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### How to add a particular noise on a signal?

I have a simple ADC model (an input signal == sampled signal ). The adc should be modelled as with following values: 1.5 V (peak to peak).. meaning --> +1.5 V --> 0 dBFS ... how to do this ? The ...
46 views

### Difference between formula of SNR and SQNR?

Is there any difference between formula/expressionsof SNR and SQNR? where SNR is Signal to noise ratio and SQNR is signal to quantization noise . The following DSP SE question shows both SNR and SQNR ...
114 views

### How we can quantize a sampled signal in MATLAB?

I have a continuous time signal $x(t)=\sin(2πft)$ where $0 \leq t \leq 3$. I want to sample the continuous time signal and then quantize that sampled signal and then plot both sampled and quantized ...
79 views

### confusion sampling vs quantization?

while converting analog signal to digital equivalent,we have a process that is called analog to digital conversion and it has two main steps/stages sampling and quantization? I am confused whether y ...
20 views

### Understanding shift in Q values?

Can any one help me understand why there is a shift in Q values? It seems there is a DC offset/bias. How do I remove it or set it accordingly to make it equal to the I values/waveform? I am using a ...
54 views

I am trying to find a way to evaluate what would be the minimum sampling rate used in a modulated waveform using matlab / Simulink. The real scenario would be let say a M-PSK waveform of Y bandwidth ...
85 views

### Is there a relation between the dead zone of sigma delta modulator and filter order?

This question refers to the link https://pure.tue.nl/ws/portalfiles/portal/1546321/521243.pdf. In chapter 4 it discusses the topic of dead zone, which appears in the delta sigma modulator. Dead zone ...
36 views

### Nyquist sampling theorem / Nyquist - Shannon theorem evaluation over M-PSK

I am trying to simulate an M-PSK Tx-Rx System on Simulink and analyse what the effect of sampling rate reduction would have on it. More, particular I am trying to prove what Nyquist sampling theorem ...
37 views

### Sample & Hold: Estimate jitter delay of an ADC

I've got a question regarding the effects of sample and hold. My input signal is $x$, and my output signal $x_{SH}$. The error between the signals is $e_{SH} = x_{SH}-x$. The sampling frequency is ...
64 views

### Conversion from counts to dB

I have a sound signal, recorded by a hydrophone, which units are counts. I would like to convert the counts into dB re uPa (Decibels relative to microPascals), is that possible?
146 views

### DC Spur in DAC output

I have a design in which a signal from ADC is filtered and then played by DAC. In FPGA the real signal is converted to quadrature using DDS with 70 MHz frequency. After filtering, the baseband signal ...
140 views

### How to adjust receiver gains to avoid saturation and quantization noise to optimise post digital processing?

I am using a Hack RF One as SDR and the software GNU Radio to receive and process signals emitted from a drone. Given that the drone is moving and is emitting signals from a wide zone, received signal ...
42 views

### Does FFT magnitude of recorded sound depends on the sound card used?

Based on some reading, here's my understanding of how sound recording works: Microphone outputs a voltage based on sound pressure. The microphone voltage is amplified and the amplified voltage goes ...
192 views

### Faster way to find the quantization level of a sample

Given a sequence of real numbers that represent a sound signal i.e [1.8, 2.2, 2.2, 1.9, -1.5, -0.7], we must quantize this sequence by dividing the range [-4, 4] to 32 equal parts. If we had to do ...
37 views

### What is the minimum and maximum cutoff frequencies for the antialiasing filter for this ADC?

https://www.analog.com/en/products/ad9675.html https://www.analog.com/media/en/technical-documentation/data-sheets/AD9675.pdf It says in the data sheet that the Anti-Aliasing Filter has : "...
32 views

### Do Audio Interface manufacturers use A-weighted Measurements to make specs look better?

Recently I came across a reputed music-tech teacher who said audio interface manufacturers use A-weighted measurements to show dynamic range in their specs so that they look better on spec sheets and ...
158 views

