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Performance of concatenated walsh/PN spreading sequences for CDMA systems Sebeni, Johnson Oghenevwareh
Abstract
The Bit Error Rate (BER) performance on the forward link of a Code Division Multiple Access (CDMA) system using the concatenated orthogonal Walsh/m-sequence scheme for bandwidth spreading is studied. Expressions are derived for the BER for single cell systems using the Gaussian approximation and the characteristic function method. Performance results obtained using these expressions are compared to those obtained by Monte Carlo simulation. It was found that BER estimates using the Gaussian approximation are inaccurate because of statistical dependence among the interference terms. To take advantage of multipath diversity, the performance of the Rake receiver is compared to that of the correlation receiver for such systems. A modified Rake receiver is suggested whose BER performance is shown to be better than that of the Rake and correlation receiver especially for Rician fading multipath channels with Rice factor greater than 2dB. The area-averaged BER on the forward link of a multiple cell CDMA system is evaluated. A lognormal probability density function (pdf) is suggested to approximate the distribution of the ratio of the sum of average power of the received signals from other base stations to that of the received signal from the controlling base station which is assumed to be the one with the lowest attenuation to the mobile. A comparison of areaaveraged BER's obtained using this approximate pdf and the Gaussian approximation to those obtained by Monte Carlo simulation shows a reasonable agreement.
Item Metadata
Title |
Performance of concatenated walsh/PN spreading sequences for CDMA systems
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Creator | |
Publisher |
University of British Columbia
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Date Issued |
1998
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Description |
The Bit Error Rate (BER) performance on the forward link of a Code Division Multiple
Access (CDMA) system using the concatenated orthogonal Walsh/m-sequence scheme
for bandwidth spreading is studied. Expressions are derived for the BER for single cell
systems using the Gaussian approximation and the characteristic function method. Performance
results obtained using these expressions are compared to those obtained by
Monte Carlo simulation. It was found that BER estimates using the Gaussian approximation
are inaccurate because of statistical dependence among the interference terms.
To take advantage of multipath diversity, the performance of the Rake receiver is
compared to that of the correlation receiver for such systems. A modified Rake receiver
is suggested whose BER performance is shown to be better than that of the Rake and correlation
receiver especially for Rician fading multipath channels with Rice factor greater
than 2dB.
The area-averaged BER on the forward link of a multiple cell CDMA system is evaluated.
A lognormal probability density function (pdf) is suggested to approximate the
distribution of the ratio of the sum of average power of the received signals from other
base stations to that of the received signal from the controlling base station which is
assumed to be the one with the lowest attenuation to the mobile. A comparison of areaaveraged
BER's obtained using this approximate pdf and the Gaussian approximation
to those obtained by Monte Carlo simulation shows a reasonable agreement.
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Extent |
4671640 bytes
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Genre | |
Type | |
File Format |
application/pdf
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Language |
eng
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Date Available |
2009-05-26
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Provider |
Vancouver : University of British Columbia Library
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Rights |
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.
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DOI |
10.14288/1.0064881
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URI | |
Degree | |
Program | |
Affiliation | |
Degree Grantor |
University of British Columbia
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Graduation Date |
1998-11
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Campus | |
Scholarly Level |
Graduate
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Aggregated Source Repository |
DSpace
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Item Media
Item Citations and Data
Rights
For non-commercial purposes only, such as research, private study and education. Additional conditions apply, see Terms of Use https://open.library.ubc.ca/terms_of_use.