Interleave Division Multiple Access Research Articles

Notice of Removal: Applications of Advanced Computer Communication and Control Technology for Modern Substations

This paper proposes a novel approach to achieve monitoring and control of modern substations using advanced computer communication and control technology. The proposed approach is based on a code division multiple access (CDMA) and interleave division multiple access (IDMA) system joining with optical-fiber communication technology to realize the utility infrastructure of Smart Grid. Recently, owing to the rapid growth on optical-fiber communication, it can offer standardized communication technology for wide-area, metropolitan-area, and local-area networks. Moreover, optical-fiber communication technologies offer not only significant benefits on connection among different CDMA-IDMA systems such as rapid deployment, higher baud rate (equal or higher than 14 Tb/s), enhanced bandwidth, less bit error rate (equal or less than 10-9), less optical-amplifier quantities, reduced interference among them, lower signal attenuation, etc. but also the advantages of being more suitable for remote-end applications in Smart Grid environment. With spreading spectrum modulation and demodulation combing encoding, it can be used to transmit data and images over power lines to accomplish opportunities and challenges in the effort on comparisons and assure safety, security, and reliability in order to achieve reliability and demand efficiency for modern substations of the utility system as a supervisory control and data acquisition (SCADA) system.

Conversion‐less algebraic interleaver architecture for low‐latency IDMA systems

AbstractThis letter presents a conversion‐less algebraic interleaver architecture for low‐latency interleave division multiple access (IDMA) systems. The existing architectures adopt the two‐step approach that first generates a set of sequential indices, and then converts it into a set of interleaved indices, elongating the latency. In contrast, the proposed structure directly produces the interleaved indices by employing a logic that keeps returning the next index corresponding to the current one. As a result, it can greatly alleviate the latency compared with the existing schemes in the literature.

Joint Intra/Inter-Slot Code Design for Unsourced Multiple Access in 6G Internet of Things

Unsourced multiple access (UMA) is the technology for massive, low-power, and uncoordinated Internet-of-Things in the 6G wireless system, improving connectivity and energy efficiency on guaranteed reliability. The multi-user coding scheme design is a critical problem for UMA. This paper proposes a UMA coding scheme based on the T-Fold IRSA (irregular repetition slotted Aloha) paradigm by using joint Intra/inter-slot code design and optimization. Our scheme adopts interleave-division multiple access (IDMA) to enhance the intra-slot coding gain and the low-complexity joint intra/inter-slot SIC (successive interference cancellation) decoder structure to recover multi-user payloads. Based on the error event decomposition and density evolution analysis, we build a joint intra/inter-slot coding parameter optimization algorithm to minimize the SNR (signal-to-noise ratio) requirement at an expected system packet loss rate. Numerical results indicate that the proposed scheme achieves energy efficiency gain by balancing the intra/inter-slot coding gain while maintaining relatively low implementation complexity.

Progressive pattern orthogonal interleaver set for interleave division multiple access based, non orthogonal multiple access schemes: Beyond 5G perspective

Abstract This communication suggests an orthogonal interleaver set for interleave division multiple access (IDMA) based non orthogonal multiple access (NOMA) schemes from beyond 5G viewpoint to support enormous increase in user count. The method generates an orthogonal interleaver set by providing two mother interleavers as seed to generate other users’ interleaving patterns progressively. The key feature of the proposed scheme is that it reduces implementation complexity and memory requirement at the base station, while implementing iterative multiuser detection (MUD), which most of the interlaever designs suggested in literature do not consider. It provides additional security to the user data due to progressively changing mother interleavers’ pattern along with the conventional purpose of providing unique identity for individual users in the system. The proposed orthogonal interleaver set is tested through simulations under multiple IDMA system configurations. It has been observed that it preserves the bit error rate (BER) performance of the IDMA scheme along with the optimal implementation complexity and minimal information exchange requirement between base station and mobile station to share the interleaver design.

