Implementation of Hidden Markov Model spectrum prediction algorithm

BACKGROUND A hidden Markov model (HMM) is used for exon prediction on DNA of genes Plasmodium falciparum that has a model structure based on exon region structure in coding sequence (CDS). The objective research was to develop a new structure model to predict exon on DNA-genes of Plasmodium falciparum based on CDS structure using the HMM system. METHODS Model design in CDS, between two exon regions can be found one intron region and the model state number is used for its region. Its state number is used by separating start codon from first exon region and stop codon from the last exon region up to 9. The Viterbi algorithm and the backward-forward method for transition as well as emission states are used for training process. Furthermore, Viterbi and Baum-Welch algorithms are used for the testing process. The correlation coefficient (CC) was used as performance indicator, as the ratio of the estimated state in the output and the original state in the input of the model. RESULTS The simulation results has shown that the CC values depend on the given of the backward-forward transition state values randomly. The model with state number 9 showed the highest average of CC values of 0.7289 for Viterbi algorithm, and is 0.7166 for Baum-Welch algorithm. However, the lowest average of CC values has been found for the model with state number five. Its values are 0.6735 by using Viterbi algorithm and 0.6661 by using Baum-Welch algorithm. CONCLUSION The new structure model based on HMM system was valid to predict exon on DNA-genes of Plasmodium falciparum.

The discrete channel hidden Markov models indicate the temporal statistical characteristics of the generated error sequences by fading channels with memory precisely. In this paper first the optimal order of the hidden Markov models is estimated using Baum Welch algorithm (BWA) with comparing statistics such as average loglikelihood and autocorrelation function for error modelling of IEEE 802.16/WiMAX standard. As a perfect alternative to HMM error models, a new efficient stochastic swarm intelligent-based particle swarm optimization (PSO)-HMM is suggested for this standard to find the global and optimal solution. Comparing the proposed method with the conventional (BWA) by performing numerical simulations using error sequences of various lengths, the results indicate the superiority of the PSO approach even when the target sequences are as short as 2000 in length; moreover, the appropriateness of the PSO-HMM is investigated for different sampling periods. It can be concluded that the PSO with two states arrives at high level of accuracy in contrast to HMM with much higher number of states. For validating the proposed method, the burst error statistics of the PSO-HMM with respect to the autocorrelation function and error free interval distribution of the original error sequence are presented. The simulation results indicate that the PSO-HMM has better performance to find the optimal model parameters more stable than (BWA).

Background: The genomics and microarray technology played tremendous roles in the amount of biologically useful information on gene expression of thousands of genes to be simultaneously observed. This required various computational methods of analyzing these amounts of data in order to discover information about gene function and regulatory mechanisms. Methods: In this research, we investigated the usefulness of hidden markov models (HMM) as a method of clustering Plasmodium falciparum genes that show similar expression patterns. The Baum-Welch algorithm was used to train the dataset to determine the maximum likelihood estimate of the Model parameters. Cluster validation was conducted by performing a likelihood ratio test. Results: The fitted HMM was able to identify 3 clusters from the dataset and sixteen functional enrichment in the cluster set were found. This method efficiently clustered the genes based on their expression pattern while identifying erythrocyte membrane protein 1 as a prominent and diverse protein in P. falciparum. Conclusion: The ability of HMM to identify 3 clusters with sixteen functional enrichment from the 2000 genes makes this a useful method in functional cluster analysis for P. falciparum

ABSTRACTThe rapid expansion of the Internet of Things (IoT) and the increasing demand for wireless communication have intensified the need for efficient spectrum management in cognitive radio networks (CRNs). Traditional approaches to spectrum sensing and allocation often operate in isolation or rely on static methods, which fail to address the dynamic and evolving nature of modern wireless environments. As IoT devices proliferate and spectrum resources become increasingly congested, there is a pressing need for more adaptive and efficient spectrum management solutions. Our approach addresses this need by offering an adaptive framework that responds to the changing spectrum landscape, thereby optimizing spectrum usage and reducing interference. This research suggests improved NN joint spectrum sensing for CR‐IoTNet (INJSS‐CR). This approach leverages cognitive radio (CR) technology to enhance spectrum utilization and mitigate the impact of spectrum shortages. CR technology enables secondary users (SUs) to detect and access unused spectrum through spectrum sensing. Within the CR‐IoTNet framework, joint spectrum sensing and allocation are performed to serve SU‐IoT devices via an interference‐free channel (IFC). The system comprises multiple primary user base stations (PU‐BSs) and SU devices functioning as IoT smart objects. Additionally, we integrate an improved neural network (INN) to adapt to dynamic network conditions and monitor primary user (PU) spectrum utilization using a comprehensive multiclass (J × 8) − D feature set. This combination of advanced techniques and CR technology aims to optimize spectrum management and support the growing IoT ecosystem. In particular, the INJSS‐CR obtained the greatest accuracy of 0.9492 at a training rate of 80%.

