Abstract:
A Software Defined Radio (SDR) is a radio transceiver that is well defined in software and
whose physical layer conduct, parameters, and protocols can be fundamentally modified through
software as a waveform. This approach will increase the flexibility of the device by changing its
operating parameters while not having an upgrade or exchange of any hardware parts. Thus,
SDR provides a platform capable of supporting distinctive waveforms. The main distinction lies
in the focus of implementation, a few waveforms are designed which accomplish higher data
rate, whereas others prioritize range and transmission capacity. It is recognized that strategic
military radios need wideband and narrowband waveforms for fulfilling most of the military
requirements. Wideband networking waveform (WBNW) ensures a high data rate; this lowers
the range whereas for applications requiring long-range communication, narrowband networking
waveform (NBNW) tends to be a dominant choice.
Modern strategic VHF communication frameworks require increasing throughputs to support a
wide variety of applications for military, commercial, and civilian applications. It requires a
combination of spectral efficiency and better ber performance. To meet the heterogeneous
requirement of future wireless networks, an adaptive multimode multi-band narrowband
waveform for software-defined radio based on Continuous Phase Modulation (CPM) is presented
in this thesis. Due to higher spectral efficiency and constant envelop property provided by CPM,
we show that the proposed waveform attains higher throughput by shifting towards multiple
bandwidths and for the appropriate choice of alphabet size M, pulse length L and modulation
index, h.
In the next step a novel algorithm for link adaptation scheme for packet-based Narrowband
networking SDR waveform is proposed. To reduce the packet re-transmissions overhead, the
configurable system parameters need to be changed dynamically according to the channel
conditions ensuring specific Quality of Service (QoS) requirements and reduces the
computational complexity/power consumption by restricting the throughput to the required
value.
At the end, the BER performance of proposed multimode multiband waveform for CPM is
evaluated in AWGN and Stanford University Interim channel (SUI) channel model.
