I am looking for some expert advice from NuPIC gurus here. I have been working on the problem of decoding Morse code from noisy, real life signals as received using HF radios. I have implemented several types of signal processing and machine learning algorithms trying to improve accuracy and reduce decoding character error rate (CER) caused by various reasons, such as - poor signal-to-noise ratio - signal fading due to RF propagation - poor rhythm & timing of hand keyed CW - rapid speed changes - signal interference from adjacent frequencies
If you are interested in this subject there is more detailed descriptions on problems and solutions I have tested so far in here: http://ag1le.blogspot.com/2013/09/new-morse-decoder-part-1.html http://ag1le.blogspot.com/2014/06/new-morse-decoder-part-4.html http://ag1le.blogspot.com/2014/07/new-morse-decoder-part-6.html http://ag1le.blogspot.com/2013/01/towards-bayesian-morse-decoder.html http://ag1le.blogspot.com/2013/02/probabilistic-neural-network-classifier.html http://ag1le.blogspot.com/2012/05/morse-code-decoding-with-self.html My questions are related to NuPIC and how could I start testing whether CLA algorithm would perform better than the currently used Bayesian algorithm? The challenges I see after studying the NuPIC documentation & example code: 1) How to create encoder for building sparse representation from audio signals? (some ideas here: http://ag1le.blogspot.com/2014/05/sparse-representations-of-noisy-morse.html ) 2) If you teach NuPIC CLA to recognize Morse character set as sequence of "mark" / "space" bit patterns, how can you decode apparently random bit patterns from spatial pooler back to ASCII character set to be displayed to user? Does any of the existing classifiers allow users to create their own "codebook" (see http://ag1le.blogspot.com/2012/05/fldigi-adding-matched-filter-feature-to.html example using Kohonen Self Organizing Maps to build a codebook) 3) Does NuPIC CLA also recognize some common language patterns ("higher order sequences") that are typically used in normal ham radio contacts ? Or is there a need to chain multiple CLAs in some sort of hierarchy? regards, Mauri AG1LE
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