Block Coding Technique Research Articles

Codebook Optimization Using ACO Algorithm

The ACO algorithm, inspired by ant behavior, is used to optimize codebooks in speech processing. This study focuses on compressing speech signals efficiently to reduce bandwidth usage. Vector Quantization, a block coding technique, is employed, utilizing codebooks generated by the Linde-Buzo-Gray (LBG) algorithm. The ACO algorithm is proposed as an optimization method for these codebooks, aiming to minimize spectral distortion. Results show that ACO-optimized codebooks reduce spectral distortion. Keywords— Vector quantization, Speech compression, Linde-Buzo-Gray, ACO.

A comparative analysis of convolutional coding and block coding techniques over satellite communication

Reliable data transmission is crucial in the field of satellite communication, and many coding schemes are used to improve this reliability. Two popular coding techniques: convolutional codes and block codes were investigated and compared in this paper. Utilizing a simulated environment, the author investigates the bit error rate (BER) performance of both coding strategies along with a baseline case of no coding. The analysis reveals distinct characteristics and performance attributes of the two coding techniques across a range of signal-to-noise rate (SNR) values. Convolutional codes, with their inherent memory, offer error protection across sequences, while block codes, particularly a Hamming-like 7,3 implementation, provide localized protection for individual blocks. The findings of this study contribute to the understanding of error control strategies in satellite communication, guiding the selection and design of coding methods suitable for various operational scenarios and requirements.

On the Performance of Cache-Free/Cache-Aided STBC-NOMA in Cognitive Hybrid Satellite-Terrestrial Networks

Future wireless networks pose several challenges such as high spectral efficiency, wide coverage, massive connectivity, low receiver complexity, etc. To this end, this letter investigates an overlay-based cognitive hybrid satellite-terrestrial network (CHSTN) combining non-orthogonal multiple access (NOMA) and conventional Alamouti space-time block coding (STBC) techniques. Herein, a decode-and-forward based secondary terrestrial network cooperates with a primary satellite network for dynamic spectrum access. Further, for reliable content delivery and low latency requirements, wireless caching is employed, whereby the secondary network can store the most popular contents of the primary network. Considering the relevant heterogeneous fading channel models and the NOMA-based imperfect successive interference cancellation, we examine the performance of CHSTN for the cache-free (CF) STBC-NOMA and the cache-aided (CA) STBC-NOMA schemes. We assess the outage probability expressions for primary and secondary networks and further, highlight the corresponding achievable diversity orders. Indicatively, the proposed CF/CA STBC-NOMA schemes for CHSTN perform significantly better than the benchmark standalone NOMA and OMA schemes.

UAV-Assisted NOMA-Based Network with Alamouti Space-Time Block Coding

In this study, a 3-user system was considered in the Unmanned Aerial Vehicle-Assisted (UAV-Assisted) Non-Orthogonal Multiple Access-Based (NOMA-Based) communication network. In the network, UAV communicates with users on the ground via two antennas using the Alamouti Space-Time Block Coding (A-STBC) technique. It is considered that there are two separate scenarios where user links are designed with one antenna and two antenna systems. In the study, Monte-Carlo simulations were carried out to understand the effects of using the A-STBC technique in UAV-Assisted NOMA-Based communication networks and increased antenna diversity in receiver and transmitter in the network to the performance of the system. For the benchmark, the downlink NOMA network was used, where the receivers and the UAV are designed with a single antenna. In the simulation results, with the A-STBC technique in the system and increase in diversity, the effects of Path Loss (PL) and environmental factors on error performance were examined. Especially in high Signal to Noise Ratio (SNR) values, it has been observed that the effects of these destructive factors on error performance are highly minimized. Also, the use of A-STBC technique and the increase in diversity in the system provided considerable SNR gain. Moreover, it has been observed that full diversity gain can be achieved when the A-STBC technique is used in the UAV-Assisted downlink NOMA-Based communication system.

