6,781 research outputs found
Order Statistics Based List Decoding Techniques for Linear Binary Block Codes
The order statistics based list decoding techniques for linear binary block
codes of small to medium block length are investigated. The construction of the
list of the test error patterns is considered. The original order statistics
decoding is generalized by assuming segmentation of the most reliable
independent positions of the received bits. The segmentation is shown to
overcome several drawbacks of the original order statistics decoding. The
complexity of the order statistics based decoding is further reduced by
assuming a partial ordering of the received bits in order to avoid the complex
Gauss elimination. The probability of the test error patterns in the decoding
list is derived. The bit error rate performance and the decoding complexity
trade-off of the proposed decoding algorithms is studied by computer
simulations. Numerical examples show that, in some cases, the proposed decoding
schemes are superior to the original order statistics decoding in terms of both
the bit error rate performance as well as the decoding complexity.Comment: 17 pages, 2 tables, 6 figures, submitted to IEEE Transactions on
Information Theor
Converting Your Thoughts to Texts: Enabling Brain Typing via Deep Feature Learning of EEG Signals
An electroencephalography (EEG) based Brain Computer Interface (BCI) enables
people to communicate with the outside world by interpreting the EEG signals of
their brains to interact with devices such as wheelchairs and intelligent
robots. More specifically, motor imagery EEG (MI-EEG), which reflects a
subjects active intent, is attracting increasing attention for a variety of BCI
applications. Accurate classification of MI-EEG signals while essential for
effective operation of BCI systems, is challenging due to the significant noise
inherent in the signals and the lack of informative correlation between the
signals and brain activities. In this paper, we propose a novel deep neural
network based learning framework that affords perceptive insights into the
relationship between the MI-EEG data and brain activities. We design a joint
convolutional recurrent neural network that simultaneously learns robust
high-level feature presentations through low-dimensional dense embeddings from
raw MI-EEG signals. We also employ an Autoencoder layer to eliminate various
artifacts such as background activities. The proposed approach has been
evaluated extensively on a large- scale public MI-EEG dataset and a limited but
easy-to-deploy dataset collected in our lab. The results show that our approach
outperforms a series of baselines and the competitive state-of-the- art
methods, yielding a classification accuracy of 95.53%. The applicability of our
proposed approach is further demonstrated with a practical BCI system for
typing.Comment: 10 page
Critical Point for Maximum Likelihood Decoding of Linear Block Codes
In this letter, the SNR value at which the error performance curve of a soft
decision maximum likelihood decoder reaches the slope corresponding to the code
minimum distance is determined for a random code. Based on this value, referred
to as the critical point, new insight about soft bounded distance decoding of
random-like codes (and particularly Reed-Solomon codes) is provided.Comment: to appear IEEE Communications Letter
Improving Short-Length LDPC Codes with a CRC and Iterative Ordered Statistic Decoding
We present a CRC-aided decodingscheme of LDPC codes that can outperform the underlying LDPC code underordered statistic decoding (OSD). In this scheme, the CRC is usedjointly with the LDPC code to construct a candidate list, insteadof conventionally being regarded as a detection code to prunethe list generated by the LDPC code alone. As an example weconsider a (128,64) 5G LDPC code with BP decoding, which we canoutperform by 2dB using a (128,72) LDPC code in combinationwith a 8-bit CRC under OSD order of 3. The CRC-aided decoding scheme also achieves a better performance than the conventional one where CRC is used to prune the list. A manageable complexity can be achievedwith iterative reliability based OSD, which is demonstrated toperform well with a small OSD order
Talking the Talk: The Effect of Vocalics in an Interview
Our voices carry more than just content. People continuously make assumptions of one’s intelligence, credibility, personality, and other characteristics merely based on the way we talk. As the diversity of individuals in the workplace increases, so too do the differences in how those individuals talk. It is important that we understand how these different ways of speaking are being perceived in the workplace. More specifically, how are individuals being perceived prior to being hired via the interview process? This Honors Capstone project aims to understand the impact that vocal characteristics in an individual have on the interviewer’s perception of the interviewee, and how that impacts the hiring process. This project will offer professionals of all ages tangible advice on ways to increase one’s chances of receiving a job just by altering aspects of one’s voice
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