Research in the field of random access protocols for narrow-band systems started as early
as the 1970s with the introduction of the ALOHA protocol. From the research done in
slotted narrow-band systems, it is well known that contention results in all the packets
involved in the contention being unsuccessful. However, it has been shown that in the
presence of unequal power levels, ore of the contending packets may be successful. Ibis
is a phenomenon called capture. Packet capture has been shown to improve the
performance of slotted narrow-band systems.
Recently, much work has been done in the analysis of spread-spectrum ALOHA type
code-division multiple access (CDMA) protocols. The issue of designing power control
techniques to improve the performance of CDMA systems by reducing multiple access
interference (MAl) has been a subject of much research. It has been shown that in the
presence of power control schemes, the performance of spread-ALOHA CDMA systems
is improved. However, it is also widely documented that the design of power control
schemes capable of the ideal of compensation of radio propagation techniques is not
possible for various reasons, and hence the imperfections in power control.
None of the research known to the author has looked at capture in spread-ALOHA
systems, and to a greater extent, looked at expressions for the performance of spreadALOHA
systems in the presence of capture. In this thesis we introduce spread-ALOHA systems with capture as a manifestation of the
imperfections in power control. We propose novel expressions for the computation of the
perfonnance ofspread-ALOHA systems with capture. / Thesis (M.Sc.Eng.)-University of KwaZulu-Natal, 2005.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:ukzn/oai:http://researchspace.ukzn.ac.za:10413/2824 |
| Date | January 2005 |
| Creators | Mpako, Vuyolwethu Maxabiso Wessels. |
| Contributors | Takawira, Fambirai. |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Thesis |
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