시공간 블록 코드의 난수 코드를 활용한 데이터 보호 기법

This paper proposes a random coded data protection technique in space-time block code. The traditional space-time block coding technique could be faced with open radio environments, so it has to overcome severe radio hijacking problems. In case of trying to avoid open radio issue, usually source data blocks are encrypted but it occurs heavy burden to the transmitter and receiver. This paper proposes a simple random coded timing sequence of data blocks, its effect results in received signals

Back Propagation Artificial Neural Network for Improving the Performance of STBC-based OFDM with Subcarrier Power Modulation

Orthogonal Frequency Division Multiplexing with Subcarrier-Power Modulation (OFDM-SPM) has recently been proposed as a promising, potential transmission technique for future wireless communications (i.e., 6G and beyond) due to its multiple beneficial characteristics, including higher spectral efficiency, low latency with good reliability while maintaining low complexity. In this paper, Orthogonal Frequency Division Multiplexing with Subcarrier-Power Modulation and Space-Time Block Coding (OFDM-SPM-STBC) technique is compounded with Back Propagation Artificial Neural Network (BPANN) in a multiple-input-single-output (MISO) setup to study, investigate and quantify the wireless system's performance of their combination over a multi-path Rayleigh fading channel. Particularly, we analyze two main performance metrics: bit-error-rate (BER) and throughput of the newly designed technique called OFDM-SPM-STBC-BPANN, and then quantify the amount of resulting gains in both BER and throughput due to using the proposed system. We also consider two scenarios for OFDM-SPM-STBC-BPANN transmission. The first one is the power re-assignment policy (PRP), and the second one is the power saving policy (PSP). It is found that the sub-carrier optimized power-reassignment scheme provides the best BER performance for the proposed transmission scheme. In contrast, the PSP for SPM is seen to provide an intermediate improvement in the average BER. The performance of the system in terms of BER and Throughput is improved furthermore by implementing Feed-Forward Back-Propagation Artificial Neural Network (BPANN) at the receiver side. It is observed an average SNR gain of about 7 dB in the BER by implementing BPANN with OFDM-SPM-STBC. It is also found that the optimized power-reassignment scheme provides the best BER performance for the proposed OFDM-SPM-STBC transmission scheme with BPANN at the receiver.

Design of MIMO F-OFDM System Model for PAPR Reduction in the Growth of 5G Network

A compact 5G technology can be defined as a system which consist of high signal data transmission, maximizing frequency diversity and can combat noise interference. By theory, it is significantly to improve system’s performance in order to obtain better voice quality, tolerance to noise interference, excellent spectral efficiency, higher network capacity, low latency and frequency selective fading in multipath environment, which is robust to the channel impairments. 5G network uses multipath environment or multiple transmissions technique, which known as multiple input multiple output, (MIMO). MIMO operates with multiple antennas technology, which includes the multiple transmitters with receivers’ circuits to minimize errors and optimize data speed. For the transmission efficiency, multiple antenna system model is commonly put together with digital data encoding method called Orthogonal Frequency Division Multiplexer (OFDM), where the carrier signals have high spectral efficiency and immunity to frequency fading. MIMO-OFDM configuration has introduced to increase the diversity gain and improve the system capacity. Currently, filtering is implemented to overcome out-of-band radiation for the spectrum efficiency and meet the diversified expectation for the growth of 5G network. The main drawback in MIMO F-OFDM system is its high peak-to-average-power-ratio (PAPR). This paper discusses the parameter specification in reducing PAPR in MIMO F-OFDM system. The proposed parameters are utilizing block coding technique that is Enhancement Asymmetric Arithmetic Coding (EAAC), together with numbers of antenna configuration to overcome the problem of high PAPR. From the simulation results, the PAPR reduced at 6.85% using block coding technique and MIMO antenna configuration and it is verified with the existing system with MIMO-OFDM. Overall, the communication system model will lead to the mutual harmonization among society with new parameters of MIMO F-OFDM and block coding technique.

