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# Cdma Orthogonal

14 Threads found on edaboard.com: Cdma Orthogonal

## Generating CDMA codes for different symbols of the same user

Hello, I know that in a cdma system every user should use mutually orthogonal codes so that data from different user can be separated in the receiver and we can create these codes, for example, using Walsh/Hadamard matrices or PN sequences. My question is, if a user is transmitting e.g. 100 symbols and there are 10 transmitting us

## orthogonal walsh demodulator in simulink

hello can someone explain how to implement 64 ary orthogonal walsh demodulation in simulink. i need it in cdma reverse link implementation. an urgent reply would be appreciated. 8-)

## CDMA modelling in MATLAB

Walsh-Hadamard codes are very simply generated codes used in cdma downlink when transmission is synchronous, they are a set of perfectly orthogonal code generated as: H(0) = ; H(n+1) = ;

## CDMA simulation in Matlab using orthogonal complementary codes

need a matlab code for occ-cdma system

## Two User CDMA-OFDM (MC-CDMA) code

hi iam doing ofdm-cdma matlab code. the problem when i simulate for 2 users i get the recieved data wrong or when try to simulate using raylighy channels. i cant decide what is wrong with the code if some one can help me thanks %% code clc clear all close all sf=64; user1=randint(16, 1, 2) user2=randint(16, 1, 2); % Create BPSK mod-dem

Hi to all, I have done some research on multicarrier cdma for a while by using the command hadamard to generate the orthogonal spreading codes of size L=2^n in MATLAB. I have recently seen that there might be some differences between these 3 codes. So my questions are: 1) is there any difference between 3 spreading codes: i) Walsh ii) hadamar

## Does TDMA has more channel capcity than FDMA.

In book of Andrea Goldsmith, it is written that "TDMA, FDMA, and orthogonal cdma are all equivalent in the sense that they orthogonally divide up the signaling dimensions, and they therefore create the same number of orthogonal particular, given a signal space of dimension 2BT, N orthogonal channels of (...)

## Why Complex numbers are used to generate Scrambling codes

Why Complex numbers are used to generate Scrambling codes in cdma / Wcdma ? other way..why scrambling codes are complex numbers instead normal digital codes ? For Channelization codes orthogonal digital codes are used, then why same type of digital codes are not used for Scrambling codes ?

## is there near far effect in LTE

What is LTE? Is it related with cdma?

## Question about noise in CDMA and orthogonal sequences

Hi, I did'nt understand what is meant by 'the users are effected by each other'.Infact, in cdma, each receiver generates a unique PN(Pseudo Noise)sequence.Hence,if a transmitter wants to send data to a particular receiver only,then it has to modulate its data with the PN sequence of that particular doing so, a particular receiver o

## Looking for valuable info about noise in CDMA

Hi, In cdma we spread the energy spectrum of signals over a large BandWidth using orthogonal Pseudo Codes. Say, if 4 users data is spread over a spectrum of X BandWidth. when user 1 despreads in that bandwidth using the code provided to him, the data of other users appear as noise to user1 over the X BW. So if number of users are incresed

## Decoding a signal for 2 users simultaneously in CDMA?

(just an idea) As the cdma codes are orthogonal. If we correlate all the PN codes with received signal (considering that received signal is time aligned. Otherwise algo needs extension to consider delay or non-alignment), we will get different power level for all the available PN codes. Now set a threshold, from knowledge base, to consider vali

## Difference between OFDM, OFDMA, SS-OFDM, MC-CDMA, GMC-CDMA

1- OFDM : orthogonal frequency division multiplexing... the data is transmitted using a set of frequencies which are orthogonal 2- OFDMA... MA is multiple access technique for orthognal frequency division 3- SS-OFDM: is a hybrid technique using spread spectrum and OFDM 4- MC-cdma : MCcdma is multi- carrier code (...)

## what's difference between PN ,Walsh code ,long & short c

IN cdma2000 , what's difference between PN , walsh coed , long code and short code? how to work in forward and reverse channel?