Fixed‐latency architecture for multi‐stage algebraic interleavers in interleave division multiple access systems

In this letter, a fixed-latency interleaver architecture is proposed for interleave division multiple access (IDMA) systems. The existing multi-stage algebraic interleaver suffers from the high latency originated from a series of multipliers and adders residing in each stage. In contrast, the proposed interleaver employs a simple conversion logic built by precomputing all the requisites in advance. Since the logic is completely irrelevant to the number of stages, the interleaving pattern of the proposed structure can be randomized as much as it is needed without exacerbating the latency at all.

A 97-mW Bitwise-Early-Terminating Multiuser Detector for IDMA Systems

This brief presents a low-power multiuser detector that can terminate its processing earlier than usual for interleave division multiple access (IDMA) systems. As a baseline detection algorithm, a recently proposed bitwise early termination (BET) is adopted. Despite algorithmically feasible, the BET has never been realized in circuitry yet, pending the demonstration of physical practicality. For the first time ever, we efficiently implement the BET in a 65-nm CMOS technology, and demonstrate that it is indeed effective in realizing a fast and low-power detector. In doing so, we organize an essential set of information bits to examine the feasibility of the BET, and define a systematic procedure of manipulating the set of bits. In addition, we build an efficient hardware architecture that enables the proposed manipulation procedure. Through an extensive comparison with the state-of-the-art detectors in the literature, we validate that the prototype implementation completes the detection at the earliest, and draws the lowest power. Specifically, the proposed 16-user detector takes 3.98 iterations per bit, and dissipates 97 mW to process one 8192-chip frame. In contrast, even the latest low-power counterpart iterates 6 times, and consumes 24% more power.

Transform-Domain-Based Cognitive Radio Networks for Harsh Interference Environments

In harsh interference environments, there are all kinds of electromagnetic interference to disturb the communication links. In this article, by integrating transform domain communication system (TDCS) into cognitive radio (CR), transform-domain-based cognitive radio (TD-CR) is proposed to flexibly adopt TD-based spread spectrum technology to generate an adaptive anti-interference modulation waveform over the idle spectrum, which will improve both the anti-interference performance and spectrum efficiency of CR in the harsh interference environments. First, the transmitter and receiver of the TD-CR system are designed, where the key technologies, including spectrum sensing, spectrum magnitude shape, random phase mapping, fundamental modulation waveform, and signal detection, are described. Second, novel interleave-division multiple access and clustering multiple access for the TD-CR are proposed to improve the multiuser spectrum access ability. Thirdy, artificial-intelligence-enabled TD-CR is proposed to achieve intelligent spectrum sensing and optimal waveform transform by a cognitive engine. Then simulation results are provided to verify the anti-interference performance of the TD-CR. Finally, some future research challenges are discussed.

Optimizing the stochastic deployment of small base stations in an interleave division multiple access‐based heterogeneous cellular networks

SummaryThe use of small base stations (SBSs) to improve the throughput of cellular networks gave rise to the advent of heterogeneous cellular networks (HCNs). Still, the interleave division multiple access (IDMA) performance in sleep mode active HCNs has not been studied in the existing literature. This research examines the 24‐h throughput, spectral efficiency (SE), and energy efficiency (EE) of an IDMA‐based HCN and compares the result with orthogonal frequency division multiple access (OFDMA). An energy‐spectral‐efficiency (ESE) model of a two‐tier HCN was developed. A weighted sum modified particle swarm optimization (PSO) algorithm simultaneously maximized the SE and EE of the IDMA‐based HCN. The result obtained showed that the IDMA performs at least 68% better than the OFDMA on the throughput metric. The result also showed that the particle swarm optimization algorithm produced the Pareto optimal front at moderate traffic levels for all varied network parameters of SINR threshold, SBS density, and sleep mode technique. The IDMA‐based HCN can improve the throughput, SE, and EE via sleep mode techniques. Still, the combination of network parameters that simultaneously maximize the SE and EE is interference limited. In sleep mode, the performance of the HCN is better if the SBSs can adapt to spatial and temporal variations in network traffic.

