An efficient software implementation of a forward error correcting code

Error control coding improves reliability and efficiency of wireless communication systems. This research delves into the latest advancements in error control coding schemes for wireless communication systems, with a specific focus on their application within the domain of Low Power Wide Area Networks (LPWANs) such as Narrowband Internet of Things (NB-IoT) systems, LoRa energy-efficient hardware design, random access control systems, and wireless sensor networks. In the context of LPWANs, particularly NB-IoT systems, we investigate the adaptive coding and modulation (ACM) in NB-IoT systems, which adapts coding rates and modulation techniques to changing channel circumstances. Comprehensive analysis of the literature review shows that the proposed approaches are more energy efficient and less error-prone than fixed coding and modulation schemes. Using Cell Design Methodology (CDM), Single Error Correction (SEC) codes are optimized for energy efficiency. Power and energy efficiency have improved in standard CMOS and CDM logic systems. This impacts IoT devices, memory storage, and security systems. Next, Forward Error Correction (FEC) is examined for ALOHA-based random-access control systems wherein packet loss rate and spectral efficiency metrics are mathematically calculated. FEC is beneficial, especially when time and frequency synchronization diverge. Monte Carlo simulations studied in the literature shows that FEC improves satellite communication systems. This review establishes benefits of FEC, notably in satellite communications systems. In addition, Wireless Sensor Networks (WSNs) error control techniques and network reliability and performance are examined along with Convolutional, Turbo, Low density parity check codes(LDPC), and Polar error correction coding (ECC) methods. We learn about their benefits, drawbacks, and implementation challenges by assessing their efficacy, efficiency, and applicability in wireless sensor networks (WSN) applications. This study further highlights advancements of energy-efficient error control coding when, integrated into network designs alongwith the trade-offs between efficacy and intricacy to help improve wireless communication networks. Finally, this study summarizes current error control coding approaches for wireless communication systems. We provide insights into improving reliability, energy conservation, and efficacy by examining ACM, CDM, FEC, and error correction coding (ECC) across varied domains including LPWAN and IoT technologies with earnest hope to facilitate researchers, engineers, and professionals working in the field of error control coding in wireless communication.

Forward error correction (FEC) coding, modulation formats like differential phase shift keying (DPSK) and adaptive electronic equalization to mitigate, e.g. polarization mode dispersion (PMD) are some of the methods applied in current direct-detection optical communication systems, which are limited to a spectral efficiency of 1 bit/s/Hz. Coherent single-carrier QPSK systems with polarization multiplexing (PolMUX) allows to attain an spectral efficiency of up to 4 bit/s/Hz. However, to guarantee a bit error rate (BER) <; 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-15</sup> adaptive multiple-input multiple-output (MIMO) equalization as well as outer FEC coding has to be included which results in less than 4 bit/s/Hz in commercial 40 Gbit/s systems. From wireline and wireless systems it is well known that larger symbol alphabets in combination with FEC coding (denoted as coded modulation) and orthogonal frequency division multiplexing (OFDM) can significantly enhance the spectral efficiency. However, in order to exploit the channel capacity of the fiber the modulation itself needs to be capacity achieving. In this contribution we apply capacity achieving constellations in an optical OFDM system and jointly design mapping and low-density parity-check (LDPC) codes for an iterative decoding scheme, namely bit-interleaved coded modulation with iterative decoding (BICM-ID). The authors expect this coding scheme to be most appropriate for future optical transponders to utilize long haul communications close to channel capacity.

The preference improvement resulting from modifications to the original ARQ scheme proposed by E.J. Weldon (1982) for use in systems with finite-receiver buffers was analyzed in a previous paper. A modification involving the use of parity retransmission is studied. One drawback of using forward error correcting (FEC) codes is that the parity bits result in a degradation in efficiency under good channel conditions: the maximum throughput is limited to the FEC code rate. Two type II ARQ schemes which overcome this problem are studied. Lower bounds on the throughputs of the two schemes are obtained. The throughput of the type II ARQ scheme is no longer limited by one-half the rate of the FEC code used. Under good channel conditions, the throughput with the type II ARQ scheme is equivalent to not using FEC; as the channel degrades, it approaches the throughput with a rate one-half FEC code.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

We propose an explicit construction of full-diversity space-time block codes, under the constraint of an error correction capability. Furthermore, these codes are constructed in order to be suitable for a serial concatenation with an outer linear forward error correcting (FEC) code. We apply the binary rank criterion, and we use the threaded layering technique and an inner linear FEC code to define a space-time error-correcting code. When serially concatenated with an outer linear FEC code, a product code can be built at the receiver, and adapted iterative receiver structures can be applied. An optimized hybrid structure mixing MMSE turbo equalization and turbo product code decoding is proposed. It yields reduced complexity and enhanced performance compared to previous existing structures.

