Thesis-2014-Villarreal-Reyes.pdf (58.24 MB)
Convolutional coding schemes with convenient power spectral density characteristics
thesis
posted on 2014-09-30, 08:00 authored by Salvador Villarreal-ReyesThis thesis analyses the effects caused by the introduction of convolutional coding schemes over
the power spectral density (PSD) of impulse radio (IR) based ultra wideband (UWB)
communication systems. This is an important topic since UWB emissions are expected to comply
with spectral masks imposed by various regulatory bodies.
The spectral analysis of convolutionally codedlMarkov-driven IR-based UWB signals is carried
out by assuming that the data stream at the encoder input is generated by a binary Markov source
(BMS). The signal model covers a wide variety of IR-based modulation schemes such as pulse
position modulation (PPM), binary phase shift keying (BPSK), pulse amplitude modulation (P AM),
biorthogonal PPM (BOPPM), PAMlPPM and pulse shape modulation (PSM), combined with
periodic or random time hopping (TH) and/or direct sequence (DS) multiplication. In addition the
inclusion of attenuation and random jitter has been accounted for in the signal model. Novel closed
form PSD expressions for convolutionally codedlMarkov-driven IR-based UWB signals are
obtained by performing the spectral analysis of the signal model. The formulas provided clearly
identifY. the relative contributions of different parameters allowing enhanced design of UWB
systems.
It is shown that convolutional encoders can be used to generate IR-based UWB signals with
advantageous PSD characteristics. The analysis presented in this dissertation focuses on spectral
line suppression/elimination. Novel maximum free distance (MFD) binary to M-ary convolutional
encoders with spectral line suppression capabilities for M-ary PPM based UWB systems are
presented. Moreover, novel MFD binary convolutional encoders which generate BPSKlQ-BOPPM
IR-based UWB signals whose PSD is spectral line-free are introduced. Results show that for IRbased
UWB systems these convolutional encoders offer improved PSD characteristics when
compared to the standard non-coded case and the best convolutional encoders known. As well, it is
demonstrated that by using these convolutional encoders improved PSD characteristics and
improved bit error rates (BER) can be achieved simultaneously.
History
School
- Mechanical, Electrical and Manufacturing Engineering
Publisher
© Salvador Villarreal-ReyesPublisher statement
This work is made available according to the conditions of the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0) licence. Full details of this licence are available at: https://creativecommons.org/licenses/by-nc-nd/4.0/Publication date
2007Notes
A Doctoral Thesis. Submitted in partial fulfilment of the requirements for the award of Doctor of Philosophy of Loughborough University.EThOS Persistent ID
uk.bl.ethos.487684Language
- en