In recent year, the most emerging and growing field of research and development is “Internet of Things” (IoT). This is due to advancement in wireless sensor network (WSN) which operate in the unlicensed industrial, scientific and medical (ISM) spectrum band. However, many wireless technologies operate in the same unlicensed spectrum, make it overcrowded and hence resulted in spectrum scarcity among those bands, the performance of WSN will degrade as their popularity increases. According to FCC report, most of the licensed spectrum is underutilized, sharing of underutilized licensed spectrum among unlicensed devices is a promising solution to the spectrum scarcity issue. Cognitive Radio (CR) is one of the capable technology that allows sensor nodes (as a Secondary Users (SUs)) to detect and use the underutilized licensed spectrum temporarily when Primary Users (PUs) not using it. With recent advances in Cognitive Radio (CR) technology, possible to apply the Dynamic Spectrum Access (DSA) model in WSNs to get access to underutilized licensed spectrum, possibly with better propagation characteristics, but as the existing protocols and algorithms developed for CRNs and WSNs are not directly applicable to CR-based WSNs and required new protocols. In this paper, we present a survey on the novel design of CR-based MAC, identify the main advantages and challenges of using CR technology, and compare the different method of improving energy efficiency. We believe that CR-WSN is the next-generation WSN. In this paper, we also discussed the open issues to motivate new research interest in this field.

The advancement of 5G technology raises the need for wireless communication, increasing the number of customers who use it. The wireless communication band will become too crowded to support the increasing number of users in the future, resulting in a crowded spectrum. Furthermore, existing wireless technology has security flaws, limited capacity, and poor service quality. The implementation of cognitive radio (CR) technology is intended to improve the efficiency of the existing system and meet the bandwidth requirements of expanding users. Automatic modulation classification (AMC) is critical in CR technology. The objective of this research paper is to develop a modulation classifier by using a convolutional neural network classifier (CNN). The proposed classifier’s performance is evaluated at various SNRs and training rates in AWGN and fading channels. The study revealed that the model is more efficient than existing models in identifying 11 digital and analog modulation classes with less computational complexity and higher accuracy.

Research into cutting-edge systems that can satisfy the rising needs for greater data rate and increased reliability is becoming more and more necessary as wireless communication technologies continue to evolve. To enhance the spectral and energy efficiencies, this study examine the performance of massive multiple input multiple output (mMIMO) communication systems using wavelet-order orthogonal frequency division multiplexing (W-OFDM). Also, a communication system was created based on W-OFDM Massive MIMO using MATLAB to model its operation. The simulated system's various stages of operation was examined through detailed analysis and its performance was compare with prior studies and practical networks on OFDM. Key performance metrics, specifically the data throughput, was evaluated to assess the effectiveness and viability of the system. The simulation results indicates that W-OFDM can achieve up to 35% reduction in peak-to-average-power-ratio (PAPR) compared to the traditional OFDM, with a 20% improvement in BER performance under Rayleigh fading conditions. Also, the spectral efficiency of W-OFDM mMIMO outperforms convectional OFDM by 15%, making it a viable technology for future communication networks requiring high data rates and reliability. This implies that, the analytical evaluation confirms that W-OFDM mMIMO provides substantial benefits for improving energy and spectral efficiencies in wireless communication systems, addressing the challenges of increased user demands for high spectrum. This study contributes to the understanding of MIMO systems' performance optimization, highlighting the importance of antenna configuration and cell distance. Comprehensive analysis of spectral efficiency and energy efficiency trade-offs in MIMO systems and identification of optimal antenna configuration for maximum energy efficiency, addressing some of the challenges of future wireless communication systems.

We propose a simple, fast, deterministic pre-fitting approach which derives the Baum–Welch algorithm initial values directly from the input data. Such pre-fitting has the purpose of improving the fitting time for a given Hidden Markov Model (HMM) while maintaining the original Baum–Welch algorithm as the fitting one. The fitting time is improved by avoiding the Baum–Welch algorithm sensitiveness through the generation of parameters closer to the global maximum likelihood. Furthermore, by keeping the original Baum–Welch algorithm as the fitting one, we guarantee that all related methods will continue to work properly. On the other hand, the pre-fitting generates the HMM parameters directly derived from time-series data, without any data transformation, using an [Formula: see text] operation.

