VCP2 limitation on minimum number of bits to decode

Niraj Ghanekar

Hi All,

I am trying to use VCP2 in 6670 DSP to decode the data of 15 bits. My constraint length "K", is 5. But my decoded bits are not correct. When I give frame length as 16 then it is able to decode successfully. I am using tailed trace back mode for VCP2.

In other document for 64xx, I read that for viterbi algorithm to work fine, minimum state metrics it needs to collect is sm(k), where k is 2^(K-1). So in my case it will be 16. Please let me know is there any limitation like this on 6670 DSP.

Thanks in advance.

Thanks & Regards,

Niraj

over 13 years ago

0 Chad Courtney over 13 years ago

TI__Mastermind 30825 points

The VCP2 implementation is the same for all devices with VCP2.

Best Regards,

Chad

0 Niraj Ghanekar over 13 years ago in reply to Chad Courtney

Prodigy 85 points

Hi Chad,

Thanks for your answer. So I am assuming that there is a limit on frame length that we provide to VCP2. This limit is due to state metrics and I must provide minmum frame length of 2^(K-1) for VCP2 to work fine.

Please let me know your say on this.

Thanks & Regards,

Niraj

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VCP2 limitation on minimum number of bits to decode