Crest Factor Reduction in MC-CDMA Employing Carrier Interferometry Codes
<p>This paper addresses signal compactness issues in MC-CDMA employing carrier interferometry codes using the measure of crest factor (CF). Carrier interferometry codes, applied to <math alttext="$N$"> <mi>N</mi> </math>-carrier MC-CDMA systems, enable <ma...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
| Published: |
SpringerOpen
2004-01-01
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| Series: | EURASIP Journal on Wireless Communications and Networking |
| Subjects: | |
| Online Access: | http://dx.doi.org/10.1155/S1687147204406094 |
| Summary: | <p>This paper addresses signal compactness issues in MC-CDMA employing carrier interferometry codes using the measure of crest factor (CF). Carrier interferometry codes, applied to <math alttext="$N$"> <mi>N</mi> </math>-carrier MC-CDMA systems, enable <math alttext="$2N$"> <mn>2</mn><mi>N</mi> </math> users to simultaneously share the system bandwidth with minimal degradation in performance (relative to the <math alttext="$N$"> <mi>N</mi> </math>-orthogonal-user case). First, for a fully loaded (<math alttext="$K=N$"> <mi>K</mi><mo>=</mo><mi>N</mi> </math> and <math alttext="$K=2N$"> <mi>K</mi><mo>=</mo><mn>2</mn><mi>N</mi> </math> users) MC-CDMA system with practical values of <math alttext="$N$"> <mi>N</mi> </math>, it is shown that the CF in downlink transmission demonstrates desirable properties of low mean and low variance. The downlink CF degrades when the number of users in the system decreases. Next, the high CF observed in the uplink is characterized and the poor CF in a partially loaded downlink as well as uplink is effectively combated using Schroeder's analytical CF reduction techniques.</p> |
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| ISSN: | 1687-1472 1687-1499 |