I am a PhD student in EE with pathway in signal processing and communication.

## Re: Why do we do upsampling before convolving the impulse response of filter and transmitted signal

That clear up some confusion. However 1- we usaully upsamle by the filter length, is this to get the symbol time right ? Can you please elaborate on the time domain...

## Why do we do upsampling before convolving the impulse response of filter and transmitted signal

HiI have seen in various codes for implementing the digital communication systems, people before performing the convolution of matched filter and transmitted signal,...

## Re: OFDM

If Ber vector is all zeros then it makes sense why semilogy produces empty graph.

## Re: FIR All pass filter with Linear Phase

You are right the rectangular in time domain is sinc. I will choose a window as well . How can I assure taps are symmetric ? because multiplying with a window gives...

## Re: FIR All pass filter with Linear Phase

This is just shifted delta I modified my question to account for that.

## FIR All pass filter with Linear Phase

Hi EveryoneI know most all pass filters are IIR filter and FIR filter with symmetry has a linear phase. Now I would like to design a FIR filter in which it has constant...

## FD IQ imbalance impairment model

I want to design FD (frequency dependent ) IQ (In-phase,Quadrature) distortion that changes the phase mismatch linearly like a+b*K ( where K is the subcarriers 1...

## FFT and IFFT scaling factor in OFDM

Hello EveryoneI had a question about normalizing OFDM transmit power after IFFT across each subcarrier. I have simulated OFDM with BPSK and according to different...

## How to calculate the FFT period?

HelloI have a question about finding the FFT duration for 802.11a preamble. According to standards when the bandwith is 20MHz and for N=64 we have 20 MHz/64 =312.5...

...

## Creating Frequency Selective time invariant channel

Hi everyoneI am wondering if anyone can explain how to generate frequency selective time invariant channel. This means that no Doppler shift and I only need to implement...

## Re: Generating Bandlimited Noise

Thanks. However in the attached link the variance of noise is calculate to be Fs*N0. However using what I have is like (Fs/2)*K*T. I know N0 for Johnson noise is...

## Re: Generating Bandlimited Noise

This is what I think and exactly opposite what this website says :https://dsp.stackexchange.com/questions/17494/how-...So according to what you say Johnson noise...

## Generating Bandlimited Noise

Hi EveryoneI would like to simulate the Johnson noise in a computer. I know its power is P=K*T*B where B is bandwidth and T is the temperature. I know it is random...

## Re: Code vs Uncoded EbN0

Thanks but I do not get how come two equations are the same according to articles you were referring to my equation would be correct. Can you elaborate why following...

## Code vs Uncoded EbN0

I would like to calculate E_b/N_0  when the code rate is R_c for BPSK signal. What I got this$$E_b/N_0= \frac{1}{2R_mR_c \sigma^2}$$and that is the case also according...

## Relationship between SNR and EbNo when there is coding

I would like to know what would be the relationship between EbNo and SNR when there is a coding rate of Rc=K/N. Normally when there is no channel coding according...

## Re: How to estimate the SNR

Hi KazCan you explain about the artefact and what you mean by that. I know detrend the signal by subtracting its mean. But can you explain about Following :for single...

## Re: How to estimate the SNR

Hi Rick It is a "real-world" signal.

## Re: How to estimate the SNR

Yes the signal is the noisy BPSK signal so noise at the top of -1 and 1 however we do not know about other factors that might be multiplied by the signal meaning...

## How to estimate the SNR

Hi I would like to know can anyone suggest me techniques to estimate the #SNR for a given noisy signal. I do not know the amplitude of my signal but I do know that...

## Re: ADPLL vs Linear PLL

Yes, phase detector is realized as a multiplier and VCO unit is rad/Volt since output of loop filter is voltage and I will have phase at the output of VCO. phase...

## Re: ADPLL vs Linear PLL

I know everything in Matlab is digital but the main distinction between my linear PLL and ADPLL is that ADPLL assumes VCO and multiplier have gain of 1.

## Re: ADPLL vs Linear PLL

Thank you so much Shahram.

## Re: ADPLL vs Linear PLL

Thanks.Can you please point me to the paper or set of parameters that let you design ADPLL with low bandwidth.

## Re: ADPLL vs Linear PLL

Yes, ADPLL is all digital PLL and LPLL is a linear PLL or analog one. in ADPLL I am not taking the VCO and phase detector gain into the account and assume they are...

I wonder can anyone elaborate about the difference between ADPLL and linear PLL. I have implemented both version in Matlab but the loop bandwidth for the ADPLL...