Joint Device Detection, Channel Estimation, and Data Decoding With Collision Resolution for MIMO Massive Unsourced Random Access

In this paper, we investigate a joint device activity detection (DAD), channel estimation (CE), and data decoding (DD) algorithm for multiple-input multiple-output (MIMO) massive unsourced random access (URA). Different from the state-of-the-art slotted transmission scheme, the data in the proposed framework is split into only two parts. A portion of the data is coded by compressed sensing (CS) and the rest is low-density-parity-check (LDPC) coded. In addition to being part of the data, information bits in the CS phase also undertake the task of interleaving pattern design and CE. The principle of interleave-division multiple access (IDMA) is exploited to reduce the interference among devices in the LDPC phase. Based on the belief propagation (BP) algorithm, a low-complexity iterative message passing (MP) algorithm is utilized to decode the data embedded in these two phases separately. Moreover, combined with successive interference cancellation (SIC), the proposed joint DAD-CE-DD algorithm is performed to further improve performance by utilizing the belief of each other. Additionally, based on the energy detection (ED) and sliding window protocol (SWP), we develop a collision resolution protocol to handle the codeword collision, a common issue in the URA system. In addition to the complexity reduction, the proposed algorithm exhibits a substantial performance enhancement compared to the state-of-the-art in terms of efficiency and accuracy.

Performance Analysis of MITA Interleaver on Hybrid Systems using Diversity

The demands of 5 thgeneration communication devices such as greater throughput, coverage and reliability cannot be easily met by any one physical media. Recently, wireless and powerline channels were combined and diversity techniques were employed to improve reliability using only the OFDM technique. In this paper, the hybrid system with diversity techniques is implemented and evaluated using Interleave Division Multiple Access (IDMA) scheme. As the strength of the IDMA scheme heavily relies on the adapted interleaving algorithm, in the paper interleaving algorithms such as Random, Tree and recently proposed Multiplicative Interleaving with Tree Algorithm (MITA) interleavers are compared on the grounds of computation complexity, memory occupied and bit error rate (BER). For analysis of BER, over MATLAB environment, the hybrid system assumes Rayleigh fading channel and Additive White Gaussian Noise (AWGN) on wireless medium and Symmetric alpha stable (SαS) noise on powerline channel. The outcome of comparison parameters verifies the superior performance of MITA interleaver in a hybrid system over the IDMA scheme.

Performance Analysis of Error Control Codes for Underwater Wireless Acoustic Communication

In underwater acoustic communication, the information transmitted from 1 sensor node to another is corrupted due to errors persuaded by the noisy channel and other issues. To reduce the bit error rate, it is essential to propose suitable error regulator structure. In this paper, we simulate the performance analysis of Orthogonal Frequency Division Multiplexing Interleaver Division Multiple Access Multiple Input Multiple Output scheme with different channel codes to improve bit error rate performance. Bit error rate and consumed power are measured by communicating arbitrarily generated information through AWGN network. From the simulation results and assessment of the 2 divergent channel coding, 2 interleavers and 3 modulation techniques. We conclude that turbo codes with random interleaver and binary phase shift keying are best suitable to improve reliability performance for underwater wireless acoustic communication. To reduce the burst error in underwater acostic communication we propose an hybrid approach IDMA OFDM MIMO. BER performance is improved upto 10−6.
 HIGHLIGHTS
 
 In underwater acoustic communication to reduce bit error rate, we simulate the performance analysis of Orthogonal Frequency Division Multiplexing Interleaver Division Multiple Access Multiple Input Multiple Output scheme
 We propose a hybrid approach with 2 divergent channel coding, 2 interleavers and 3 modulation techniques
 Finally, we observe from simulation results that turbo code with binary phase shift keying and random interleaving improves bit error rate performance
 
 GRAPHICAL ABSTRACT

Robust Rateless Spatially Coupled Repeat-Accumulate-Repeat Multi-User Codes on IDMA Systems

In this paper, we design a kind of robust rateless multi-user code, which is called spatially coupled repeat-accumulate-repeat (SC-RA-R) code, for the interleave-division multiple-access (IDMA) system. The code is constructed by serially concatenating a fixed outer spatially coupled repeat-accumulate (SC-RA) code with an adjustable inner irregular repetition code. It achieves rateless property by simply adjusting the parameters of the inner repetition code. The IDMA system with the proposed SC-RA-R multi-user codes can adapt to varying channel qualities and varying number of users via rateless property while keeping encoder and decoder implementation unchanged. Analytical extrinsic information transfer (EXIT) functions are derived to determine belief propagation (BP) decoding thresholds of SC-RA-R codes on the IDMA system. The optimization expression is also given under the constraint that repeat parameters are monotonically non-decreasing with the sum rate decreasing. The numerical results show that the maximum achievable sum rates of the SC-RA-R codes can be close to the Shannon bound for arbitrary channel qualities. Besides, our proposed SC-RA-R codes have better BP thresholds and bit-error-rate (BER) performances than the conventional optimal parallel-concatenate codes (PCC) and the optimal partially repeated spatially coupled low-density parity-check (PR-SC-LDPC) codes on IDMA systems.

