ADC Interpolation Gain

Started by pacman101 in comp.dsp8 years ago 11 replies

Hello, I've been reading a lot about increasing ADC quantization gain through oversampling and then applying an interpolation filter. I...

Hello, I've been reading a lot about increasing ADC quantization gain through oversampling and then applying an interpolation filter. I understand that for every 4x oversampling you can increase the SNR by 6 dB or 1-Bit and that lowers the quantization noise floor. However, say my ADC is sampling two tones at 1 kHz and 2 kHz using a 14-bit theoretical ADC. Theoretically my SNR is 6 dB * ...


Oversampling algorithm for root raised cosine pulse shaping filter

Started by chowash in comp.dsp13 years ago 3 replies

hello ! I am working on a design of a Root Raised Cosine Pulse Shaping Filter and my design of filter taps are on the basis of sampling...

hello ! I am working on a design of a Root Raised Cosine Pulse Shaping Filter and my design of filter taps are on the basis of sampling frequency which is of 4 times the BB frequency. Now to use this filter in the Tx section, I need to oversample my input data by 4 times. I would like to have a suggestion from you regarding the type of Oversampling Algoirthm that I can use for this purpose. ...


how to understand sigma-delta adc in time domain?

Started by lxx.helen in comp.dsp10 years ago 6 replies

I'm trying to think of a way to understand sigma-delta ADCs in time domain. Up to my understanding, two key technology of sigma-delta ADCs...

I'm trying to think of a way to understand sigma-delta ADCs in time domain. Up to my understanding, two key technology of sigma-delta ADCs are oversampling and noise shaping. In frequency domain, oversampling evenly spreads the square(delta)/12 quantization noise between 0 and samping frequency fs. Then with the help of decimation filter, we can remove the noise out of baseband fB. So, the rem...


Oversampling

Started by richkt9 in comp.dsp12 years ago 5 replies

Hi All, Can anyone provide matlab code fragments to explain to me how to use the kronecker delta to oversample a signal, s, by a factor of k...

Hi All, Can anyone provide matlab code fragments to explain to me how to use the kronecker delta to oversample a signal, s, by a factor of k ? I'd really appreciate any help anyone can give on this, Many thanks, R.


Sigma Delta Modulator A/D

Started by naebad in comp.dsp13 years ago 1 reply

I have read a bit about oversampling. Understand most of the theory but get stuck at the easy bit. If we sample with one a one bit ADC - how...

I have read a bit about oversampling. Understand most of the theory but get stuck at the easy bit. If we sample with one a one bit ADC - how do we get 16 bits back from this single bit to do the processing? Naebad


manchester encoding decoder

Started by Thierry in comp.dsp9 years ago 7 replies

Hi, I have to implement a receiver/decoder for a typical manchester encoded signal. I have to use a mircocontroller for this. someone tipped me...

Hi, I have to implement a receiver/decoder for a typical manchester encoded signal. I have to use a mircocontroller for this. someone tipped me on using what he called "oversampling and counter algorithm". but i can't find any useful reference. any help please. cheers PS. I have no background on communication


implementing on dsp

Started by Zeph80 in comp.dsp10 years ago 2 replies

I have to implement several QPSK narrowband carriers 24 ksym/sec,32Khz BW I have several basic questions since I've haven't worked with...

I have to implement several QPSK narrowband carriers 24 ksym/sec,32Khz BW I have several basic questions since I've haven't worked with DSPs before and am in the process of data collection before I pick a processor. 1. I want to do several of these channels in 1 dsp,since I will only be doing scrambling,encoding, and pulse shaping(oversampling by 5) then output I and Q at baseband each going...


Oversampling in OFDM

Started by Mas Bas in comp.dsp14 years ago 1 reply

Hi, I have a question related with the OFDM transmitter. What is the commonly method to increase the sampling rate ? - Increasing the IFFT...

Hi, I have a question related with the OFDM transmitter. What is the commonly method to increase the sampling rate ? - Increasing the IFFT size and insert zero in the inpput ? or - Insert zero in the IFFT output and followed by interpolation filter ? What is the trade-off ? anyone can help ? Thanks. Buzz


Oversampling and the FFT

Started by JohnReno in comp.dsp13 years ago 5 replies

Hello, I was recently working with a DSP engineer who was making an argument to me that if I didn't oversample (above Nyquist) that I would be...

Hello, I was recently working with a DSP engineer who was making an argument to me that if I didn't oversample (above Nyquist) that I would be "losing information," and I still fail to understand exactly what information I would be losing. The context of our particular application, is that we are dwelling on a signal for a fixed period of time (a design constraint), but we can sample at whatever ...


My first Digital Filter: Can I ask your help?

Started by gpezzella in comp.dsp9 years ago 13 replies

Hello this is the first time that I approach to DSP so I'm really newbie. I have to write a program that realize a Low Pass Filter at 50...

Hello this is the first time that I approach to DSP so I'm really newbie. I have to write a program that realize a Low Pass Filter at 50 Hz. My processor (ATTINY) have 10bit ADC so for first time I have used Oversampling and Decimation technique for add 3 "Virtual Bit" First Question: Since my Oversampled Frequency is: 4^3 * F-nyquist = 64 * 100 = 6.4KHz ...