Performance Analysis of OSTBC-NOMA System in the Presence of Practical Impairments

This paper investigates the performance of a power-domain downlink non-orthogonal multiple access (NOMA) system in the presence of practical impairments such as channel estimation error (CEE), feedback delay (FBD) and imperfect successive interference cancellation (SIC), where the base station communicates with multiple users by applying orthogonal space-time block coding (OSTBC) technique in order to exploit the benefits of transmit diversity. Outage probability (OP), ergodic capacity and fairness index analyses are conducted in case channels are subjected to Nakagami-m fading in order to illustrate the level of system performance, and closed-form mathematical expressions are obtained. Furthermore, to demonstrate the impact of CEE and FBD, asymptotic OP is also maintained. The analytical results validated by Monte Carlo simulations demonstrate that all performance metrics reach a non-zero fixed value in high signal-to-noise region due to the CEE and FBD while imperfect SIC worsens the performance of user with the lowest power allocation to the full outage. In addition, NOMA outperforms its counterpart orthogonal multiple access in terms of OP and ergodic capacity generally. Also, G <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> -OSTBC code has higher fairness index than G <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> -OSTBC code.

Joint Time-Reversal Space-Time Block Coding and Adaptive Equalization for Filtered Multitone Underwater Acoustic Communications.

Underwater acoustic (UWA) sensor networks demand high-rate communications with high reliability between sensor nodes for massive data transmission. Filtered multitone (FMT) is an attractive multicarrier technique used in high-rate UWA communications, and can obviously shorten the span of intersymbol interference (ISI) with high spectral efficiency and low frequency offset sensitivity by dividing the communication band into several separated wide sub-bands without guard bands. The joint receive diversity and adaptive equalization scheme is often used as a general ISI suppression technique in FMT-UWA communications, but large receive array for high diversity gain has an adverse effect on the miniaturization of UWA sensor nodes. A time-reversal space-time block coding (TR-STBC) technique specially designed for frequency-selective fading channels can replace receive diversity with transmit diversity for high diversity gain, and therefore is helpful for ISI suppression with simple receive configuration. Moreover, the spatio-temporal matched filtering (MF) in TR-STBC decoding can mitigate ISI obviously, and therefore is of benefit to lessen the complexion of adaptive equalization for post-processing. In this paper, joint TR-STBC and adaptive equalization FMT-UWA communication method is proposed based on the merit of TR-STBC. The proposed method is analyzed in theory, and its performance is assessed using simulation analysis and real experimental data collected from an indoor pool communication trial. The validity of the proposed method is proved through comparing the proposed method with the joint single-input–single-output (SISO) and adaptive equalization method and the joint single-input–multiple-output (SIMO) and adaptive equalization method. The results show that the proposed method can achieve better communication performance than the joint SISO and adaptive equalization method, and can achieve similar performance with more simpler receive configuration as the joint SIMO and adaptive equalization method.

Analysis and Demonstration of Quasi Trace Orthogonal Space Time Block Coding for Visible Light Communications

In the VLC context, pulse position modulation (PPM) and similar modulations are typically used when the overall complexity of the transmitter is required to be low or the system needs to support dimming, i.e., dynamically control the illumination level of the transmitter. However, despite the power efficiency of PPM, it is known to be bandwidth inefficient. Having known the trade-off between reliability and spectral efficiency, in this paper we propose a PPM-based space-time block coding (STBC) technique named as quasi-trace-orthogonal (QTO), derived from trace-orthogonal, to increase the spectral efficiency of PPM VLC’s by limiting the reliability loss. We provide Monte-Carlo simulations for a $4\times 4$ MIMO-VLC system and validate the results experimentally, and show that for a given signal-to-noise-ratio, the QTO-STBC based 4-PPM VLC system offers higher spectral efficiency at a cost of higher symbol error rate compared to trace-orthogonal STBC.

Investigating the Performance of Various Channel Estimation Techniques for MIMO-OFDM Systems using Matlab

This paper simulates and investigates the performance of four widely-used channel estimation techniques for MIMO-OFDM wireless communication systems; namely, super imposed pilot (SIP), comb-type, spacetime block coding (STBC), and space-frequency block coding (SFBC) techniques. The performance is evaluated through a number of MATLab simulations, where the bit-error rate (BER) and the mean square error (MSE) are estimated and compared for different levels of signal-to-noise ratio (SNR). The simulation results demonstrate that the comb-type channel estimation and the SIP techniques overwhelmed the performance of the STFC and STBC techniques in terms of both bit-error rate (BER) and mean square error (MSE).

