HAS MATLAB CORRECTLY PERFORMED CDMA SIMULATION

[Communications_Engineer]

walsh matrix matlab

Hello, I have a question for my fellow members, we have studied that for CDMA, lets take CDMA2000, we modulo-2 add (or simply XOR) our data sequence with our Walsh sequence (albeit at a higher rate). However, in the CDMA2000 demo and the WCDMA demo in Simulink and also in some Matlab CDMA codes that I got, we have only performed simple multiplication.

Surely, this cant be right can it?

Secondly, the spreading is performed after modulation, however, all standards say that spreading be performed before modulation. So why is this?


-----------------------------------------------------------------------------------------------
groups.yahoo.com/group/telecom_research

 

[Communications_Engineer]

matlab cdma

C'mon I saw so many people giving expert advice on CDMA at so many posts here, they even uploaded Matlab simulations, can some one answer my simple question

 

[aapatel374]

yes i have successfully run matlab prog.for cdma by xoring with walsh code.

 

[Communications_Engineer]

Hello, I actually put this question some time ago and I got the answer to my question.


But aapatel374 can you tell me the difference between Walsh codes and Hadamard codes

------------------------------------------------------------
groups.yahoo.com/group/telecom_research

 

[aapatel374]

by walsh codes hadamard matrix is generated.
ea.
if we 1st take 0 then
2bit matrix is
00 ----- walsh code
01 ----- walsh code
4 bit matrix is
0000 -----walsh code
0101------ walsh code
0011 ------walsh code
0110 ----walsh code

 

[Communications_Engineer]

I know about WH matrix but I'm asking the difference between Walsh and Hadamard matrix because most books do talk about a difference

 

[aapatel374]

i will trying to find & tell u

 

[Mynul]

aapatel374
please send me your program please
i need it soon
i have some problem doing the coding
i am facing problem to assign time period of data and code.
please help me by sending your program
mynul_77@yahoo.com

 

[Mynul]

"aapatel374"
please send me the program you have done using xor.
it is very urgent for me.
mynul_77@yahoo.com

 

[aapatel374]

hi here is my program