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Differential spatial modulation uses the antenna index to transmit information, which improves the spectral efficiency, and completely bypasses any channel side information in the recommended setting. A generalized distributed multiple turbo coded-cooperative differential spatial modulation based on distributed multiple turbo code is put forward and its performances in Rayleigh fading channels is analyzed. The generalized distributed multiple turbo coded-cooperative differential spatial modulation scheme is a coded-cooperation communication scheme, in which we proposed a new joint parallel iterative decoding method. Moreover, the code matched interleaver is considered to be the best choice for the generalized multiple turbo coded-cooperative differential spatial modulation schemes, which is the key factor of turbo code. Monte Carlo simulated results show that the proposed cooperative differential spatial modulation scheme is better than the corresponding non-cooperative scheme over Rayleigh fading channels in multiple input and output communication system under the same conditions. In addition, the simulation results show that the code matched interleaver scheme gets a better diversity gain as compared to the random interleaver. [ABSTRACT FROM AUTHOR]

Application of deep learning to error control coding is gaining special attention and neural network architectures on decoding are approached to compare with conventional ones. Turbo codes conventionally use BCJR algorithm for decoding. In this paper, performances of neural Turbo decoder and deep learning-based Turbo decoder are examined. A category of sequential codes are utilized to construct the RSC (Recursive Systematic Convolutional) codes as basic elements for Turbo encoder. Sequential codes suit the requirement of memory element present in convolution codes, which act as components for Turbo encoder. Turbo decoders are constructed by two means; as neural Turbo decoder and deep learning Turbo decoder. Both structures are based on recurrent neural network (RNN) architectures. RNN architectures are preferred due to the presence of memory as a feature. BER performance of both is compared with that of a convolutional Viterbi decoder in awgn channel. Both the structures are studied for different input data-lengths and code rates. [ABSTRACT FROM AUTHOR]

In collaborative combat operations, the challenges brought by the communication adversities of tactical data links are becoming increasingly prominent. Ensuring the reliable connection of tactical data links has always been a key issue, especially considering the increasing impact of external interference on the signal at the receiving end of the system, which in turn affects the bit error rate (BER) of the tactical data link system. To address this challenge, this paper proposes a tactical data link anti-interference scheme based on cyclic code shift keying (CCSK) spread spectrum and minimum shift keying (MSK) modulation fusion frequency hopping technology, named CCSK-FMSK, and introduces turbo code and cyclic redundancy check (CRC) coding to construct a tactical data link model based on CCSK-FMSK. Specifically, CCSK-FMSK disperses interference power by expanding the signal spectrum, enhancing the anti-interference ability of tactical data links. CRC coding and Turbo coding achieve error detection and correction by introducing supervised symbols. In addition, this paper proposes a soft despreading and a soft demodulation algorithm corresponding to CCSK spread spectrum and MSK modulation to achieve cascade with Turbo decoder and improve the error rate performance and robustness of the model. Compared with existing models, the tactical data link based on CCSK-FMSK has better BER performance. [ABSTRACT FROM AUTHOR]

This paper investigates the design of a modified matrix interleaving algorithm as a way to improve the performance of turbo codes. This proposed solution, known as the matrix-dithered golden (MDG) interleaver, utilizes the characteristics of a matrix interleaver combined with the golden section theory. The performance of the proposed interleaving method is compared with that of matrix (M), random (R), and dithered golden (DG) interleavers. The comparison is made in terms of bit error rate (BER), frame error rate (FER), computational complexity, and storage memory requirement. The turbo coded system is implemented and simulated using Matlab/Simulink software. Results of simulations performed both in the additive white Gaussian noise (AWGN) channel and the Rayleigh fading channel demonstrate the effectiveness of the proposed interleaver. The MDG interleaver is an effective replacement for random interleavers, as it improves BER and FER performance of the turbo code and is also capable of reducing the storage memory requirement without increasing the system's complexity. [ABSTRACT FROM AUTHOR]