Code Domain Non- Orthogonal Multiple Access Schemes for 5G and Beyond Communication Networks: A Review

Future communication networks may encounter various issues in order to facilitate heavy heterogeneous data traffic and large number of users, therefore more advanced multiple access (MA) schemes are being developed to meet the changing requirements. The research space on making more robust MA scheme is continuously increasing, so it becomes significant to analyze the various schemes to determine the appropriate MA scheme for 5G networks. Therefore, in this paper the comprehensive overview of the most popular and recent MA schemes is presented for 5G networks. This paper mainly classifies the MA techniques in orthogonal MA (OMA) and various types of non-OMA (NOMA) techniques. Specifically, we introduce RSMA (Rate splitting multiple access) and IDMA (interleave division multiple access). Further the close attention is paid to NOMA family, including code-domain NOMA (e.g., SCMA (sparse code multiple access)), power-domain NOMA. Above all, from this exploration, the opportunities and challenges could be notified in MA schemes and further the optimum MA technique can be point out among discussed MA schemes for 5G and beyond communication networks.

Tensor-based approach for blind separation of interleave-NOMA 5G system

Nowadays, wireless broadband communication has experienced tremendous growth. The requirement for various new and advanced multiple access techniques is constantly increasing. The interleave division multiple access (IDMA) technique has attracted the attention of the scientific community as an opportune code domain non-orthogonal multiple access (NOMA) for future communication standards. In this system, the detection of the signals received from different users is done by specific interleavers.In this paper, and regarding the transmission-rate loss caused by the use of spreading codes and interleavers in the IDMA systems, we are going to place ourselves in a blind separation context for IDMA signals. For this purpose, a study of a purely deterministic approach, which is the tensor decomposition, as well as a theoretical study of the Canonical Polyadic (CP) model’s existence and uniqueness issues, is also carried out. Then, a tensor modeling of the IDMA emitter and the proposal of a new form of the interleavers will be undertaken. The separation and equalization of received signals using the CP tensor decomposition compelled us to examine the methods utilized to carry out this decomposition, as well as suggest two iterative blind receivers that take use of the algebraic features of the suggested model. On the other hand, the application of an exact performance criterion will be performed, taken into account the scale and permutation indeterminacy constraints.

Intelligent reflected surfaces assisted code domain non-orthogonal multiple access scheme

Abstract The propagation medium plays a crucial role in any wireless communication networks, the channel between the transmitter and the receiver, deteriorate the quality of the received signal due to the uncontrollable interactions such as scattering, reflection, and refraction in the channel with the surrounding objects. To overcome this challenge, the recent advent of recongurable intelligent surfaces can be helpful, in which the network operators can control the radio waves, eg, the phase, amplitude, frequency, and even polarization, of the impinging signals without the need of complex decoding, encoding, and radio frequency processing operations. On the other hand, few research papers reported an efficient code domain non orthogonal multiple access (NOMA) such as Interleave division multiple access (IDMA) system for wireless information transfer. Persuaded by the capability of this arising RIS technology, the present article is aimed to provide the modified framework of IDMA (code-domain NOMA) communication system based on RIS technology. Simulation results demonstrate that the proposed system achieves better SNR performance than the conventional IDMA framework.

