Electronics > RF, Microwave, Ham Radio

Proposal for another amateur radio data mode

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profdc9:
Hello,

I have a proposal for a new HF amateur data mode.  It is intended for conversational use or contest QSOs.  It is intended to be simple enough to be implemented on microcontrollers such as an Arduino but also employ forward error correction in the form of the (24,12,8) extended Golay code.  It is called SCAMP (Simple Conversational Amateur Messaging Protocol).  It uses either on-off keying like CW or 2FSK like RTTY45, and so can use a simple crystal oscillator for OOK or a frequency synthesizer such as SI5351A for FSK, and a direct conversion receiver.  It is intended for HF digital communications on simple portable homebrewed transceivers, especially those that can operate from solar power or remotely.

I have attached my initial draft specification of the data mode.  Any comments would be appreciated, especially from those who have experience with coding theory.

73,
Dan
KW4TI

RoGeorge:
Not a ham, no idea about the proposal, just that there are a few name collisions already for the word "SCAMP".

radiolistener:
what is the reason for that?
There are already existing protocols like FT8 and other, and they already include error correction and designed to receive a weak singal in a noisy environment.

You can receive FT8 on microcontrollers such as STM32.

MartinL:
The reasons are explained very clearly in the attached document...

FT8 is not practical on low end microcontrollers. Even the mcHF SDR, which is based on an STM32F4 and implements digital modulations like FreeDV onboard, doesn't have the power to implement FT8 decode. The STM32 implementation that's been demonstrated is on the STM32F7, a 200MHz Cortex-M7 part.

FT8 and similar also depend on having a fairly complex transceiver, capable of upper sideband modulation. What Dan is proposing here is viable for an 8-bit MCU connected to a trivial homebuilt transceiver like the Pixie.

I've read through the proposal. I don't really have the expertise to comment on the Golay coding scheme and error correction. I do think the mixed 6-bit/8-bit encoding approach could use some work, but that's a fairly minor detail at this stage.

Best thing would be to make it possible to try out! Perhaps implementing it in fldigi or similar.

sv3ora:
When I see people asking the reason about something, I feel that they are so close-minded!

I have done something that is also intended for portable communications and simple gear. My mode does not use any MCU, not even any microchip!
It uses it's own "keyboard"as well as "display" so it is a complete system.

In a more elaborate system the "keyboard" can be replaced with many switches and trimmer resistors for each key.
The display can be replaced with a bargraph voltmeter (LM chip), with each LED to represent a letter.

It is shown here
http://qrp.gr/kiss703

If implemented using microcontrollers and filters, or computers, It can go down in bandwidth at the FT-8 levels, or even more.

Enjoy!
73
DE sv3ora

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