Presence Of Mutual Interference Research Articles

Deep-Learning Channel Estimation for IRS-Assisted Integrated Sensing and Communication System

Integrated sensing and communication (ISAC), and intelligent reflecting surface (IRS) are envisioned as revolutionary technologies to enhance spectral and energy efficiencies for next wireless system generations. For the first time, this paper focuses on the channel estimation problem in an IRS-assisted ISAC system. This problem is challenging due to the lack of signal processing capacity in passive IRS, as well as the presence of mutual interference between sensing and communication (SAC) signals in ISAC systems. A three-stage approach is proposed to decouple the estimation problem into sub-ones, including the estimation of the direct SAC channels in the first stage, reflected communication channel in the second stage, and reflected sensing channel in the third stage. The proposed three-stage approach is based on a deep-learning framework, which involves two different convolutional neural network (CNN) architectures to estimate the channels at the full-duplex ISAC base station. Furthermore, two types of input-output pairs to train the CNNs are carefully designed, which affect the estimation performance under various signal-to-noise ratio conditions and system parameters. Simulation results validate the superiority of the proposed estimation approach compared to the least-squares baseline scheme, and its computational complexity is also analyzed.

Improved rank selection algorithm

Problem statement. A rank algorithm for selecting radio emission modes for operation in conditions of heterogeneity of sources and complex interference conditions, including the possible presence of mutual interference, is synthesized.Objective. The synthesis purpose is to ensure the independence of mode recognition from particular features of radio emission observation. Algorithm input is the primary signal processing result that includes such estimations as pulses durability, frequency and amplitude dynamics, and absolute variations. Primary decision statistics are formed using these values: observable signal base and relation variations of frequency and amplitude. Secondary statistics are formed based on primary ones using median and recursive or maximum and recursive smoothing. Each of the decision statistics in the multi-threshold procedure is transformed into a row of ranks, the size of which corresponds to the number of recognized modes. In aggregate, these lines form a ranking table (matrix) with colons representing recognized modes’ discrete descriptions. Fluent observation processing includes rank formation for used decision statistics. Mode recognition is performed either following a ranking table or using an additional voting procedure 2/3. An alternative approach consists of constructing the Manhattan mismatch metric of the current and reference ranks and making a decision on the criterion of the minimum mismatch metric.Results. Mode recognition performed on results of this comparison using unbalance metrics minimum criterion. Thresholds in frames of the ranking procedure are formed heuristically at ranking table formation. They are then used at fluent rank formation for observable modes. The performed numerical experiment shows that maximal and recursive filtration provides an errorless selection of all observable modes. This filtration represents the composition of maximum selection in sliding window and subsequent recursive first-order filtration. An additional advantage of this filtration is a simpler maximum selection in comparison with the median one. In perspective, it can provide increased operating speed.Practical implications. Performed consideration shows that rank selection is worthwhile at the observation of heterogeneous irradiation sources. Algorithm strength is decision simplicity in a complex situation. Additional algorithm advantage is the possibility of extending alternative irradiation modes and, hence, for more representative data sets.

Optimal routing and one hop routing for D2D communications in the presence of mutual interference

The concept of device to device (D2D) communications allows to increase the capacity of cellular systems. In such systems, a D2D pair directly communicate without passing through the base station and use the same frequency band. Therefore, this communication generates interference to the base station. In some contexts, the D2D pair are not close to each other and relaying should be performed. In this paper, we investigate the performance of different routing protocols for D2D communications. The network is composed of D2D pair, multiple relays organized in clusters, a cellular user communicating with a base station. In such network, there is interference from the relays to the base station and interference from the cellular user to the relays. We call it mutual interference. We investigate optimal and suboptimal routing for D2D communications in the presence of interference. Optimal routing consists to select the path among available ones with the largest end-to-end signal to interference plus noise ratio. A sub-optimal one-hop routing is also proposed.

Evaluation of mutual interference between bovine α-lactalbumin peptide and its isotope-labeled peptide in whey protein analysis using liquid chromatography-tandem mass spectrometry

Internal standard (IS) method is commonly used to correct the matrix effect of samples in the liquid chromatography-tandem mass spectrometric (LC–MS/MS) analysis of whey proteins. However, the presence of mutual interference between some peptides and their isotope-labeled peptides distorts the MS signals, requiring a fundamental evaluation to understand the phenomenon of signal variations. In this study, a simple strategy is proposed to evaluate the effects of sample pretreatment, materials and dilution of solutions on the MS signals of α-lactalbumin (VGINYWLAHK) and β-lactoglobulin peptides using two typical LC–MS/MS systems, Q-Trap and Q-Orbitrap. The strategy adapts the experimental MS data to optimize methods, thus providing meaningful solutions to suppress the mutual interference presented in the analysis of peptides. As a result, the strategy through the combination of 100-fold dilution and plastic injection vial improves the quantitation results of α-lactalbumin peptide significantly. While the β-lactoglobulin peptide presents different phenomenon of signal variations when compared with that of α-lactalbumin peptide, revealing that each peptide needs to be optimized individually. The calibration effect of different IS was also studied in fifteen infant milk powders to confirm the mutual interference impact to quantification result. These results indicated that a simple strategy through the combination of sample dilution and plastic injection vial could be well extended to quantitative analysis of any other peptide in the complex systems.