The research domain of underwater communication has garnered much interest among researchers exploring underwater activities. The underwater environment differs from the terrestrial setting. Some of the main challenges in underwater communication are limited bandwidth, low data rate, propagation delay, and high bit error rate (BER). As such, this study assessed the underwater acoustic (UWA) aspect and explored the expression of error performance based on t‐distribution noise. Filter orthogonal frequency‐division multiplexing refers to a new waveform candidate that has been adopted in UWA, along with turbo and polar codes. The empirical outcomes demonstrated that the noise did not adhere to Gaussian distribution, whereas the simulation results revealed that the filter applied in orthogonal frequency‐division multiplexing could significantly suppress out‐of‐band emission. Additionally, the performance of the turbo code was superior to that of the polar code by 2 dB at BER 10−3. [ABSTRACT FROM AUTHOR]

In order to address the drawbacks of recognition algorithm used for recursive system convolutional codes (RSC), such as low fault tolerance and high computational complexity, a novel recognition algorithm was proposed in this study. Firstly, it clearly demonstrated that the rational fraction in binary domain is capable of expanding into recurring series, and the problem of cyclic period could be solved by means of impulse response and analytical matrix. Secondly, in order to reduce the workload of computation placed on the algorithm, a polynomial database was constructed by traversing the constructed RSC code. Then, the specific matrix operation was conducted. In case of a correct ergodic polynomial, the result vector code weight tends to be significantly larger than the ergodic polynomial is incorrect, so as to realize the recognition of the polynomial. Finally, as revealed by the theoretical analysis, the fault-tolerance of the proposed algorithm was solely relevant to the code weight of the recurring series rather than the coding constraint length. The simulation results validated not only the effectiveness of the algorithm but also the correctness of the fault-tolerant performance analysis. When the error code reached as high as 0.1, the recognition rate of some polynomials was higher, and the computational complexity was lower compared to the existing algorithms. [ABSTRACT FROM AUTHOR]

Abstract Turbo codes are extensively used in wireless communication standards due to its capacity approaching performance. Maximum-A-Posteriori (MAP) algorithm and Soft Output Viterbi Algorithm (SOVA) are widely accepted decoding algorithms for Turbo codes. SOVA is a variant of Viterbi Algorithm and is less complex with moderate error correction performance as compared to MAP algorithm. In this paper, the branch symmetry property of radix-2 butterfly has been incorporated in to the SOVA algorithm to reduce the complexity of branch metric computation. The simulation results show that the computational complexity is reduced without degrading the error correction performance. Turbo CODEC block with SOVA and the low complex SOVA has been created in GNU Radio and the results were verified. [ABSTRACT FROM AUTHOR]

Abstract In this paper, analysis is made on bit error rate (BER) performance for digital video broadcasting using Turbo coded Orthogonal Frequency Division Multiplexing(OFDM).The aim is to achieve energy efficiency in extremely noise environment channel condition. Turbo coding is one of the most attractive coding techniques since it has been proposed, because it can achieve the error correction capability near Shannon's limit. Turbo code provides significant coding gain by utilizing two relatively simple constituent convolutional encoders, which are concatenated in parallel through an interleaver. The performance of 64 QAM with turbo encoding technique is verified for various code rates at different bit error rates. The BER performance is strongly influenced by signal to noise ratio. Use of parallel concatenated convolutional codes (PCCC) turbo encoder with interlever and soft decision BCJR decoder provides better performance by randomization. The fading channels considered here are Additive White Gaussian noise (AWGN) along with Rician Fading Channel. Result shows that for E b /N o Value of 20dB, lower code rates are performed better BER performance (10-3) i.e. errors observed are less for lower code rates at 20dB of E b /N o value. The structure of the SIMULINK design is developed for different code rates with Turbo coded OFDM, 64 QAM and the results are analyzed using a BER tool of MATLAB version 2017a. [ABSTRACT FROM AUTHOR]