Survey Paper on Performance Evaluation of 4G and 5G System using Space Time Block Coding Technique

International Journal of Computer Sciences and Engineering (A UGC Approved and indexed with DOI, ICI and Approved, DPI Digital Library) is one of the leading and growing open access, peer-reviewed, monthly, and scientific research journal for scientists, engineers, research scholars, and academicians, which gains a foothold in Asia and opens to the world, aims to publish original, theoretical and practical advances in Computer Science,Information Technology, Engineering (Software, Mechanical, Civil, Electronics & Electrical), and all interdisciplinary streams of Computing Sciences. It intends to disseminate original, scientific, theoretical or applied research in the field of Computer Sciences and allied fields. It provides a platform for publishing results and research with a strong empirical component. It aims to bridge the significant gap between research and practice by promoting the publication of original, novel, industry-relevant research.

Investigating the Performance of Various Channel Estimation Techniques for Mimo-Ofdm Systems Using Matlab

This paper simulates and investigates the performance of four widely-used channel estimation techniques for MIMO-OFDM wireless communication systems; namely, super imposed pilot (SIP), comb-type, spacetime block coding (STBC), and space-frequency block coding (SFBC) techniques. The performance is evaluated through a number of MATLab simulations, where the bit-error rate (BER) and the mean square error (MSE) are estimated and compared for different levels of signal-to-noise ratio (SNR). The simulation results demonstrate that the comb-type channel estimation and the SIP techniques overwhelmed the performance of the STFC and STBC techniques in terms of both bit-error rate (BER) and mean square error (MSE).

Impact of transmission techniques in asymmetric RF/FSO system over Nakagami‐m and gamma‐gamma fading channels with pointing errors

SummaryIn this paper, the performance of transmission techniques on the fixed‐gain amplify‐and‐forward–based asymmetric radio frequency/free space optical (RF/FSO) communication system is studied. The RF link and FSO link are, respectively, modeled by the Nakagami‐m and Gamma‐Gamma fading channels under the effect of zero boresight and non‐zero boresight pointing errors subject to heterodyne detection. Maximum ratio transmission (MRT) and orthogonal space‐time block coding (OSTBC) techniques are the transmission scenarios considered at the system source while selection combining is used for reception at the relay and destination for the signal detection. Moreover, a unified cumulative density distribution (CDF) of end‐to‐end signal‐to‐noise ratio is derived for the system. By utilizing this channel statistical CDF, the closed‐form expressions for the outage probability and average bit error rate for the M‐ary phase shift keying modulation are then obtained for the system. The analysis presented illustrates that both the atmospheric turbulence and pointing error significantly degrade the system performance. Based on this, the MRT transmission technique offers a better performance compared with the OSTBC techniques under the same system conditions. The accuracy of the analytical results is verified by Monte‐Carlo simulations.

PAPR Reduction Using Huffman and Arithmetic Coding Techniques in F-OFDM System

Filtered orthogonal frequency division multiplexing (F-OFDM) was introduced to overcome the high side lobes in the OFDM system. Filtering is implemented in the system to reduce the out-of-band emission (OOBE) for the spectrum utilization and to meet the diversified expectation of the upcoming 5G networks. The main drawback in the system is the high peak to average ratio (PAPR). This paper investigates the method used in reducing the PAPR in the F-OFDM system. The proposed method using the block coding technique to overcome the problem of high PAPR are the Arithmetic coding and Huffman coding. This research evaluates the performance of F-OFDM system based on the PAPR values. From the simulation results, the PAPR reduction of the Arithmetic coding is 8.9% lower, while the Huffman Coding is 6.7% lower in the F-OFDM system. The results prove that the Arithmetic Coding will out-perform the Huffman coding in the F-OFDM system.

BER Performance Evaluation for MIMO-OFDM for Underwater Channel

The transmission of information in underwater communication is a challenging issue because it is affected by noise from various sources that are due to multipath propagation, signals in underwater channels experience inter symbol interference. In a typical radio frequency communication, orthogonal frequency division multiplexing is widely employed to combat the effects of ISI, because OFDM obviates the need for complex equalization techniques. In this paper, the designing OFDM model using Simulink and various OFDM model designs will be surveyed, and accordingly, design is done. The Orthogonal space-time block Coding Technique will be introduced to this OFDM Model with different channels. Underwater Communication constitutes problems like the data rate will be the lowest and even the data loss rate, multi-path fading, and maximum error bits. So, this OFDM model is designed to overcome all the drawbacks of underwater communication and Orthogonal space-time block coding is chosen as the best method among various error coding techniques which will provide the best result.

