Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics 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

How to generate trellis in Matlab ?

Status
Not open for further replies.
M

magouliana

Newbie level 4
Joined
Feb 15, 2008
Messages
5
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,281
Activity points
1,320
Hi,

I want to generate a trellis in matlab. The constraingth length is 3 and the code is [1+D^2]. The problem is that my outputs must be 0 or 1 or -1. As I saw in poly2trellis function the output is only positive.
Can you suggest me anything? Thanks in advance.
The state table is the following

in cur nxt out
1 00 00 0
0 00 10 1
1 10 01 0
0 10 11 1
1 01 00 -1
0 01 10 0
1 11 01 -1
0 11 11 0
 

Re: trellis in matlab

Is it possible to just edit the trellis object returned by matlab to suit your requirement. ie; change the "trellis.output" array to what you want?

- b
 

Re: trellis in matlab

Many thanks for the reply.

My problem now is when I test the istrellis i got that the trellis is not correct.
for example the trellis:
trellis= struct('numInputSymbols',2,'numOutputSymbols',2, 'numStates',4,'nextStates',[0 0;1 0;0 1;1 1],'outputs',[0 1;0 1;-1 0;-1 0])

when I run the command:
[isok,status] = istrellis(trellis)

I get:
The 'outputs' field must be an octal matrix with numStates rows and numInputSymbols columns.

and the problem is that I use and negative value as an output...

Any suggestions?
 

trellis in matlab

Dont know if this works:
Say you give values of 0,1,2,3 for outputs (so that it is positive), and later map 3 to -1 after the decoder provides output.
 

Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top