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In this paper, a joint digital signal processing (DSP) scheme including partial response shaping and trellis coded modulation (TCM) technology is proposed to mitigate the bandwidth limitation of the long-reach underwater wireless optical communication (UWOC) system. The similarity of spectral responses between the partial response filter and the communication system is utilized to suppress the enhancement of noise and distortion induced by the full-response feed-forward equalizer. A random interleaver and a precoder are applied to whiten the noise and distortion. In a laboratory experiment, the minimal required received optical power of -29.8 dBm (at a BER of $3.80 \times {10^{ - 3}}$ ) is realized at a data rate of 500 Mbps. In a standard swimming pool, the proposed system successfully achieves a data rate of 500 Mbps with a transmission distance up to 150 m, at which the total attenuation is measured to be 53.47 dB. Such a data rate, enabled by the proposed joint DSP scheme, is 8.0%, 9.2%, and 14.2% higher than those achieved by solely using partial response shaping scheme, TCM scheme, and least square equalization scheme, respectively. To the best of our knowledge, this is the first time to employ the combination of partial response shaping and TCM technology in UWOC for high-speed long-reach transmission.

Problem statement: The proliferation of services and applications requiring ultra-low latency and high reliability of data transmission in communication networks leads to creating new approaches and architectures in order to ensure the simultaneous transmission of Enhanced Mobile Broadband (eMBB) and Ultra-Reliable and Low Latency Communication (URLLC) traffic. Providing efficient eMBB and URLLC multiplexing schemes with preset key performance indicators for each stream is the most challenging problem in wireless network development. Purpose: To provide a simultaneous transmission of eMBB and URLLC streams without reducing the user experience of eMBB services by developing a multiplexing scheme and the coherent architecture of physical (PHY) and media access control (MAC) layers in the downlink channel. Results: An eMBB and URLLC multiplexing scheme has been proposed, along with a coherent architecture for PHY and MAC layers, ensuring the given wireless network key performance indicators. The proposed solution performance has been estimated by simulation. The multiplexing scheme outperforms the baseline solution in Bit Error Rate and Frame Error Rate metrics. The coherent PHY and MAC layers architecture provides transmission with an arrival rate of 400 messages per millisecond and 99% message delivery probability in one millisecond. Practical relevance: The obtained results allow communication system developers to deploy centralized wireless networks at industrial objects.

Animated emoji is a kind of GIF image, which is widely used in online social networks (OSN) for its efficiency in transmitting vivid and personalized information. Aiming at realizing covert communication in animated emoji, this paper proposes an improved steganography framework in animated emoji. We propose a self-reference algorithm to improve the steganography security. Meanwhile, the relations between adjacent frames of the cover GIF image are considered to further improve the distortion function. After that we embed the secret message into the GIF image using the popular framework of Syndrome Trellis Coding (STC). Experimental results show that the proposed method can provide better security performances than state-of-the-art works.

In today’s scenario, demand for error-correcting codes with minimal error constraints for wireless communications. Multilevel coding scheme with trellis codes as component codes provides flexible data transmission rates, coding gain, diversity gain with improved spectral efficiency and low decoding complexity. This paper investigates the potential improvements by using the Multilevel coding scheme with massive Multiple-Input Multiple-Output in Cognitive Radio Networks with trellis codes as component codes. This paper discussed space-time coding with beamforming and antenna grouping according to the channel state information. Multilevel Space-time coding is based on multi-level Quadrature Amplitude Modulation signaling and beamforming to mitigate the effect of primary users for the enactment of secondary users in Cognitive Radio. The primary users provide channels dynamically to the secondary user for an unknown duration. Our transmission use Quadrature Amplitude Modulation based signals, with an adaptive grouping of antenna which weight according to the optimization, which inherently depends upon the resource allocation of the secondary user. The results show that the proposed coded system achieves Bit error rate/Symbol error rate/Frame error rate and Signal to noise ratio varies according to sources sensing time.

Data hiding aims to embed a secret payload into a cover object without introducing significant degradation of the cover. The resulting object containing hidden information, typically also called stego, will not arouse obvious suspicion from the monitor. A number of data hiding systems have been designed for digital images and only a few focus on video sequences. Actually, video is quite desirable for data hiding due to its large capacity for carrying a payload. It motivates us to present an adaptive data hiding scheme to video sequences in this paper. In the proposed scheme, the non-zero quantized Discrete Cosine Transform (QDCT) coefficients of intra-frames are used to embed the secret payload based on ternary syndrome-trellis coding (STC) equipped with a well-designed distortion function. In order to realize data hiding with low bit-rate growth, the non-zero QDCT coefficients in complex texture regions with high amplitude are further exploited for data embedding. Experimental results have shown that, comparing with a part of related works, the proposed work provides high embedding capacity and lower bit-rate growth. And, the video quality after data hiding can be kept with a high level. In addition, the proposed work does not expose suspicious histogram distribution and block characteristics, which has shown the superiority and applicability of the proposed work.