ADSL Demodulation

Started by DougB in comp.dsp7 years ago 8 replies

Hello, In every book and article aobut ADSL processing the A/D and D/A sample rates are given as 2.208 MHz. For a transmitter implementation...

Hello, In every book and article aobut ADSL processing the A/D and D/A sample rates are given as 2.208 MHz. For a transmitter implementation at this sample rate you would get the conjugate symmetric image spewing out of your D/A since one may use up to bin 255 and there is absolutely no oversampling, and no analog filter in the world can cut-off that fast. Likewise for the receiver, any si...


changing sampling rate from 10Ksps to 10.8ksps

Started by Michele in comp.dsp12 years ago 1 reply

Hi All, I need your help in order to find a solution at the following problem: I need to change the sampling rate of a signal from the...

Hi All, I need your help in order to find a solution at the following problem: I need to change the sampling rate of a signal from the original 10ksample per sconds to 10.2 ksps. I should to do this without oversampling and decimation...which other possibilities I have? Ther is a rule that I should apply in all the case where the starting frequency and the final frequency are very clos...


Oversampling w/ Drop interpolation

Started by Dennis M in comp.dsp15 years ago 29 replies

I had a question posed to me today that got me thinking. Here was the question: "If the signal is oversampled by 10 x fs and then only every...

I had a question posed to me today that got me thinking. Here was the question: "If the signal is oversampled by 10 x fs and then only every 10'th data point is used for the final data set (without any filtering of the rest of the data points) will there be any difference in the noise from data that is sampled at only fs? The result is the same number of points." My answer was yes, ...


Oversampling and quantization...

Started by kl31n in comp.dsp12 years ago 18 replies

Hopefully some of you can point me to the solution of this problem. If I oversample a signal, I quantize it and then I reduce the sampling...

Hopefully some of you can point me to the solution of this problem. If I oversample a signal, I quantize it and then I reduce the sampling rate with a decimator by a factor M, I can improve the QSNR by a factor of log2(M). Nice and easy. But what if I lower the sampling rate using a fitting technique? I mean if I know how the signal is done and I retrieve some parameters out of it using a f...


Oversampling 8KHz to 44.1KHz

Started by ggabe in comp.dsp14 years ago 16 replies

There's a 8KHz audio sample rate I want to convert up to 44.1KHz sample rate. What's the right approach to keep Mr. Nyquist happy?

There's a 8KHz audio sample rate I want to convert up to 44.1KHz sample rate. What's the right approach to keep Mr. Nyquist happy?


Question related to Sigma-Delta Datasheets

Started by Kiran in comp.dsp12 years ago 7 replies

Hi All, I am going to be selecting a specific sigma-delta converter for an application and am getting a bit confused on the terminology. I...

Hi All, I am going to be selecting a specific sigma-delta converter for an application and am getting a bit confused on the terminology. I have read up on the theory and understand it. Looking at this datasheet: http://focus.ti.com/lit/ds/symlink/ads1251.pdf On the first page, it says 20kHz data rate. Further down, on page 8, it talks about the oversampling and says that the output r...


Choice of Oversampling Ratio in Comm Simulations

Started by Randy Yates in comp.dsp13 years ago 12 replies

Hi Folks, When we simulate a communication system, say, QPSK with simple AWGN, I've noticed that a high sample rate (N*Fsym Fsymthe symbol...

Hi Folks, When we simulate a communication system, say, QPSK with simple AWGN, I've noticed that a high sample rate (N*Fsym Fsymthe symbol rate) is used. Typically it seems N=8. Why is this done? -- % Randy Yates % "She's sweet on Wagner-I think she'd die for Beethoven. %% Fuquay-Varina, NC % She love the way Puccini lays down a tune, and %%% 919-577-9882 ...


Oversampling technique need help...

Started by glias in comp.dsp7 years ago 26 replies

Hello all, I have IR preamp with a gain of 64dB, the output noise is about 50mV peak to peak for a signal of 4V peak peak (max) and the bandwidth...

Hello all, I have IR preamp with a gain of 64dB, the output noise is about 50mV peak to peak for a signal of 4V peak peak (max) and the bandwidth is 350kHz. I have a AD7626 (16 bits 10MSPS ADC) which is largly suffisient for my aplpication. I would want to know what would be the best method to filter the noise (which is white noise and 1/f noise which come from the IR detector) in my band of i...


Calculate variance of noise

Started by cpshah99 in comp.dsp11 years ago 6 replies

HI All I really need your help to understand this noise concept. Can you please tell me how to calculate noise variance for...

HI All I really need your help to understand this noise concept. Can you please tell me how to calculate noise variance for bandpass simulation? And does oversampling affects noise variance calculation. Your help will be greatly appreciated. Thanks Chintan


oversampling from 8khz to 44.1khz using multistage filter

Started by pragati in comp.dsp13 years ago 21 replies

hello all, I want to design a sample rate converter to convert the sampling rate from 8khz to 44.1khz. What should be the designing steps? What...

hello all, I want to design a sample rate converter to convert the sampling rate from 8khz to 44.1khz. What should be the designing steps? What about multistage fiter design.Please help me out!!! regards, pragati