Authors:
Mohammad Kaisb Layous Alhasnawi
1
;
Ronald G. Addie
2
and
Shahab Abdulla
3
Affiliations:
1
Faculty of Administration and Economics, Sumer University, Thi-Qar and Iraq
;
2
School of Agricultural, Computational and Environmental Science, University of Southern Queensland, Toowoomba and Australia
;
3
Open Access College, University of Southern Queensland, Toowoomba and Australia
Keyword(s):
OFDM, Spread-spectrum OFDM, Spectrum Sharing, Ideal Channel, Galois Field, Nearly Orthogonal.
Related
Ontology
Subjects/Areas/Topics:
Performance Analysis of Wireless Networks
;
Routing Protocols, Qos, Scheduling and Congestion Control
;
Telecommunications
;
Wireless and Mobile Technologies
;
Wireless Information Networks and Systems
Abstract:
Orthogonal frequency division multiplexing (OFDM) systems are reviewed and the Shannon bound is discussed as a criterion of efficient spectrum use and a design criterion. The problem of efficient sharing of spectrum by wireless communication systems is discussed and combined use of direct-sequence spread-spectrum (DSSS) coding and OFDM is proposed as an approach which can achieve efficient spectrum sharing. A system which enables DSSS, with codes from the Galois field of order f where f is a prime larger than 2, to be used efficiently in conjunction with OFDM is then defined, analysed, and implemented. Experiments with this system are described.