In a practical 4- $\lambda $ coarse wavelength division multiplexing (CWDM) intensity modulation direct detection (IM/DD) system, different wavelength channels achieve different transmission performances due to 1) inter-channel component differences and 2) chromatic dispersion (CD) – chirp interaction. Large channel performance discrepancies could significantly degrade the average pre- forward error correction (pre-FEC) bit error rate (BER) performance of the system. To improve the system’s robustness against channel performance discrepancies, we propose to employ a symbol-level wavelength-interleaver in conjunction with four-dimensional - 4-level pulse amplitude modulation - trellis coded modulation (4D-PAM4-TCM). We experimentally compare the performances of the proposed wavelength-interleaved 4D-PAM4-TCM system and a conventional 4D-PAM4-TCM system in a 4- $\lambda \,\,\times100$ Gb/s CWDM IM/DD link over 0–20 km. We observe that the wavelength-interleaved 4D-PAM4-TCM system outperforms the conventional 4D-PAM4-TCM system in terms of receiver sensitivity required at the KP4 FEC threshold when sizable channel performance discrepancies exist in such systems.

This paper proposes a robust reconstruction scheme for image/ video transmission in space-time trellis coding (STTC) based MIMO wireless multimedia sensor networks (WMSN). The information bits of the image/ video stream are modulated using STTC prior to transmission over the MIMO wireless channel between the multimedia sensors and the cluster head. At the receiver, a novel total variation sequence detector (TVSD) is developed that employs an anisotropic total variation (TV) regularized cost function to leverage the bounded variation property of the image/ video stream, in addition to the coding and diversity advantages of the STTC, for improved image/ video recovery. For reconstruction, a novel bi-layered hierarchical trellis based modified Viterbi decoder is developed to decode the optimal bit sequence corresponding to the least TV cost function using appropriately modified node and branch metrics. Simulation results using several test images and video sequences demonstrate the improved reconstruction performance of the proposed scheme, especially in the low SNR regime (0 - 10 dB), in comparison to the conventional maximum likelihood (ML) decoder, which makes it ideally suited for implementation in practical WMSN.

Two new four-dimensional modulation schemes, 4DTCM-SP-128QAM and 4DTCM-SP-128TQAM, are proposed with lower BER. The simulation show that they can obtain 2.53dB and 1.33dB gain respectively with great potential used in long-haul optical transmission system.

Trellis coded modulation (TCM) is a technique combining modulation with coding using trellises designed with heuristic techniques that maximize the minimum Euclidean distance of a codebook. We propose a neural networks based decoder for decoding TCM. We show experiments with our decoder that suggest the use of Convolutional Neural Network (CNN) with Recurrent Neural Network (RNN) can improve decoding performance and provide justification for the same. We show the generalization capability of the decoder by training it with small block length and testing for larger block length. We also test our decoder for its performance on noise model unseen in the training.

To increase the energy and spectral efficiency of radio engineering systems, it is advisable to combine the methods of space-time coding with the use of multi-element receiving and transmitting antennas in promising radio communication systems and signal-code structures. The joint efficiency of spatiotemporal coding with two receiving and transmitting antennas, together with signal-code structures, is analyzed by modeling methods in the MATLAB environment. Based on the results of the analysis, a reasonable joint choice of methods of multi-position modulation in combination with noise-resistant and space-time coding in radio engineering systems for various purposes is possible.

Sparse code multiple access (SCMA) is one of the Non-Orthogonal Multiple Access (NOMA) that attracts many researchers for its promising future uses in 5G systems. In this paper, a Computer Generated-Sparse Code Multiple Access (CG-SCMA) is proposed. CG-SCMA generates a complex SCMA codebook that maximizes the Minimum Euclidian Distance (MinED) of 16-point star-QAM. This codebook is generated using computer program to specify the most appropriate values for this constellation. Then Trellis Coded Modulation (TCM) is used to divide the constellation into four sub constellations to maximize MinED. The new codebook reaches MinED for four sub constellations {3.46, 2.16, 2.16, 3.46} and achieves increment over SCMA codebook based 16-point star-QAM by 10.1%. The multiplexer and de-multiplexer for proposed codebook and traditional SCAM codebook is implemented using netFPGA-1G-CML Kintex-7. it can speed up the process by 597.6 times over MATLAB simulator and decreasing BER compared to open literature codebooks.

