## Forums Search for: QPSK

## QPSK Spectrum in simulink

Hi everyone. I just want to plot the QPSK baseband spectrum from the output data of the QPSK simulink block. However the output of this...

Hi everyone. I just want to plot the QPSK baseband spectrum from the output data of the QPSK simulink block. However the output of this block are the symbol coordenates in the signal space and when I use "spectrum scope" i don't get the theorical spectrum for the qpsk (the sinc function..). How can I do it? Can I use the qpsk block? thanks in advance!

## QPSK for BER performance

hi all, Below is the QPSK i have done to calculate the BER. However, the dectection part is wrong. Can anyone advise what is...

hi all, Below is the QPSK i have done to calculate the BER. However, the dectection part is wrong. Can anyone advise what is the correct syntax. Appreciate the help greatly. Thanks %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

## Simulink model of a QPSK modem

Hi everybody, I'm working on a Simulink QPSK modem for a Altera Stratix platform and I'm a bit lost. Does anybody have a model in simulink of a...

Hi everybody, I'm working on a Simulink QPSK modem for a Altera Stratix platform and I'm a bit lost. Does anybody have a model in simulink of a QPSK modem that can help me developing mines? If anybody could send me a model I will be really thanked. Bye!

## simulating QPSK modulation

inHi, I want to simulate a QPSK transmission through a multipath channel. I see that some people use 1 sample per symbol while...

Hi, I want to simulate a QPSK transmission through a multipath channel. I see that some people use 1 sample per symbol while others use 8 or 16. Could someone give me some hints about the advantages and disadvantages of each option? I'm thinking about... - whether

## QPSK

inCan some one get me a source code as to how i go about simulating qpsk symbols? The constraints are: symbol rate - 1 /sec and...

Can some one get me a source code as to how i go about simulating qpsk symbols? The constraints are: symbol rate - 1 /sec and chip rate is 128sec.

## QPSK or BPSK for ZF equalization

Hi all!! I implemented in Matlab some different ZF equalizations, but I should change the input signal froma random [+1/-1] signal to a QPSK...

Hi all!! I implemented in Matlab some different ZF equalizations, but I should change the input signal froma random [+1/-1] signal to a QPSK or BPSK signal (choosing number of samples, oversampling and so on..), but I have no idea of how doing it. Could anyone give me some advices or some code-examples? Thank you all in advance, Ella PS:here there

## Passband QPSk modulator...simul

Hi, I am having a weird problem with a passband QPSK simulation I am working on. I just need the modulated output for further...

Hi, I am having a weird problem with a passband QPSK simulation I am working on. I just need the modulated output for further pprocessing and dont want the demodulation in my simulation. When I just use the M-PSK modulator the transmitted output is like a square wave. When ther

## Qn on QPSK demodulation

Dear all, I've a problem demodulating in QPSK. My transmitter is a vector signal analyzer (VSG) and a labVIEW programme is used to capture...

Dear all, I've a problem demodulating in QPSK. My transmitter is a vector signal analyzer (VSG) and a labVIEW programme is used to capture the data. Matlab is used to despread the data using PN sequence of 1024 bits, after which the data is being demodulated. Below is a portion of the code using BPSK, % Read off Gain Factor and offset Gain_factor = fread(fid, 1, 'double'); Offset = frea...

## measuring Baudrate from QPSK signals

inGood morning, does anybody has an idea, how to measure the baudrate also known as the symbolrate of a QPSK signal - I have a Real-Array and...

Good morning, does anybody has an idea, how to measure the baudrate also known as the symbolrate of a QPSK signal - I have a Real-Array and an Imag-Array of data-streams? 1. How should I proceed? 2. Is finding zero-crossing from the signal a good approach? 3. Does anybody has source-code concerning this . Thanx a lot in advance for your support. Best regards. Bochao

## Symbol Sync for QPSK !!

Hi all, i trying to implement the QPSK mod and Demod in matlab. I'm not able to get the Symbol Sync for QPS based on Early and Late...

Hi all, i trying to implement the QPSK mod and Demod in matlab. I'm not able to get the Symbol Sync for QPS based on Early and Late Gate Integrators. Can one help me regarding this or forward me some material that can help me implement this in matlab. Thanks, Abhishek Abhishek Agarwal

## SOVA for QPSK symbols.

Hi All, I am new member of this group and I need a method to compute the soft decisions using SOVA for QPSK symbols. I am using a rate...

