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This paper presents a non-binary finite-stat Markov channel (FSMC) that captures both the soft-decision information and the temporal correlation of a discrete fading channel (DFC) with 2ξ quantization levels. The parameters of the FSMC that approximate the DFC with fixe parameters are found using the Baum-Welch algorithm. An iterative decoding scheme, based on the sum-product algorithm, is also discussed...
This paper reports low bit-error-rate (BER) polar codes concatenated low density parity check (LDPC) codes for wireless communication systems. The LDPC code has been validated on the error correction capable to approaching the theoretical value. However, the BER performance of this code is still limited because of the effect of the error floor. Therefore, a concatenated coding scheme based on polar...
Sparse-code multiple-access (SCMA) is a novel multiplexing method to increase the capacity of wireless communication systems. By giving users non-orthogonal codebook with few non-zero entries, the SCMA approach can highly improve the spectral efficiency, compared with traditional orthogonal ones such as CDMA, with tolerable detection complexity. Therefore, it has been considered as an option for 5G...
In order to address a wide variety of future requirements, Generalized Frequency Division Multiplexing (GFDM), a non-orthogonal multicarrier scheme, is considered as one of the most promising techniques available today. To improve the orthogonality of the conventional GFDM system, a multi-taper implementation of GFDM (MGFDM) using discrete prolate spheroidal sequences (DPSSs) or multi-tapers, which...
New multiple access techniques aim to increase the spectral efficiency by overloading the system, i.e., with those techniques the number of users served is greater than the number of system radio channels. Multicarrier-code division multiple access (MC-CDMA) allows the system to be overloaded when multiuser-maximum-likelihood-detector (MU-MLD) is used. Nevertheless, an overloaded system may be affected...
Molecular communications (MC) is a promising paradigm which utilizes molecules to implement communication among nano-machines. Cooperative relaying strategies can be used to extend communication distance and achieve reliable remote communications. In this paper, a two-hop diffusion-based molecular communication with three nano-machine nodes is considered. To mitigate the drawback of traditional cooperative...
Polar codes has a better bit error rate (BER) performance than low-density parity-check (LDPC) and turbo codes with lower coding and decoding complexity. The polar-coded cooperation can provide significant enhancement of data rate and link reliability. However, simply binary coded cooperation cannot meet the requirements of spectral efficiency. In order to improve the spectral efficiency, this paper...
In this paper, we propose an advanced polar encoding scheme with successive cancellation list (SCL) decoder for visible light communication (VLC). As much high-profile channel coding methods, polar codes have achieved the symmetric capacity of binary-input discrete memoryless channels (B-DMCs) based on channel polarization. By taking advantages of simple recursive encoding structure and confirmed...
We propose a scheme of ultraviolet (UV) communication system, with polar channel coding method. The bit error rate (BER) performance of the UV polar code scheme is analyzed by simulations and offline experiments, in contrast with low-density parity-check (LDPC) scheme. Results suggest that the polar code scheme has a better BER performance than LDPC scheme in the UV communication system.
Although Orthogonal Frequency Division Multiplexing (OFDM) seems to be a solution to achieve the demand of high data rates and immunity to the multipath fading channel, it has some drawbacks. High Peak to average power ratio (PAPR) is the most significant problem of these drawbacks. The main objective of this paper is to introduce a modified PAPR reduction technique named as samples clipping and then...
Molecular communication via diffusion (MCvD) is a new research area that considers the communication using messenger molecules in a diffusive fluidic channel. In this area, various modulation methods have been proposed to overcome the problems in the channel, especially the inter symbol interference (ISI). However, these methods are generally considered and tested for the channels that do not change...
In this paper, we mainly focus on the optimization of multi-level coded modulation scheme in terms of sub-channel code rate optimal assignment and irregular QC-LDPC code construction with the aid of EXIT chart analysis. Simulation results show that the proposed MLCM scheme can achieve additional 0.1dB NCG compared with the UEP coded modulation scheme.
In this paper, we analyze differential binary modulation for decode-and-forward (DF) based cooperative free space optical (FSO) network utilizing piecewise linear (PL) approximation and Gamma-Gamma (GG) fading links. We adopt subcarrier intensity modulation (SIM) scheme and a single relay for transmitting the binary phase shift keying (BPSK) modulated data over the FSO channels. The PL decoder considers...
This paper proposes a parallel double Gray mapping scheme that is suited to circular quadrature amplitude modulation (QAM) constellations using partial channel coding associated with collaborative decoding. Using the proposed scheme, We compare the bit error rate (BER) performance of circular 1024QAM and 2048QAM schemes to that of rectangular 1024QAM and cross 2048QAM schemes, respectively. Computer...
New Raptor codes, based on low rate low-density parity-check (LDPC) codes, are proposed for short message length over various channels. The proposed Raptor codes are obtained by pre-coding the information bits by low rate LDPC codes and utilizing a low constant average degree distribution with high intermediate symbol recovery rate (ISRR). Simulation results demonstrate that the proposed Raptor codes...
This paper investigates the performance of convolutional codes with quadrature amplitude modulation transmitted over the Bernoulli-Gaussian impulsive noise channel. First, the performance superiority of blanking over clipping of the symbols affected by noise pulses is proved through the computation of a lower bound on the bit error rate. Next, lower and upper bounds on the bit error rate performance...
A concatenated soft-decision channel coding scheme consisting of an inner LDGM code and an outer staircase code is proposed. The soft-decision LDGM code is used for error reduction while the majority of bit errors are corrected by the low complexity hard-decision staircase code. Decoding complexity of the concatenated code is quantified by a score based on the number of edges in the LDGM code Tanner...
This paper is concerned with block Markov super-position transmission of BCH (BMST-BCH) codes. Compared with other BMST codes, BMST-BCH codes can achieve a lower error floor with an encoding memory of two, which is critical to reduce both delay and implementation complexity. To further reduce the implementation complexity, we propose a hard-decision sliding-window decoding algorithm, in which only...
Multithreshold decoders (MTD) for the self-orthogonal codes (SOC) are considered. It is shown that applying of MTD for the well chosen codes provides almost optimum decoding. Noted that MTD using is difficult to provide a low decoding error probability at the a large noise level due to a small code distance of SOC. For reducing the error probability we propose a concatenated coding scheme formed by...
In the paper, we will discuss the powerfull class of channel codes referred to as turbo codes. We commence with a brief discussion for MAP and log-MAP decoding algorithms. Then we work with proposed turbo decoding method, which is called as PL-log-MAP. Some numerical results and research experiments, such as simulation for bit error rate estimation and images transmission have been presented. It is...
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