Spinal Codes Research Articles

Spinal code based on lightweight hash function

Spinal code based on lightweight hash function

Tight Upper Bounds on the BLER of Spinal codes over the AWGN Channel

Tight Upper Bounds on the BLER of Spinal codes over the AWGN Channel

Low Complexity Encoding Design for Fiber Optic Measurement While Drilling Communication System Based on Superposition Spinal Codes

Low Complexity Encoding Design for Fiber Optic Measurement While Drilling Communication System Based on Superposition Spinal Codes

Analysis and Optimization of the HARQ-Based Spinal Coded Timely Status Update System

The age of information (AoI) is a new metric to measure the timeliness of various status update systems, and hybrid automatic repeat request (HARQ) transmission scheme is usually applied to ensure higher timeliness. However, little research considers encoding delay, propagation delay, decoding delay and feedback delay in the HARQ-based coded status update system. To the best of our knowledge, in this paper, the HARQ-based Spinal coded timely status update system with all the practical delay elements is considered for the first time. We derive the average AoI expression of the system and analyze the monotony of the AoI expression to give an average AoI upper bound. Then we optimize the HARQ transmission scheme to minimize the AoI. To decrease the complexity of the optimization algorithm, we separate it into two steps. First, we optimize the puncturing pattern of Spinal codes and propose a transmission scheme under incremental tail transmission puncturing (ITTP) pattern. Second, we optimize the number of symbols in each round under the ITTP transmission scheme, and propose the optimal transmission scheme under the coarse-grained ITTP pattern. Simulation results show that the proposed transmission scheme can significantly decrease the AoI compared to the baseline transmission schemes.

Improved encoding structure and decoding algorithms for spinal codes

To improve the error correction performance, an innovative encoding structure with tail-biting for spinal codes is designed. Furthermore, an adaptive forward stack decoding (A-FSD) algorithm with lower complexity for spinal codes is proposed. In the A-FSD algorithm, a flexible threshold parameter is set by a variable channel state to narrow the scale of nodes accessed. On this basis, a new decoding method of AFSD with early termination (AFSD-ET) is further proposed. The AFSD-ET decoder not only has the ability of dynamically modifying the number of stored nodes, but also adopts the early termination criterion to curtail complexity. The complexity and related parameters are verified through a series of simulations. The simulation results show that the proposed spinal codes with tail-biting and the AFSD-ET decoding algorithms can reduce the complexity and improve the decoding rate without sacrificing correct decoding performance.

Partial Self-Concatenation Structure and Performance Analysis of Spinal Codes Over Rayleigh Fading Channel

Spinal codes are a new family of rateless codes which have been proved to be capacity-achieving over both the additive white Gaussian noise (AWGN) channel and the binary symmetric channel (BSC). However, over the Rayleigh fading channel between the vehicle nodes, the error performance of Spinal codes is not satisfactory since the tail message blocks of Spinal codes are prone to error. To solve this issue, this paper proposes a new practical partial self-concatenation coding structure of Spinal codes, named <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$N$</tex-math></inline-formula> tail-protected Spinal codes, to pointedly protect tail message blocks of Spinal codes over the flat Rayleigh fading channel. Theoretical performance analysis and simulation results are also provided to validate and verify the effectiveness of the proposed <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$N$</tex-math></inline-formula> tail-protected Spinal codes.

Polar-UEP spinal concatenated encoding in free-space optical communication.

Aiming at the poor bit error rate (BER) performance of spinal code in free-space optical communication, a polar-UEP (unequal error protection) spinal concatenated coding scheme for free-space optical communication is proposed. This work combines the unequal error protection characteristics of spinal codes and the construction characteristics of polar codes, using bit sorting and interleaving, to give the best protection of the polar code's information bits, and the bits that are prone to error. Simulation results show that the bit error rate performance of the more important bits and the less important bits of the polar-UEP spinal concatenated code is better than that of the spinal code. When the turbulence intensity is 0.1, compared with the fixed rate coding scheme such as the polar code, the concatenated code generates 0.7 dB-1.2 dB gain at a BER of 10-4. Besides, its BER under different turbulence intensity is lower than that of the spinal code and polar code, and this provides a solution for the efficient application of the spinal code in free-space optical communication.

