The effect of carrier frequency offsets on downlink and uplink MC-DS-CDMA

Author

Steendam, Heidi ; Moeneclaey, Marc

Author_Institution

Telecommun. & Inf. Process. (TELIN) Dept., Ghent Univ., Gent, Belgium

Volume

19

Issue

12

fYear

2001

fDate

12/1/2001 12:00:00 AM

Firstpage

2528

Lastpage

2536

Abstract

In this paper, we study the sensitivity of uplink and downlink MC-DS-CDMA to carrier frequency offsets, assuming orthogonal spreading sequences. For both uplink and downlink MC-DS-CDMA, we show that the performance rapidly degrades for an increasing ratio of maximum frequency offset to carrier spacing. We point out that the degradation in the uplink is larger than in the downlink because only the former is affected by multiuser interference. For a given (small) ratio of maximum frequency offset to carrier spacing, enlarging the spreading factor in a fully loaded system does not affect the downlink degradation but strongly increases the uplink degradation. Finally, we show that the downlink degradations of MC-DS-CDMA and fully loaded MC-CDMA are the same, provided that for both systems the ratio of frequency offset to carrier spacing is the same

Keywords

code division multiple access; radiofrequency interference; spread spectrum communication; carrier frequency offsets; carrier spacing; degradation; downlink MC-DS-CDMA; maximum frequency offset; multicarrier direct-sequence CDMA; multiuser interference; orthogonal spreading sequences; spreading factor; uplink MC-DS-CDMA; Bandwidth; Degradation; Downlink; Frequency synchronization; Interference; Local area networks; Multiaccess communication; Multicarrier code division multiple access; OFDM modulation; Transmitters;

fLanguage

English

Journal_Title

Selected Areas in Communications, IEEE Journal on

Publisher

ieee

ISSN

0733-8716

Type

jour

DOI

10.1109/49.974617

Filename

974617