Performance of a binary pulse position modulated ultra-wideband system with direct sequence spreading for multiple access

by Venkatesan, Vinod

Abstract (Summary)
There has been tremendous technological advancement in the area of high-speed

indoor wireless local area networks (WLAN's) in recent years. All the existing tech-

nologies such as IEEE 802.11a,b are bandwidth limited and high powered systems. The

challenge any wireless technology faces is to minimize both the power consumption and

the cost (implementation and bandwidth). The capacity of these systems is governed

by the shannon's capacity theorem, C=Blog2 (1+SNR) where B is the available band-

width and SNR is the signal-to-noise power ratio. If the technology is not limited

by bandwidth, it is possible to achieve capacities close to the shannon's limit. Ultra-

Wideband (UWB) is a technology which spans the entire frequency spectrum (dedicated

and unlicensed). It is capable of achieving high data rates over short distances with

low power consumption. This thesis analyzes the error performance of a UWB system

with pulse position modulation (PPM) for data modulation and direct sequence (DS)

spreading for multiple access over indoor lognormal fading channels. A RAKE receiver

is used to combine a subset of the resolvable multipath components using the maximal

ratio combining technique. Inter-path and multiple access interferences are modeled and

incorporated into the bit error rate (BER) expressions. Performance of the optimally-

spaced and orthogonal signaling schemes are compared. Some effects of non-idealities in

the receiver signal processing are briefly described.

Bibliographical Information:

Advisor:Liu, Huaping; Magana, Mario

School:Oregon State University

School Location:USA - Oregon

Source Type:Master's Thesis

Keywords:ultra wideband devices pulse modulation electronics signal processing


Date of Publication:01/12/2004

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