🚀 go-pugleaf

RetroBBS NetNews Server

Inspired by RockSolid Light RIP Retro Guy

Article View: comp.dsp
Article #520

Re: Costas Loop in Digital Form

#520
From: Lawrence Esker
Date: Fri, 17 Nov 1989 15:22
25 lines
1998 bytes
In article <2628@radio.oakhill.UUCP> charlie@oakhill.UUCP (Charlie Thompson) writes:
>I am looking for software implementations of a Costas Loop. I
>have the original old paper written by the man himself but I
>was looking for someone who might have done this in software
>such as DSP code for one of the DSP's or even C for that matter.
>-Charlie Thompson

I've found that the Costas loop is not very good compared to some later
developments.  It was also impossible to convert to a digital form (as hardware
counters, multipliers, etc.)  Get the book Phaselock Techniques by Floyd M.
Gardner and read chapter 11.  It presents several evolved forms, such as the
Early-Late gate and the Transition Tracking Loop that are superior in
performance than the Costas loop, are hybrid digital/analog designs, and can
trace their functional for back to the Costas loop.

I've personally designed an all digital version of the Transition Tracking Loop
and it was an order of magnetude less complexity than an all digital version
of the Costas loop would be.  Admittadly, this has nothing to do with DSP or
C code, but if an all digital hardware solution is obvious from the theory and
simpler to design, I would think a software solution would be obvious and
computationally less expensive.
--
---------- Lawrence W. Esker ----------  Modern Amish: Thou shalt not need any
                                         computer that is not IBM compatible.
UseNet Path: __!mailrus!sharkey!itivax!abaa!esker  ==  esker@abaa.UUCP
Technical Details
Message-ID: <4858@abaa.UUCP>
Path: arc1-ca.pugleaf.net!utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!iuvax!ux1.cso.uiuc.edu!tank!eecae!abaa!esker
References: <2628@radio.oakhill.UUCP>

Show Full Headers
Complete Article Headers
Path: arc1-ca.pugleaf.net!utzoo!attcan!utgpu!jarvis.csri.toronto.edu!mailrus!iuvax!ux1.cso.uiuc.edu!tank!eecae!abaa!esker
From: esker@abaa.uucp (Lawrence Esker)
Newsgroups: comp.dsp,sci.electronics,rec.ham-radio
Subject: Re: Costas Loop in Digital Form
Keywords: PLL
Message-ID: <4858@abaa.UUCP>
Date: 17 Nov 89 15:22:05 GMT
References: <2628@radio.oakhill.UUCP>
Reply-To: esker@abaa.UUCP (Lawrence Esker)
Followup-To: comp.dsp
Organization: Allen Bradley
Lines: 25