Development of Enhanced Ultra Wideband Antenna designs and Rake Receivers for Indoor Wireless Systems
The ultra-wideband (UWB) technology in the present and future is considered as one of the wide promising wireless technologies. For this reason, there are many indoor short range wireless applications such as mobile devices, laptops, scanners, printers, and flash drives are suitable in use. These...
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| Format: | Thesis |
| Language: | English |
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| Online Access: | http://dspace.unimap.edu.my:80/xmlui/bitstream/123456789/59812/1/p.1-24..pdf http://dspace.unimap.edu.my:80/xmlui/bitstream/123456789/59812/2/Full%20Text.pdf |
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| Summary: | The ultra-wideband (UWB) technology in the present and future is considered as one of
the wide promising wireless technologies. For this reason, there are many indoor short
range wireless applications such as mobile devices, laptops, scanners, printers, and flash drives are suitable in use. These devices are going to be miniaturized all over the world to be lightweight for carrying and low cost purposes. This characteristic increases the real demand on designing small size UWB systems. In this thesis, five UWB antenna designs and five UWB rake-receiver structures are proposed to cover the entire UWB frequency range (3.1-10.6 GHz) as defined by Federal Communication Commission
(FCC) that consequently provides many challenges in the wireless communication area
including antenna design and receiver scheme. These proposed antennas have small
sizes and improved gain and radiation efficiency compared with the literature ones and
the performances are analyzed under several antenna parameters to guarantee that the
transmitted signal will be correctly recovered at the receiver end. The small antenna
designs are low profile printed patch with planar ground plane antennas that satisfy
UWB technology requirements and they are namely: bird feet-shaped patch antenna,
planar finger-shaped patch antenna, rake-shaped patch antenna, slotted and notched
rectangular patch antenna, and spade-shaped patch antenna. The designed antennas have
compact sizes of 1.575 x 40 x 35 mm3, 1.575 x 30 x 28 mm3, 1.575 x 30 x 30 mm3,
1.575 x 30 x 26 mm3, and 1.575 x 30 x 28 mm3; and cover the following frequency
bands 3.1-12 GHz, 3.5-12 GHz, 3-12 GHz, 3.3-14 GHz, and 3.5-12 GHz; respectively.
The substrate material used is Taconic TLY-5 to reduce the cost of antenna. It has
demonstrated that the simulation results are agreed with the measurement results of the
proposed antennas which are suitable for UWB wireless systems including ultra-wide
bandwidth, return loss less than -10 dB over this bandwidth, omni-directional radiation
patterns, high surface current distribution, high gain and very good radiation efficiency.
The other part of this thesis focuses on the miniaturizing the rake-receiver by reducing
the correlators used and obtain improved system performance. This improvement led to
increase the UWB promising ability to provide high data rate at low power consumption
(-41.3 dBm/MHz). Rake receivers suitable for resolvable multi-path components
(MPCs) with multi-path techniques to provide diversity and to capture as much energy
as possible from the received signals. Five rake-receiver structures of four fingers each
are proposed with selective and partial maximal ratio combining (MRC) techniques and
they are namely: symbol sign distribution rake-receiver, signal sign separation MRC
rake-receiver, demodulation rake-receiver, adaptive filter of M-max partial update
recursive least square (RLS) algorithm rake-receiver, and minimum mean square error
(MMSE) equalized rake-receiver. These five rake-receiver structures were all simulated
by using MATLAB software to indicate that interferences and noises are effectively
suppressed by reducing the bit error rate (BER) of UWB wireless communication
systems especially at 0 dB signal to noise ratio (SNR). The simulation results show the
mitigating of error bit probability of selective and partial rake receivers on standard
IEEE 802.15.3a channel models (CM1, CM2, CM3, and CM4) for different number of
users. |
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