Abstract:
Continuously altering wireless benchmarks and protocols have resulted in
conscious shift in the direction of the programming methodology involved in
designing / implementing new radio systems. This has led to a tremendous interest in
Software Defined Radios (SDR). They offer flexibility in choosing economical
modulation schemes and robust coding thereby enabling reliable communication.
Modulation and demodulation techniques in digital signal processing are the key
technology of the SDR implementation; therefore, researchers are probing into new
avenues of these digital techniques through a variety of software platforms. GNU
(GNU’s Not Unix) Radio is gratis / open source software which contains numerous
signal processing building blocks available to realize wireless simulations based on
software. Software radios provide a flexible mean to realize a lot of waveforms which
can be deal with a single hardware platform by simply changing the programming /
code.
Adaptive modulation technique offers spectral efficiency for communication
systems by adapting the modulation scheme in accordance with the instantaneous
channel / wireless conditions, interference state and throughput or data rate needs. The
adaptive structure helps in dynamically altering the communication method basing on
the attributes of the arriving signal and characteristics of the propagation channel.
This thesis presents a comprehensive framework for establishing and effectively
operating an adaptive modulation / coding technique based on the wireless channel
parameters. As a result of this framework our indigenous SDR development
organizations may analyze and adapt their waveforms.
