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history of coding

Started by RichD June 10, 2019
On Monday, June 10, 2019 at 4:11:53 PM UTC-7, Eric Jacobsen wrote:
> On Mon, 10 Jun 2019 12:51:17 -0700 (PDT), RichD > <r_delaney2001@yahoo.com> wrote:
> >Recently I attended a coding seminar. The speaker > >very briefly reviewed the relevant history; > >first Hamming codes, ~1960: BCH codes, ~1970: convolutional, > >1995: polar, 2002: LDPC
> >Clue me in - what was the advance in each case? > >I worked on a BCH project once, that seemed fairly > >efficient, how is it, or other algorithms, deficient?
(snip)
> You'll probably find different histories out there from different > sources, as the lineage of some of these aren't all that clear. It's > like asking when the FFT algorithm was invented...you may get vastly > different answers.
It seems to me that part of it is the ability to process such signals at an appropriate speed. My favorite in the history of transforms and coding is ICT, the Integer Cosine Transform. It is similar to DCT, but the coefficients are optimized for speeding up the forward transform, at the expense of slowing down the inverse transform: https://ntrs.nasa.gov/search.jsp?R=19940025116 Specifically, the forward transform is done on the CDP1802, a microprocessor from the 8080 and 6502 days that doesn't have hardware multiply. It seems to me that the math for the more complicated coding systems might have been around for years, but no ability to use them until computing hardware caught up.