Analysis of Detection Methods for Space Frequency Block Code MIMO-OFDM System in Fast Fading Channels

Multiple antennae with the multicarrier trans-receiver system have increased diversity gain and higher data rates. For high performance 4G wireless communication, the multiple inputs and multiple outputs with orthogonal frequency division multiplexing (MIMO-OFDM) employing Space Frequency Block Codes which provides frequency and spatial diversity in fast fading environments to provide reliability of transmission. Space Frequency Block Code technique encodes data by using frequency diversity on multiple antennae. The challenge of these space-frequency diversity transmitted signal is a detection of original symbols at receiver in a fast fading environment. In this paper, it has been analyzed four detection methods, Simple maximum-likelihood, Joint maximum-likelihood, Zero-forcing and Decision-feedback. The evaluation of the detection methods is done on the basis of the Signal to Noise Ratio, Bit Error Rate and complexity of implementation in fast fading channels under three vehicular speeds i.e. 3km/hr, 60km/hr, and 120km/hr.

IMPROVING STFBC MIMO OFDMA WITH CHANNEL ESTIMATION USING DFT AND DCT TECHNIQUE

Higher demand in rapid data transmission makes the wireless technology become more popular in this new modern era. However due to the many users that want to have access in the same time, it can cause congested traffic and affect the data rate. OFDMA modulation scheme with combination of MIMO will support high data signal and become one of the best solutions that can fulfil everybody’s dream. These MIMO OFDMA system is based on the diversity coding and appropriate channel estimation in order to achieve maximum diversity order for each user and minimize the interference that have been generated during the transmission. Thus, in this paper in order to boost the overall system performances, Space Time Frequency Block Code (STFBC) and channel estimation technique involving Discrete Fourier Transform (DFT) and Discrete Cosine Transform (DCT) are going to be tested to compare their performance. The result states that when using STF block code, it will gain better performance in MIMO OFDMA system by producing lower bit error rate compare to existence DCT and DFT.

On the Performance Enhancement When Combining STBC and Channel Estimation Techniques in Underground MIMO Channels

One way to enhance the channel data rate in enclosed environments is by incorporating multiple-input-multiple-output (MIMO) systems. Very often, this comes at the cost of data reliability. Motivated by the proven efficiency of space-time block coding (STBC) technique in conventional MIMO systems in improving the communication quality, we propose to incorporate it in wireless underground MIMO communication system and investigate data reliability at the reception in terms of bit error rate (BER). For this purpose, an intensive channel measurement campaign was performed in a mine-laboratory in northern Canada to obtain the perfect channel state. As a second step, the underground MIMO channel is estimated by sending a pilot sequence and using minimum mean square error (MMSE) principle on the received pilots. The resulting MIMO channel estimate is used to evaluate the data part in the STBC block and perform a decision using the maximum likelihood (ML) detector. Moreover, both the channel and transmitted data estimates are given analytically, and the degradation of the BER performance of the system due to MMSE estimation errors is studied using Monte Carlo simulations.

Decode-and-Forward cooperative vehicular relaying for LTE-A MIMO-downlink

Cooperative multiple-input multiple-output technology allows a wireless network to coordinate among distributed single or multiple antenna deployments and achieves considerable performance gains compared to those provided by conventional transmission techniques. It promises significant improvements in spectral efficiency and network coverage and is a major candidate technology in various standard proposals for the fourth-generation wireless communication systems. We propose to use cooperative multiple antenna deployment links in Long Term Evolution-Advanced networks where vehicles act as relaying terminals using Decode-and-Forward relaying. To maintain orthogonality of signals, we deploy a modified Alamouti-based Space–Time Block Coding technique. Our approach allows exploitation of the multiplexing capability and spatial diversity of typical multiple antenna schemes in distributed way. We further contribute by deriving error rate, diversity gain and outage probability closed form expressions as a benchmark to assess our analysis and future research studies. Our findings indicate that significant diversity gains and reduced error rates are achievable. As well, a noticeable reduction in the required transmitting power, and an increase in coverage distance are observed compared to traditional single antenna deployments.