Experiment 10:Signal Processing Application

This was a Group Experiment performed by Aishwarya Bannore, Varad Choudhari, Gauri Joijode, Amisha Khimani and Apoorva Laharia. We choose "Morse Code Generator from a given Analog Signal" as an application.

Problem Definition : 1) Accept Analogy input and convert it into Digital Signal(Binary).
2) Covert Binary to Morse and implement the dots and dashes as 0 and 1 respectively.
    (Dots = 1 = LED ON, Dash = 0 =LED OFF)

Patent Review :
Portable Morse Code Signaling DevicePatent No. : US3668684
Inventors : Johnson, Donald W.
                 Stovall, Ronald J.
                 Wheelock, Larry A.
Publication : 20th December, 1970
Summary :
This invention tells about a signaling device which flashes a coded signal which is electronically generated. A diode encoder having a plurality of switches is provided to select flip-flops that are set which, upon clearing of the shift register, provide a Morse code signal. Two oscillators are used, one to pulse the shift register and a second one to pulse diode encoder for resetting flip-flops.
Applications :
Morse code is used to a encode a message to be transmitted by sound or light signal. Signals are encoded for privacy purposes. The above device will send the Morse code in the form of a light which can be a mean of communication.

IEEE Paper Review:Morse Code Generator using Microcontroller and Alphanumeric Keypad
Publisher : Paparao Nalajala
                 Bhavana Godavarth
                 M Lakshmi Raviteja
                 Deepthi Simhadri
Summary :
This research paper proposes a technique of generation of Morse code using a alphanumeric keypad and microcontroller interface. Morse code being a reliable source of transmission for private data, is used in military and navy applications. For a person with no idea of Morse code wants to generate it for sending messages this method can be used.
Hardware :
The alphanumeric keyboard is interfaced to the microcontroller which is used to type the message in English. The microcontroller changes this message to Morse code which is the displayed on the LCD.
Application :
Morse code is very crucial in communication for sending distress calls and in Military and Navy communication systems.

Patent : https://drive.google.com/open?id=0BwzFGc0wvjNvRXYwNEZLTHh2emM
Portable Morse Device : https://drive.google.com/open?id=0BwzFGc0wvjNvb1k2WXBCd25wMlU
Plagiarism : https://drive.google.com/open?id=0BwzFGc0wvjNvckgwMG44ZGhvOVE
IEEE Paper : https://drive.google.com/open?id=0BwzFGc0wvjNvRnk3eWxRRk1pMVU

Experiment 9: Basic Operations using DSP Processor

We studied programming on a DSP kit using Assembly Level Language. The kit used was TMS320F28375. This was demonstrated by a senior in our class. Instructions required for Arithmetic, Logical and Shift Operations were demonstrated. The changes in the values of the registers before and after execution of each operation were observed. The DSP was programmed using Code Composer Studio.

Experiment 8: Design of FIR Filter using FSM

We performed design of Linear Phase FIR Filter using Frequency Sampling Method. We took two case: Low Pass FIR Filter and High Pass FIR Filter using Scilab. We specified the stop band and pass band attenuation, stop band and pass band frequencies and sampling frequency in each case. We studied the magnitude and phase spectrum for each case. Phase response for both LPF and HPF remains same as long as the order is kept same in both cases.

FSM : https://drive.google.com/open?id=0BwzFGc0wvjNvbng1WWJIWlYwNkU

Experiment 7: Design of FIR Filter using Windowing Method

We performed design of Linear Phase FIR Filter using Windowing Method. We took two case: Low Pass FIR Filter and Band Pass FIR Filter using Scilab. We specified the stop band and pass band attenuation, stop band and pass band frequencies and sampling frequency in each case. Depending on the value of Pass Band Attenuation we can choose the Window Function from:  Rectangular, Bartlett, Hamming, Hanning and Blackman. We studied the magnitude and phase spectrum for each case. The observed phase spectrum in each case is linear.

FIR Filter: https://drive.google.com/open?id=0BwzFGc0wvjNvMnBtWHBWNy1XVjQ
Window: https://drive.google.com/open?id=0BwzFGc0wvjNvQVNORGJ6VmJocWc

Experiment 6: Design of Chebyshev IIR Filter

We performed design of Low Pass and High Pass Chebyshev Filter and observed its Magnitude plots using Scilab. We have used BLT method for the filter design. We specified the stop band and pass band attenuation, stop band and pass band frequencies and sampling frequency in each case. The observed and the calculated values of the stop band and pass band attenuation are nearly same. Number of ripples in the pass band gives the order of the filter. In magnitude response, Chebyshev is equiripple in pass band and monotonic is stop band.

Chebyshev : https://drive.google.com/open?id=0BwzFGc0wvjNvNDV0c2lQdm5nOVk

Experiment 5: Design of Butterworth Filter

We performed design of Low Pass and High Pass Butterworth Filter and observed its Magnitude plots using Scilab. We specified the stop band and pass band attenuation, stop band and pass band frequencies and sampling frequency in each case. Order can be increased for greater accuracy. All poles in both HPF and LPF Butterworth Filter lie inside the unit circle. So both filters are stable.

Butterworth Filter : https://drive.google.com/open?id=0BwzFGc0wvjNvMGYxTG42aGRoTU0

Experiment 4: Filtering of Long Data Sequence

We performed Filtering of Long Data Sequence using Overlap Add Method(OAM) and Overlap Save Method(OSM) using C programming. These methods find their applications in processing real time signals. These algorithms decrease the delay in getting the output. In OAM the signal is decomposed into N sequences and zero padding is added. In OSM the decomposed signal of the first short length consists of zero, since the second signal consists the first signal as well, it saves the data.

OAM : https://drive.google.com/open?id=0BwzFGc0wvjNvR0tqVDY0UkhoVFE
OSM : https://drive.google.com/open?id=0BwzFGc0wvjNvSDFsR21tS3RZeEU