Total capacities of and maximum numbers of users in strictly bandlimited CDMA and FDMA Gaussian channels

R. S. Cheng

doi:10.1109/MILCOM.1992.244156

Total capacities of and maximum numbers of users in strictly bandlimited CDMA and FDMA Gaussian channels

R. S. Cheng^*

^*Corresponding author for this work

Research output: Chapter in Book/Conference Proceeding/Report › Conference Paper published in a book › peer-review

1 Citation (Scopus)

Abstract

The author compares the total capacities of strictly bandlimited additive white Gaussian noise channels with CDMA (code division multiple access) and FDMA (frequency division multiple access) signaling. Theoretically, orthogonal signaling such as FDMA achieves the total capacity of a strictly bandlimited channel by using the sinc pulse with a 'brickwall' spectrum. However, when raised cosine pulses are used, it is found that maintaining orthogonality between users' signals is no longer optimal and the total capacity of the CDMA channel is larger than that of the FDMA channel. The maximum numbers of users supported by CDMA and FDMA are compared, assuming that each user has the same available power and demands the same capacity. It is found that, in a strictly bandlimited channel, CDMA can support up to 70% more users than FDMA, depending on the rolloff factor, the symbol signal-to-noise ratio, and the number of users.

Original language	English
Title of host publication	Military Communications Conference, MILCOM 1992
Publisher	Institute of Electrical and Electronics Engineers Inc.
Pages	247-251
Number of pages	5
ISBN (Electronic)	078030585X
DOIs	https://doi.org/10.1109/MILCOM.1992.244156
Publication status	Published - 1992
Externally published	Yes
Event	1992 Military Communications Conference, MILCOM 1992 - San Diego, United States Duration: 11 Oct 1992 → 14 Oct 1992

Publication series

Name	Proceedings - IEEE Military Communications Conference MILCOM
Volume	1992-October

Conference

Conference	1992 Military Communications Conference, MILCOM 1992
Country/Territory	United States
City	San Diego
Period	11/10/92 → 14/10/92

Bibliographical note

Publisher Copyright:
© 1992 IEEE.

Access to Document

10.1109/MILCOM.1992.244156

Cite this

Cheng, R. S. (1992). Total capacities of and maximum numbers of users in strictly bandlimited CDMA and FDMA Gaussian channels. In Military Communications Conference, MILCOM 1992 (pp. 247-251). Article 244156 (Proceedings - IEEE Military Communications Conference MILCOM; Vol. 1992-October). Institute of Electrical and Electronics Engineers Inc.. https://doi.org/10.1109/MILCOM.1992.244156

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title = "Total capacities of and maximum numbers of users in strictly bandlimited CDMA and FDMA Gaussian channels",

abstract = "The author compares the total capacities of strictly bandlimited additive white Gaussian noise channels with CDMA (code division multiple access) and FDMA (frequency division multiple access) signaling. Theoretically, orthogonal signaling such as FDMA achieves the total capacity of a strictly bandlimited channel by using the sinc pulse with a 'brickwall' spectrum. However, when raised cosine pulses are used, it is found that maintaining orthogonality between users' signals is no longer optimal and the total capacity of the CDMA channel is larger than that of the FDMA channel. The maximum numbers of users supported by CDMA and FDMA are compared, assuming that each user has the same available power and demands the same capacity. It is found that, in a strictly bandlimited channel, CDMA can support up to 70\% more users than FDMA, depending on the rolloff factor, the symbol signal-to-noise ratio, and the number of users.",

author = "Cheng, \{R. S.\}",

note = "Publisher Copyright: {\textcopyright} 1992 IEEE.; 1992 Military Communications Conference, MILCOM 1992 ; Conference date: 11-10-1992 Through 14-10-1992",

year = "1992",

doi = "10.1109/MILCOM.1992.244156",

language = "English",

series = "Proceedings - IEEE Military Communications Conference MILCOM",

publisher = "Institute of Electrical and Electronics Engineers Inc.",

pages = "247--251",

booktitle = "Military Communications Conference, MILCOM 1992",

}

Cheng, RS 1992, Total capacities of and maximum numbers of users in strictly bandlimited CDMA and FDMA Gaussian channels. in Military Communications Conference, MILCOM 1992., 244156, Proceedings - IEEE Military Communications Conference MILCOM, vol. 1992-October, Institute of Electrical and Electronics Engineers Inc., pp. 247-251, 1992 Military Communications Conference, MILCOM 1992, San Diego, United States, 11/10/92. https://doi.org/10.1109/MILCOM.1992.244156

Total capacities of and maximum numbers of users in strictly bandlimited CDMA and FDMA Gaussian channels. / Cheng, R. S.
Military Communications Conference, MILCOM 1992. Institute of Electrical and Electronics Engineers Inc., 1992. p. 247-251 244156 (Proceedings - IEEE Military Communications Conference MILCOM; Vol. 1992-October).

Research output: Chapter in Book/Conference Proceeding/Report › Conference Paper published in a book › peer-review

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AU - Cheng, R. S.

PY - 1992

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N2 - The author compares the total capacities of strictly bandlimited additive white Gaussian noise channels with CDMA (code division multiple access) and FDMA (frequency division multiple access) signaling. Theoretically, orthogonal signaling such as FDMA achieves the total capacity of a strictly bandlimited channel by using the sinc pulse with a 'brickwall' spectrum. However, when raised cosine pulses are used, it is found that maintaining orthogonality between users' signals is no longer optimal and the total capacity of the CDMA channel is larger than that of the FDMA channel. The maximum numbers of users supported by CDMA and FDMA are compared, assuming that each user has the same available power and demands the same capacity. It is found that, in a strictly bandlimited channel, CDMA can support up to 70% more users than FDMA, depending on the rolloff factor, the symbol signal-to-noise ratio, and the number of users.

AB - The author compares the total capacities of strictly bandlimited additive white Gaussian noise channels with CDMA (code division multiple access) and FDMA (frequency division multiple access) signaling. Theoretically, orthogonal signaling such as FDMA achieves the total capacity of a strictly bandlimited channel by using the sinc pulse with a 'brickwall' spectrum. However, when raised cosine pulses are used, it is found that maintaining orthogonality between users' signals is no longer optimal and the total capacity of the CDMA channel is larger than that of the FDMA channel. The maximum numbers of users supported by CDMA and FDMA are compared, assuming that each user has the same available power and demands the same capacity. It is found that, in a strictly bandlimited channel, CDMA can support up to 70% more users than FDMA, depending on the rolloff factor, the symbol signal-to-noise ratio, and the number of users.

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Total capacities of and maximum numbers of users in strictly bandlimited CDMA and FDMA Gaussian channels

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