### Calculating filter coefficients of a Moving average with error correction

I have an oversampling ADC where I need to correct Gain/offset errors 'during' each conversion. This also links to my previous question - Moving average and linearization of two piecewise linear ...
65 views

### Moving average and linearization of two piecewise linear systems

I have 2 oversampling ADC's running parallelly, each to process data in a specific range of the input as shown below: Each ADC can process only half cycle range of a sine wave. Each ADC adds its own ...
135 views

### Sampling - Higher order harmonics

I have been studying about the sampling theorem and it seems that even though we sample at a frequency with the nyquist criterion, the harmonics (due to sampling process) remain within the nyquist ...
191 views

### How to plot noise shaped spectrum of First order Incremental Sigma Delta ADC's output?

A little background: This question is about viewing the output spectrum of incremental delta sigma modulators (IDSM). IDSM is a subcategory of general delta sigma modulators where the integrators are ...
540 views

### Higher order harmonics during sampling

I am studying about the sampling theorem in conjunction for ADC. I got little confused while reading about aliased frequencies. I see that as per the Nyquist theorem, the sampling frequency (fs) ...
384 views

### Are resolution increase and noise reduction from oversampling mutually exclusive?

Oversampling a signal means sampling it with a significantly higher sampling frequency than the Nyquist rate. As far as I know, there are three advantages: Easier design of anti alias filter Increase ...
390 views

### Calculating SFDR from FFT of ADC output

A few months ago, as part of my summer internship, I had performed interfacing of an ADC with FPGA (Zynq-7000). The goal was to take an analog signal from a signal generator, feed it to the ADC and ...
405 views

### Why use a 1-bit ADC in a Sigma Delta Modulator?

When looking at the discrete model of a Sigma-Delta Modulator as shown below, we can see that the quantizer is modelled as a white-noise source $e[n]$. From this model, we can derive the noise shaping ...
153 views

### Very fundamental question: by what number do you divide your ADC counts?

What number is it correct to divide by your ADC counts as a first step in converting counts to voltage? For example, in a 10 bit ADC, is it correct to divide by 1024 or 1023? I have always divided by ...
46 views

### Proper way to implement a decimation

I have an input signal with bandwidth 2.5 MHz. Let's say it's filtered using analog Butterworth low-pass filter. I would like to sample the signal using AD9203 10-bit 40 Msps ADC. If I understand ...
416 views

### How does harmonic distortion occur in ADCs?

We are currently testing an ADC at my workplace and the Total Harmonic Distortion is an important spec. It got me to thinking as to how it occurs in the first place 1) Can there be harmonic ...
153 views

### ADC sampling rate in OFDM baseband processor

I have optical OFDM baseband TX and RX implemented in FPGA. The design is tested using one FPGA board in loopback connection from DAC to ADC via coaxial cable. It works fine, the BER is about 1.10^-8 ...
54 views

