PBRS

[aasif bashir dar]

hi all,

i want to know there is option of setting bits:

1. order(???)
2.alternate(i.e alternate zeros and ones)
so on

what do order and other option means.
with regards

[alistu]

Hi Aasif,

I believe “order” is used to set the length of the sequence that is generated by this component, and it reads sequence length information from layout parameters in script mode. If “Alternate” operation mode is chosen, an alternate sequence of ones and zeros is generated by PRBS generator.

Regards

[Aabid Baba]

Hello Asif,
You can infer from the meaning of order itself , it is nothing but defines the the order of sequence length in which the bits are transmitted.
I agree with Alistu , it must read the sequence length from the layout parameters in script mode only.
And as far as Alternate operation mode is concerned , it describes the scene about arrangement of sequence in terms of alternate zeroes and ones that we receive from the pseudorandom binary sequence generator.

Regards

[aasif bashir dar]

hi alistu,

order , alternate, probability, ones, zeros…. they all are options in one parameter in the PBRS component under the name operation mode.

if i select ORDER option, the sequence of bits is different from that of alternate and probability.

i understand all of options among them, but have confusion regarding ORDER, AND probability.

with regards

[alistu]

Hi Aasif,

The ones and zeros in the sequence are chosen with a probability as you know. Now when the probability mode is chosen, the “mark probability” option becomes available. Any number that is chosen between zero and one indicates the probability of ones generated in the output bit sequence of the component.

Regards

[aasif bashir dar]

hi alistu ,
thanks for your reply.
but iam not still able to clear the logic behind the option “order”.

i further want to know that how could i select my own user defined sequence say 10101111011101,instead of the pseudo-random sequence. how can dothat at the transmitter end.

with regards

[alistu]

Hi Aasif,

I believe the user defined bit sequence has been well explained by Naazira. The order in mathematics is the power of a number. For example, in the equation 2^6=64 , the order of 2^6 is 6. Here in PRBS generator, the sequence length is produced as 2^k, where k is the order and has to be determined.

regards

[Naazira Badar]

Hi Aasif..
Well you can always have your own defined bit sequence.
Select User-defined bit sequence generator from the library. Then in the option ‘bit sequence’, you can enter the sequence you want.
Hope this is what you meant to ask.

Regards.

[aasif bashir dar]

hi naazira,

thanks for your reply.

[aasif bashir dar]

hi alistu and naazira,
thanks for your reply.
i appreciate both of for your valuable suggestion.
for simulation purposes, which option among order, alternate, probabilty must be choosen, so that results after simulation can be applied to practical scenario.
with regards

[alistu]

You’re welcome Aasif. In practice, the number of ones and zeros is usually considered the same, since this is a more random behavior for the input data, so probability would better not be other than 0.5. Also, the place of zeros and ones is random, so alternate option is not necessary. So I’d go with “order”, which is the default mode.

Regards

[aasif bashir dar]

hi all,
thanks alistu for your simple and easy explanation. i was also using ‘order ‘ as my option in PBRS gennerator,and i wanted to be sure what those terms mean, and i am doing my design correct.
i appreciate responses of all .

with regards

[alistu]

You’re welcome Aasif. The “order” option cannot be accessed unless the “order” option is chosen in operation mode. I still have doubts about one thing, though. When the order option is not chosen, how the lengt of the sequence is calculated. We know the length should be given from layout parameters, but how?

Regards

[Naazira Badar]

Hi Aasif..
Are you talking about the parameter ‘order’ where in a logarithmic formula is written ?

Regards.

[aasif bashir dar]

hi naaazira,
in pseudo random sequence(PBRS) gennerator component of optisystem , you can check the component properties.by default there is OPERATION MODE set to ORDER in main parameters.
just beneat that there is logarithmic formula is written.

with regards

[Naazira Badar]

Okay Aasif, I’ll check it and let you know.

Regards.

[aasif bashir dar]

hi naazira,

you are welcome

[Ranjeet Kumar]

sir,
It is a pseudo random bit generators as it name suggest we can’t set bits. its bits order is random only its order, probability, alternate, ones and zeroes will be changed.

[aasif bashir dar]

hi ranjeet,

please check all the comments above and my query.you will figure out what the real point of discussion was. still thanks for your reply

with regrds

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