The improvement of energy efficiency and spectral efficiency in networks is achieved by seamlessly integrating energy harvesting, cognitive radio technologies, and Non-Orthogonal Multiple Access (NOMA) techniques. These complementary strategies optimize resource usage and address challenges related to energy consumption. Additionally, the adaptability and versatility of Unmanned Aerial Vehicles (UAVs) offer innovative solutions for enhancing coverage performance, thereby improving connectivity, efficiency, and reliability. We introduce a novel approach called the Deep Reinforcement Learning-Random Walrus (DRL-RW) algorithm, which combines Deep Reinforcement Learning (DRL) with the Random Walrus optimization (RWO) technique for efficient spectrum resource allocation and energy harvesting management in dynamic environments. The DRL-RW algorithm enables UAVs to learn optimal spectrum-sharing strategies and energy harvesting policies, while the RWO enhances the algorithm's adaptability and speed in exploring diverse solutions. Simulation results demonstrate the effectiveness of the DRL-RW algorithm, showing significant improvements in several performance metrics, including reduced energy consumption, enhanced computation time, improved convergence, increased signal-to-noise ratio, higher throughput, extended network lifetime, and increased harvested energy. These findings underscore the efficacy of the DRL-RW approach in addressing challenges associated with energy management in cognitive radio networks. The integration of UAVs, NOMA networks, and this novel algorithm represents a promising direction for developing energy-efficient communication systems.

The wireless communication has undergone a revolution due to advancements in technology. For each new user or application to be a part of communication network the preliminary requirement is the allocation of frequency spectrum band. This frequency band is a limited resource and it is impossible to expand its boundaries. So the need is to employ intelligent, adaptive and reconfigurable communication systems which can investigate the requiremenmts of the end user and assign the requisite resources in contrast to the traditional communication systems which allocate a fixed amount of resource to the user under adaptive, autonomic and opportunistic cognitive radio environment. Cognitive radio technology has emerged from software defined radios wherein the key parameters of interest are frequency, power and modulation technique adopted. The role of cognitive radio is to alter these parameters under ubiquitous situations. The spectrum sensing is an important task to determine the availability of the vacant channels to be utilised by the secondary users without posing any harmful interference to the primary users. In multi carrier communication using digital signal processing techniques, filter bank multi carrier has an edge over other technologies in terms of bandwidth and spectral efficiency. The present paper deals with the multi rate FIR decimation and interpolation filter approach for physical layer of cognitive radio under binary symmetric fading channel environment.

Credit scoring become an important task to evaluate an applicant by a banker. Many models and tools are available for making initial lending decisions. This paper presents an Hidden Markov Models (HMMs) for modeling credit scoring problems. Baum-Welch algorithm - an iterative process for estimating HMM parameters are often used to developed such models and improve the pattern recognition for many problems. We introduce HMM/Baum-Welch initial model selection: a tool developed to test the impact of choosing initial model to train Baum-Welch process. Experiments results show that the performance of learned models depend on different way of generating the initial models used in credit scoring.

Integration of Cognitive Radio Technology with unmanned aerial vehicles: Issues, opportunities, and future research challenges

The Hidden Markov Model (HMM) has become increasingly popular in the last several years because it is used in a wide range of applications. There are some inherent limitations of this type of statistical model. The major limitation of HMM is large hidden state space, which limits their practical purview. The objective of this work is to reduce the task of solving some classical algorithms (Forward, Backward, Baum-Welch) by review of their theoretical aspects, offering faster improved algorithms based on the decomposition technique which represent a general approach to solving a problem by breaking it up into smaller ones and solving each of the smaller ones separately.

The profile hidden Markov model (PHMM) is widely used to assign the protein sequences to their respective families. A major limitation of a PHMM is the assumption that given states the observations (amino acids) are independent. To overcome this limitation, the dependency between amino acids in a multiple sequence alignment (MSA) which is the representative of a PHMM can be appended to the PHMM. Due to the fact that with a MSA, the sequences of amino acids are biologically related, the one-by-one dependency between two amino acids can be considered. In other words, based on the MSA, the dependency between an amino acid and its corresponding amino acid located above can be combined with the PHMM. For this purpose, the new emission probability matrix which considers the one-by-one dependencies between amino acids is constructed. The parameters of a PHMM are of two types; transition and emission probabilities which are usually estimated using an EM algorithm called the Baum-Welch algorithm. We have generalized the Baum-Welch algorithm using similarity emission matrix constructed by integrating the new emission probability matrix with the common emission probability matrix. Then, the performance of similarity emission is discussed by applying it to the top twenty protein families in the Pfam database. We show that using the similarity emission in the Baum-Welch algorithm significantly outperforms the common Baum-Welch algorithm in the task of assigning protein sequences to protein families.

We propose applying the hidden Markov models (HMM) theory to the problem of blind channel estimation and data detection. The Baum-Welch (BW) algorithm, which is able to estimate all the parameters of the model, is enriched by introducing some linear constraints emerging from a linear FIR hypothesis on the channel. Additionally, a version of the algorithm that is suitable for time-varying channels is also presented. Performance is analyzed in a GSM environment using standard test channels and is found to be close to that obtained with a nonblind receiver.