Spinal Codes Over Fading Channel: Error Probability Analysis and Encoding Structure Improvement

In order to facilitate the reliability of data transmission of Spinal codes over the fading channel, performance analysis of Spinal codes is conducted, and an improved encoding structure is proposed. First, we derive an approximate frame error rate (FER) upper bound for Spinal codes over the Rayleigh fading channel in the finite block length (FBL) regime. Then, inspired by the FER analysis process, we propose an improved encoding structure, named self-concatenation structure, to reduce the FER of Spinal codes. In addition, a parallel structure is proposed for Spinal codes to improve the decoding throughput. For the self-concatenation structure, simulation results show that it exhibits a significant gain in anti-noise performance compared with the original Spinal codes over the Rayleigh fading channel. For the parallel structure, we find that by combining the parallel structure with the self-concatenation structure, not only is the encoding and decoding throughput of Spinal codes significantly improved but also the FER of Spinal codes is reduced.

Autoencoder-Based Unequal Error Protection Codes

We present a novel autoencoder-based approach for designing codes that provide unequal error protection (UEP) capabilities. The proposed approach, based on a generalization of an autoencoder loss function, provides a versatile framework for the design of message-wise and bit-wise UEP codes. Using an associated weight vector, the generalized loss function can be used to trade off error probabilities corresponding to different importance classes and to explore the region of achievable error probabilities. For message-wise UEP, we compare the proposed autoencoder-based UEP codes with a union of random coset codes. For bit-wise UEP, the proposed codes are compared with UEP rateless spinal codes and the superposition of random Gaussian codes. In all cases, the autoencoder-based codes show superior performance while providing design simplicity and flexibility in trading off error protection among different importance classes.

Multi-source spinal coding for coded caching multicast transmissions in wireless networks

Recently, coded caching has been treated as a promising technique to alleviate the traffic burden in wireless networks. To support high efficient coded caching multicast transmissions, the time-varying heterogeneous channel conditions need to be considered. In this paper, a practical and novel multi-source spinal coding (MSSC) scheme is developed for coded caching multicast transmissions under heterogeneous channel conditions. By exploring joint design of network coding and spinal coding (SC), MSSC can achieve unequal link rates in multicast transmissions for different users. Moreover, by leveraging the rate-less feature of SC in our design, MSSC can well adapt the link rates of all users in multicast transmissions without any feedback of time-varying channel conditions. A maximum likelihood (ML) based decoding process for MSSC is also developed, which can achieve a linear complexity with respect to the user number in the multicast transmission. Simulation results validate the effectiveness of the MSSC scheme. Compared to the existing scheme, the sum rate of MSSC in multicast transmissions is improved by about 20%. When applying MSSC in coded caching systems, the total transmission time can be reduced by up to 48% for time-varying channels.

Design of segmented CRC‐aided spinal codes for IoT applications

Rateless spinal codes can achieve reliable transmission with high throughput performance, which is required by some power-constrained applications, such as internet of things (IoT). In this study, the cyclic redundancy check (CRC) is divided into segments. We design the segmented CRC-aided (SCA) spinal codes and propose a novel hybrid decoding algorithm. The decoder can terminate the decoding process earlier when an error decoding is detected in any segment. Moreover, a more targeted symbol transmission strategy after decoding errors occur is provided and we call it as the transmitting redundant symbols for specific segments (RSSS) strategy. The RSSS strategy saves the transmitting symbols by transmitting a variable number of symbols, thus improving the throughput of the system. Furthermore, we design a new tail-biting structure for SCA-spinal codes to compensate for the disadvantage of poor error detection ability for short segment CRC bits. The simulation results show that the proposed SCA-spinal codes can reduce the decoding complexity and improve the throughput of the system. The transmission delay can also be reduced by dividing the information bits and CRC bits into an appropriate number of segments.

Novel reconciliation protocol based on spinal code for continuous-variable quantum key distribution

Reconciliation is a crucial procedure in post-processing of continuous-variable quantum key distribution (CV-QKD) system, which is used to make two distant legitimate parties share identical corrected keys. The adaptive reconciliation is necessary for practical systems to cope with the variable channel. Many researchers adopt fixed-rate error correction codes to implement adaptive reconciliation, such as the punctured LDPC code; however such protocol can achieve high efficiency only in a small range of signal-to-noise ratios (SNRs). In this paper, the spinal-based rateless reconciliation protocol for CV-QKD is first proposed. The proposed adaptive reconciliation protocol can achieve high efficiency in a much larger range of SNRs. Because the protocol we propose uses the code with short length and simple encoding/decoding structure, the design and implementation complexities of our protocol are greatly decreased. Meanwhile, its parallel attribute makes it suitable for hardware implementation, which means it has the potential of achieving high-throughput reconciliation. Moreover, the security of proposed protocol is investigated and proved. Experimental results show that the reconciliation efficiency of the spinal-based protocol maintains around $$95\%$$ in a larger SNR range (0,0.5), and even exceeds $$96.5\%$$ at extremely low SNR ( $$\le 0.032$$ ) with quite low frame error rate (FER) ( $$\le 5.2\%$$ ). Both the theoretical analysis and experimental results demonstrate that the proposed adaptive reconciliation protocol is a suitable candidate for the long-distance CV-QKD systems.