As an important equipment of the ultra-supercritical turbine systems, real-time and accurate control of reheater tube temperature is the key to the normal operation of the system. To improve the accuracy of reheater tube temperature prediction, an integrated adversarial long short-term memory deep network is proposed in this study. Considering the correlation and dynamics between reheater temperature features, different types of single long short-term memory deep networks are batch mixed and stacked in parallel to integrate adversarial training. The training process shares network layer weight parameters to synthesize the decision boundary of each network and complete the dichotomous integration. The proposed networks predict information for the next ten time steps, wirelessly approximate the mapping relationship between multi-source input and output data, and maximize the prediction accuracy and generalization. The proposed networks with single long short-term memory deep networks and 21 algorithms are compared for temperature prediction on the reheater tubes of thermal power plants in Guangdong Province, China, from March 2020 to May 2020. Compared with 90 networks without an integrated adversary, the mean square error obtained by the integrated networks have a 90.85% reduction. Furthermore, compared with the algorithm with the second smallest error among the 22 algorithms, the mean absolute percentage error obtained by the integrated networks is significantly reduced by 99.66%, and the mean absolute error is reduced by 98.36%. • An integrated adversarial long short-term memory deep networks method is proposed. • Proposed network integrates three types of deep networks with adversarial features. • The proposed networks have strong data fitting ability and high prediction accuracy. • Exact reheater tube temperature of ultra-supercritical turbo-generator is obtained. [ABSTRACT FROM AUTHOR]

This paper presents the Parallel and Serial Concatenated Turbo Polar-Convolutional Codes (CTPCCs) to improve the performance of polar codes in the finite code length regime. Both proposed concatenated codes use the Systematic Polar Code (SPC) and Recursive Systematic Convolutional (RSC) code as constituent codes. The iterative decoding algorithms of the proposed systems consist of a Soft Cancellation (SCAN) decoder with a single internal iteration for the SPC and SOVA or LogMap decoder for the RSC code. The simulation results show that the performance of the Parallel Concatenated Turbo Polar-Convolutional Code (PCTPCC) at low signal-to-noise ratios (SNRs) is better than that of the Serial Concatenated Turbo Polar-Convolutional Code (SCTPCC) and also better than the performance of other Turbo Polar Codes (TPCs). At BER = 10−2, the proposed PCTPCC with SOVA and LogMap algorithms has about 0.3 dB and 0.25 dB performance gains over the SCTPCC models, respectively. In the high SNR regions, the performance of the SCTPCC with the LogMap algorithm significantly outperforms that of other models. At BER = 10−6, the proposed SCTPCC models with SOVA and LogMap algorithms outperform the PCTPCC model by gains of 0.3 dB and 0.25 dB, respectively. The PCTPCC model with the SOVA decoder is superior to other models in terms of complexity. [ABSTRACT FROM AUTHOR]

This paper investigates the multiple relay codedcooperation scheme based on asymmetric turbo code (ATC) with multiple receive antennas over Rayleigh block fading channels. An encoding scheme based on ATC is proposed for coded-cooperation, i.e. distributed asymmetric turbo code (DATC). The code matched interleaver (CMI) is selected by a rigorous comparison with a uniform- random interleaver (URI). This optimum choice of interleaver at the relay nodes provides maximum benefit from DATC coded-cooperation scheme. Practically in any wireless communication system, the channel side information (CSI) is usually unknown at the receiver. Therefore, spatial normalized least mean square (NLMS) adaptive transversal filters are employed to estimate the CSI at the destination node. Moreover, in coded-cooperation scheme, the effectiveness and validation of spatial NLMS adaptive transversal filters is also verified by simulation results. Quadrature phase shift keying (QPSK) is used in codedcooperation scheme and corresponding soft-demodulators are employed along with joint iterative soft-input soft-output (SISO) decoder at the destination node. Monte Carlo simulations show that the proposed scheme incorporates coding gain, diversity gain and cooperation gain successfully, which eventually results in net gain of 2.7 to 3.5 dBs over non-cooperation ATC counterpart. [ABSTRACT FROM AUTHOR]

Classical Turbo code suffers from high error floor due to its small Minimum Hamming Distance (MHD). Newly-proposed 3D-Turbo code can effectively increase the MHD and achieve a lower error floor by adding a rate-1 post encoder. In 3D-Turbo codes, part of the parity bits from the classical Turbo encoder are further encoded through the post encoder. In this paper, a novel Bit-Interleaved Coded Modulation (BICM) system is proposed by combining rotated mapping Quadrature Amplitude Modulation (QAM) and 3D-Turbo code to improve the Bit Error Rate (BER) performance of 3D-Turbo code over Raleigh fading channel. A key-bit protection scheme and a Two-Dimension (2D) iterative soft demodulating-decoding algorithm are developed for the proposed BICM system. Simulation results show that the proposed system can obtain about 0.8-1.0dB gain at BER of 10~6, compared with the existing BICM system with Gray mapping QAM. [ABSTRACT FROM AUTHOR]

