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Multiple-input multiple-output (MIMO) combined with multi-user massive MIMO has been a well-known approach for high spectral efficiency in wideband systems, and it was targeted to detect the MIMO signals. The increasing data rates with multiple antennas and multiple users that share the communication channel simultaneously lead to higher capacity requirements and increased complexity. Thus, different detection algorithms were developed for the Massive MIMO.

This paper focuses on the various literature analyzes on various detection algorithms and techniques for MIMO detectors. Here, it reviews several research papers and exhibits the significance of each detection method.

This paper provides the details of the performance analysis of the MIMO detectors and reveals the best value in the case of each performance measure. Finally, it widens the research issues that can be useful for future researchers to be accomplished in MIMO massive detectors

This paper has presented a detailed review of the detection of massive MIMO on different algorithms and techniques. The survey mainly focuses on different types of channels used in MIMO detections, the number of antennas used in transmitting signals from the source to destination, and vice-versa. The performance measures and the best performance of each of the detectors are described.

The purpose of this work is to propose a new multi‐user detector which cascades the linear G‐SIC with some linear PIC stages to form a new linear hybrid multi‐user detector.

Multistage interference cancellation multi‐user detectors became an increasingly important area of research due to their relative low computational complexity. The performance comparison of the proposed linear HIC is studied and presented using matlab environment to investigate the bit error rates. For DS/CDMA system, each user is characterized by its own code. The signals from users are spread by appropriately design sequences and then transmitted over an AWGN channel with BPSK modulation.

By the cascade of the linear G‐SIC and the traditional PIC, a low complexity multi‐user detector is found capable of reducing the long detection delay compared with the linear G‐SIC. The advantages of the linear G‐SIC and PIC can be exploited substantially.

The paper proposes an algorithm that can combat the MAI with less complexity, and also can speed the convergence compared with other detectors.

The purpose of this paper is to introduce the analysis and performance of a hybrid multiple access scheme which combines interleave division multiple access (IDMA) and code division multiple access (CDMA), referred to as IDMA/CDMA. With experimentations, the scheme can achieve good performance with simple user ends for the system.

IDMA technique is employed as the uplink transmission and CDMA technique as the downlink transmission. The performance comparison of IDMA and IDMA/CDMA downlink is studied with Monte Carlo simulations to investigate the bit error rates. For IDMA/CDMA downlink, the signals are interleaved by random interleavers, spreaded by M‐sequence and orthogonal Gold sequence, respectively, and then transmitted over an AWGN with BPSK modulation. Moreover, a channel estimation approach for IDMA based on expectation maximization (EM) algorithm is also presented.

The multi‐user detection (MUD) algorithm in uplink IDMA systems is much simpler than that used in traditional CDMA systems. It is also well known that the orthogonal spreading codes in CDMA can effectively help suppress the MAI in the synchronized environments. But for the asynchronized application, the performance of CDMA systems will degrade due to the serious multiple user interference. According to traditional IDMA and orthogonal code division multiple access/IDMA signal detection algorithms, every UE has to detect all of the signals of other users for iterative detection. The advantages of IDMA and CDMA technologies can be utilized substantially.

The proposed hybrid multiple access scheme can achieve a very simple chip‐by‐chip iterative MUD strategy at base station, and the simplified receiving operation at UE. On the other hand, this paper also evaluates channel estimation approach for IDMA based on EM algorithm.

Non-orthogonal multiple access (NOMA) is a much hopeful scheme, which is deployed to enhance the spectral efficiency (SE) significantly, and it also enhances the massive access that has attained substantial concern from industrial and academic domains. However, the deployment of superposition coding (SC) at the receiver side resulted in interference. For reducing this interference, “multi-antenna NOMA” seems to be an emerging solution. Particularly, by using the channel state information at the transmitter, spatial beam forming could be deployed that eliminates the interference in an effective manner.

