereas the second method is faster and is based on geometric constraints only. The performance of the methods is evaluated in terms of acquisition time, number of measurements, and calibration accuracy on a 4-cable UACDPR prototype. The results highlight the merits and shortcomings of both methods, namely, trade-offs between the velocity of data collection and the precision of pose estimation.

Massive Multiple-Input Multiple-Output (mMIMO) technology represents a significant advancement in wireless communications, particularly within the realm of 5G networks. mMIMO enhances network capacity, coverage, and efficiency by leveraging a large number of antennas at the base station (BS) to simultaneously serve multiple user equipment (UE). Beamforming, a technique integral to mMIMO, directs signals to specific users, optimizing signal strength and minimizing interference. This whitepaper is a short survey for the SRS based beamforming vs. the Codebook based beamforming.

Nowadays, increasing demands for on-line wire diagnosis using reflectometry have imposed serious challenges on signals processing, bandwidth control and interference mitigation. On-line diagnosis aims at detecting and locating faults accurately while the target system is running. In this work, a new reflectometry method, named "Orthogonal Multi-Tone Time Domain Reflectometry" (OMTDR), is proposed. OMTDR, based on Orthogonal Frequency Division Multiplexing (OFDM), is a suitable candidate for on-line diagnosis as it permits interference avoidance, bandwidth control and data rate increase thanks to the use of orthogonal tones and guard intervals. Over the diagnosis function, OMTDR adds communication between sensors to more accurately determine faults position in a multi-branch network using a distributed strategy. OMTDR was tested on a branched network consisting of three cables with different lengths, with sensors at each cable end. Here, the sensors signals are carefully constructed using a resource allocation scheme to use frequencies below and above the prohibited bandwidth, used by the target system, for communication and diagnosis. Simulation results show that the proposed method performs well in a branched wiring network as it permits to detect and locate faults accurately even when the target system is operating.

In this paper we describe the designing of MIMO(Multiple input and multiple output ) system along with scheduling technology which schedule the beam depending on SINR ratio keeping it different from other scheduling techniques like RR and PF techniques. This paper describe the effect of scheduling to compare different parameter for the dynamic resource allocation.Now a days communication industry increasing spontaneously In this late century, use of mobile and cellular services are very common .In the proposed method of SINR scheduling technique signals are scheduled according to their signal to noise plus interference ratio. We tried to develop the effective scheduling technique that support the QPSK and implementing lower complexity into MIMO estimated channel. We resolve the inter cell interference between the base station and destination which causes a large effect system capacity. Intercellular interference become more problematic with the decrease in cell size

Aeronautical mobile telemetry (AMT) based on 3GPP’s LTE standard is implemented in a proof-of-concept system. The solution tackles the very high Doppler shifts expected in flight tests with the use of an appliqué that can be inserted between the transmit/receive ports of the Test Article (TA) and the antennas. This appliqué estimates the Doppler shift and proactively compensates for it on the uplink signal being transmitted by the TA. The overall system has been tested under different operational conditions in a laboratory setup as well as in the field. In the laboratory setup, the desired operating conditions are created with a set of Software-Defined-Radio-based channel emulators coupled with a computer to control their behavior. In order to carry out field tests, an operational LTE network has been created at the Edwards Air Force Base (EAFB) with two base stations, backhaul links, and a core network. In this paper, we provide descriptions of both laboratory and field test setups...

Efficient acquisition of channel state information (CSI) is quite complicated process but immensely essential to exploit probable benefits of massive multiple input multiple output (MIMO) systems. Therefore, a deep learningbased model is utilized to estimate channel feedback in a massive MIMO system. The proposed improvised deep learning-based channel estimation (IDLCE) model enhances channel reconstruction efficiency by using multiple convolutional layers and residual blocks. The proposed IDLCE model utilizes encoder network to compress CSI matrices where decoder network is used to downlink reconstruct CSI matrices. Here, an additional quantization block is incorporated to improve feedback reconstruction accuracy by reducing channel errors. A COST 2,100 model is adopted to analyse performance efficiency for both indoor and outdoor scenarios. Further, deep learning-based model is used to train thousands of parameter and correlation coefficients much faster and to minimize computational complexity. The proposed IDLCE model evaluate performance in terms of normalized mean square error (NMSE), correlation efficiency and reconstruction accuracy and compared against varied state-of-art-channel estimation techniques. Excellent performance results are obtained with large improvement in channel reconstruction accuracy.

Highlights • A cable-suspended robot is presented with a spatial purely translational motion. • Several special architectures are identified with distinctive and useful features. • The singularity-free/reachable/interference-free workspaces are analytically found. • The theoretical findings are validated by experimental tests. • The robot can perform dynamic trajectories outside the static equilibrium workspace.

