Description
In the last few years, there has been a new development in wireless technology. An unprecedented transformation in the design, deployment, and application of short range wireless devices and services is in progress today and systems based on the emerging Ultra-wideband radio (UWB) radio technology with the potential to provide solutions for many of today's problems in the areas of spectrum management and radio system engineering. UWB radio is a rapidly developing wireless technology that promises unprecedented data rates for short-range commercial radios, combined with precise positioning and high energy efficiency. The approach employed by UWB radio devices is based on sharing already occupied spectrum resources by means of the overlay principle, rather than looking for unoccupied but possibly unsuitable new bands. This thesis covers the aspect of pulse generation of orthogonal UWB signals using the Haar based functions. We have generated a closed-form expression using which an infinite number of orthogonal signals can be designed. These signals not only fit to the Federal Communications Commission (FCC) regulations for power emission for indoor communications within the stipulated bandwidth of 3.1-0.6 GHz but also demonstrate extremely high power spectral efficiency. For a pulse width of 1.8 ns, the power spectral efficiencies of the designed pulses ranged from 75% to 90% for these pulses. A detailed design analysis is provided in this thesis. The performance of the designed signals was investigated under different modulation schemes, namely, pulse position modulation (PPM), pulse shape modulation (PSM), and a new scheme which is a combination of PPM and PSM. It was shown that the designed signals provided an efficient and robust means of communication under Additive White Gaussian Noise(AWGN) channel and under a multipath channel using the Saleh-Valenzuela model.