This survey analyzes the literature review and diverse techniques regarding the NOMA-based spatial modulation (SM) environment. It reviews a bunch of research papers and states a significant analysis. Initially, the analysis depicts various transmit antenna selection techniques that are contributed in different papers. This survey offers a comprehensive study regarding the chronological review and performance achievements in each contribution. The analytical review also concerns on the amplitude phase modulation (APM) selection schemes adopted in several contributions. Moreover, the objective functions adopted in the reviewed works are also analyzed. Finally, the survey extends with various research issues and its gaps that can be useful for the researchers to promote improved future works on NOMA-based SM.

This paper contributes to a review related to NOMA-based SM systems. Various techniques and performance measures adopted in each paper are analyzed and described in this survey. More particularly, the selection of transmission antenna and APM are also examined in this review work. Moreover, the defined objective function of each paper is also observed and made a chronological review as well. Finally, the research challenges along with the gaps on NOMA-based SM systems are also elaborated.

This paper presents a brief analysis of NOMA-based SM systems. To the best of the authors’ knowledge, this is the first work that uses NOMA-based SM systems to enhance SE.

The purpose of this paper is to present an up-to-date survey on the non-orthogonal multiple access (NOMA) technique with co-operative strategy, a fast-evolving fifth-generation (5 G) technology. NOMA is used for serving many mobile users, both in power and code domains. This paper considers the power-domain NOMA, which is now discussed as NOMA.

The first part of the paper discusses NOMA-based cooperative relay systems using different relay strategies over different channel models. In various research works, the analytical expressions of many performance metrics were derived, measured and simulated for better performance of the NOMA systems. In the second part, a brief introduction to diversity techniques is discussed. The multiple input and multiple output system merged with cooperative NOMA technology, and its future challenges were also presented in this part. In the third part, the paper surveys some new conceptions such as cognitive radio, index modulation multiple access, space-shift keying and reconfigurable intelligent surface that can be combined with NOMA systems for better performance.

The paper presents a brief survey of diverse research projects being carried out in the field of NOMA. The paper also surveyed two different relaying strategies that were implemented in cooperative NOMA over different channels and compared several performance parameters that were evaluated and derived in these implementations.

The paper provides a scope for recognizable future work and presents a brief idea of the new techniques that can be united with NOMA for better performance in wireless systems.

Automobile development needs more and more collaborative work involving geographical dispersed designers, that brings difficulty for model verification, conception review and assembly process evaluation, so a collaborative virtual environment for automobile based on network is required. In this kind of environment, designers can do interactive assembly operations collaboratively, such as grasp, move, release, collision detection (CD), assembly evaluation report generation, etc. Furthermore, automobile structure becomes more complicated, how to process this large real‐time data effectively in real‐time interactive virtual environment is a great challenge. The purpose of this paper is focus on this.

A distributed parallel virtual assembly environment (DPVAE) is developed. In this environment, the mechanism of event synchronization based on high‐level architecture/run‐time infrastructure) is applied to realize multi‐user collaboratively interactive operation. To meet the large data set real‐time processing demand, a creative parallel processing approach supported by a single supercomputer or a parallel processing environment composed of common personal computer in a high‐speed local area network is developed. The technologies such as real‐time CD, multiple interactive operation modals are applied in DPVAE and several auxiliary tools are provide to help achieving whole scheme review, component model verification and assembly evaluation.

This paper finds that DPVAE system is an available and efficient tool to support automobile collaborative assembly design.

Designers can discuss and verify the assembly scheme to realize the previous design scenario in DPVAE, so it is useful for reducing costs, improving quality and shortening the time to market, especially for new type automobile development.

A combination of distributed technology and parallel computing technology is applied in product virtual assembly, solving the problems including collaborative work of multi‐user and large data real‐time processing successfully, that provides a useful tool for automobile development.