Bitwise Early Termination of Multiuser Detection for IDMA Systems

This letter presents an early termination scheme for iterative multiuser detection in interleave division multiple access (IDMA) systems. Instead of handling an entire frame as a whole, each bit in the frame is separately considered. If further iterations are found to be dispensable in determining a bit, the estimate of the bit is immediately finalized, and all the calculations associated with the bit are bypassed afterward, diminishing the computational complexity. To confirm the dispensability, all log-likelihood ratios (LLRs) associated with a bit are examined. Once their magnitudes exceed a threshold, their statistical measures are unlikely to change even after a few more iterations, implying that further iterations are unnecessary. As a countermeasure for infrequent behaviors deviating from such an expectation, the signs of the LLRs in two consecutive iterations are compared. If they all match, the bitwise procedure is terminated. For the remaining bits not fulfilling the criterion, the procedure continues as usual. As a result, in the realm of practical signal-to-noise ratios, a significant number of iterations and operations can be discarded while sustaining the near-optimal error rate.

EXIT Analysis of Interleaver Division Multiple Access System with LDPC Code

Extrinsic Information Transfer(EXIT) characteristics are extensively used in iterative detection and decoding of turbo type processing. This paper makes an exploratory study of the issue of EXIT characteristic analysis for Low-Density Parity Check (LDPC) coded Interleaver Division Multiple Access (IDMA) system in Multiple Access Channel(MAC) condition. By using simulation method and extrinsic information calculation, the a priori information of the IDMA detector and the extrinsic information can be gained. In the same way, the a priori information and extrinsic information of the LDPC decoder in the system can be procured. The EXIT characteristic of the detector illustrates the convergence the detection algorithm of IDMA, while the EXIT characteristic of the LDPC decoder illustrates the convergence nature of the optimized degree profile,which shows the reasonability of LDPC coded IDMA system and the reliability of the optimized degree optimized algorithm for multiple access channel.

Impact of Equalizer step size in Underwater Acoustic Communication Channel

The Underwater Acoustic Channel (UAC) is a time variant channel and its multipath effects create ISI. This is one of the most important obstacles in the UAC channel which reduces the transmission rate. To remove this obstacle, a proper filter has to be designed in the receiver section. In this article, optimal step size for equalizer is computed and compared the results with the known techniques namely Decision Feedback Equalizer with interleave division multiple access (DFE IDMA) and Cyclic Prefix - Orthogonal Frequency Division Multiplexing (CP-OFDM) Equalizer. Channels are modeled using ray tracing methods. The various factors considered are ambient noise, attenuation loss, bottom and surface loss. The overall path loss for channels is computed by summing up the attenuation loss, surface and bottom loss. Simulation results evident that for short range UAC channel, the BER in the order of 10-2 is achieved using proposed methodology with least Eb/No compared to standard DFE method.

On the performance of modulo based Deci power interleaver in code domain NOMA system

Non-orthogonal multiple access (NOMA) is the potential multiple access considered for next generation (5G/6G) mobile communication and most of the research papers have been focused on power-domain NOMA. However, this research paper makes an effort to contribute to understand another aspect of NOMA i.e. code domain NOMA due to its better performance in large system where number of resources and users grows unboundedly. Interleave division multiple access (IDMA) is an established framework for code domain implementation of NOMA transmission and the performance of IDMA depends greatly on the interleavers as they are used to distinguish among the users. So, a unique Deci power interleaver (DPI) has been proposed and analyzed in this paper for the suggested IDMA scheme. The proposed interleaver is based on modulo operation, which reduce the bandwidth requirement and computational complexity without any performance degradation. Simulation experiments have been carried out to compare the DPI with random and other interleavers with coded and uncoded scenario in IDMA system.

Simulation and Performance Analysis of Interleave Division Multiple Access (IDMA) in Comparision with Code Division Multiple Access (CDMA)

This paper provides a study of Interleave division multiple access (IDMA) system by implementing in MATLAB and comparison with Code division multiple access (CDMA) in terms of performance. By using MATLAB we can analyze data, develop algorithms, create models and applications as it is more familiarized to engineers and scientists. CDMA is a technology used in 4G. This system provides multiple access communication capabilities. In CDMA as the number of users increase, the overall quality of performance decreases. So to overcome the drawbacks in CDMA, a new technology IDMA has been developed with the inheritance and advancement of CDMA. IDMA is a technology that is explored world‐wide in 5G Communication system. IDMA is a multiuser scheme where users are separated by unique interleaver sequences.