A new family of decision delay-constrained MAP decoders for data transmission over noisy channels with ISI and soft-decision demodulation

2002 ◽  
Author(s):  
E. Baccarelli ◽  
R. Cusani ◽  
G. Di Blasio
Keyword(s):  
Data Transmission ◽  
Soft Decision ◽  
Noisy Channels ◽  
Decision Delay ◽  
New Family

scholarly journals Error Exponents and α-Mutual Information

Entropy ◽  
2021 ◽  
Vol 23 (2) ◽  
pp. 199
Author(s):  
Sergio Verdú
Keyword(s):  
Mutual Information ◽  
Data Transmission ◽  
Systematic Approach ◽  
Optimization Problems ◽  
Noisy Channels ◽  
Simple Method ◽  
Error Exponent ◽  
Error Exponents ◽  
Rényi Divergence ◽  
Cost Constraints

Over the last six decades, the representation of error exponent functions for data transmission through noisy channels at rates below capacity has seen three distinct approaches: (1) Through Gallager’s E0 functions (with and without cost constraints); (2) large deviations form, in terms of conditional relative entropy and mutual information; (3) through the α-mutual information and the Augustin–Csiszár mutual information of order α derived from the Rényi divergence. While a fairly complete picture has emerged in the absence of cost constraints, there have remained gaps in the interrelationships between the three approaches in the general case of cost-constrained encoding. Furthermore, no systematic approach has been proposed to solve the attendant optimization problems by exploiting the specific structure of the information functions. This paper closes those gaps and proposes a simple method to maximize Augustin–Csiszár mutual information of order α under cost constraints by means of the maximization of the α-mutual information subject to an exponential average constraint.

scholarly journals Robust compressed domain watermarking algorithm for video protection and authentication in noisy channels

2019 ◽  
pp. 1340-1354
Author(s):  
NAVEEN CHEGGOJU ◽  
VISHAL SATPUTE
Keyword(s):  
Copyright Protection ◽  
Data Transmission ◽  
Error Rates ◽  
Video Watermarking ◽  
Compressed Domain ◽  
Compressed Video ◽  
Noisy Environments ◽  
Noisy Channels ◽  
Data Authentication ◽  
Main Challenge

This paper introduces a robust and noise-resilient compressed domain video watermarking technique for data authentication and copyright protection. In recent years, watermarking has emerged as an essential technique to be equipped with data transmission. The main challenge pertaining to transmission is to protect the watermark from noise introduced by the channel. Here, we address this issue by watermark replication and by using the independent pass coding (INPAC) algorithm for compression. A replicated watermark is embedded into the video by the proposed blind video watermarking algorithm and then the watermarked video is compressed by the INPAC algorithm. The compressed video is transmitted through binary symmetric channels and tested under various bit error rates to evaluate the proposed algorithm in noisy environments. The results obtained suggest that the proposed algorithm is capable of handling noise efficiently and the overhead due to key embedding is observed to be only about 3%.

scholarly journals Immunity of the Data Transmission Channel with FHSS when Soft Decoding by Means of Spectral Density Estimation of Interference Power

2020 ◽  
pp. 843-854
Author(s):  
Valery P. Berdychev ◽  
Alexander A. Bliznyuk ◽  
Sergey B. Zhironkin ◽  
Andrey A. Pshenitsyn ◽  
Alexander A. Kuchin
Keyword(s):  
Spectral Density ◽  
Density Estimation ◽  
Data Transmission ◽  
Spread Spectrum ◽  
Noise Immunity ◽  
Transmission Channel ◽  
Interference Power ◽  
Soft Decision ◽  
Spectral Density Estimation ◽  
Soft Decoding

The characteristics of noise immunity of a coherent data transmission channel with Frequency Hopping Spread Spectrum (FHSS), orthogonal signals and Reed-Solomon code with its soft decoding have been obtained using spectral density estimation of interference power, which is a combination of two Gaussian noise interference, they are barrage jamming and one concentrated in the FHSS band part. It is found that when the volume of an orthogonal signals ensemble increases, noise immunity rises due to the accuracy growth of the spectral density estimation of the interference power, which in turn provides an accuracy growth of posterior probability estimation used for soft-decision decoding

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