# LimeSDR-Mini GR-3.8 Block Transmit Distortion

**URL:** <https://discourse.myriadrf.org/t/limesdr-mini-gr-3-8-block-transmit-distortion/7223>\
**Category:** LimeSDR\
**Created:** [28 June 2021 04:53 UTC](https://discourse.myriadrf.org/t/limesdr-mini-gr-3-8-block-transmit-distortion/7223 "2021-06-28T04:53:14Z")\
**Posts on this page:** 1\
**Showing post:** 6

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**Author:** ![phoenix](https://avatars.discourse-cdn.com/v4/letter/p/0ea827/32.png) [@phoenix](https://discourse.myriadrf.org/u/phoenix)\
**Post date:** [4 August 2021 23:49 UTC](https://discourse.myriadrf.org/t/limesdr-mini-gr-3-8-block-transmit-distortion/7223/6 "2021-08-04T23:49:56Z")

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Hi @DaveM,

Recently I experimented with BPSK based packet data transfer with LimeSDR-mini. I used Gnuradio 3.8 to create the flow graph. It’s working in simulation mode perfectly. But I’m yet to resolve the issue with LimeSDR mini. Looks like some synchronization problem is happening between transmitter and receiver hardware. I’m not an RF engineer, so having some difficulties to pinpoint the problem.

You might get some idea from my post here for the BPSK flow graph. I’m trying to understand the problem and will report back if any success.

> [@Packet Data Transfer using BPSK Modulation with LimeSDR-Mini](https://discourse.myriadrf.org/t/packet-data-transfer-using-bpsk-modulation-with-limesdr-mini/7237):
>
> Hi, I’m learning to implement a grc flow-graph with BPSK modulation to send and receive text/image file or send chat message via UDP socket. It’s working in simulation mode perfectly as I intended but with real hardware obviously lot of issues are happening. Ref: [https://wiki.gnuradio.org/index.php/Simulation\_example:\_BPSK\_Demodulation](https://wiki.gnuradio.org/index.php/Simulation_example:_BPSK_Demodulation) Initially, I was receiving only garbled data with limesdr-mini but after further reading I found that’s due to phase ambiguity problem in the receiver. Then I…

Cheers!

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