Re: [Discuss-gnuradio] Receiving errors with Viterbi decoder block/Decoding AIM spacecraft

[Marcus Müller]

Hi Michael,

I'm just jumping in to advertise a GRC feature: if you use the
"screenshot" menu item (identical to the printer button in the tool
bar), you get a png of your canvas, rather than a picture of your UI and
everything.

Best regards,
Marcus

On 01/30/2016 05:50 PM, Michael Sabino wrote:
> Here's an image of the flowgraph, in addition:
> http://i.imgur.com/45B2MyL.png
>
>
> Michael
>
> On 1/30/16, Michael Sabino <address@hidden> wrote:
>> I abandoned the FSM constructor and decided to just use the decode
>> CCSDS27 block.
>>
>>
>> Michael
>>
>> On 1/30/16, Achilleas Anastasopoulos <address@hidden> wrote:
>>> Michael,
>>>
>>> I haven't seen your flowgraph, but as I wrote in my previous email you
>>> are
>>> using the fsm constructor probably in the wrong way:
>>>
>>> You are confusing the (n,k,K) parameters of a CC.
>>> k = number of input bits per period
>>> n = number of output bits per period
>>> K = constraint length of the code (related to the memory it requires)
>>>
>>> If you want to build a (2,1,*) CC then you need to call the fsm
>>> constructor
>>> with these two numbers AND a vector of 2x1=2 integers representing the
>>> two
>>> generator polynomials.
>>> (If you think about it the constraint length parameter need not be input
>>> to
>>> the constructor because it can be derived from the generator polynomials)
>>>
>>>
>>>
>>> *fsm::fsm(int k, int n, const std::vector<int> &G)*
>>>
>>> so in the above example it should be something like
>>>
>>>
>>> *fsm(1,2, *
>>>
>>>
>>> *[79,109])*
>>>
>>> On the other hand, i don't know if this is what you want to do.
>>>
>>> If you tell us the exact parameters of the code you want to build I
>>> would be able to help more.
>>> (the rate of the code 1/2 that you gave in your previous email is not
>>> sufficient, because R=1/2=2/4 so a (4,2,*)
>>> CC will also have the same rate but it would require you to provide 4
>>> x 2 =8 generator polynomials to construct it).
>>>
>>>
>>> Achilleas
>>>
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