Turbo code finds wide applications in mobile com- munication, deep space communication, satellite communica- tion and short-range communication despite its high compu- tational complexity and iterative nature. Realizing capacity approaching turbo code is a great achievement in the field of communication systems due to its efficient error correction ca- pability. The high computational complexity associated with the iterative process of decoding turbo code consumes large power, introducing decoding delay, and reducing the through- put. Hence, efficient iteration control techniques are required to make the turbo code more power efficient. In this paper, a simple and efficient early iteration termination technique is introduced based on absolute value of the mean of extrinsic information at the component decoders of turbo code. The simulation results presented clearly show that the proposed method is capable of reducing the average number of iter- ations while maintaining performance close to that of fixed iteration termination. The significant reduction in iteration achieved by the method reduces decoding delay and complex- ity while maintaining Bit Error Rate performance close to standard fixed iteration turbo decoder. [ABSTRACT FROM AUTHOR]

Software Defined Radio (SDR) is the technology which has given researchers the opportunity and flexibility of integration and intercommunication of existing and future networks together. The radio spectrum is the most vital resource for a mobile operator in today’s world of modern wireless communications. After analyzing the spectrum allocation map one can conclude that the most of the prime spectrums falling under the licensed bands have already been allocated for licensed users for exclusive use. There are very few unlicensed bands for the unlicensed users. SDR offers a perfect solution to this problem of spectrum scarcity being experienced in wireless communication systems. The demand for reliable, high data rate transmission has increased significantly these days, which leads the way to adoption, of different digital modulation techniques. The aim of this paper was to analyze Frequency Shift Keying (FSK) Transceiver built using Laboratory Virtual Instrumentation Engineering Workbench (LabVIEW) and to measure the reduction in data errors in the presence of Forward Error Correction (FEC) channel coding algorithms namely the Convolution and the Turbo Codes. Through this design a graphical representation of Bit Error Rate (BER) vs E b / N 0 where ( E b ) is Energy per bit and ( N 0 ) is Spectral noise density has been given in the presence of Additive White Gaussian Noise (AWGN) introduced in the channel. FSK is widely used for data transmission over band pass channels; hence, we have chosen FSK for the implementation of SDR. The SDR transceiver module designed has been fully implemented and has the ability to navigate over a wide range of frequencies with programmable channel bandwidth and modulation characteristics. We are able to build an interactive FSK based SDR transceiver in a shorter time with the use of LabVIEW. The outputs achieved show a low BER for very high data rates in the presence of AWGN noise. [ABSTRACT FROM AUTHOR]

The study presented in this paper shows that the coding gain between different allocation modalities between turbo encoder and quadrature amplitude modulator with 16 signal points is over 0.6dB in fading environment. The study presents comparatively the performances obtained with the single binary and double binary turbo codes of memory 4 (with 16 states) used in the LTE and DVB standards. It took into consideration the channel with flat fading, non-selective in frequency, of Ricean type for various degrees of strength. Because of the preferential protection offered by the quadrature amplitude modulation, the various modes of binary allocation between turbo encoding and the quadrature amplitude modulation provide very different bit error rates performances. The hierarchies in performance are strongly influenced by the signal per noise ratio at which work is done. The presented results are a guide for choosing the most adequate binary allocation modality between coding and modulation for specific applications. [ABSTRACT FROM AUTHOR]

The article introduces a novel concept of a PLC modem as a complement to the existing G3 and PRIME standards for communications using medium- or high-voltage overhead or cable lines. The proposed concept is based on the fact that the levels of impulse noise and frequency selectivity are lower on high-voltage lines than on low-voltage ones. Also, the demands for "cost-effective" circuitry design are not so crucial as in the case of modems for low-voltage level. In contract to these positive conditions, however, there is the need to overcome much longer distances and to take into account low SNR on the receiving side. With respect to the listed reasons, our concept makes use ofMCM, instead of OFDM. The assumption of low SNR is compensated through the use of an efficient channel coding based on a serially concatenated turbo code. In addition, MCM offers lower latency and PAPR compared to OFDM. Therefore, when using MCM, it is possible to excite the line with higher power. The proposed concept has been verified during experimental transmission of testing data over a real, 5 km long, 22 kV overhead line. [ABSTRACT FROM AUTHOR]

