DSP Apllication on One Dimensional Signal

IEEE Paper Review: Design of AM Modulation Signal Generator based on Matlab/DSP builder.               
Authors: Junshan Gao, Nan Liu, Xinghu Xu  
Publisher :- IEEE  
Published in: 2010 2nd International Conference on Industrial & information Systems

Summary - Design of traditional AM Modulator requires high hardware theoretical knowledge. Further to vary modulation index or modulating signal frequency, entire designed hardware is to be modified;there by increasing system cycle development & reducing usability of existing system. An alternative to this is Direct Digital Synthesis(DDS) is an all digital frequency synthesis technology.

DDS is a total digital frequency synthesizer,including phase accumulator,wave memorizer, conversion of D/A and LPF.

AM Modulation Signal Generator was first established using Matlab/Dsp builder. It was the simulated to check whether desired operation was achieved. It can then be converted to realize VHDL document for system level realization using RTL level code.

 

Paper - > http://ieeexplore.ieee.org.sci-hub.cc/document/5565794/?reload=true

Patent Review : Amplitude & Phase Modulator

Application No - PCT/US2001/043502

Patent No - WIPO Patent Application WO/2002/049300

Date of Patent - 06/20/2002

Inventors - Pehlke, David R., Hadjichristos, Aristotle, Camp Jr., William O

Summary - 

However, To ensure reliable wireless communication between hand held devices, Mobile terminals usually have significant constraints on overall operating power. 
An RF power amplifier circuit comprising of -  a power amplifier biased for saturated mode operation and operative to generate an RF output signal by amplifying a constant envelope RF input signal ; a modulator comprising a resistive load(voltage controlled resistor - Field Effect Transistor) for coupling an operating voltage input of power amplifier to a supply voltage.
An RF signal that includes frequency or phase information in addition to amplitude information may be separated into first and second signal components. The first signal is at the desired transmit frequency and has a constant amplitude envelope, but includes the phase or frequency modulation information of the original RF signal to be amplified.
The second signal is an amplitude modulation (AM) signal and represents the AM information in the original RF signal to be amplified.
 A balanced power amplifier circuit (2 - stage) is then required to combine 2 signals to recover original modulating signal.

Patent - > http://www.freepatentsonline.com/WO2002049300A2.pdf