The design and analysis of a 4-DOF multi-link cable driven parallel mechanism is presented. In contrast to many existing cable driven parallel mechanism, the proposed manipulator's rigid links are serially articulated. This design preserves the advantages associated with cabledriven parallel mechanisms, and introduces the advantages in having a serial kinematic structure. The kinematic and kinetic analysis is presented, with focus on the different types of cable routings. Several aspects of the manipulator design and assumptions are also discussed. The solving of inverse dynamics and wrenchclosure workspace problems are important in the control and analysis of the mechanism. A detailed example for a two-link mechanism inspired by a human arm consisting of the shoulder and elbow joints is included.

This document provides an overview of the proposed innovations and activities in Task 1.1 of Work Package 1 (WP1) of the ARTIST4G project, related to interference avoidance. Focus is on the technical approaches applicable at the physical layer, which are grouped into four different classes of innovations related to single-cell multiuser MIMO schemes, multi-cell multiuser MIMO schemes, advanced 3D beamforming and enabling functionalities. Descriptions of the proposed innovations are given including basic ideas, potential of performance, simulation results, realization options and possible implementation restrictions.

The focus of this thesis is the design of a 5G radio access networks and the development of a tool capable of simulating one dimensioning. The main goal is to calculate the cell radius and respective usage percentage for different variations of a certain scenario. Thus, a model was developed, which consists mainly of coverage and capacity planning. Both downlink and uplink directions of the links between the base station and the user equipment are studied. In the downlink connection is only studied the frequency band 3500 MHz, while in uplink are also studied the bands 800 and 1800 MHz. This thesis only focuses on the study of urban environment, for which are variations regarding some input parameters like user density, frequency band and bandwidth, cell edge target throughput, traffic profile and MIMO. These parameters were studied in order to understand the impact on the cell radius and respective usage percentage. In this way, a model was implemented, which according to the input...

In this paper we describe the designing of MIMO(Multiple input and multiple output) system along with scheduling technology which schedule the beam depending on SINR ratio keeping it different from other scheduling techniques like RR and PF techniques. This paper describe the effect of scheduling to compare different parameter for the dynamic resource allocation.Now a days communication industry increasing spontaneously In this late century, use of mobile and cellular services are very common .In the proposed method of SINR scheduling technique signals are scheduled according to their signal to noise plus interference ratio. We tried to develop the effective scheduling technique that support the QPSK and implementing lower complexity into MIMO estimated channel. We resolve the inter cell interference between the base station and destination which causes a large effect system capacity. Intercellular interference become more problematic with the decrease in cell size Keywords-Mimo ,Millimeter Wave Scheudling Interferencece I.

This paper presents an efficient interval-analysis-based algorithm to solve the direct geometrico-static problem (DGP) of underconstrained cable-driven parallel robots (CDPRs). Solving the DGP for a generic CDPR consists of finding all possible equilibrium poses of the end effector for the given cable lengths. Since cables impose unilateral constraints, configurations with one or more slack cables may occur. When the number of taut cables is smaller than six the robot is underconstrained and the DGP solutions must be found considering loop-closure and mechanical equilibrium equations simultaneously. The presented algorithm can find all DGP solutions of a generic CDPR in a numerically robust and safe way. By using interval analysis the proposed procedure can directly search for real solutions with non-negative cable tensions and it can take advantage of the physical constraints of the robot. The implemented procedure is discussed in detail, and the testing and experimental validation...

Single-Carrier Frequency Division Multiple Access (SC-FDMA) is a promising technique for high data rate indoor Terahertz (THz) communications in future beyond 5G systems. In an indoor propagation scenario, the Line-Of-Sight (LOS) component may be blocked by the obstacles. Thus, efficient THz SC-FDMA communications require a fast and reliable Beam Alignment (BA) method for both LOS and Non-Line-Of-Sight (NLOS) scenarios. In this paper, we first adopt the hierarchical discrete Fourier transform codebook for LOS BA, and introduce the hierarchical k-means codebook for NLOS BA to improve the beamforming gain. Simulation results illustrate that the hierarchical DFT codebook and the hierarchical k-means codebook can achieve the beamforming gain close to that of the maximum ratio transmission in LOS and NLOS cases, respectively. Based on these two codebooks, we propose a Multi-Armed Bandit (MAB) algorithm named Hierarchical Beam Alignment (HBA) for single-user SC-FDMA THz systems to reduce ...