In order to achieve higher data rate, higher spectral efficiency and greater transmission distance, the scheme of trellis coded modulation with three dimension 9QAM mapping based on a novel probabilistic shaping (PS) method is proposed in this paper. The bit error rate performance of three dimension 9QAM–TCM is investigated by simulation and compared with three dimension 8QAM–TCM scheme. Research results show that the Eb/N0 of the proposed three dimension 9QAM–TCM scheme is 1.2 dB smaller than that of three dimension 8QAM–TCM at the bit error rate of 10−4.

Interleaver design has been an intense research area since the invention of turbo codes, both from theoretical and technological perspectives, still receiving the attention of engineers. This work is a theoretical treatment on the subject of interleaver design, bringing into focus the odd-even constraint. Odd-even interleavers constrain information symbols at odd (even) positions to remain at odd (even) positions after interleaving. Having been adopted in a range of operational communication standards as parts of turbo codes on the one hand, and having raised scepticism about their gain in the literature of turbo trellis-coded modulation on the other hand, these interleavers have motivated the present article. Concretely, the authors perform a bit-error analysis of turbo-code ensembles generated by the odd–even uniform interleaver , following the union-bound approach by Benedetto et al. for the analysis of the uniform interleaver. They find that the odd–even constraint does not affect the interleaver gain of uniform-interleaver ensembles; rather, it triggers a redistribution of multiplicities that leads to slightly worse performance mainly in the error-floor region. The authors' findings are corroborated by bit-error-rate simulations.

As we are entering the 5G era, high demand is made of wireless communication. Consistent effort has been ongoing in multiple-input multiple-output (MIMO) systems, which provide correlation on temporal and spatial domain, to meet the high throughput demand. To handle the characteristic nature of wireless channel effectively and improve the system performance, this paper considers the combination of diversity and equalization. Space-Time trellis code is combined with single-carrier modulation using two-choice equalization techniques, namely: minimum mean squared error (MMSE) equalizer and orthogonal triangular (QR) detection. MMSE gives an optimal balance between noise enhancement and net inter-symbol interference (ISI) in the transmitted signal. Use of these equalizers provides the platform of investigating the bit error rate (BER) and the pairwise error probability (PEP) at the receiver, as well as the effect of cyclic prefix reduction on the receivers. It was found that the MMSE receiver outperforms the QR receiver in terms of BER, while in terms of PEP; the QR receiver outperforms the MMSE receiver. When a cyclic prefix reduction test was carried out on both receivers, it yields a significant reduction in BER of both receivers but has no significant effect on the overall performance.

In the paper, we introduce the 8-state trellis-coded modulation (TCM) scheme using sphere packing four-dimensional (4D) non-cubic constellations on the basis of a novel set-partitioning (SP) method. Sphere packing four-dimensional formats have a higher asymptotic power efficiency (APE) because the spatial arrangement of constellation points is more dense. The scheme can further alleviate the contradiction between spectral efficiency (SE) and APE in 4D modulation format. The SP process of 4D non-cubic constellations is completed in the condition that the minimum Euclidean distance between the constellation points and the number of nearest neighbors are adequately considered. We compared these 4D TCM formats to their corresponding 4D formats (i.e., dicyclic4_16, b4_32, b4_64, SP-QAM4_128 and 256-D4) in the 800 km standard single-mode fiber (SSMF) transmission system. Through measurements of bit error rate (BER) performance, at the BER = 1 × 10−3, the coding gains are 5.7 dB, 3.8 dB, 3.6 dB, 3.9 dB and 4.1 dB respectively.

We propose a novel seven-level pulse amplitude modulation (PAM-7) combined with trellis coded modulation (TCM) for data center applications. Four symbols are combined in the 4D space to encode ten information bits. The novel scheme called 4D PAM-7 TCM is experimentally demonstrated with commercially available devices at 1550 nm at rates of 210/225 Gbit/s. Excellent performance is achieved by employing advanced digital signal processing algorithms both at transmitter and receiver. The TCM scheme is compared with the PAM-6 modulation format which has the same spectral efficiency. The 4D PAM-7 TCM format improves the sensitivity by 5.5 dB compared to the best PAM-6 results assuming that the system works with the KP4 FEC. The TCM solution may transport the next Ethernet data rate of 800G using $4\times 200\text{G}$ transceivers.

