scholarly journals Area-Efficient Early-Termination Technique for Belief-Propagation Polar Decoders

Electronics ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 1001
Author(s):  
Choi ◽  
Yoo
Keyword(s):  
Error Correction ◽  
Bit Error Rate ◽  
Error Rate ◽  
Belief Propagation ◽  
Early Termination ◽  
Experimental Results ◽  
Polar Codes ◽  
Termination Criterion ◽  
Area Efficient

Early-termination techniques for a belief-propagation (BP) decoder of polar codes can improve the decoding throughput by finishing a decoding iteration when an early-termination condition is satisfied. In the BP decoders, the early-termination condition plays an important role, as it affects decoding iteration savings. In this letter, an area-efficient early-termination criterion is proposed, which simplifies the previous threshold-based termination condition by completely eliminating redundant computations. According to the experimental results, the proposed structure for (1024, 512) polar codes can reduce 72.7%, 66.5%, and 59.7% of hardware resources without any degradation in the error-correction performance and decoding throughput compared to the previous threshold-based, information-BER (bit error rate)-based, and frozen-BER-based early-termination techniques, respectively.

scholarly journals A Low-Complexity Ordered Statistics Decoding Algorithm for Short Polar Codes

2019 ◽  
Vol 9 (5) ◽  
pp. 831
Author(s):  
Yusheng Xing ◽  
Guofang Tu
Keyword(s):  
Error Correction ◽  
Error Rate ◽  
Complexity Analysis ◽  
Signal To Noise Ratio ◽  
Low Complexity ◽  
High Signal ◽  
Polar Codes ◽  
Decoding Algorithm ◽  
Low Snr ◽  
Ordered Statistics

In this paper, we propose a low-complexity ordered statistics decoding (OSD) algorithm called threshold-based OSD (TH-OSD) that uses a threshold on the discrepancy of the candidate codewords to speed up the decoding of short polar codes. To determine the threshold, we use the probability distribution of the discrepancy value of the maximal likelihood codeword with a predefined parameter controlling the trade-off between the error correction performance and the decoding complexity. We also derive an upper-bound of the word error rate (WER) for the proposed algorithm. The complexity analysis shows that our algorithm is faster than the conventional successive cancellation (SC) decoding algorithm in mid-to-high signal-to-noise ratio (SNR) situations and much faster than the SC list (SCL) decoding algorithm. Our addition of a list approach to our proposed algorithm further narrows the error correction performance gap between our TH-OSD and OSD. Our simulation results show that, with appropriate thresholds, our proposed algorithm achieves performance close to OSD’s while testing significantly fewer codewords than OSD, especially with low SNR values. Even a small list is sufficient for TH-OSD to match OSD’s error rate in short-code scenarios. The algorithm can be easily extended to longer code lengths.

scholarly journals Performance Improvement of Ber Based on Multipath Forward Error Correction Diversity in Wireless Communication Channels

2020 ◽  
Vol 23 (1) ◽  
pp. 159-171
Author(s):  
Ahmad Baheej
Keyword(s):  
Wireless Communication ◽  
Error Correction ◽  
Bit Error Rate ◽  
Error Rate ◽  
Communication Systems ◽  
Forward Error Correction ◽  
Multiple Input Multiple Output ◽  
Wireless Communication Systems ◽  
Forward Error ◽  
Diversity Technique

The multipath phenomenon is a major factor that is continually affected negatively the performance of wireless communication systems. Since the receiver gets different copies of the transmitted signal from various paths at different times. Consequently, destructive or constructive interference can occur. Therefore, the performance of wireless communication systems is poor in term of bit error rate. This phenomenon can be taken as an advantage if the multiple – input – multiple – output antenna systems are employed at both transmitter and receiver sides (antenna diversity) to improve the bit error rate performance. This paper focuses on the combination of multipath forward error correction diversity technique with vertical-Bell laboratories layered space-time coding. This will lead to enhance the bit error rate in wireless communication systems. The proposed system used Rayleigh and additive white Gaussian noise as two different channel models. The multipath forward error correction diversity technique treats the multipath propagated signals as unessential copies, to utilise them to enhance the bit error rate limitation in the multiple – input – multiple – output systems. The simulation results showed that the performance of the proposed system can be gradually improved by increasing the number of utilised multipath signals in the multipath forward error correction diversity technique

Design and Implementation of LDPC Encoder / Decoder in the Atmospheric Laser Communication

2014 ◽  
Vol 672-674 ◽  
pp. 883-887
Author(s):  
Li Min Chang ◽  
Qing Wei Dong ◽  
Ye Zhan
Keyword(s):  
Bit Error Rate ◽  
Error Rate ◽  
Belief Propagation ◽  
Ldpc Codes ◽  
Bp Algorithm ◽  
Laser Communication ◽  
Coding Gain ◽  
Paper Briefly ◽  
Design And Implementation ◽  
And Performance

The paper briefly introduces the structure principle and excellent characteristics of protograph LDPC codes and designs the serial encoding circuit based on FPGA. On the basis of the further study of Belief Propagation (BP) algorithm, λ-min algorithm and A - min algorithm, decoder is designed adopting the complexity and performance eclectic mixed decoding algorithm. Meanwhile, it is verified by the simulation. The result shows that coding gain can be up to about 6 to 8 db, if it meets the requirements of 10-5bit error rate.

