Digital phase shifter with DSP

[kirgizz]

digital phase shifter

Hi,
I want to design a phase shifter with an operation range 0-360 degree.
Input signal can have two signal forms: sine and TTL. I have a Motorola 56xx DSP to solve this problem.

It is possible? Can anybody give me some advice or links please :?:

 

[brmadhukar]

dsp phase shift

Hi,
Does your question mean you have only two waveforms to be phase shifted. If it is thcase, just store the waveforms in a buffer and depending on the required phase you need to access these from particular locations using circular addressing. I am assuming fundamentals only.
B R M

 

[eemapir]

phase shift dsp

hi every body
i want to get pdfsabout dsp and fpga
can you help me
thnak you 8)

 

[kirgizz]

dsp phase shifter

Thank you brmadhukar for the advice.

I really have only two waveforms to be phase shifted. You mean, it can
be implemented in the DSP-device? Ok, I try to find something about it ( circular addressing and dependences).

 

[Circuit_seller]

digital phase shifters

Hi kirgizz

To phase shift input signal the best approach is using an all-pass linear phase filter with group delay equal to your need.

Regards

 

[kirgizz]

all pass filter design 360 degree phase shift

to Circuit_seller

thank you for the advice. Can an all-pass linear phase filter be implemented in this Motorola DSP without having problems with big load?

 

[Circuit_seller]

what are shifters in dsp

Hi

Sorry, i have no experiences in working with motorola DSPs.

Regards

 

[claint]

phase shift a digital signal dsp

All pass filter can give the desired phase

 

[Circuit_seller]

digital phase shifter*fpga

Hi

Remember that an all-pass filter can only realized with IIR filters.

Regards

 

[kirgizz]

digital all pass filter dsp

Thank you very much .

How do you mean, is it possible to implement a digital phase shifter,
a demodulator and two low-pass filters in one DSP with 100 MIPS performance? This all assuming that sampling frequency of ADC is 48KHz and the signal processing must be performed in real-time. :?:
I unfortunately can't estimate the effort that this tasks will make.

 

[satellite]

phase change dsp

Dear Circuit_seller,

do you have any material or reference on linear phase all-pass filters design?

 

[Circuit_seller]

matlab phasenverschiebung mit allpass

Hi

If you want to delay signal in multiple of sampling period, you can easily use a buffer to delay samples.
Also you can design a fractional band linear phase all-pass filter using MATLAB.
If you want a linear phase in whole the band you can combine interploation and a buffer to delay signal (General Case).
For example if you want to delay a signal by 2.5 * samplnig period, you should upsample the signal by 2 and delay it by 5 and then downsample it by 2.
Choosing the best way for required speed depends on your application.
Regards

 

[kirgizz]

shifter in digital signal processors

I want to change the phase by 1 degree step at the run time of my application. It means a variable phase shifter.

I've seen some examples using adaptive digital filters in the internet.
And I think they could be used for variable phase shifting. But there are
many variations. :?
I don't know which method I will use because of lack of detailed information.

Does anyone have an idea?


regards

 

[kirgizz]

shifter in dsp

Hi, everybody.

Litlle question:
Aare there any modifications of an all-pass filter with variable shifting?
The coefficients could be computed at the run-time, are they?


regards

 

[ZmGor]

shifter in dsp

Use Kotelnikov theorem, function s(t)=sum(s(nT)*sinc(x)); x=pi*(t-nT)/T;
Allows to restore an original signal in any point (phase between samples).

 

[claint]

dsp of shifter

Hi,
If your input signal is a complex signal (with x and y value), and the desired angle to rotate is given, you can use CORDIC architecture. All pass filter only allow fixed phase between the input and the output. You can not change the coefficients unless you make these coeff to be programable, but this will cause complexity.
Claint