This paper proposes the interleaving gain in two different distributed turbo-coding schemes: Distributed Turbo Codes (DTC) and Distributed Multiple Turbo Codes (DMTC) for half-duplex relay system as an extension of our previous work on turbo coding interleaver design for direct communication channel. For these schemes with half-duplex constraint, the source node transmits its information with the parity bit sequence(s) to both the relay and the destination nodes during the first phase. The relay received the data from the source and process it by using decode and forward protocol. For the second transmission period, the decoded systematic data at relay is interleaved and re-encoded by a Recursive Systematic Convolutional (RSC) encoder and forwarded to the destination. At destination node, signals received from the source and relay nodes are processed by using turbo log-MAP iterative decoding for retrieving the original information bits. We demonstrate via simulations that the interleaving gain has a large effect with DTC scheme when we use only one RSC encoder at both the source and relay with best performance when using Modified Matched S-Random (MMSR) interleaver. Furthermore, by designing a Chaotic Pseudo Random Interleaver (CPRI) as an outer interleaver at the source node instead of classical interleaves, our scheme can add more secure channel conditions. [ABSTRACT FROM AUTHOR]

In our previous paper [1] , a novel CPCD technique has been introduced to significantly improve decoding of LDPC codes over the known sum product algorithm (SPA) decoding. However, results presented in [1] were limited to shorter low density parity check (LDPC) codes and transmission over an addition white Gaussian noise (AWGN) channels using QPSK modulation. In this study, we demonstrate that CPCD can achieve significant gains regardless of the length of the code or the modulation technique used for transmission or the type of the channel including fading channels. In addition, a novel turbo-CPCD technique that follows the principle of turbo LDPC is introduced. It is shown here that CPCD and turbo-CPCD can perform about 0. 2 − 1. 5 dB better than SPA decoding and turbo LDPC codes. [ABSTRACT FROM AUTHOR]

In this work, a robust watermarking algorithm is presented for video copyright protection. The algorithm is based on hybrid transforms using the combination of DWT and DCT. In the scheme, the luminance component of the key frames is firstly decomposed by a DWT, and then the approximation sub-band in the wavelet domain is selected on which DCT is applied. Following that, the watermark information which is sorted by the pseudo-random and encoded by Turbo codes is embedded into the DCT domain. The experimental results show that the proposed algorithm not only has better invisibility, but also has better robustness to a variety of common attacks. [ABSTRACT FROM AUTHOR]

Interleaving along with error correction coding is an effective way to deal with different types of error in digital data communication. Error burst due to multipath fading and from other sources in a digital channel may be effectively com- bated by interleaving. Normally the interleaver / deinterleaver pair is often designed as reconfigurable architectures able to deal with requirements of large data length variability found in the newest communication standards. In this work reconfigurable interleaver architecture for the turbo decoder in 3rd Generation Partnership Project (3GPP) standard is presented. The interleaver is a key component of radio communication systems. Using conventional design methods, it consumes a large part of silicon area in the design of turbo encoder and decoder. The proposed interleaver utilizes the algorithmic level hardware simplifications and generates 100 manage the flow of data streams to achieve very low cost solution. The proposed technique reduces consumption of FPGA resources to a large extent compared with existing state-of-the-art interleaver for turbo codes. The proposed architecture consumes only 4856 logic elements by hardware optimization. [ABSTRACT FROM AUTHOR]

Abstract: In the area of wireless communication system, researchers are concentrating on powerful forward error correction (FEC) coding techniques. A literature survey has shown that in the field of mobile Wi-Max environment Turbo code provides a coding gain close to Shannon limit. Since the performance of turbo codes depend on iterative decoding algorithms. Among various soft outputs decoding algorithms, Maximum A Posteriori (MAP) algorithm is used, which works on the principle of symbol estimation of the received signal. This paper presents logarithmic version of MAP decoding algorithm (Log-MAP). The author has taken efforts to modify the available Log MAP decoding algorithm in order to reduce the computational complexity. The results are presented for this new developed Max-Log-MAP decoding algorithm. Bit Error Rate (BER) performance and computational complexity of these algorithms are compared with reference to the standard defined by IEEE802.16e for mobile Wi-Max system. [Copyright &y& Elsevier]