For the satellite communication, power efficiency and spectrum efficiency are all important requirements to keep the high speed data transmission and longer expectation of operation life of satellite. So, the Consultative Committee for Space Data Systems (CCSDS) has discussed many possible communication technology candidates and eventually has decided the 4D-8PSK-TCM (4 dimensional 8 phase shift keying trellis coded modulation) as one recommendation for X-band satellite communication system. Therefore, it is very important to propose the design structure of transmitter and receiver of the 4D-8PSK-TCM communication system and to evaluate the communication performances. In this paper, at first, the design method of 4D-8PSK-TCM system recommended in CCSDS for X-band satellite communication will be described in detail for the design of the transmitter and receiver. Secondly, the characteristics of peak to average power ratio (PAPR), spectrum characteristic, and constellation characteristic according to the square root raised cosine filtering are determined for each transmission efficiency mode. Finally, BER performances according to each reception processing step are evaluated and analyzed. As simulation results, the trajectory of the transmission signal according to the roll-off factor value and the PAPR characteristic and the spectral characteristic have been obtained. Acceptable PAPR characteristics have been obtained when the roll-off factor values are 0.35 and 0.5, and the spectral waveforms have been confirmed. Especially, it is confirmed that the receiver system using both the auxiliary trellis and the general trellis in the receiver is improved by 2 dB than the single auxiliary trellis system.

Ternary trellis coded modulation (TTCM) is introduced. This combines triangular signal constellations with ternary convolutional codes. The performance of TTCM is presented and compared with binary trellis coded modulation (BTCM) which employs square quadrature amplitude modulation (SQAM) and binary convolutional coding. Ternary set partitioning (TSP) is used for TTCM, and binary-to-ternary conversion is determined that is suitable for TTCM. A construction for M-ary triangular QAM (TQAM) which is compatible with TSP is presented. The performance of BTCM is compared with that of TTCM.

Steganography is to embed secret information into digital media and minimize the distortion caused by data embedding. The JPEG is a widely used image compression format, and many JPEG images transmitted on the network are double compressed. Most of the existing steganography algorithms mainly use the single compressed images as the embedded carrier of secret information while rarely taking advantage of the double compressed images. However, the double compressed operation usually leads to changes in the statistical characteristics of images. Therefore, the minor changes caused by steganography can be confused by double compression operation to achieve the purpose of concealing embedding operation. This paper proposes a secure JPEG double compression (DC) steganographic scheme based on irregular discrete cosine transformation (DCT) and coefficients distribution (IDCD-JDS), which can obtain less statistical detectability. The minimum distortion function is designed according to the fact that the statistical distribution of the double compressed images has periodic peaks and valleys as well as multiple irregular intervals. By using the syndrome trellis coding (STC) to embed secret information, the modifications are limited to regions that are difficult to detect. The quality factors (QF) relationship between the first and second compression is further studied to explore the effective range for double compressed images so that the proposed algorithm can achieve better performance under different conditions. The experiments show that this scheme can reduce the embedding change by utilizing the inherent statistical distribution and irregular block complexity in double compressed images, and it performs better than the existing methods.

The radio frequency spectrum has become very congested and scarce. A response to this dilemma is the implementation of visible light communications (VLC) technology, which is enabled by the dramatic development of light emitting diodes (LEDs) and laser diodes (LDs). VLC has become the most popular emerging telecommunication technology. This is due to the interesting advantages that it provides, which include an unlicensed and large bandwidth, a high throughput capability and a low implementation cost. VLC needs a pivot network in medium and long distance transmissions. The amplify-and-forward scenario between the backbone network and VLC is cost-effective owing to its simplicity when compared to the decode-and-forward scenario. MPSK-CSK is a typical example of cascaded systems in AF scenario with VLC where the backbone channel utilises PSK to convey the message. In this paper, we investigate a forward error correction scheme for cascaded MPSK-CSK systems. A convolutional encoder is added to the MPSK-CSK scheme to construct the hybrid trellis coded modulation scheme. Selected 8HTCM systems using set partitioning are investigated and results for a Gaussian channel are presented. Numerical results reveal that 8HTCM achieves up to 2.129 dB of asymptotic coding gain when compared to the corresponding un-coded MPSK-CSK system.

Contrast enhancement is widely used to improve the visual quality of images. This paper proposes a distortion function for steganography in enhanced images. The pixel prediction error and the cost of the pixel value itself are joint to fit the unique properties of enhanced image. Given a cover image, each pixel is predicted by its neighbors. The prediction error, which reflects the texture complexity, are combined with the cost of the pixel value itself to form the final distortion function. With the proposed distortion function, secret data can be embedded into the enhanced cover image with minimal image distortion using syndrome trellis coding (STC). As a result, less detectable artifacts left in the stego images, so that high undetectability is achieved.