Sorry for this question, I'm still new in signal processing area. In OFDM system, let $x$ be the received signal, what do we call the process of multiplying the received signal $x$ by $e^{-j2\pi F_c ... 1answer 74 views ### How can i record 1 MHz signal and do a real-time processing in a PC? [closed] I have a 1 MHz signal from transducer that needs to be analyzed in real-time condition, so the sampling needs to be more than 2 MHz. It consists of digital filtering, turn into spectogram and feed ... 1answer 524 views ### How can I mimic this ADC for a given resolution, sampling rate and input with MATLAB or Python? I'm quite new to the area so I need help to progress at some point. Basically I have a signed 16 bit ADC which means it maps -10V to +10V range to 16 bit. So the max voltage +10V is 2^15-1 = 32767; ... 1answer 175 views ### Any better way to detect Signal with ADC Overflow problem? I am trying to create an algorithm to detect signal with "ADC overflow" as shown in picture on lower right. It happened because someone had incorrectly down converted an int16 signal into int8 signal. ... 1answer 99 views ### Can I apply CWT on a digital signal? First, I am so sorry for my dumb and stupid question, I am very beginner with signals. Say that I have an ultrasonic sensor cabled to an ADC (Analog to Digital Converter). The ADC converts the analog ... 1answer 73 views ### Determining the features of the DSP I need to sample a signal of 40MHz with a sampling frequency of 120MHz at least with a 8/12 bits ADC and send them through the USB serial port of a PC. That means the serial communication bandwith ... 2answers 96 views ### Sampling theory Imagine I have a 1 kHz sine wave with very low noise. (Assume a signal generator output with 1v peak to peak clean signal). I am using an ADC to sample this signal. Take the following cases: Sample ... 1answer 596 views ### comparison between Fourier transform and autocorrelation function If the Fourier Transform of a signal is enough to determine its spectral density, why do we complicate our lives by defining the autocorrelation function? 1answer 200 views ### Lock-In Amplifier Sampling Rate For a digital lock-in amplifier (synchronous demodulator) I have a sinusoidal reference signal in the range of 10-15kHz, the amplitude and phase I want to observe changes very slowly <10Hz. My ... 0answers 60 views ### Modelling of quantization noise with logarithmic steps I have to modell the quantization noise of ADC. I only know that the maximum relative error is 1 dB. Since this is logarithmic, I find it hard to formulate an appropriate model for the quantization ... 3answers 792 views ### Precision measurement of sine wave amplitude with ADC I want to measure amplitude of a sine wave input precisely with a limited resolution ADC. As an example suppose that I have$1\textrm{ MHz}$pure sine wave input to the$320\textrm{ Msps}10$-bit ... 1answer 174 views ### What is Audio codec in simplified term? I am trying to understand what a codec actually is Wikipedia says In hardware, audio codec refers to a single device that encodes analog audio as digital signals and decodes digital back ... 0answers 74 views ### Usage of a TI DSP EVM and ADC card I'm not quite sure if I can ask about a vendor-specific hardware here, please teach me if not. We have a TI's DSP EVM, one of EVMK2Ls (XEVMK2LX/XTCIEVMK2LX) and wanna do some digital signal ... 1answer 805 views ### Quantization Noise for Coherent Sampling - Phase Noise? Update: See added thoughts at bottom of this post. Under general sampling conditions not constrained by what is described below (signal uncorrelated to sampling clock), quantization noise is often ... 1answer 310 views ### Frequency measurement from acoustic emission sensor data(VDC RMS) Currently, I am facing a problem about understanding FFT concept and getting exact frequency with acoustic emission sensor data(VDC RMS data). I want to measure the sound frequency from the acoustic ... 2answers 4k views ### Bandwidth with complex sampling On the transmit side, I have a 20 MHz carrier frequency carrying a signal with bandwidth of 40 MHz (so 0 Hz to 40 MHz, center at 20 MHz). On the receive side, I have a dual channel ADC with each ... 1answer 802 views ### Calculate THD From DFT Plot Consider the following DFT plot below, showing the output spectrum of an 9-bit ADC. I want to calculate the THD (Total Harmonic Distortion). I am wondering how to do it correctly. I am aware of the ... 2answers 590 views ### Nyquist frequency and DC Im studying the DSP book by Steven W. Smith. On page 41 he covers the Nyquist frequency. He makes up an example by writing the following. ... consider an analog signal composed of frequencies ... 1answer 1k views ### Realize Simulink block “Ideal ADC Quantizer” in Matlab Yesterday I posted following topic: "FFT alternates '0' for a quantized SIN wave". During post editing I was perturbed by some affair, I didn't formulate correctly the problem. So, my post was blocked ... 0answers 550 views ### FFT magnitude of ADC samples, converting back to$\textrm{dBm}$I am generating a sinusoid from a signal generator set at a specific$\textrm{dBm}\$ and inputting this into an ADC as a real input (not IQ). I take a 256 point FFT on the resulting samples (raw signed ...
Consider the analog signal, $$x(t) = 2\cos(3000\pi t)+3\sin(4000\pi t)+7\cos(6000\pi t)$$ If the sampling rate is 8000 samples per second and quantized at 8 bits, find: Discrete values at any two ...