Owing to the numerous part models and massive datasets used in automobile assembly design, virtual assembly software cannot simulate a whole vehicle smoothly in real time. For this reason, implementing a new virtual assembly environment for massive complex datasets would be a significant achievement. The paper aims to focus on this problem.

A new system named “Grid‐enabled collaborative virtual assembly environment” (GCVAE) is proposed in the paper, and it comprises three parts: a private grid‐based support platform running on an inner network of enterprise; a service‐based parallel rendering framework with a sort‐last structure; and a multi‐user collaborative virtual assembly environment. These components would aggregate the idle resources in an enterprise to support assembly simulation with a large complex scene of whole vehicle.

The system prototype proposed in the paper has been implemented. The following simulations show that it can support a complex scene in a real‐time mode by using existing hardware and software, and can promote the efficient usage of enterprise resources.

Using the GCVAE, it is possible to aggregate the idle resources in an enterprise to run assembly simulations of a whole automobile with massively complex scenes, thus observably reducing fault occurrence rates in future manufacturing.

The paper introduces a new grid‐enabled methodology into research on collaborative virtual assembly system which can make the best use of idle resources in the enterprise to support assembly simulations with massively complex product models. A video‐stream‐based method was used to implement the system; this enables designers to participate ubiquitously in the simulation to evaluate the assembly of the whole automobile without hardware limitations.

The purpose of this study is to provide a framework to detect and prevent virtual property theft in virtual world environments. The issue of virtual property theft is a serious problem which has ramifications in both the real and virtual world. Virtual world users invest a considerable amount of time, effort and often money to collect virtual property, only to have them stolen by thieves. Many virtual property thefts go undetected and often only discovered after the incident has occurred.

This paper presents the design of an autonomic detection framework to identify virtual property theft at two key stages: account intrusion and virtual property trades. Account intrusion is an unauthorized user attempting to gain access to an account and unauthorized virtual property trades are trading of items between two users which exhibit theft characteristics.

Initial tests of this framework on a synthetic data set show an 80 per cent detection rate. This framework allows virtual world developers to tailor and extend it to suit their specific requirements. It provides an effective way of detecting virtual property theft while being low maintenance, user friendly and cost effective.

To the author’s knowledge, there is no detection framework, system or tool that works on virtual property theft detection in virtual world environments without access to authentic virtual world data or attack data (because of privacy issues and unwillingness of virtual world environments companies to collaborate). The topic of virtual property theft, lack of existing labelled data sets, user anonymity, size of virtual world environments data sets and privacy issues with virtual world companies and a number of other critical factors distinguish this paper from previous studies.

The goal of our work is to discuss the fundamental issues of privacy and anomaly‐based intrusion detection systems (IDS) and to design an efficient anomaly‐based intrusion IDS architecture where users' privacy is maintained.

In this work, any information that can link intrusion detection activity to a user is encrypted so as to pseudonyze the sensitive information. A database of encrypted information would then be created which becomes the source database for the IDS. The design makes use of dynamic key generation algorithm that generates key randomly when an intrusion is detected. The keys are only released when an intrusion occurs and immediately swapped to protect harm access to the mapping database.

The result after testing the new privacy maintained IDS architecture on an application package shows greater improvement over the ordinary IDSs. Privacy complaints reduced considerably from between 8 and 16 per week to about 1‐2.

We only tested the new privacy maintained IDS on a package, it would also be interesting to test the design on some other systems. There is a possibility that time to detection would increase because of the encryption/decryption part of the new design. All the same, we have designed an IDS architecture where privacy of users on the systems is guaranteed.

This work provides a background for researchers in IDS and it requires further improvements and extensions.

The work shows that it is possible to design an IDS architecture for maintaining privacy of users on the network. The result shows the originality of the new design.

Organizations more often than not lack comprehensive security policies and are not adequately prepared to protect their systems against intrusions. This paper puts forward a review of state of the art and state of the applicability of intrusion detection systems and models. The paper also presents a classification of literature pertaining to intrusion detection.