We consider a cognitive radio system where the secondary transmitter varies its transmit power based on all the information available from the spectrum sensor. The operation of the secondary user is governed by its peak transmit power constraint and an average interference constraint at the primary receiver. Without restricting the sensing scheme (total received energy, or correlation etc), we characterize the power adaptation strategies that maximize the secondary user's SNR and capacity. We show that, in general, the capacity optimal power adaptation requires decreasing the secondary transmit power from the peak power to zero in a continuous fashion as the probability of the primary user being present increases. We find that that power control that maximizes the SNR is binary, i.e., if there is any transmission, it takes place only at the peak power level. Numerical results for common spectrum sensing schemes show that the SNR and capacity maximizing schemes can be very different. With an average transmit power constraint at the secondary radio, both the SNR and capacity optimal power control schemes are observed to be non-binary. Further, we find that with secondary channel knowledge at the cognitive transmitter, the optimal SNR with an average transmit power constraint is unbounded.

In this document we provide performance assessments of the most promising techniques that were studied within Work Package 1 (WP1) of the ARTIST4G project related to interference avoidance. The results are based on evolved techniques that were identified and classified in deliverable D1.1 and investigated in deliverable D1.2 and D1.3, as well as novel alternative techniques that are introduced and assessed in this document. Based on the insights from these performance results we provide a synthetic perspective over the most promising solutions for interference avoidance. We argue that these solutions can reach a satisfactory trade-off in terms of performance benefits vs complexity of implementation. Some of these techniques are also identified as complementary techniques towards an integrated interference

In this paper, we propose several frequency reuse coordination schemes for interference management in orthogonal frequency division multiple access. The aim of these schemes, working together with time and frequency domain packet scheduling, is to achieve reuse of 1 at sector level in a tri-sectorized base station scenario. Inter-sector interference is strong at the frontier between sectors, and a tight coordination scheme needs be applied. To support this coordination scheme, the users' location information is then essential to determine if a user is prone to suffer strong inter-sector interference. The performance of these resource allocation algorithms is compared with schemes based on fractional frequency reuse, where reuse of 1 at cell level is assumed.

This paper focuses on the study of a cable-driven parallel robot (CDPR) for the automated handling of payloads from a ship. Handling operations are performed at sea, under calm to mild weather conditions, thus both the payload and the ship (on which the robot is installed) may possess oscillatory motions. The tasks the robot has to perform are (i) payload autonomous tracking and picking on the sea surface, and (ii) payload lifting. Robot and task modelling are introduced, as well as the controllers used to achieve such operations.

To meet the increasing demand for spectrum in communication system, Long Term Evolution (LTE) system has been proposed. It allowed users to use a new and much wider spectrum comparing to the other previous technologies. To utilize the full capacity of the LTE system Frequency Reuse (FR) has been adapted. It is a promising aspect of transmission of high rate data stream with better system capacity and fading immunity in the modern Long-Term Evolution-Advanced (LTE-A) system. Fractional Frequency Reuse (FFR) is the commonly used frequency reuse technique to increase the system capacity. But the problem is, with introduction of FR, it also increases the Inter Cell Interference (ICI) of the system. The out of cell interference coming from the neighbouring e-NodeBs (eNB) as a result of using the same frequency band and they act as an interference source. This ICI decreases the system capacity, resulting in hampering of communication, browsing and in worst case no connection at all. This ...

Interference management techniques like inter-cell interference coordination (ICIC) will play a key role in enabling high spectral efficiency in future wireless OFDMA-based cellular systems. The aim of ICIC is to lower inter-cell interference by coordinating the usage of spectrum resources among neighboring cells. Especially for the cell-edge users, avoiding the reuse of the same resources in neighboring cells yields a significant increase in SINR and thus capacity. In this paper, we consider decentralized ICIC schemes for the uplink of an LTE system in which base stations perform selfish resource allocation decisions. System level simulations in a multi-cell scenario show the convergence of the distributed schemes towards Nash equilibria. The mean cell throughput as well as the 5% CDF user throughput are compared to those achieved by frequency reuse 1 and 3 deployments. The simulation results show that the proposed schemes adapt well to varying uniform and especially non-uniform traffic loads.

In this paper, we have presented the 3D cables parallel robot in pyramid’s form. The dynamic equation has been established including the dynamic behavior, in this context; we investigated to use the Runge Kutta method of 4th order to solving non-linear partial differential equation of our system. The main contribution of this work is firstly: a graphical user interface (GUI) has been developed and implemented based on the geometric model, in order to visualizing the position of end effect or, taking account model uncertainties and payload variation. Secondly, we have studied and solved our system’s dynamical equation with implementation the PD control. This last, applied for different trajectories so as to test the accurate tracking the desired trajectory simulation using MATLAB software. As a result, the simulation tests on this robot verify the efficiency performance of the proposed controller.

This paper focuses on the study of a cable-driven parallel robot (CDPR) for the automated handling of payloads from a ship. Handling operations are performed at sea, under calm to mild weather conditions, thus both the payload and the ship (on which the robot is installed) may possess oscillatory motions. The tasks the robot has to perform are (i) payload autonomous tracking and picking on the sea surface, and (ii) payload lifting. Robot and task modelling are introduced, as well as the controllers used to achieve such operations.