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

[Michael Sabino]

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
>>
>