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

Recently, the powerline communication (PLC) mechanism has attracted the attention of researchers across the globe since it demonstrates the least bit error rate in comparison to conventional wireless communication, apart from the merit of no extra cost for implementation of wired communication infrastructure. To make signal transfer over PLC system with no hassling, various multiple access schemes inclusive of Orthogonal Frequency Division Multiple Access (OFDMA), Interleave Division Multiple Access (IDMA) etc. have been employed in the defined communication system. In order to facilitate more reliable communication over PLC channel, the OFDMA and IDMA schemes are combined together, termed as integrated IDMA (IIDMA) scheme. All the variant of IDMA Scheme, inbuilt with interleaving mechanism as its heart, accumulates the merits of original IDMA Scheme in addition to the merits of other multiple access scheme duly coupled with it for intended purpose. In the literature, the researchers have evaluated the IDMA and its variant multiple access schemes with various interleavers, however still there remains scope for improvement in the performance of communication systems with induction of appropriate interleaver. In this paper, a novel interleaver named as Multiplicative Interleaving with Tree Algorithm (MITA) has been implemented over OFDM-IDMA systems and evaluated against existing other interleavers in MATLAB environment. The performance result evidently indicates the superiority of the suggested interleaver in terms of Bit Error Rate (BER), memory consumed and computing complexity. Thus MITA interleaver can be implemented for enhanced performance of the communication system.

Recently, the demand for reliable and high-speed wireless communication has rapidly increased. Orthogonal frequency division multiplexing (OFDM) is a modulation scheme that is the newest competitor against other modulation schemes used for this purpose. OFDM is mostly used for wireless data transfer, although it may also be used for cable and fiber optic connections. However, in many applications, OFDM suffers from burst errors and high bit error rates. This paper presents the utilization of a helical interleaver with OFDM systems to efficiently handle burst channel errors and allow for Bit Error Rate (BER) reduction. The paper also presents a new interleaver, FRF, the initial letters of the authors’ names, for the same purpose. This newly proposed interleaver summarizes our previous experience with many recent interleavers. Fast Fourier transform OFDM (FFT-OFDM) and Discrete Wavelet Transform OFDM (DWT-OFDM) systems are used to test the efficiency of the suggested scheme in terms of burst channel error removal and BER reduction. Finally, the general complexity of the FRF interleaver is different from that of the helical interleaver in terms of hardware requirements. The performance of the proposed scheme was studied over different channel models. The obtained simulation results show a noticeable performance improvement over the conventional FFT-OFDM and the FFT-OFDM systems with the helical interleaver. Finally, the disadvantage of the proposed FRF interleaver is that it is more complex than the helical interleaver.

The paper presents a modification of the interleaver used to construct Parallel Concatenated Block (PCB) codes with flexible lengths. This is accomplished for PCB codes whose interleaved message blocks have at most two bits of a message block. For this purpose, a two-step permutation is implemented, ensuring that the minimum weight of PCB codes has low multiplicity and is obtained from messages with weight one. Conducted analysis and simulations confirm that the new interleaver improves the performance of the PCB code (by 0.25 dB), which is evident at medium to high signal-to-noise ratios. Such improvement is evident for long-length PCB codes.

The use of error-correcting codes (ECCs) is essential for designing reliable digital communication systems. Usually, most systems correct errors under cooperative environments. If receivers do not know interleaver parameters, they must first find out them to decode. In this paper, a blind interleaver parameters estimation method is proposed using the Kolmogorov–Smirnov (K–S) test. We exploit the fact that rank distributions of square matrices of linear codes differ from those of random sequences owing to the linear dependence of linear codes. We use the K–S test to make decision whether two groups are extracted from the same distribution. The K–S test value is used as a measure to find the most different rank distribution for the blind interleaver parameters estimation. In addition to control false alarm rates, multinomial distribution is used to calculate the probability that the most different rank distribution will occur. By exploiting those, we can estimate the interleaver period with relatively low complexity. Experimental results show that the proposed algorithm outperforms previous methods regardless of the bit error rate.

This paper investigates the turbo coded-spatial modulation (TC-SM) scheme based on code matched interleaver (CMI) for multiple input multiple output (MIMO) antenna system. The information bits for the selection of transmit active antenna and for the M-QAM modulated symbols are protected by a forward error correcting turbo code. In this work, we demonstrate that parallel encoding and decoding construction of the TC-SM scheme enabled us to effectively extend the TC-SM scheme to a turbo coded-cooperative spatial modulation (TCC-SM) scheme with CMI placed at the relay node. Numerical results based on Monte Carlo simulations revealed that the TCC-SM and TC-SM schemes outperform state of the art polar coded-cooperative spatial modulation (PCC-SM) and polar coded spatial modulation (PC-SM) schemes, respectively, under identical conditions. This performance improvement in bit-error rate (BER) of the proposed TCC-SM and TC-SM schemes occurred due to the joint soft input soft output log maximum a posteriori probability (SISO-Log-MAP) iterative decoding at the receiver. Furthermore, the mathematical error performance of the TC-SM scheme has also been presented. The numerical results demonstrate that the proposed TCC-SM scheme offers robustness not only in BER performance over the practical (non-ideal) source to relay channel but also presents less encoding and decoding complexity as compared to the PCC-SM scheme.

The main aim of this work is to find a way to improve a turbo code performance by designing a new interleaver structure based on the cross entropy (CE). The goal is to compare the performance of the CE method to a more popular interleaver such as the dithered golden interleaver. This study describes the performance of the turbo code – binary phase shift keying (BPSK) modem which was designed at the Instrumentation Division, Centre of Space Techniques. The simulation results are detailed in terms of the optimal solution observed along with the estimated bit-error rate against Eb/N0. The authors compare the performance of turbo codes for different interleaver sizes and different number of iterations (resulting trade-off curves) assuming two channel types (Gaussian and Rayleigh channels). For the simulated cases of the interleavers, good performance is obtained with the CE interleaver when transmitting data both in short block length (N = 400 bits), and long block length (N = 1024).

Most of the research works carried so far concentrated on decoders and interleavers. The performance of Turbo codes depends on different constituent components such as encoder, decoder and interleaver with metrics of bit error rate and complexity. In this paper a new interleaver structure using sub interleavers is proposed to provide a faster turbo codes for channel with less effect of noise. The major concern of this work is to find an optimum number of sub interleavers which satisfies certain limits of bit error rate and processing time. The simulation was performed using MATLAB and the results shows that the processing time has been reduced to about 10% than the conventional block interleaver.

A multi-objective genetic algorithm is tailored to optimize the design of a wavelength interleaver/deinterleaver device. An interleaver combines data streams from two physical channels into one. The deinterleaver does the opposite job. The WDM requirements for this device include channel spacing of 50 GHz, channel bandwidth of 20 GHz, free spectral range of 100 GHz, maximum channel dispersion of 30 ps/nm, and maximum crosstalk of −23 dB. The challenges for the optimization process include the lack of a closed-form expression for the device performance and the trade-off between the conflicting performance parameters. So, for this multi-objective problem, the proposed approach maneuvers to find a compromise between the performance parameters within a few minutes, saving the designer the laborious design process previously proposed in the literature, which relies on visually inspecting the Z-plane for the dynamics of the transmission poles and zeros. Designs of better performance are achieved, with fewer ring resonators, a channel dispersion as low as 1.6 ps/nm, and crosstalk as low as −30 dB.