On the Probabilistic Model for Primary and Secondary User Activity for OFDMA-Based Cognitive Radio Systems: Spectrum Occupancy and System Throughput Perspectives

Cognitive radio systems are a promising solution to the spectrum scarcity problem but accurate modeling of both primary and secondary user activity, spectrum utilization, and system throughput are vital to achieve good performance in such systems. In this paper, we consider a set of primary users that are distributed in space based on a Poisson point process and demand for the available spectrum. We assess the effect of these demands on primary user activity, spectrum occupancy, and total system throughput under various subcarrier-request distributions and fading environments. The asymptotic mean number of active primary users and occupied subcarriers are analytically derived and evaluated further considering the primary network traffic and the average probability of miss-detection of an occupied subcarrier by a single sensing secondary user. It is seen that the average probability of miss-detection is a function of system traffic and the subcarrier-request distribution of primary users and that for extreme primary user traffic, the applied subcarrier-request distribution and total number of provided subcarriers cannot improve further the asymptotic sensing accuracy of the secondary user. Finally, the primary network and the secondary user throughputs in the presence of mutual interference due to imperfect detection of secondary users are investigated and their asymptotic values for large primary network traffic, primary user transmit power, and secondary user transmit power are analytically derived. The results are critically investigated, formulated as theorems and compared with simulations. It is observed that analytical and simulation results are in perfect agreement. It is shown that increasing the primary network transmit power benefits both the primary network and the secondary user throughputs.

Dynamics of additional food provided predator–prey system with mutually interfering predators

Use of additional/alternative food source to predators is one of the widely recognised practices in the field of biological control. Both theoretical and experimental works point out that quality and quantity of additional food play a vital role in the controllability of the pest. Theoretical studies carried out previously in this direction indicate that incorporating mutual interference between predators can stabilise the system. Experimental evidence also point out that mutual interference between predators can affect the outcome of the biological control programs. In this article dynamics of additional food provided predator–prey system in the presence of mutual interference between predators has been studied. The mutual interference between predators is modelled using Beddington–DeAngelis type functional response. The system analysis highlights the role of mutual interference on the success of biological control programs when predators are provided with additional food. The model results indicate the possibility of stable coexistence of predators with low prey population levels. This is in contrast to classical predator–prey models wherein this stable co-existence at low prey population levels is not possible. This study classifies the characteristics of biological control agents and additional food (of suitable quality and quantity), permitting the eco-managers to enhance the success rate of biological control programs.

The probability of the information symbol estimation error in radio communication systems with wideband phase-shift keyed signals in the presence of mutual interference

Coherent reception of phase-shift keyed signals in the presence of multiaccess mutual interference is considered. It is assumed that signals with random initial phases and amplitudes containing regular and random components are received. With allowance for phase fluctuations of the synchronizing channel, analytic expressions are obtained for the mean probability of the error of information symbol value estimation in the case of the reception of such signals. The reception efficiency depending on the signal-to-noise and interference-to-noise ratios and on the number of interfering signals is analyzed.

Voltammetric trace metal determinations by cathodic and anodic stripping voltammetry in environmental matrices in the presence of mutual interference

Arsenic(III), selenium(IV), copper(II), lead(II), cadmium(II), zinc(II) and manganese(II) have been determined in environmental matrices by differential pulse cathodic (DPCSV) and anodic (DPASV) stripping voltammetry. The voltammetric measurements were carried out using, as the working electrode, a stationary mercury electrode, and a platinum electrode and a Ag ∣ AgCl ∣ KCl (sat) electrode as the auxiliary and reference electrode, respectively. An ammonia+ammonium chloride buffer of pH 9.0 was employed as the supporting electrolyte. The analytical procedure was verified by the analysis of the standard reference materials: Sea Water BCR-CRM 403, Estuarine Sediment BCR-CRM 277, Ulva Lactuca BCR-CRM 279 and Mussel Tissue BCR-CRM 278. The precision and accuracy, expressed as relative standard deviation and relative error, respectively, were lower than 5% in all cases, while the detection limit for each element was around 10 −9 mol l −1. In the presence of high reciprocal interference, the standard addition method considerably improved the resolution of the voltammetric technique. The analytical procedure was transferred and applied to samples drawn in the Goro Bay (Ferrara, Italy).