An Adaptive and Flexible Brain Energized Full Body Exoskeleton With IoT Edge for Assisting the Paralyzed Patients

The paralyzed population is increasing worldwide due to stroke, spinal code injury, post-polio, and other related diseases. Different assistive technologies are used to improve the physical and mental health of the affected patients. Exoskeletons have emerged as one of the most promising technology to provide movement and rehabilitation for the paralyzed. But exoskeletons are limited by the constraints of weight, flexibility, and adaptability. To resolve these issues, we propose an adaptive and flexible Brain Energized Full Body Exoskeleton (BFBE) for assisting the paralyzed people. This paper describes the design, control, and testing of BFBE with 15 degrees of freedom (DoF) for assisting the users in their daily activities. The flexibility is incorporated into the system by a modular design approach. The brain signals captured by the Electroencephalogram (EEG) sensors are used for controlling the movements of BFBE. The processing happens at the edge, reducing delay in decision making and the system is further integrated with an IoT module that helps to send an alert message to multiple caregivers in case of an emergency. The potential energy harvesting is used in the system to solve the power issues related to the exoskeleton. The stability in the gait cycle is ensured by using adaptive sensory feedback. The system validation is done by using six natural movements on ten different paralyzed persons. The system recognizes human intensions with an accuracy of 85%. The result shows that BFBE can be an efficient method for providing assistance and rehabilitation for paralyzed patients.

Compressive Spinal Codes

It is well known that spinal codes can essentially approach channel capacity for equiprobable source, and achieve seamless rate adaptation at the same time. But how to design an optimal spinal codes for non-equiprobable source is still an open problem. This paper proposes a novel Sparse Spinal (S-Spinal) codes design, which can essentially approach channel capacity for non-equiprobable and compressible source, and its seamless rate adaptation is also preserved. The main idea is to utilize source distribution information at the spinal decoder. The sparser the source is, the less symbols the receiver needs. The rateless feature of spinal codes can provide fine-grain compression ratio. The different decoder designs for Binary Symmetrical Channel (BSC) and Additive White Gaussian Noise (AWGN) channel are proposed, since their priori information is different. We also analyze and prove the S-Spinal codes with a practical pruning decoder can essentially achieve the channel capacity. The experimental results show that the proposed S-Spinal is very close to channel capacity of both BSC and AWGN channel for non-equiprobable source, and can achieve seamless rate adaption in practical system.

Websites Designed for Students with Special Needs

According to Friedman & Bryen, (2007), a person with a disability is one with a long-term physical, intellectual, mental or sensory impairment, which interferes with their social equality in relation to others. Disability, thus, varies widely across countries. Borg, Berman-Bieler, & Khasnabis (2015), indicated that by 2004, about 93 million children aged 14-years and below, suffered from moderate to severe disabilities. Examples of common disabilities include hearing loss, down syndrome, cerebral palsy, brain injury, intellectual and learning disability, congenital anomalies, muscular dystrophy, blindness, spinal code injuries, visual loss and speech impairments (Borg, Berman-Bieler, & Khasnabis, 2015) Assistive technology has become a common term in discussions regarding children with disabilities. This term includes technology, which assists disabled persons to carry out their activities or to facilitate their activities. They include technologies used to facilitate mobility, vision, hearing, communication and cognition. This paper will explore how web designs can be used to assist in the learning process. One such common disability is that of dyslexia, which is a medical condition that makes it difficult for students to read and learn and which lends itself well to assistive technologies (HKSAR, 2008). It is estimated that one in every 10 people have dyslexia (HKSAR, 2008). The condition exists across a range of cultures, abilities and conditions and is usually gene related and thus, runs in the family. While it cannot be cured, there are practical approaches that can help overcome the barriers presented by the condition. Dyslexia can be termed as a learning difference meaning that the brain approaches tasks differently to other people and affects the way people communicate (HKSAR, 2008). Since dyslexia does not affect the individual’s intelligence, it can be managed by using a different communication model in the learning process (Friedman & Bryen, 2007). Assistive technology such as the use of specialized websites can, therefore, be used to assist children with dyslexia. Keywords: Dyslexia, Cognitive Disability, Technology, Accessibility, and Autism. DOI : 10.7176/JEP/10-30-14 Publication date :October 31 st 2019

Design and Analysis of a Low-Complexity Decoding Algorithm for Spinal Codes

In order to facilitate reliable and efficient data transmission in time-varying environments, a block dynamic decoding algorithm for spinal codes is proposed in this paper. First, the code tree is divided into several decoding units to scatter the decoding complexity. According to the results of the last decoding, the decoder will modify the scope of nodes accessed with dynamic parameters, which improves the execution efficiency of the algorithm. Furthermore, the complexity and related parameters of the algorithm are analyzed and verified by some simulations. The results show that the proposed algorithm has the ability to enhance the bandwidth efficiency (or rate ) performance, and to reduce both complexity and frame error rate.