Hi All, I am new member of this group and I need a method to compute the soft decisions using SOVA for QPSK symbols. I am using a rate 1/2 systematic convolutional code with following trellis structure: trellis = poly2trellis ( 3, [5 7], 5 ); Please suggest me

## Please help: BER for QPSK in OFDM over Rayleigh matlab code doesn't work.

I try to implement the matlab code on BER for QPSK in OFDM over rayleigh channel (with n taps). However the result is a straight line. There must...

I try to implement the matlab code on BER for QPSK in OFDM over rayleigh channel (with n taps). However the result is a straight line. There must be something wrong in my code but I cannot figure it out what is wrong. Could you please help me to check it. I have to hand the work soon. Please please please help. Thank you very much. [QUOTE]clear; clc; N=64; % FFT size Nsd = 48; % Number of ...

## creating BPSK, QPSK, DPSK modulated signals

I need some help in creating BPSK, QPSK, DPSK modulated signals. If someone know the modem design by using the signals above, it...

I need some help in creating BPSK, QPSK, DPSK modulated signals. If someone know the modem design by using the signals above, it will be great help Thanks

## QAM demapper

inHi, is there anyone who can explain me how does it work the QAM demapper in the DVB demo of Simulink? Can you please give hints on how create a...

Hi, is there anyone who can explain me how does it work the QAM demapper in the DVB demo of Simulink? Can you please give hints on how create a demapper for 16 QAM and QPSK? Thanks a lot. Riccardo Calonaci

## Frequency divider

inHi Guys, My question has something to do with frequency multiplier and divider in a PLL. For example, before a QPSK is fed into...

Hi Guys, My question has something to do with frequency multiplier and divider in a PLL. For example, before a QPSK is fed into a PLL, i have to pass the signal through a 4th power device and bandpass it. I could do this by muliplying 4 times. However, i am not sure how to

## Some pieces of Software

Hello, I just wanted to ask some help regarding digital communications. Could anyone send me any piece of information...

Hello, I just wanted to ask some help regarding digital communications. Could anyone send me any piece of information concerning how the non-linearities of certain devices (mixers, power amplifiers, ...) may affect the digital communication schemes (QPSK, ODFM, ...)? Do

## SC-FDE

Dear all, I am simulating Single Carrier Frequency Domain Equalizer in AWGN Channel.. I used the QPSK BER curve and modified that to make...

Dear all, I am simulating Single Carrier Frequency Domain Equalizer in AWGN Channel.. I used the QPSK BER curve and modified that to make the SC-FDE. I am using 512 fft size and guard interval of 56. As awgn channel is used ,there is no operation in between the fft & ifft at the receiver. Should I do the zero padding at the transmitter?. If anyone

## Newbie to OFDM

inHello Everyone, I started working recently on OFDM. I am trying to use simulink to build a simple system with four sub-carriers. However, I...

Hello Everyone, I started working recently on OFDM. I am trying to use simulink to build a simple system with four sub-carriers. However, I am unable to comprehend the results I am getting. Here is what I am doing: 1. I am using a Bernoulli Binary data Generator 2. It's output is QPSK modulated. 3. After separating the real and complex parts I concatenate the matrix and zero pad it to...

## bits to symbols and vice versa

inHi, Is there some easy way to encode and decode QPSK symbols to bits? For exmple 0 -> 00, 1-> 10, 2 -> 01, 3 -> 11. I didn't...

Hi, Is there some easy way to encode and decode QPSK symbols to bits? For exmple 0 -> 00, 1-> 10, 2 -> 01, 3 -> 11. I didn't find any function that does that. Of course one can write a simple function with four if - clauses, but can you do it more elegantly?

## OFDM Simulation

Dear all, I have some problems regarding the simulation of OFDM Chain to obtain the BER curve...Pls help me ..it is very urgent. Great...

Dear all, I have some problems regarding the simulation of OFDM Chain to obtain the BER curve...Pls help me ..it is very urgent. Great helps are appreciated. 1). Noise Variance & Zero Padding...- in my understanding , we have to normalize the tranmited bits not the symbol when plotting the BER vs EbNo curve. Is that right?. After qpsk modulation .