Signal fading is a major problem in the tropical regions. Here the signals get highly attenuated for torrential rain, hence the signal power diminishes and the bit error rate (BER) increases. To enhance the signal to noise ratio (SNR) or to minimize the BER a communication link model using trellis coded modulation (TCM) for 5G communication has been proposed in this paper for the tropical regions. Various diversity techniques have been applied to minimize BER in the tropical regions. STBC (Space-Time Block Coding) MIMO technique is a spatial diversity technique which has been used in the proposed model in this paper. Bit error rate values are obtained for MIMO multi path fading distributions viz. Rayleigh fading distribution and Rician fading distribution. BER values are also attained in respect of different MIMO techniques (2x2, 3x3 and 4x4). The 4x4 STBC MIMO System has been generated using hardware co-simulation block and the results are implemented in Xilinx kintex-7 FPGA board. From the analysis of the result it is observed that Rayleigh fading distribution reflects better performance than that of Rician fading distribution. 4x4 MIMO Technique renders better result in comparison with that of lower MIMO techniques.

RNN-based joint equalization and decoding methods are proposed for data center with TCM signals. Numerical results show compared with traditional DSP algorithms, our method improves power sensitivity by 2.2dB@BER=3.8×10-3 with 96% reduced complexity.

This paper describes an innovative approach for the transmission and decoding of Trellis Coded Modulation (TCM) schemes over band limited digital communication channel in an environment influenced by the Additive White Gaussian Noise (AWGN). Amemoryless channel is being considered so that the Inter-symbol Interference (ISI) effect over the transmitted signals is zero. A Zeros Symbol Sequence (ZSS) of very short length has been transmitted along with the information transmission. This sequence is used to bring the minimum mean square path estimation close to all zero sequences, and it is termed as Tie-Zero Symbol Sequence (TZSS). The TZSS is used to improve the Likelihood Sequence Estimation (LSE) of the decoder during the decoding process. The Soft Output Viterbi Algorithm (SOVA) has been implemented on the receiving side of the transmission system for the LSE in the optimum sense. Modified decoding approach has been proposed for the decoding of TZSS. An improved error performance has been demonstrated through computer simulation.

This article is a continuation of the study of enhanced Mobile BroadBand and Ultra-Reliable and Low Latency communication multiplexing methods in the downlink of fifth-generation wireless networks. Based on a previous study, the following approach to multiplexing eMBB and URLLC data streams based on Trellis-Coded Modulation using LDPC codes for fifth generation networks in soft decision mode using different quantization levels is proposed.

In this letter, we propose a trellis-coded non-orthogonal multiple access (NOMA) scheme. The signals for different users are produced by trellis coded modulation (TCM) and then superimposed on different power levels. By interpreting the encoding process via the tensor product of trellises, we introduce a joint detection method based on the Viterbi algorithm. Then, we determine the optimal power allocation between the two users by maximizing the free distance of the tensor product trellis. Finally, we manifest that the trellis-coded NOMA outperforms the uncoded NOMA at high signal-to-noise ratio (SNR).

The problem of single domain embedding and encoder dependence exists in almost all adaptive MP3 steganographic schemes, leading to relatively concentrated modification, limited embedding capacity, long execution time, and re-compression. Therefore, a fast and secure MP3 steganographic scheme with multi-domain is proposed in this paper. First, to enlarge the embedding capacity and spread the modifications, we extract the linbits and sign bits of quantized modified discrete cosine transform (QMDCT) coefficients to combine multi-domain. Second, a distortion function is designed based on the statistical properties of the inter and intra frames for better security. The message is embedded into the multi-domains by incorporating the syndrome trellis coding (STC) with the distortion function. Finally, the embedding method is able to get rid of the MP3 encoder and further avoid the problems of re-compression. Experiments illustrate that our scheme achieves a significant improvement in imperceptibility and statistical undetectability. In addition, the execution time is decreased by 63.6% ∼ 76.7%, and the embedding capacity is increased by at least 47.4%.

