Relation between data rate and higher modulation rate

[chillin4ever]

Hello
How does higher data modulation is a system effect the data rates.
Lets say we are using GMSK and 8PSK ; so we have 1 bit per symbol vs. 3 bits per symbol so the data rate triples.
But does that also mean that we can transmit more bits per second in 8psk than gmsk ?
If yes ; then why.

(am confused here ; in 8psk we can send same # of bits ; its just that it has more information per bit but how does it allow us to send more bits per second)

regards

 

[hamed_sotoudi]

I think that u cant find out the difference between baudrate and bit rate.in 8psk every sample on the reciever means 3 bit so in both system if we send one sample the reciver in the first interpret that sample one bit but in 8psl in interpret that sample as 3 bit so the bit rat in 8psk is triple.

 

[chillin4ever]

Ok that i understand but what am confused is how does it increases Bits/Sec <----- if it took 1 bit/sec to transmit for a transmitter ; in 8psk since 3 bits equals 1 sysmbol...will not it take 3 seconds to transmit those 3 bits ???

 

[RFDave]

You don't transmit bits, you transmit symbols. In 8-psk, each symbol represents 3 bits. So, you are transmitting 270.833 kSymbols/Sec. for GMSK, each symbol is 1 bit. For 8 PSK, each symbol is 3 bits. Does that help?

Dave