A Orthogonal Time Frequency Space (OTFS) system has demonstrated its potential advantages in high-mobility communication scenarios. A low complexity detection algorithm is always a critical challenge for the OTFS receiver. In this paper, we propose a novel detection chain based low-complexity successive interference cancellation (SIC) symbol detection algorithm for OTFS system. Specifically, we first set a protection interval in OTFS data frames, which can provide some inter-symbol interference (ISI)-free areas in received signals. Based on these ISI-free areas, we can construct the detection chain to determine the detection order of the SIC algorithm based on the association relationship of received signals. Furthermore, in order to mitigate the error propagation of the SIC algorithm, we propose a detection direction selection scheme, which can provide the direction selection gain and significantly improve the performance. Moreover, we analyze the complexity of the proposed SIC algorithm. Compared with many existing detection algorithms, the proposed SIC algorithm can significantly reduce the detection complexity. Simulation results show that in the channel scenario with the line of sight (LOS) path, the proposed algorithm outperforms that of message passing (MP) and maximal ratio combining (MRC) algorithms at high SNRs. Furthermore, in the channel scenario without the LOS path, the proposed algorithm is close to MP and MRC algorithms.

In this paper we present a novel secure quantum turbo coded (QTC) superdense (SD) coding scheme. We have integrated SD with QTC to benefit from the inherent near optimum performance of turbo codes. We have further incorporated the quantum secure direct communication (QSDC) protocol within the proposed QTC-SD system for the sake of ensuring absolute security. Explicitly, the QSDC protocol exploits dummy entangled pairs for detecting the presence of eavesdropper. Hence, the proposed scheme ensures absolute security, detects the presence of an eavesdropper and considers practical issues when error is induced in a quantum depolarizing channel. Furthermore, we have experimentally determined the noise threshold levels for the proposed QTC-SD system to detect the presence of an eavesdropper.

In this contribution, the performance of a Distributed Self-Concatenated Convolutional Coding (DSECCC) scheme is analyzed by using Iterative Decoding (ID) for cooperative communications (CC) with the aid of relay selection (RS) and power allocation (PA). In the RS based DSECCC-ID scheme, where the transmit Signal to Noise power Ratio (SNR) is equal for both source and relay, we can achieve the minimum value of the required SNR at both destination and relay simultaneously by choosing a relay at an appropriate geographical location. By contrast, in the PA based DSECCC-ID scheme, where the position of the relay is in the middle, minimum required transmit SNRs are used both at the source and the relay. These schemes are analyzed with the help of binary Extrinsic Information Transfer (EXIT) charts. From our simulation results, we found that the RS based DSECCC-ID scheme outperforms the PA based DSECCC-ID scheme.

In this treatise, we investigate an inter-layer (IL) decoded self-concatenated coded system conceived for scalable video coding (SVC). In SVC, when the base layer (BL) is corrupted due to channel-induced decoding errors, the enhancement layers (ELs) are discarded by the SVC decoder. The proposed IL coding technique implants the systematic information of the BL into the systematic bits of the ELs using exclusive-OR (XOR) operations. The IL coding is combined with a self-concatenated code, which is a near-capacity iterative detection aided channel codec using a single encoder and a single decoder. At the receiver, the IL decoding technique is activated for correcting the errors residing in the error-infested BL. In our experiments, the proposed system is combined with a number of the traditional unequal error protection (UEP) arrangements for benchmarking the system performance. Our simulation results demonstrate that the proposed technique is capable of further improving the system performance of the traditional UEP assisted system by an Eb/N0of about 3 dB at a peak signal-to-noise ratio (PSNR) of 36 dB. When viewed from a different perspective, the attainable gain can be quantified as a PSNR improvement of 2.9 dB at Eb/N0= -5 dB, while imposing a marginal complexity increase of 1.5%.

Robust video transmission using iteratively detected Self-Concatenated Coding (SCC), multi-dimensional Sphere Packing (SP) modulation and Layered Steered Space-Time Coding (LSSTC) is proposed for H.264 coded video transmission over correlated Rayleigh fading channels. The self-concatenated convolutional coding (SECCC) scheme is composed of a Recursive Systematic Convolutional (RSC) code and an interleaver, which is used to randomise the extrinsic information exchanged between the self-concatenated constituent RSC codes. Additionally, a puncturer is employed for improving the achievable bandwidth efficiency. The convergence behaviour of the MIMO transceiver advocated is investigated with the aid of Extrinsic Information Transfer (EXIT) charts. The proposed system exhibits an $E_b/N_0$ gain of about $9~dB$ at the PSNR degradation point of $1~dB$ in comparison to the identical-rate benchmarker scheme.