Rateless Polar-Spinal Coding Scheme With Enhanced Information Unequal Error Protection

In this paper, a rateless coding scheme with enhanced unequal error protection (UEP) property is proposed by concatenating the systematic polar code (SPC) and spinal code, where SPC is used as the outer code and spinal code is the inner code. The novel concatenated polar-spinal coding scheme is designed to provide an improved UEP for the information with different reliability requirements. At the receiver, a tail CRC-aided Bubble decoding is proposed to improve the performance of spinal codes effectively. Moreover, the rateless transmission control is designed carefully for the time-varying channels. The total complexity of joint concatenated decoding process is reduced. Simulation and analysis verify that the novel rateless polar-spinal coding scheme can provide better UEP performance for the information of each importance level in contrast to some existing UEP rateless coding schemes.

Q-Learning-Based Spinal Code Transmission Strategy in Long Distance FSO Communication

In this paper, a spinal code transmission strategy based on Q-learning algorithm is proposed for long distance free space optical communication. The strategy adopts the Q-learning algorithm with the main objective of reducing the retransmission times to optimize the decoding waiting time and improve the transmission efficiency. The simulation results illustrate that, under the same turbulent conditions, the average retransmission times of the proposed transmission strategy is maintained at about one time, which is 94-99% less than the traditional spinal code transmission strategy and 78-92% less than the linear transmission strategy. Thus effectively improves the transmission efficiency of long-distance optical communication.

Origin and classification of spontaneous discharges in mouse superficial dorsal horn neurons

Superficial laminae of the spinal cord possess a considerable number of neurons with spontaneous activity as reported in vivo and in vitro preparations of several species. Such neurons may play a role in the development of the nociceptive system and/or in the spinal coding of somatosensory signals. We have used electrophysiological techniques in a horizontal spinal cord slice preparation from adult mice to investigate how this activity is generated and what are the main patterns of activity that can be found. The results show the existence of neurons that fire regularly and irregularly. Within each of these main types, it was possible to distinguish patterns of spontaneous activity formed by single action potentials and different types of bursts according to intra-burst firing frequency. Activity in neurons with irregular patterns was blocked by a mixture of antagonists of the main neurotransmitter receptors present in the cord. Approximately 82% of neurons with a regular firing pattern were insensitive to synaptic antagonists but their activity was inhibited by specific ion channel blockers. It is suggested that these neurons generate endogenous activity due to the functional expression of hyperpolarisation-activated and persistent sodium currents driving the activity of irregular neurons.

Research and Implementation of Rateless Spinal Codes Based Massive MIMO System

The potential performance gains promised by massive multi‐input and multioutput (MIMO) rely heavily on the access to accurate channel state information (CSI), which is difficult to obtain in practice when channel coherence time is short and the number of mobile users is huge. To make the system with imperfect CSI perform well, we propose a rateless codes‐aided massive MIMO scheme, with the aim of approaching the maximum achievable rate (MAR) as well as improving the achieved rate over that based on the fixed‐rate codes. More explicitly, a recently proposed family of rateless codes, called spinal codes, are applied to massive MIMO systems, where the spinal codes bring the benefit of approximately achieving the MAR with sufficiently large encoding block size. In addition, the multilevel puncturing and dynamic block‐size allocation (MPDBA) scheme is proposed, where the block sizes are determined by user MAR to curb the average retransmission delay for successfully decoding the messages, which further enhances the system retransmission efficiency. Multilevel puncturing, which is MAR dependent, narrows the gap between the system MAR and the related achieved rate. Theoretical analysis is provided to demonstrate that spinal codes with the MPDBA can guarantee the system retransmission efficiency as well as achieved rate, which are also verified by numerical simulations. Finally, a simplified but comparable MIMO testbed with 2 transmit antennas and 2 single‐antenna users, based on NI Universal Software Radio Peripheral (USRP) and LabVIEW communication toolkits, is built up to demonstrate the effectiveness of our proposal in realistic wireless channels, which is easy to be extended to massive MIMO scenarios in future.