Implementation of an Error-Coding Scheme for Teleradiology System

2011 ◽  
pp. 1131-1143
Author(s):  
Shobha Rekh ◽  
Subha Rani ◽  
Hepzibah Christinal ◽  
Easter Selvan
Keyword(s):  
Turbo Codes ◽  
Communication Systems ◽  
Turbo Code ◽  
Wireless Channel ◽  
Mobile Environment ◽  
Coding Scheme ◽  
Coding Schemes ◽  
Error Coding ◽  
Teleradiology System ◽  
Proper Design

Teleradiology, sending of x-rays, is the most common application of telemedicine in use today. Mobile telemedicine is the latest area of research where the patient can be monitored remotely by a doctor. In this paper, we propose a teleradiology system whereby the communication is established via cellular networks and cell phones. Since the data is sent over a wireless channel, it is more prone to data loss due to the mobile environment. To prevent data from getting lost due to noise in the wireless channel, an error-coding scheme is applied. Turbo code is a powerful error coding technique employed nowadays in communication systems. In this paper we apply turbo codes to an x-ray image and an ECG image and simulate the transmission system by adding Gaussian noise to the image. The performance of Turbo codes, in terms of bit error rate is better than other error coding schemes even in the region where the signal strength is very low. The Quality of the image is retained in the receiving end by proper design of the error-coding scheme. An analysis has been done on various parameters considered in the design of turbo codes. The images obtained after decoding are found to be suitable for recognition and diagnosis by the doctors in their mobile phones. This novel technology will enhance the health care in rural area where the opinion of a specialized doctor is not available.

Implementation of an Error-Coding Scheme for Teleradiology System

2006 ◽  
Vol 1 (4) ◽  
pp. 15-28
Author(s):  
Shobha Rekh ◽  
Subha Rani ◽  
Hepzibah Christinal ◽  
Easter Selvan
Keyword(s):  
Coding Scheme ◽  
Error Coding ◽  
Teleradiology System

scholarly journals Introducing perforation when applying turbo codes

2021 ◽  
Vol 2094 (3) ◽  
pp. 032061
Author(s):  
A A Sidorenko
Keyword(s):  
Data Transmission ◽  
Turbo Codes ◽  
Communication Systems ◽  
Digital Communication ◽  
Turbo Code ◽  
Code Sequence ◽  
Transmission Channel ◽  
Comparison Results ◽  
Decoding Efficiency ◽  
Digital Communication Systems

Abstract The problem of adapting the degree of redundancy introduced in the process of error-correcting coding to the changing characteristics of the data transmission channel is urgent. Turbo codes, used in a variety of digital communication systems, are capable of correcting multiple errors occurring in the data transmission channel. The article compares the decoding efficiency for various options for introducing perforation into the code sequence generated by the turbo code encoder. Based on the comparison results, recommendations were made on the most appropriate option for the introduction of perforation.

Digital Communications and a Smart World

2019 ◽  
pp. 136-163
Author(s):  
Hua Zhong
Keyword(s):  
Turbo Codes ◽  
Iterative Decoding ◽  
Communication Systems ◽  
Information Transfer ◽  
Turbo Code ◽  
Digital Communications ◽  
Substantial Reduction ◽  
International Standards ◽  
Extrinsic Information ◽  
Likelihood Ratios

This chapter is devoted to digital communications in a smart world. The author examines turbo codes that are currently introduced in many international standards and implemented in numerous advanced communication systems, applied in a smart world, and evaluate the process of extrinsic information transfer (EXIT). The convergence properties of the iterative decoding process, associated with a given turbo-coding scheme, are estimated using the analysis technique based on so-called EXIT charts. This approach provides a possibility to predict the bit-error rate (BER) of a turbo code system with only the extrinsic information transfer chart. The idea is to consider the associated soft-input soft-output (SISO) stages as information processors, which map input a priori log likelihood ratios (LLRs) onto output extrinsic LLRs. Compared with other methods, the suggested approach provides insight into the iterative behavior of linear turbo systems with substantial reduction in numerical complexity.

scholarly journals Improving the performance of BICM-ID and MLC systems with different FEC codes

2013 ◽  
Vol 11 ◽  
pp. 87-93 ◽  
Author(s):  
T. Arafa ◽  
W. Sauer-Greff ◽  
R. Urbansky
Keyword(s):  
Turbo Codes ◽  
Channel Coding ◽  
Communication Systems ◽  
Forward Error Correction ◽  
Convolutional Codes ◽  
Coded Modulation ◽  
Modulation Formats ◽  
Coding Schemes ◽  
Multilevel Modulation ◽  
Exit Charts