## Re: PLL in presence of noise

Thanks Y(J)S, Rick and Slartibartfas. I can estimate the phase of reference signal accurately and now I would like to use my PLL to track the frequency (estimate...

## Re: PLL in presence of noise

There are many technique for frequency estimation but I am looking for to estimate it using PLL and I have a estimate of phase and i have a vector of derivative...

## PLL in presence of noise

Hi Assume I have a vector of phases and I take a derivative from them and I obtained the frequencies however I am looking for to estimate the frequency of signal...

## Re: All digital PLL loop bandwidth

Thanks gmsk1 if I have loop bandwidth in terms of natural frequency can I represent Wn=2*pi*fn/Fs, that is the only place I am using frequency component. Also is...

## Re: All digital PLL loop bandwidth

I need a analytical expression for loop bandwidth vs other parameters like damping ratio and natural frequency like the 3dB bandwidth of continuous time system....

## All digital PLL loop bandwidth

HiI would like to know can anyone explain to me how to obtain the loop bandwidth for all digital PLL(ADPLL). I can define this for the second transfer function to...

## Re: Estimating Frequency in PLL from phase

Your explanation makes a perfect sense to me and that is how I think about PLL. However what I getting after lock happens is for example assume frequency of incoming...

## Re: Estimating Frequency in PLL from phase

Thanks. I have a second order loop but I implemented it digitally, which means my NCO is just integrator in discrete domain which means it is like Z/Z-1 and I have...

## Estimating Frequency in PLL from phase

HiAssume I have a digital PLL that outputs phase estimate of the reference signal, however I am wondering can I estimate the frequency signal according to the...

## Re: Test PLL against step change in phase

Thanks Olivert, however I have a question regardless of value I use for theta or F, can you tell me what should be plotted against time, I mean what do you call...

## Re: Phase locked Loop Bandwidth for second order system

Thanks shahram that was very helpful.

## Re: Test PLL against step change in phase

I am looking for comparing the performance of system by comparing the reference phase and output phase to see whether they match eventually. In your case how may...

## Re: Test PLL against step change in phase

I know what step change would do to my signal or PLL but I was asking is above code reasonable to check whether PLL is working or not (close to zero phase error)....

## Test PLL against step change in phase

I wrote a simulation for second order PLL and I would like to test it with a input to see whether my PLL can track the phase.  I would like to change phase of my...

## Re: Phase locked Loop Bandwidth for second order system

Thanks Shahram. I have a closed loop transfer function and I would like to find the analytical expression for loop bandwidth. I got it by finding the 3-dB bandwidth...

## Re: Implementing generic first order transfer function

I am trying to implement the transfer function in s domain in Matlab but not symbolically, that's all I am looking for. Any technique or method you know about that. You...

## Re: Implementing generic first order transfer function

Great, answer I am familiar with bilinear transformation where s=2/T (z-1)/(z+1) so I can convert the s domain to z domain. I do not really know any technique that...

## Implementing generic first order transfer function

Hi Can anyone tell me how to implement generic first order transfer function  a1s+a2/(b1s+b2) in Matlab meaning with for...

## Re: Phase locked Loop Bandwidth for second order system

Thanks. I am trying to simulate a generic second order PLL and need to express the coefficients of my filters and other parameters based on the loop bandwidth. my...

## Phase locked Loop Bandwidth for second order system

Hi everyone I would like to know can anyone tell me how to determine the #PLL bandwidth ? I read that it can be set to 1/10 or 1/20 of reference frequency however...

## Re: How to sample received pulse after root raised cosine

The problem is as I stated above this corresponds to 0 0 1 1 1. what you said is like 0 0 0 1 1 1 0

## Re: How to sample received pulse after root raised cosine

Thank you. However I cannot even obtain the correct bits in the first case. below waveform corresponds to 0 0 1 1 1 so how can I obtain 0 0 1 1 1 back. it seems...

## Re: How to sample received pulse after root raised cosine

This is the zero padded version of pulses after passing through transmitted filter and matched-filter. I added 66 zeros to end of the vector. But now how can I sample...

## Re: How to sample received pulse after root raised cosine

yes I upsampled first and oversampling factor is 8.and step 5 is doing downsampling but still I am not receiving correct bits.After downsampling not enough bits...

## Re: How to sample received pulse after root raised cosine

Thanks. That is my question how can I sample correctly? I know finding maximum entire data is not correct for matched filter I know I should sample at the peak...

## How to sample received pulse after root raised cosine

Hi everyoneI am generating series of 1 and 0. then pulse shaped them with root raised cosine (#RRC) and after than deciding to do match filtering and recovering...

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