This document generally describes how to use Forward Error Correction (FEC) codes to efficiently provide and/or augment reliability for data transport. primary focus of this document is the application of FEC codes to one-to-many reliable data transport using IP multicast. This document describes what information is needed to identify a specific FEC code, what information needs to be communicated out-of-band to use the FEC code, and what information is needed in data packets to identify the encoding symbols they carry. procedures for specifying FEC codes and registering them with the Internet Assigned Numbers Authority (IANA) are also described. This document should be read in conjunction with and uses the terminology of the companion document titled, The Use of Forward Error Correction (FEC) in Reliable Multicast.

Thanks to the large buffering time of off-line streaming applications, erasure resilient forward error correction (FEC) codes can improve the reliability of communication particularly well. However real-time streaming puts hard restrictions on the buffer size making FEC inefficient for combating long link failures on single path routes. Path diversity is orthogonal to buffering and permits real-time streaming to also benefit from application of FEC. We introduce a capillary routing algorithm offering layer by layer a wide range of multi-path routing topologies starting from a simple solution and evolving toward reliable routing patterns with highly developed path diversity. The friendliness of a multi-path routing pattern is rated by the overall amount of FEC redundancy required for combating the non-simultaneous failures of all links of the communication footprint. We rated the friendliness of a dozen of capillary routing layers, built on several hundreds of network samples obtained from a random walk mobile ad-hoc network (MANET). The overall requirement in redundant FEC codes decreases substantially as the spreading of the routing grows

Chapter 17 - Error-Control Coding Techniques and Applications

In this work we present a complete set of techniques devoted to offer robustness against frame losses in distributed speech recognition over packet-switched networks. The proposed scheme is composed of tree techniques, two of them are applied at the sender and the last one in the recognizer itself. On one hand, a media-specific forward error correction (FEC) technique is used to allow the recovery of information within the bursts. On the other hand, a recognizer-based technique well known by its remarkable ability to reduce the effects of long consecutive frame losses during recognition, the weighted Viterbi algorithm (WVA), is used to handle the additional information introduced by FEC codes. Moreover, a double stream strategy whereby interleaving can be applied along with FEC codes without any delay increase, is also applied. The application of interleaving allows to reduce the perceived burst length at the receiver, further improving the recognition performance. As a result, the proposed scheme can provide an acceptable performance even under extremely adverse channel conditions.

Forward error correction (FEC) allows the receiver to correct erasure without asking retransmission. This advantage is significant for several applications where retransmission is not available or desirable. In recent years, applying FEC codes to peer-to-peer data distribution networks is an innovation. In this way, the downloader can efficiently reconstruct the data from the encoding symbols multicasted from multiple distributors. However, FEC codes suffer from pollution attacks where the attackers corrupt some encoding symbols such that the data can not correctly be reconstructed. Although Krohn et al. propose a homomorphic hash based verification scheme, the scheme is specifically designed for Fountain codes and the variants. That is, the scheme can not apply to other FEC codes and suffers from another specific attacks, distribution attacks. Thus, in this paper we propose a new verification scheme for polynomial based FEC codes like Vandermonde codes. The scheme can defend against not only pollution attacks but distribution attacks. The analysis also shows the security and feasibility of the proposed scheme.

Complex position code parallel combinatory spread spectrum (CPC/PC/SS) communication system with forward error correction (FEC) coding scheme is proposed in this paper, and performances are analyzed. CPC/PC/SS system with FEC coding scheme can be designed to have higher data transmission capability, even several times compared to ordinary PC/SS system on Gaussian channel.The proposed FEC coding is separately applied to the combination data of orthogonal codes and the state data of their transmitting orthogonal code, and less redundant FEC code is enough to the state data of orthogonal codes by this coding scheme. Therefore, the total information rate exceeds that offered by the conventional overall FEC coding is applied. Simulation results show that the error rate performance of the CPC/PC/SS systems equipped with the proposed FEC coding is lower than conventional PC/SS system.