Introduction: Real communication channels used for high-speed data transmission are characterized by substantial linear distortions leading to a significant decrease in the effectiveness of the known coded modulation techniques developed for distortion-free channels. This means that a modified coded modulation technique should be created, which would take into account the channel distortions. Purpose: Using multidimensional signal sets to build up multilevel trellis-coded modulation constructions with multidimensional constellations and multi-stage decoding, matched to the channels with linear distortions, and study of their main characteristics. Results: A new approach was developed to the design of trellis-coded modulation constructions for channels with linear distortions, based on the combination of two techniques: decomposition of the channel into a set of independent memoryless subchannels and time-frequency multilevel coding. The high level of flexibility of the proposed trellis-coded modulation constructions makes it possible to effectively take into account linear channel distortions and compensate for them, due to the rational choice of the number of the subchannels and optimization of the energy distribution between the subchannels. It also provides a wide-range tradeoff between performance and decoding complexity. The relationships between the basic parameters of the proposed class of trellis-coded modulation constructions were obtained in an explicit form. These relationships allow you to provide tradeoffs between the transmission rate, the minimum distance, and the decoding complexity. Examples of multilevel trellis-coded modulation constructions based on multidimensional Barnes — Wall lattices are given. A comparative study showed that as the value of the permissible decoding complexity increases, constructions with larger values of both the number of subchannels and the cardinality of the signal constellation become more preferable. Practical significance: The proposed class of trellis-coded modulation constructions allows you to effectively take into account and to overcome the influence of linear channel distortions common in communication channels used for high-speed data transmission. An additional advantage of these constructions is a relatively small value of the crest factor of transmitted signals and thereby more efficient use of the transmitter's power.

The implementation of a 25.6-Gb/s four-level pulse-amplitude-modulation (4-PAM) reduced-state sliding-block Viterbi detector (VD) is presented. The power consumption of the VD is 105mW at a supply voltage of 0.7 V, corresponding to an energy efficiency of 4.1 pJ/b. A data rate of 30.4 Gb/s is achieved with an energy efficiency of 5.3 pJ/b at a supply voltage of 0.8 V. The VD, implemented in an experimental chip fabricated in 14-nm CMOS FINFET, exploits set-partitioning principles and embedded per-survivor decision feedback to reduce implementation complexity and power consumption. The active area of the VD with 12 slices, each operating at one-eighth of the modulation rate, is $0.507\times0.717$ mm2. Experimental results showing system performance are obtained by using a (215–1)-bit pseudo-random binary sequence. The impact of the synchronization length and survivor path memory length on the detector design and system performance are shown. A new pipelined reduced-state sequence detector algorithm is presented for high-speed implementations. A novel speculative symbol timing recovery scheme is proposed. New simulation results are obtained to compare the performance of the Reed–Solomon (RS)-encoded 4-PAM scheme with that of the concatenated RS 4-D 5-PAM trellis-coded-modulation (TCM) scheme over an ideal band-limited additive-white-Gaussian-noise channel. Drawing on the results achieved for the VD, novel design techniques for a high-speed low-complexity eight-state 4-D 5-PAM TCM decoder is proposed.

In this paper a new approach of digital communication system, The 4D8 PSK TCM Encoder Decoder design is presented. TCM encoder and decoder have been implemented as per specification given Consultative Committee for Space Data System (CCSDS) for satellite application. Encoder implementation is straight forward but in Decoder part most complex blocks involved. Among these blocks TMU unit and VD are most complex and consume more power.In this paper a new approach of ACSU unit implementation and simulation is presented. Adopted architecture shows better performance in the device utilization and power consumption of system.

Capable of achieving massive connectivity and high reliability, the NOMA technique has been well recognized as a potential candidate for 5G mobile communications. Being a key technique of code-domain NOMA, codebook design has drawn great attention due to its potential to improve the coding gain of the system. Trellis coded modulation (TCM) techniques have been considered as an effective approach to optimize the coding gain through signal set expansion without causing bandwidth expansion. In this article, we propose a framework to apply the multi-dimensional TCM (MD-TCM) techniques in code-domain NOMA to jointly design the superposed codewords. Starting with a basic TCM-based NOMA system, we present the design criteria based on which joint multi-layer codeword design for code-domain NOMA is elaborated. Three TCM-based NOMA applications are extended: TCM-based NOMA for MIMO systems, TCM-based NOMA for cooperative relay systems, and TCM-based NOMA for vehicular systems. Open research issues in these scenarios are also discussed.

Orthogonal frequency division multiplexing (OFDM) with index modulation (IM) is a multicarrier transmission technique for frequency-selective fading channels. Although it is energy and spectral efficient, its performance may not be satisfactory as some active subcarriers can be suppressed by fading. In this letter, we consider trellis coded modulation (TCM) for OFDM-IM in order to improve the detection performance of active subcarriers by increasing the Hamming distance between index symbols. We devise mapping rules for TCM for two cases and it is shown that the diversity order can be improved, which results in a lower probability of index error.