Abstract: This paper proposes a self-adaptive decoding scheme based on cross-entropy (CE). Good BER performance can be achieved with lower complexity. The fixed minimum iterative number scheme has been proposed to modify the shortage of the traditional stopping criterion scheme, whose calculations of CE expend hardware resource too much. However, iterative numbers which correspond to different SNRs are varied. It is improper to set a unique minimum iterative number (Imin) for all SNRs. In order to further improve the performances, this self-adaptive decoding scheme is proposed. For various SNRs, different minimum iterative numbers, which are determined by the statistics of the iterative numbers, should be set instead of being unique. The SNR criterion is also adopted in this scheme to further reduce the complexity. Simulation results confirm that the iterative receiver with this self-adaptive scheme has achieved a similar performance with the fixed iterative number scheme but it is of a considerably reduced complexity due to the decreased iterative number of decoding and fewer calculations of CE. [Copyright &y& Elsevier]

Abstract: Cooperation diversity allows mobiles share their antennas to achieve uplink transmit diversity. A particularly powerful variation of user cooperation framework is coded cooperation, which partitions the code words of each mobile and transmits portions of each code word through independent fading channels. This paper mainly focuses on coded cooperation, and its improved framework, which is called space-time cooperation, and investigates the application of turbo codes in both frameworks. The analysis and simulation results show that both of the frameworks achieve impressive gains, and space-time cooperation improves the performance of coded cooperation in fast fading. [Copyright &y& Elsevier]

The excellent features of the sixth generation (6G) of wireless technology enthuses researchers to apply advanced and complex techniques on mobile communication networks, which is what this paper explores. As a result of the ability of 6G to exchange vast data rates and network programming, the Cooperative Network Coding (CoNC) technique can be implemented to improve the connectivity and diversity within 6G applications. Though CoNC is usually implemented at the second stage, this paper proposes dividing the first stage into two Half-Cycle stages, and then applying CoNC at the second Half-Cycle stage. The resulting Bit Error Rate (BER) behaviour is investigated on the physical layer for direct data exchange in 6G local mobile networks over an Additive White Gaussian Noise (AWGN) channel. Partial Unit Turbo Code (PUTC) (4,2,1,4) and (8,4,3,8) are used by each mobile node as the forward error correction technique, which means that each mobile acts as a Base Station (BS) for other mobiles in the local network by applying CoNC on the received packets, and then each mobile node (or BS), either Amplify-and-Forward (AF), or Decode-re-encode-amplify and Forward (DF), acts. When full connectivity is not achieved at the end of the first two Half-Cycle stages, new Half-Cycle stage transmissions follow, and the BER behaviour for all additional Half-Cycle stages is obtained. The results illustrate that applying CoNC at the second Half-Cycle stage of the first general stage produces a limited BER loss. To mitigate the damage in the BER, a soft-decision PUMTC decoder is also proposed. [ABSTRACT FROM AUTHOR]

This paper addresses turbo codes with component convolutional codes as those in the Long Term Evolution (LTE) standard. We consider the interleaver lengths of the form L = 32 k L Ψ , with k L ∈ { 1 , 3 } and Ψ is a product of prime numbers greater than three. For these interleaver lengths, we have shown that a true cubic permutation polynomial (CPP) f 1 x + f 2 x 2 + f 3 x 3 (mod L) , under the constraint f 3 = 0 (mod p i) when a prime p i > 3 and 3 does not divide (p i − 1) , always has an inverse true CPP, except when f 3 = L ∕ (4 k L) and f 2 ∈ { L ∕ 16 , 3 L ∕ 16 , 5 L ∕ 16 , 7 L ∕ 16 }. For the previously mentioned exception, a true CPP has an inverse true quadratic PP (QPP). For CPP interleavers with true inverse CPPs, we have shown that the minimum distance is upper bounded by the values of 44, 36, and 27, for three different classes of coefficients. Previously, it was shown that for the same interleaver lengths and for QPP interleavers, the upper bound on the minimum distance is equal to 50. Due to the symmetry of the classical turbo codes, the minimum distance is also upper bounded by the value of 50 for CPP interleavers with a QPP inverse. The nonlinearity degrees for all considered CPP interleavers are computed. Several examples of d m i n -optimal CPP interleavers and their inverse QPPs are given. [ABSTRACT FROM AUTHOR]