An improved OCDMA/OCDMA scheme based on displaced orthogonal user sets

被引：11

作者：

Vanhaverbeke, F ^{[1
]}

Moeneclaey, M ^{[1
]}

机构：

[1] Univ Ghent, TELIN Dept, B-9000 Ghent, Belgium

来源：

IEEE COMMUNICATIONS LETTERS | 2004年 / 8卷 / 05期

关键词：

interference cancellation; oversaturated channels; quasi-orthogonal sequences;

D O I：

10.1109/LCOMM.2004.827453

中图分类号：

TN [电子技术、通信技术];

学科分类号：

0809 ;

摘要：

We introduce a new type of OCDMA/OCDMA for oversaturated channels, by displacing in time the orthogonal signature sets of the users. A displacement by an integer multiple of a chip period considerably improves the performance of iterative detection of the user data, as compared to quasi-orthogonal sequences (QOS) and conventional random O/O sequences. An additional displacement by half a chip period reduces the variance of the cross correlation between the. users of the two sets by up to 50%, and results in an additional performance improvement for square root cosine rolloff chip pulses. This improved O/O system can accommodate a number of Users equal to twice the spreading gain N, when N greater than or equal to 32. For a practical rolloff of 25% and N = 128, the acceptable channel overload Can almost be tripled with improved O/O as compared to conventional O/O.

引用

页码：265 / 267

页数：3

共 14 条

[1] Spreading codes for direct sequence CDMA and wideband CDMA cellular networks
Dinan, EH
Jabbari, B
[J]. IEEE COMMUNICATIONS MAGAZINE, 1998, 36 (09) : 48 - 54
[2] Overview of multicarrier CDMA
Hara, S
Prasad, R
[J]. IEEE COMMUNICATIONS MAGAZINE, 1997, 35 (12) : 126 - 133
[3] Low complexity optimal joint detection for oversaturated multiple access communications
Learned, RE
Willsky, AS
Boroson, DM
[J]. IEEE TRANSACTIONS ON SIGNAL PROCESSING, 1997, 45 (01) : 113 - 123
[4] Proakis J. G., 2008, Digital communications, V5th
[5] MULTIUSER SIGNALING IN THE SYMBOL-SYNCHRONOUS AWGN CHANNEL
ROSS, JAF
TAYLOR, DP
[J]. IEEE TRANSACTIONS ON INFORMATION THEORY, 1995, 41 (04) : 1174 - 1178
[6] VECTOR ASSIGNMENT SCHEME FOR M+N USERS IN N-DIMENSIONAL GLOBAL ADDITIVE CHANNEL
ROSS, JAF
TAYLOR, DP
[J]. ELECTRONICS LETTERS, 1992, 28 (17) : 1634 - 1636
[7] Multiple access using two sets of orthogonal signal waveforms
Sari, H
Vanhaverbeke, F
Moeneclaey, M
[J]. IEEE COMMUNICATIONS LETTERS, 2000, 4 (01) : 4 - 6
[8] Extending the capacity of multiple access channels
Sari, H
Vanhaverbeke, F
Moeneclaey, M
[J]. IEEE COMMUNICATIONS MAGAZINE, 2000, 38 (01) : 74 - 82
[9] *TIA EIA, 2001, 3GPP2 TIAEIA
[10] VANHAFERBEKE F, 2002, IEEE INT C COMM ICC

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