This paper investigates the transmission of H.264 /AVC video in the 3GPP Multimedia Broadcast/Multicast Streaming service (MBMS). Application-layer forward error correction (FEC) codes are used to combat transmission errors in the radio access network. In this FEC protection scheme, the media RTP stream is organized into source blocks spanning many RTP packets, over which FEC repair packets are generated. This paper proposes a novel method for unequal error protection that is applicable in MBMS. The method reduces the expected tune-in delay when a new user joins into a broadcast. It is based on four steps. First, temporally scalable H.264 /AVC streams are coded including reference and non-reference pictures or sub-sequences. Second, the constituent pictures of a group of pictures (GOP) are grouped according to their temporal scalability layer. Third, the interleaved packetization mode of RFC3984 is used to transmit the groups in ascending order of relevance for decoding. As an example, the non-reference pictures of a GOP are sent earlier than the reference pictures of the GOP. Fourth, each group is considered a source block for FEC coding and the strength of the FEC is selected according to its importance. Simulations show that the proposed method improves the quality of the received video stream and decreases the expected tune-in delay.

The growing demands on high-speed data transmission over long distances require optimized communication systems with bandwidth efficient modulation techniques like Quadrature Amplitude Modulation (QAM). However, the various design parameters of these QAM based systems conflict each other and the complex interdependence makes it difficult and time consuming to appropriately tune the parameters towards an optimal solution for a given set of constraints. Therefore, throughout this paper we analyze various conflicting design parameters of QAM and derive objective optimized trade-offs. More specifically, we study in detail the effects and interdependencies of parameters in the matched filter, the Forward Error Correction (FEC) code pair and the modulation order and span the design and solution space through experimental and numerical results. We discuss the observed effects and show how a selection of parameters can be concluded under various constraints. Furthermore, a pareto optimality search on our design space points out the best combinations of modulation order, filter and FEC design parameters for maximizing the performance under various Signal-to-Noise Ratio (SNR) conditions of the channel. For instance, if the channel is constrained by a SNR of 10dB and the tolerable Bit Error Rate (BER) is 10−3, then 16-QAM with a required 2/3 FEC yields 33.3% higher performance than 64-QAM with a required 1/3 FEC. Thus, the outcomes of this paper are a comprehensive elaboration on the cross-effects of conflicting design parameters and a set of optimized solutions under various constraints.

The area of digital communications has undergone a significant transformation in the last twenty years due mostly to the discovery of iterative forward error correction (FEC) codes (such as turbo codes) and iterative demodulation techniques (such as turbo equalization). Waveforms developed for the High Frequency (HF) band typically place an interleaver between the FEC scheme and the transmitted symbols. The purpose of this interleaver is to decorrelate the errors caused by slow fading multipath channels encountered on HF. If no interleaver is used, most standard EEC schemes become ineffective (e.g. convolutional codes). Although HF waveforms were not designed with the notion of iterative demodulation techniques in mind, it turns out that these techniques can be applied to single-carrier HF waveforms which utilize FEC and interleaving by iteratively exchanging soft information between the equalizer and the FEC decoder. This paper will investigate the benefits of applying iterative demodulation techniques to the 3200 and 9600 bit per second waveforms defined in STANAG 4539 as a function of the Doppler spread and multipath spread encountered on HF channels.

Severe energy constraints and hence the low power communication requirements amplify the significance of the energy efficient and preferably cross-layer error control mechanisms in wireless sensor networks (WSN). In this paper, a cross-layer methodology for the analysis of error control schemes in WSNs is presented such that the effects of multi-hop routing and the broadcast nature of the wireless channel are investigated. More specifically, the cross-layer effects of routing, medium access and physical layers are considered. This analysis enables a comprehensive comparison of forward error correction (FEC) and automatic repeat request (ARQ) in WSNs. FEC schemes improve the error resiliency compared to ARQ. In a multi-hop network, this improvement can be exploited by reducing the transmit power (transmit power control) or by constructing longer hops (hop length extension), which can be achieved through channel-aware routing protocols. The results of our analysis reveal that for certain FEC codes, the hop length extension decreases both the energy consumption and the end-to-end latency subject to a target PER compared to ARQ. Thus, FEC codes can be regarded as an important candidate for delay sensitive traffic in WSNs. On the other hand, transmit power control results in significant savings in energy consumption at the cost of increased latency. Moreover, the cases where ARQ outperforms FEC codes are indicated for various end-to-end distance and target PER values

In this paper, we consider a broadcast application for mobile terminals where the access points are connected to the source via a fixed network. Random Linear Network (RLN) coding is used in the fixed network to maximize its transmission rate and a wireless connection is used between the access points and the terminal. In order to reduce variations in the transmission delay and offer more flexibility to the terminal, we perform the network decoding in the terminal. We investigate the error correction capability of RLN coding using the ordered statistics decoding (OSD) algorithm. Taking into account the forward error correcting (FEC) code used on the wireless link, a product code is built by combining the FEC code and the RLN code and turbo decoded in the terminal. The proposed scheme efficiency is analyzed through its simulated and theoretical performance under additive white Gaussian noise (AWGN) and non frequency-selective block Rayleigh fading channels.