Abstract. In bandwidth limited communication systems, the high data rate transmission with performance close to capacity limits is achieved by applying multilevel modulation schemes in association with powerful forward error correction (FEC) coding, i.e. coded modulation systems. The most important practical approaches to coded modulation systems are multilevel coding with multistage decoding (MLC/MSD) and bit interleaved coded modulation with iterative demapping and decoding (BICM-ID). Multilevel modulation formats such as M-QAM, which can be used as a part of coded modulation systems, have the capability of multilevel protection. Based on this fact, we investigate the methods to improve the performance of BICM-ID using multiple interleavers with different binary channel coding schemes such as convolutional codes, turbo codes and low-density parity-check (LDPC) codes. Moreover, an MLC system with parallel decoding on levels (PDL) at the receiver is considered. In our contribution, we propose to design the individual coding schemes using the extrinsic information transfer (EXIT) charts for individual bit levels in the constellation. Our simulation results show that the BICM-ID systems, taking into account different bit-level protections, can provide an improvement of 0.65 dB, 1.2 dB and 1.5 dB for 256-QAM with turbo, LDPC and convolutional codes, respectively. On the other hand, MLC systems with PDL designed using EXIT charts for individual bit levels can slightly improve the performance and eliminate the error floor compared to the systems with MSD.

scholarly journals A Parallel Turbo Decoder Based on Recurrent Neural Network

2021 ◽  
Author(s):  
Li Zhang ◽  
weihong fu ◽  
Fan Shi ◽  
Chunhua Zhou ◽  
Yongyuan Liu
Keyword(s):  
Neural Network ◽  
Turbo Codes ◽  
Communication Systems ◽  
Turbo Code ◽  
Error Rates ◽  
Learning Ability ◽  
Turbo Decoder ◽  
Lstm Network ◽  
T Distribution ◽  
Decoding Delay

Abstract A neural network-based decoder, based on a long short-term memory (LSTM) network, is proposed to solve the problem of high decoding delay caused by the poor parallelism of existing decoding algorithms for turbo codes. The powerful parallel computing and feature learning ability of neural networks can reduce the decoding delay of turbo codes and bit error rates simultaneously. The proposed decoder refers to a unique component coding concept of turbo codes. First, each component decoder is designed based on an LSTM network. Next, each layer of the component decoder is trained, and the trained weights are loaded into the turbo code decoding neural network as initialization parameters. Then, the turbo code decoding network is trained end-to-end. Finally, a complete turbo decoder is realized. Simulation results show that the performance of the proposed decoder is improved by 0.5–1.5 dB compared with the traditional serial decoding algorithm in Gaussian white noise and t-distribution noise. Furthermore, the results demonstrate that the proposed decoder can be used in communication systems with various turbo codes and that it solves the problem of high delay in serial iterative decoding.

scholarly journals Performance analysis of highly improved hybrid turbo codes for 4G wireless networks

2019 ◽  
Vol 8 (4) ◽  
pp. 398
Author(s):  
M. Jose Raj ◽  
Dr. Sharmini Enoch
Keyword(s):  
Wireless Networks ◽  
Turbo Codes ◽  
Communication Systems ◽  
Turbo Code ◽  
Error Correcting Code ◽  
Low Complexity ◽  
Error Correcting Codes ◽  
4G Wireless ◽  
Low Complex ◽  
Digital Communication Systems

Efficient error correcting codes are essential in modern digital communication systems. Highly Improved Hybrid Turbo Code (HIHTC) is a low complex error and efficient error correcting code with excellentBit Error Rate (BER) which is comparable to Low Complexity Hybrid Turbo Codes (LCHTC), Improved Low Complexity Hybrid Turbo Codes (ILCHTC) and other Hybrid Turbo Codes. Rate 1/3 HIHTC shows a BER of 10-5 for E b/No of 1.7 dB which is closer to the E b/No of Improved Low Complexity Hybrid Turbo Codes. In this paper we analyze the performance of HIHTC in comparison with otherLow Complexity Hybrid Turbo Codes, for their performance in 4G and 5G wireless networks  

scholarly journals Turbo Codes Performance Optimization over Block Fading Channels