In this paper, we consider coding schemes designed for two nodes communicating with each other with the aid of a relay node, which receives information from the two nodes in the first time slot. At the relay node we combine a powerful Superposition Coding (SPC) scheme with Iteratively-Decoded Self-Concatenated Convolutional Codes (SECCC-ID), which exchange mutual information between each other. It is assumed that decoding errors may be encountered at the relay node. The relay node then broadcasts this information in the second time slot after re-encoding it, again, using a SECCC encoder. At the destination, an amalgamated SPC-SECCC block then detects and decodes the signal either with or without the aid of a priori information. Our simulation results demonstrate that the proposed scheme is capable of reliably operating at a low BER for transmission over both AWGN and uncorrelated Rayleigh fading channels. We compare the proposed scheme's performance to a direct transmission link between the two sources having the same throughput. Additionally, the SPC-SECCC system achieves a low BER even for realistic error-infested relaying.

In this contribution we propose a robust H.264 coded wireless video transmission scheme using iteratively decoded self-concatenated convolutional coding (SECCC). The proposed SECCC scheme is composed of constituent recursive systematic convolutional (RSC) codes and an interleaver is used to randomise the extrinsic information exchanged between the constituent RSC codes. Additionally, a puncturer is used to increase the achievable bandwidth efficiency. At the receiver self-iterative decoding is invoked between the hypothetical decoder components. The performance of the system was evaluated using the H.264/AVC source codec for interactive video telephony. Furthermore, EXIT charts were utilised in order to analyse the convergence behaviour of the SECCC scheme advocated. We demonstrate the efficiency of this approach by showing that the video quality is significantly improved, when using the binary SECCC scheme. More explicitly, the proposed system exhibits an Eb/N0gain of 6 dB at the PSNR degradation point of 2 dB in comparison to the identical-rate benchmarker carrying out RSC coding and puncturing, while communicating over correlated Rayleigh fading channels.

In this paper 3-D Extrinsic Information Transfer (EXIT) charts are used to design binary Self-Concatenated Convolutional Codes employing Iterative Decoding (SECCC-ID), exchanging extrinsic information with the soft-decision demapper to approach the channel capacity. Recursive Systematic Convolutional (RSC) codes are selected as constituent codes, an interleaver is used for randomising the extrinsic information exchange of the constituent codes, while a puncturer helps to increase the achievable bandwidth efficiency. The convergence behaviour of the decoder is analysed with the aid of bit-based 3-D EXIT charts, for accurately calculating the operating EbN0threshold, especially when SP based soft demapper is employed. Finally, we propose an attractive system configuration, which is capable of operating within about 1 dB from the channel capacity.

The powerful tool of EXtrinsic Information Transfer (EXIT) charts is used to design a new serially concatenated Irregular Variable Length Coded (IrVLC) and unity-rate precoded Time-Hopping (TH) Pulse Position Modulation (PPM) aided Ultra-Wide Bandwidth (UWB) Spread-Spectrum (SS) impulse radio for near-capacity operation in Nakagami-m fading channels contaminated by Partial Band Noise Jamming (PBNJ). The benefits of the 3-stage concatenation of the TH-UWB detector, the unity-rate decoder and the outer IrVLC decoder are quantified. A number of novel Variable Length Coding (VLC) codebooks having different coding rates are utilized by the IrVLC scheme for encoding specific fractions of the input source symbol stream. More explicitly, EXIT charts are employed to appropriately select these input stream fractions to shape the inverted EXIT curve of the IrVLC in order to match that of the inner decoder and hence to achieve an infinitesimally low Bit Error Ratio (BER) at near-capacity SNR values.

