Re: [Discuss-gnuradio] Data loss during transmission (OFDM .bmp file)

[Simran Kaur]

Hi Ben,

I am trying to transmit an image using USRP Tx/RX by implementing OFDM in GNU Radio. I am losing one offset of 96 bytes. I am suspecting there is problem with my synchronization which is not detecting that offset (packet_len = 96 bytes) or probably discarding it. I also tried inserting padding using burst shaper and removing those bits using correlator. But that is not working either. Can you suggest something how to make this right?

Best,

Simran Kaur

On Tue, May 7, 2019 at 3:33 PM Ben Hilburn <address@hidden> wrote:

Hey Simran -

All of this is to say that your communications system design does not appear to be robust to the impairments and complexities of wireless channels, some of which Marcus mentioned. Can you share what your specific goal is or why you're undertaking this work? Depending on what you are trying to achieve, you might not need something quite so complex.

Cheers,

Ben

On Sun, May 5, 2019 at 2:11 PM Kevin McQuiggin <address@hidden> wrote:

Read, read read!  Simple questions often lead to very complex answers.

You might start your studies with "The Scientist & Engineer's Guide to Digital Signal Processing” by S. Smith.

Kevin

> On May 5, 2019, at 9:46 AM, Marcus Müller <address@hidden> wrote:
>
> Well, noise happens, and synchronization isn't instantaneous. Things
> that aren't detected can't be received, and bit errors that the FEC
> can't correct are bit errors in the received data.
>
> That's the beauty and the curse of wireless communications.
>
> Best regards,
> Marcus
>
> On Sat, 2019-05-04 at 20:26 -0400, Simran Kaur wrote:
>> Hello All,
>> We are trying to transmit a .bmp file using USRP Tx/Rx. However, I am
>> getting bogus header data at the receiving end. I tried transmitting
>> a text file also which clips my starting text and also it inserts
>> some invalid/unknown characters. We are losing some of the bytes for
>> e.g, the transmitted file size is of 426316 bytes, but receiving file
>> size is of 4,264,224 bytes.
>> Can somebody explain what we are doing wrong here. I have attached my
>> Tx and Rx .grc and snapshots for the reference.
>>
>> Best,
>> Simran Kaur
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