Description
Wireless communication has always been one of the important sources of communication. But since the introduction of cellular phone technology about two decades ago, it has grown at an unprecedented rate. Wireless communication has evolved a lot, and is no more limited to the telephone service. Spectrum is limited and is getting congested with increasing wireless devices and different technologies, causing interference. One of the emerging technology which has potential to provide solution for this problem is ultra Wideband (UWB) communication. UWB technology employs the approach of sharing already occupied spectrum by means of the overlay principle. UWB is a rapidly developing wireless technology which occupies a very large bandwidth of about 7.5 GHz, and promises very high data rates for short range communication. This thesis covers the aspect of pulse generation of orthogonal UWB signals using the Discrete Prolate Spheroidal Sequences (DPSS). We discuss DPSS and their characteristics. Set of 16 DPSS, 0th order through 15th order, are generated. We employ these set of DPSS to generate two different orthogonal signals for binary modulation techniques, and four different orthogonal signals for quadrature modulation techniques. Moore Penrose pseudoinverse is used while generating these pulses to meet the Federal Communication Commission (FCC) regulations for power emission for indoor communications within the stipulated bandwidth of 3.1 -- 10.6 GHz. A detailed design analysis is provided in this thesis. The performance of the designed signals is investigated under two different Binary modulation schemes and two different quadrature modulation schemes. For Binary modulation schemes we employ Pulse Position modulation (2-PPM) and Pulse Shape modulation (2-PSM). For quadrature modulation schemes we employ Pulse Shape modulation (4-PSM) and combination of PPM and PSM (4-PPM-PSM). It is shown that the designed signals provide an efficient and robust means of communication under Additive White Gaussian Noise(AWGN) channel and under a multipath channel using the Saleh Valenzuela model. Bit error rate (BER) curves are plotted for both these channel conditions.