In this contribution, we propose a distributed binary self-concatenated coding scheme using iterative decoding (DSECCC-ID) for cooperative communications. The DSECCC-ID scheme is designed with the aid of binary extrinsic information transfer (EXIT) charts. The source node transmits SECCC symbols to both the relay and the destination nodes during the first transmission period. The relay performs SECCC-ID decoding. It then re-encodes the information bits using a recursive systematic convolutional (RSC) code during the second transmission period. The resultant symbols transmitted from the source and relay nodes can be viewed as the coded symbols of a three-component parallel-concatenated SEC CC-ID encoder. At the destination node, three component DSECCC-ID decoding is performed. It is shown that the performance of the DSECCC-ID exactly matches the EXIT chart analysis. The EXIT chart gives us an insight into operation of the distributed coding scheme which enables us to significantly reduce the transmit power of the system.

Irregular Variable Length Coding Design for serial concatenated and iteratively decoded Time-Hopping (TH) Pulse Position Modulation (PPM) UltraWideBand (UWB) Spread-Spectrum (SS) Impulse radio system is considered. The proposed design is capable of low Signal-to-Noise Ratio (SNR) operation in Nakagami-m fading channel amalgamated with joint source and channel coding schemes. A number of component Variable Length Coding (VLC) codebooks with different coding rates are being utilized by IVLC scheme for encoding specific fractions of the input source symbol stream. The EXtrinsic Information Transfer (EXIT) charts are used to select these fractions in order to shape inverted EXIT curve of IVLC according to EXIT curve of the inner decoder match. The proposed scheme can achieve near-zero bit error ratio at low SNR values. This IVLC based scheme provides a gain of up to 0.45 dB over the identical-rate single class VLC based scheme.

A near-capacity time hopping (TH) pulse position modulation (PPM) based ultrawideband (UWB) impulse radio (IR) system is proposed, which invokes iteratively detected self-concatenated convolutional codes (SeCCC) and employs powerful design technique of extrinsic information transfer (EXIT) charts. Orthogonal prolate spheroidal wave function (OPSWF) based signalling pulse shapes are used for the sake of minimizing the multi-user interference (MUI) and intersymbol interference (ISI). Recursive systematic convolutional (RSC) codes are employed as constituent codes combined with an interleaver for randomising the extrinsic information exchange between the constituent codes. Furthermore, a puncturer assists us in increasing the achievable bandwidth efficiency. Iterative decoding is invoked for exchanging extrinsic information between the hypothetical decoder components at the receiver end. The convergence behaviour of the decoder is analysed with the aid of bit-based EXIT charts. Finally, we propose a novel THPPM-UWB-IR-SeCCC system configuration, which is capable of operating within about 0.9 dB of the information-theoretic limits.

In this contribution, the union bounds of self-concatenated convolutional codes (SECCCs) are derived for communications over both additive white Gaussian noise (AWGN) and uncorrelated Rayleigh fading channels. The truncated union bounds of SECCCs are very useful for studying the corresponding bit error ratio (BER) floors. Based on the truncated union bounds, various SECCCs can be designed for a desired BER floor without the need of time-consuming Monte Carlo simulations.

In this treatise extrinsic information transfer (EXIT) charts are used to design binary self-concatenated convolutional codes employing iterative decoding (SECCC-ID) for communicating over both uncorrelated Rayleigh fading and additive white Gaussian noise (AWGN) channels. Recursive Systematic Convolutional (RSC) codes are selected as constituent codes, an interleaver is used for randomising the extrinsic information exchange of the constituent codes, while a puncturer assists us in increasing the achievable bandwidth efficiency. At the receiver, self-iterative decoding is invoked for exchanging extrinsic information between the hypothetical decoder components. The convergence behaviour of the decoder is analysed with the aid of bit-based EXIT charts. Finally, we propose an attractive system configuration, which is capable of operating within about 1 dB of the information-theoretic limits.

In this contribution we design the Iteratively Decoded Self-Concatenated Convolutional Codes (SECCC-ID) using extrinsic information transfer (EXIT) charts. Good constituent Trellis Coded Modulation (TCM) codes are selected for communicating over both uncorrelated Rayleigh fading and Additive White Gaussian Noise (AWGN) channels. At the receiver iterative decoding is invoked for exchanging extrinsic information between the hypothetical decoder components. The convergence behaviour of the decoder is analysed with the aid of symbol-based EXIT charts. Similarly, the search for the best TCM constituent codes is also based on EXIT chart analysis. Finally, we demonstrate that the selected codes are capable of operating within 1 dB from the maximum achievable rate.