scholarly journals A performance enhancement of physical layer at Wi-MAX system with RLDPC code

2021 ◽  
Vol 21 (3) ◽  
pp. 1557
Author(s):  
Sandeep Bawage ◽  
Manjula S ◽  
A. M. Bhavikatti
Keyword(s):  
Turbo Codes ◽  
Error Control ◽  
Belief Propagation ◽  
Performance Enhancement ◽  
Physical Layer ◽  
Error Correction Codes ◽  
Wireless Communication Network ◽  
Channel Codes ◽  
Model Channel ◽  
Forward Error

<span>In present wireless communication network, the error correction codes plays the major role for efficient data transmission in noisy environments. To get minimum BER and PAPR has been the main aim towards the field in forward error control coding. Majority of the researchers has considered turbo codes at specific SNR over AWGN channel but have complexity issues with the iterative output decoder and causes degradation in the Wi-Max network system. In this paper, the author presents and evaluates WiMAX physical layer performance with using MIMO technologies, where a Robust-LDPC technique of coding and decoding in OFDM based WiMAX system is consider. The decoding method of RLDPC has processed by Belief Propagation at the logarithmic domain in an iterative manner, the proposed methodology shows good decoding outcome for RLDPC codes at Rician and Rayleigh channel. Moreover, the applicability of our proposed model channel codes is defined under IEEE Wi-MAX standard and the results analysis is done under different code-rate and modulation schemes.</span>

scholarly journals Forward Error Correction Using Turbo Codes for Multimedia Data

2018 ◽  
pp. 1-7
Author(s):  
M. Subramanya ◽  
Shaiesta Khuteja ◽  
K. C. Varun Kumar ◽  
S. Srilatha ◽  
B. V. Srividya
Keyword(s):  
Error Correction ◽  
Turbo Codes ◽  
Error Control ◽  
Forward Error Correction ◽  
Turbo Code ◽  
Error Rates ◽  
Multimedia Data ◽  
Channel Fading ◽  
Physical Channel ◽  
Forward Error

The swift growth in multimedia technology of wireless network has made it mandatory for the efficient transmission across erratic channel. The transmission of encoded video using error control techniques is grabbing a great attention, since it works over the recovery of the lost data and errors in the bit frames which occur as a result of congestion and physical channel fading. Turbo codes are attracting researchers because of their efficient performance. The Turbo code is made up of analogous concatenation of two Recursive Systematic Convolutional (RSC) coders parted by a  non-uniform interleaver. For different code rate and information block lengths greater than 104, these codes are capable of achieving low Bit-error rates (BERs) at SNRs within 1dB of Shannon’s limit. Turbo codes will assist to employ Viterbi decoders. More the number of iterations, higher is the error correction capacity and hence Turbo codes act as an elucidation for obtaining large coding gains.

On the iterative decoding of sparse quantum codes

2008 ◽  
Vol 8 (10) ◽  
pp. 986-1000
Author(s):  
D. Poulin ◽  
Y. Chung
Keyword(s):  
Iterative Decoding ◽  
Belief Propagation ◽  
Quantum Codes ◽  
Error Correction Codes ◽  
Heuristic Methods ◽  
Tanner Graph ◽  
Coding Scheme ◽  
Propagation Algorithm ◽  
Belief Propagation Algorithm ◽  
Quantum Error

We address the problem of decoding sparse quantum error correction codes. For Pauli channels, this task can be accomplished by a version of the belief propagation algorithm used for decoding sparse classical codes. Quantum codes pose two new challenges however. Firstly, their Tanner graph unavoidably contain small loops which typically undermines the performance of belief propagation. Secondly, sparse quantum codes are by definition highly degenerate. The standard belief propagation algorithm does not exploit this feature, but rather it is impaired by it. We propose heuristic methods to improve belief propagation decoding, specifically targeted at these two problems. While our results exhibit a clear improvement due to the proposed heuristic methods, they also indicate that the main source of errors in the quantum coding scheme remains in the decoding.

scholarly journals Adaptive Packet-Level Interleaved FEC for Wireless Priority-Encoded Video Streaming

2009 ◽  
Vol 2009 ◽  
pp. 1-14 ◽  
Author(s):  
Rouzbeh Razavi ◽  
Martin Fleury ◽  
Mohammed Ghanbari
Keyword(s):  
Video Streaming ◽  
Error Control ◽  
Estimation Error ◽  
Wireless Channel ◽  
Industry Standard ◽  
Correlated Error ◽  
Video Broadcast ◽  
Video Input ◽  
Forward Error ◽  
Picture Type

Packet-level Forward Error Control (FEC) for video streaming over a wireless network has received comparatively limited investigation, because of the delay introduced by the need to assemble a group of packets. However, packet-level interleaving when combined with FEC presents a remedy to time-correlated error bursts, though it can further increase delay if this issue is not addressed. This paper proposes adapting the overall degree of interleaved packet-level FEC according to the display deadlines of packets, transmit buffer occupation, and estimated video input to the wireless channel, all of which address the issue of delay. To guard against estimation error, the scheme applies a conservative adaptation policy, which accounts for picture type importance to ensure that display deadlines are met, thus avoiding this defect of interleaving. The paper additionally introduces a greedy algorithm that effectively groups packet-level FEC protection according to packet priority. Priority encoding adds extra protection during deep fades. As feedback is not required, the interleaving scheme is suitable for all forms of video broadcast. A Bluetooth piconet demonstrates the packet-level FEC interleaving scheme, which provides higher quality delivered video compared to the industry-standard Pro-MPEG Cop#3r2 interleaving scheme.

scholarly journals FPGA-Implemented Fractal Decoder with Forward Error Correction in Short-Reach Optical Interconnects

Entropy ◽  
2022 ◽  
Vol 24 (1) ◽  
pp. 122
Author(s):  
Svitlana Matsenko ◽  
Oleksiy Borysenko ◽  
Sandis Spolitis ◽  
Aleksejs Udalcovs ◽  
Lilita Gegere ◽  
...  
Keyword(s):  
Error Correction ◽  
Error Detection ◽  
Optical Interconnects ◽  
Error Control ◽  
Forward Error Correction ◽  
Golden Ratio ◽  
Probability Method ◽  
Additional Error ◽  
Hardware Costs ◽  
Forward Error

Forward error correction (FEC) codes combined with high-order modulator formats, i.e., coded modulation (CM), are essential in optical communication networks to achieve highly efficient and reliable communication. The task of providing additional error control in the design of CM systems with high-performance requirements remains urgent. As an additional control of CM systems, we propose to use indivisible error detection codes based on a positional number system. In this work, we evaluated the indivisible code using the average probability method (APM) for the binary symmetric channel (BSC), which has the simplicity, versatility and reliability of the estimate, which is close to reality. The APM allows for evaluation and compares indivisible codes according to parameters of correct transmission, and detectable and undetectable errors. Indivisible codes allow for the end-to-end (E2E) control of the transmission and processing of information in digital systems and design devices with a regular structure and high speed. This study researched a fractal decoder device for additional error control, implemented in field-programmable gate array (FPGA) software with FEC for short-reach optical interconnects with multilevel pulse amplitude (PAM-M) modulated with Gray code mapping. Indivisible codes with natural redundancy require far fewer hardware costs to develop and implement encoding and decoding devices with a sufficiently high error detection efficiency. We achieved a reduction in hardware costs for a fractal decoder by using the fractal property of the indivisible code from 10% to 30% for different n while receiving the reciprocal of the golden ratio.

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