Performance analysis of NR Polar Codes at short information blocks for control channels

2021 ◽  
Author(s):  
Tirthadip Sinha ◽  
Jaydeb Bhaumik
Keyword(s):  
Performance Analysis ◽  
Error Correction ◽  
Channel Coding ◽  
Signal To Noise Ratio ◽  
Additive White Gaussian Noise ◽  
Early Termination ◽  
Polar Codes ◽  
Cyclic Redundancy Check ◽  
Polar Code ◽  
Trade Offs

Abstract One important innovation in information and coding theory is polar code, which delivers capacity attaining error correction performance varying code rates and block lengths. In recent times, polar codes are preferred to offer channel coding in the physical control channels of the 5G (5 th Generation) wireless standard by 3GPP (Third Generation Partnership Project) New Radio (NR) group. Being a part of the physical layer, Channel coding plays key role in deciding latency and reliability of a communication system. However, the error correction performance degrades with decreased message lengths. 5G NR requires channel codes with low rates, very low error floors with short message lengths and low latency in coding process. In this work, Distributed Cyclic Redundancy Check Aided polar (DCA-polar) code along with Cyclic Redundancy Check Aided polar (CA-polar) code, the two variant of polar codes have been proposed which provide significant error-correction performance in the regime of short block lengths and enable early termination of decoding processes. While CRC bits improve the performance of SCL (successive cancellation list) decoding by increasing distance properties, distributed CRC bits permit path trimming and early-termination of the decoding process. The design can reduce the decoding latency and energy consumption of hardware, which is crucial for mobile applications like 5G. The work also considers the performance analysis of NR polar codes over AWGN (Additive White Gaussian Noise) for short information block lengths at low code rates in the uplink and downlink control channels using SNR (Signal to Noise Ratio) and FAR (False Alarm Rate) as the performance measures. Simulation results illustrate different trade-offs between error-correction and detection performances comparing proposed NR polar coding schemes.

scholarly journals Minimization of Bit Error Rate in Polar Codes for Achieving Channel Capacity

2019 ◽  
Vol 9 (1) ◽  
pp. 1433-1436
Keyword(s):  
Channel Capacity ◽  
Bit Error Rate ◽  
Error Rate ◽  
Low Complexity ◽  
Polar Codes ◽  
Constructive Approach ◽  
Generator Matrix ◽  
Theoretical Limit ◽  
Sequential Decoding ◽  
Channel Bandwidth

Polar codes are designed to achieve Shannon’s theoretical limit for channel capacity with low complexity constructive approach. polar codes invented by E Arikan with the exceptional phenomenon by considering the generator matrix instead of parity bits with the information bits. As the block length N increases the sequential decoding paths are increases this may cause a reduction in SNR and increases the BER, this will occupy more channel bandwidth and consumes more power to transmit the signal. To notice the issues, we proposed a more constructive approach for error-free polar codes design up to 6 Gbps with proposed priority enabled reliability sequence (PERS), bit channels and CRC aided polar codes. This approach outperforms as compared with earlier ones.

scholarly journals A Robust MP3 Steganographic Method against Multiple Compressions Based on Modified Discrete Cosine Transform

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Yunzhao Yang ◽  
Xiaowei Yi ◽  
Xianfeng Zhao ◽  
Jinghong Zhang
Keyword(s):  
Social Networking ◽  
Discrete Cosine Transform ◽  
Bit Error Rate ◽  
Error Rate ◽  
Social Networking Sites ◽  
Experimental Results ◽  
Covert Communication ◽  
Embedding Capacity ◽  
Strong Robustness ◽  
Almost All

MP3 appears in various social networking sites wildly, and it is very suitable to be applied for covert communication indeed. However, almost all social networking sites recompress the uploaded MP3 files, which leads to the ineffectiveness of the existing MP3 steganographic methods. In this paper, a robust MP3 steganographic algorithm is proposed with the ability of multiple compressions resistance. First, we discover a new embedding domain with strong robustness. The scalefactor bands of higher energy are applied as the embedding bands. The message bits are embedded by adjusting the position of the MDCT coefficients with the largest magnitude in the embedding bands. Besides, the embedding and extraction operations are realized in the process of MP3 decoding at the same time. Experimental results illustrate that our proposed method is of strong robustness against multiple MP3 compressions. The bit error rate is less than 1% at the MP3 bitrate of 320 kbps. It is worth mentioning that the proposed method is proved to be applicable to social networking sites, such as SoundCloud, for covert communication. Our method achieves a satisfactory level of embedding capacity, imperceptibility, and undetectability.

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