Baud rate explanation needed - MSK modulation

[sgergo]

Hi to all,

I'm working with a wireless module capable of transferring data with 500 kBaud. I initially thought that to transfer 1 byte I need 10 bauds (start/8bits/stop) but I just read somewhere that in FSK modulation 4 bits equals 1 baud (???). The module uses MSK (minimum shift keying) which is a form of FSK.

Now I'm not sure what kilobit/sec data rate is 500 kBaud exactly in MSK modulation. Any help or explanation would be much appreciated. Thank you.

 

[ericgibbs]

Hi to all,

I'm working with a wireless module capable of transferring data with 500 kBaud. I initially thought that to transfer 1 byte I need 10 bauds (start/8bits/stop) but I just read somewhere that in FSK modulation 4 bits equals 1 baud (???). The module uses MSK (minimum shift keying) which is a form of FSK.

Now I'm not sure what kilobit/sec data rate is 500 kBaud exactly in MSK modulation. Any help or explanation would be much appreciated. Thank you.

hi
There are some tutorials on this link.
msk modulation tutorial - Google Search

 

[EngIntoHW]

Isn't Baud Rate measured in units of bits per second?

Meaning, a Baud Rate of 500K (bps) means that every (10/500K)sec 10 bits are sent? [1 (8-bit)byte of data + 1 start bit + 1 stop bit].

 

[sgergo]

Isn't Baud Rate measured in units of bits per second?

Meaning, a Baud Rate of 500K (bps) means that every (10/500K)sec 10 bits are sent? [1 (8-bit)byte of data + 1 start bit + 1 stop bit].

AFAIK baud means one meaningful state change in the signal. If you transfer one byte with 10 bauds then 500 kBaud is 50kB/sec. If you don't need the start and stop bits then 500 kBaud is 62.5 kB/sec. Correct me if I'm wrong.

 

[nsaspook]

AFAIK baud means one meaningful state change in the signal. If you transfer one byte with 10 bauds then 500 kBaud is 50kB/sec. If you don't need the start and stop bits then 500 kBaud is 62.5 kB/sec. Correct me if I'm wrong.

Spread spectrum is a case where this is true. (baud > bit)
https://en.wikipedia.org/wiki/Spread_spectrum

The bit rate could be equal or many times the baud rate also ( the usual case).
Quadrature amplitude modulation - Wikipedia, the free encyclopedia

Cool history: https://en.wikipedia.org/wiki/SIGSALY

 

[EngIntoHW]

Thanks for the info guys!

 

[RCinFLA]

One example is GSM cellphone EDGE modulation.

It uses eight level modulation yielding 3 bits per symbol period.