This paper presents a novel adaptive JPEG steganographic scheme in Discrete cosine transform (DCT) domain using Run-length statistical complexity (RSC). Unlike the traditional complexity measurements, RSC considers the change randomness of DCT coefficients in image blocks. The distortion functions in both side-informed and non-side-informed schemes are derived by RSC and minimized by Syndrome trellis coding (STC). Experimental results show superior performance of our scheme over a wide range of embedding rates at different image quality factors compared with previous three common steganographic schemes.

Steganography aims to embed additional data into digital media secretly and minimize the distortion caused by data embedding. Up to now, the key point of minimal distortion embedding framework is to design proper distortion function. In this paper, a distortion function for JPEG steganography based on residual blocks is proposed. To obtain less statistical detectability, Residual Block Values (termed as RBVs for short) and quantization steps are both involved in the proposed distortion function. RBVs are exploited to determine the embedding risk caused by modifications in corresponding DCT block while quantization steps are exploited to determine the embedding risk of the selection channel in a block. By implementing the syndrome trellis coding (STC) to embed secret data, the modifications are constrained in hard-to-detect religions. Experiments show that the proposed method performs better than current state-of-the-art methods of JPEG steganography.

Two kinds of modified codewords for space–time block coded spatial modulation (STBC-SM) are presented in this study. The first modified codeword introduces a concept of flexible coefficients into the M-ary phase shift keying STBC-SM. A method is proposed to obtain the optimal flexible coefficients. Moreover, the first modified codewords can also be applied to the systems developed from the STBC-SM. In the second provided codewords, super-orthogonal space–time trellis codes are applied in STBC-SM. Therefore, a higher spectral efficiency is obtained compared with the original STBC-SM. Finally, the simulation results and theoretical analysis demonstrate these performance advantages of the two kinds of modified codewords for STBC-SM.

Satellite-based services, including 5G communications, require efficient high-speed communication technology. The Consultative Committee for Space Data System (CCSDS)recommends the 4 Dimension 8-ary Phase Shift Keying Trellis Coded Modulation (4D-8PSK-TCM) system to transmit large amounts of data at high speeds using X-Band, which is often used by Low Earth Orbit (LEO) satellites. In this paper, we explain the 4D-8PSK-TCM decoder with transmission efficiency of 2.0 bits/channel-symbol and build simulation model using MATLAB. The performance is evaluated in terms of the Bit Error Rate(BER) according to trace-back depth of the Viterbi decoder. We validate that the simulation model does not differ in BER performance from that of CCSDS. Also, we confirmed that the deeper trace-back depth of the Viterbi Decoder, the worse BER performance.

Studies for enhancing network speed and capacity to handle the rapid increases in traffic are being conducted. Even in optical access, which is the backbone network, studies on next generation modulation schemes that utilize phase and amplitude, rather than modulation by conventional light intensity, are being conducted. However, it is difficult to update all the terminals at once, and there is a possibility that signals with old and new modulation schemes coexist on one optical fiber. Such situations are known to yield high error rates. Therefore, this study evaluates the effectiveness of TCM (Trellis Coded Modulation), which is an error correcting scheme.

In this contribution, we consider the carrier frequency offset (CFO) estimation from encoded signals transmitted over fading channel with non-constant gain. We derive for the first time the expression of the Cramer-Rao lower bound for non-data aided (NDA) CFO estimation from trellis coded modulation (TCM) transmission over flat Rayleigh fading channel (FRFC). Existing NDA carrier frequency synchronizers based on a cyclostationary approach are then studied and generalized for encoded transmission. Behavior and performances of the estimation algorithms are presented through numerical results and are compared to the derived bounds.

In this paper, a polarization-switched QPSK (PS-QPSK) based four-dimensional trellis coded modulation polarization-switched 8PSK (4DTCM-PS-8PSK) format with unparalleled superiority of low decoding complexity and high energy efficiency is proposed for the first time, which improves the bit-error-rate (BER) performance of PS-QPSK. The BER performance of 4DTCM-PS-8PSK is simulated. Simulation results indicates that 0.6 dB and 2.6 dB gains are obtained in the BER of 1.0×103 when comparing with the traditional PS-QPSK and dual-polarization QPSK(DP-QPSK), respectively. And the coding gain can be further enhanced with the increase of signal-to-noise ratio(SNR). Therefore, the favorable performance in sensitivity reveals the proposed 4DTCM-PS-8PSK can be of great potential for long-haul optical transmission systems at the cost of few extra complexities.