2017 ◽  
Vol 2 (3) ◽  
pp. 228
Author(s):  
Fulvio Babich ◽  
Guido Montorsi ◽  
Francesca Vatta
Keyword(s):  
Fading Channels ◽  
Mobile Communications ◽  
Turbo Codes ◽  
Performance Optimization ◽  
Fading Channel ◽  
Communication Systems ◽  
Channel Model ◽  
Turbo Code ◽  
Convolutional Codes ◽  
Block Fading Channel

In this paper, the best achievable performance of a turbo coded system on a block fading channel is obtained, assuming binary antipodal modulation. A rate 1/3 turbo code is considered, obtained by concatenating, through a random interleaver, an 8-states rate 1/2 and a rate 1 convolutional codes (CC). The block fading channel model is motivated by the fact that in many wireless systems the coherence time of the channel is much longer than one symbol interval, resulting in adjacent symbols being affected by the same fading value. The fading blocks will experience independent fades, assuming a sufficient separation in time, in frequency, or both in time and in frequency. This channel model is suitable for analyzing, forinstance, wireless communication systems employing techniques such as slow frequency-hopping, as is done in the Global System for Mobile communications (GSM).In such systems, coded information is transmitted over a small number of fading channels in order to achieve diversity. The best coded information allocations over a certain number of fading channels are evaluated, using the Eades-McKay algorithm to generate distinct permutations of a multiset. Bounds on the achievable performance due to coding are derived using information-theoretic techniques. In particular, in the paper an analytical method is proposed, based on the sphere-packing bounding technique, to assess the achievable performance. Moreover, simulation results are obtained and compared with the theoretical ones.

Analysis of Turbo Code Behavior with Extrinsic Information Transfer Charts in High-Speed Wireless Data Services

2017 ◽  
Vol 9 (4) ◽  
pp. 26-36 ◽  
Author(s):  
Izabella Lokshina ◽  
Hua Zhong
Keyword(s):  
Turbo Codes ◽  
Communication Systems ◽  
Information Transfer ◽  
High Speed ◽  
Transfer Functions ◽  
Turbo Code ◽  
Substantial Reduction ◽  
International Standards ◽  
Extrinsic Information ◽  
Suggested Approach

This paper examines turbo codes that are currently introduced in many international standards and implemented in numerous advanced communication systems, and evaluates the process of extrinsic information transfer (EXIT). The convergence properties of the iterative decoding process, associated with a given turbo-coding scheme, are estimated using the analysis technique based on so-called extrinsic information transfer (EXIT) charts. This approach provides a possibility to predict the bit-error rate (BER) of a turbo code system with only the extrinsic information transfer chart. It is shown that extrinsic information transfer charts are powerful tools to analyze and optimize the convergence behavior of iterative systems utilizing the turbo principle, i.e., systems exchanging and refining extrinsic information. The idea is to consider the associated soft-input soft-output (SISO) stages as information processors, which map input a priori log likelihood ratios (LLRs) onto output extrinsic LLRs, the information content being obviously assumed to increase from input to output, and introduce them to the design of turbo systems without the reliance on extensive simulation. Compared with the other methods for generating extrinsic information transfer functions, the suggested approach provides insight into the iterative behavior of linear turbo systems with substantial reduction in numerical complexity.

scholarly journals An overview of channel coding for 5G NR cellular communications

2019 ◽  
Vol 8 ◽  
Author(s):  
Jung Hyun Bae ◽  
Ahmed Abotabl ◽  
Hsien-Ping Lin ◽  
Kee-Bong Song ◽  
Jungwon Lee
Keyword(s):  
Channel Coding ◽  
Ldpc Codes ◽  
Low Latency ◽  
Polar Codes ◽  
Coding Scheme ◽  
Coding Schemes ◽  
Successive Cancellation ◽  
New Radio ◽  
Key Characteristics ◽  
User Data

AbstractA 5G new radio cellular system is characterized by three main usage scenarios of enhanced mobile broadband (eMBB), ultra-reliable and low latency communications (URLLC), and massive machine type communications, which require improved throughput, latency, and reliability compared with a 4G system. This overview paper discusses key characteristics of 5G channel coding schemes which are mainly designed for the eMBB scenario as well as for partial support of the URLLC scenario focusing on low latency. Two capacity-achieving channel coding schemes of low-density parity-check (LDPC) codes and polar codes have been adopted for 5G where the former is for user data and the latter is for control information. As a coding scheme for data, 5G LDPC codes are designed to support high throughput, a variable code rate and length and hybrid automatic repeat request in addition to good error correcting capability. 5G polar codes, as a coding scheme for control, are designed to perform well with short block length while addressing a latency issue of successive cancellation decoding.

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