DSP application on one dimensional signal

DSP application on one dimensional signal

Patent Review :

digital processor with pulse width modulation module having dynamically adjustable phase offset capability,high speed operation and simultaneous update of multiple pulse width modulation duty cycle registers.

Application No:10/986,255Patent No:US20060064609A1Date of patent:MAR.23,2006Inventor:Kris Bryan 

Summary:

A pulse width modulation generating featuring very highy speed and high resolution capability and abilityb to gerenrate standard conlementary PWM.The patent presents theoretical and experimental based fully digital single phase true sine pwm .The proposed digitally controlledPWM  in a single chip DSP.

Link: http://www.freepatentsonline.com/EP0338798A2.html

IEEE Paper Review :

Using DSP Technology for True Sine PWM Generators for Power Inverters

Author:OVIDIU POP
Publisher:IEEE
Published in: 2014

Link:http://ieeexplore.ieee.org/document/6646780/?denied

Basic Operations using DSP Processor

Basic Operations using DSP Processor

 The processor which we worked on  TMS320F28375.A new project was created and a simple code was written to demonstrate various arithmetic and logical instructions in DSP processor. The output of the instructions was stored in the registers. The values were obtained in real-time with the help of debugging functionality of the software.

FIR Filter Design using Frequency Sampling Method

FIR Filter Design using Frequency Sampling Method

In this experiment we design digital filter using frequency sampling method.We accept input for low pass filter and high pass filter from user.And plot magnitude and phase spectrum.If order of LPF and HPF is same then phase plot is linear and same.
We observed that phase spectrum is linear within the positive lobes of magnitude spectrum, continuity is observed in phase plot forward lobes and also when the phase spectrum goes out of the range of -π to π

FIR filter design using window function

FIR filter design using window function

In this experiment  we design digital filter using window method.We accept the input specifications for two cases ; one for HPF and second for BPF and  design the filter by selecting appropriate window function.Here we used hamming window.Then we plot magnitude spectrum and phase spectrum and verify the value of Ap and As in pass band and stop band from the magnitude spectrum.
In BSF as we increase FS1 and FS2 width of main lobe increase and large range of frequencies can be filtered. 

Chebyshev filter design

Chebyshev filter design

The objective of this experiment was to design a digital chebyshev filter from analog chebyshev filter. Here we take inputs like pass band attenuation, stop band attenuation, pass band frequency, stop band frequency and sampling frequency in Hz.

After plotting the digital filter, the values of pass band and stop band attenuation were verified. As the values were not matching, it was concluded that after increasing the order of the filter, we get better matching between input and output values.
we also observe that ripple indicate the order of filter .

Butterworth Filter Design

Butterworth Filter Design

The aim of this experiment was to design a Butterworth filter.In this experiment a scilab code was developed to design a digital butterworth filter by accepting the following specifications:
1. Pass band attenuation(Ap)
2. Pass band frequency(Fp in hz)
3. Stop band attenuation(As)
4. Stop band frequency(Fs in Hz) 
5. Sampling frequency(Fs in Hz)

Analog filter was first designed according to the input specifications. After designing the analog filter, digital was designed using BLT method. The values of Ap and As were verified from the obtained magnitude response and it was observed.

overlap add and save method

We used linear convolution method  for overlap add method.Overlap Add method is based on decomposing of signal into the sequence and process each sequence with DFT algorithm method.Then we combine each sequence to get final output sequence.
In overlap save method we used circular convolution method.Here we discard repeated sequence  and get final output sequence.
OAM OSM methods are used to find output of FIR filter for real time input signals.