High-speed transmission technology is required to provide various services through Low Earth Orbit (LEO) satellites. The Consultative Committee for Space Data System (CCSDS) recommends the four Dimension 8-ary Phase Shift Keying Trellis Coded Modulation (4D-8PSK-TCM) system for high-speed transmission of large amounts of data in the X-band. In this paper, we build the 4D-8PSK-TCM system with transmission efficiency of 2.0 bits/channel-symbol using MATLAB Simulink. The performance is evaluated in terms of the Bit Error Rate (BER) and throughput over time through network-level simulator using Riverbed Modeler. The results show that there is no difference between the throughput of 4D-8PSK-TCM and that of other schemes in the X-band regardless of the simulation time. However, the 4D-8PSK-TCM has an advantage of the BER.

With regards to energy constrained Autonomous Underwater Vehicles (AUVs), and difficulties inherent to the acoustic underwater communication channel, a non-coherent method is investigated in order to improve energy consumption and reliability over traditional Frequency Shift Keying (FSK), without increasing the bandwidth. A proposed method of adapting Trellis Coded Modulation (TCM) to constant amplitude Permutated Frequency Shift Keying (PFSK) symbol constellations is evaluated. A system implementation of two PFSK methods is simulated in an Additive White Gaussian Noise channel, and field tested in an underwater channel in the Stockholm archipelago, where a binary FSK reference method is used as a comparison. The main interest is comparing electrical bit energy and bit error rate (BER) for the methods. Time variability of frequency fading, related to wind speed, is also evaluated from the field tests.

In practical applications of electromagnetic measurement while drilling (EM-MWD) in the underground coal mine, the signal-to-noise ratio (SNR) of the receiver cannot always meet the requirements of reliable communication conditions due to the earth-attenuation, interfering signal from a well site, etc. Traditional digital communication systems use independent design coding and modulation techniques to improve system performance. The coding is mainly achieved by introducing redundant bits and the improvement of error performance is at the expense of information rate. Aimed to solve this problem, we use a coding technique based on trellis coded modulation (TCM) to maximize the minimum distance between modulated output sequences and achieve significant coding gain. Simulation and experiments show that the system can improve the anti-noise performance of the system by obtaining a coding gain without reducing the transmission rate. Compared to the uncoded quadrature phase shift keying (QPSK), TCM can achieve a coding gain of at least 3 dB under the same transmitting rate. At that time, as the number of TCM system states or trace back depth increases, the coding gain is further enhanced. The TCM code modulation method can be used in an EM-MWD system to improve the system performance.

Orbital Angular Momentum (OAM) has been considered as a new dimension of wireless transmission as well as the intrinsic property of electromagnetic wave. When OAM is applied with the traditional modulation and coding, the extended Euclidean space can be established to illustrate the signal with OAM dimension. In this paper, according to whether or not the OAM is utilized as the independent dimension with orthogonality, three kinds of mathematical models of the Euclidean space are established. Some typical modulation constellations joint with the trellis coding are discussed and analyzed. The performances of Bit Error Rate (BER) and transmission capacity are evaluated by the Euclidean distance within the Euclidean space, which confirms the appealing capability of the proposed Euclidean space in the corresponding signal processing with OAM.

In order to achieve higher data transmission efficiency, a novel design of 64 state trellis coded modulation (TCM) based on three dimension 32QAM signal is presented in this paper. The simulation results show that when the BER is 10^-3, the Eb/N0 of the 64-state 32QAM-TCM scheme is 2.3dB smaller than that of the uncoded-16QAM scheme. The proposed scheme introduces significant performance improvement of bit error ratio over two dimension uncoded-16QAM scheme.

The block codes, convolutional, and turbo codes discussed in the previous chapters achieve performance improvement expanding the bandwidth of the transmitted signal. However, when coding is t p being applied to bandwidth limited channels, coding gain is to be achieved without signal bandwidth expansion. The coding gain for bandwidth limited channels can be achieved by a scheme called trellis coded modulation (TCM). The TCM is a combined coding and modulation technique that increases the number of signals over the corresponding uncoded system to compensate for the redundancy introduced by the code for digital transmission over band-limited channels.

We propose a simple nonlinear trellis-coded-modulation to realize spectral-shaping for short-reach IM-DD transmission. Simulation results show the improvement of bandwidth-limitation and chromatic-dispersion tolerances. Experimental results show the achievement of 7% HD-FEC threshold in 184-Gb/s transmission.