Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronic Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Register Log in

duo-binary signal coding SNR requirement

Status
Not open for further replies.

neoflash

Advanced Member level 1
Joined
Jul 2, 2005
Messages
492
Helped
10
Reputation
20
Reaction score
2
Trophy points
1,298
Activity points
4,759
snr requirement

Why duo-binary signal coding SNR requirement is 2.5dB more than normal binary coding?

According to my understanding, duo-binary coding will have 3 voltage level, binary code will only have two.

Thus the SNR ratio between them are 2/3, the difference should not be 2.5dB, it should be 3.5dB.

Any inputs?
 

mehtesham

Junior Member level 3
Joined
Nov 14, 2005
Messages
31
Helped
1
Reputation
2
Reaction score
0
Trophy points
1,286
Activity points
1,551
2.5dB more transmit powre is needed for duobinary for having the same error probability as binary.

as Pe of duobinary and binary are known:

Pe(duobinary)=Pe(binary) ---> St(duobinary)~=1.8*St(binary) ---> St(duo,dB)~=2.5dB+St(binary,dB)

St is transmit power.
 

neoflash

Advanced Member level 1
Joined
Jul 2, 2005
Messages
492
Helped
10
Reputation
20
Reaction score
2
Trophy points
1,298
Activity points
4,759
where is 1.8 coming from?
 

mehtesham

Junior Member level 3
Joined
Nov 14, 2005
Messages
31
Helped
1
Reputation
2
Reaction score
0
Trophy points
1,286
Activity points
1,551
you know:

St(duo)/St(bin)=[(4*Q^-1(2*Pe/3)/pi)^2]/[(Q^-1(Pe))^2]

Q^-1(x) is inverse of Q(x) function,pi=3.14

calculating numerically (from table) :

for example : Pe=10^-3 then Q^-1(2/3*10^-3)=3.26 , Q^-1(10^-3)=3.09 you have (4*3.26/pi)^2/(3.09)^2~=1.8

for Pe=10^-4,... you will get about 1.8
 

Status
Not open for further replies.
Toggle Sidebar

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Top