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A NEW SPREADING CODE FOR MULTI-USER MC-SS COMMUNICATION SYSTEMS

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Abstract (2. Language): 
Multi-carrier spread spectrum (MCSS) communication systems are able to mitigate the effects of fading, interferences and Doppler frequency shifts as well as to support multiple access schemes. It is possible to get optimum performance from MCSS systems by carefully choosing the spreading sequences. However, due to inter-user interferences, performance degrades as the number of users increases unless the transmission channels are modeled and estimated. In this paper, we present a new spreading sequence obtained from a complex quadratic sequence multiplied by a pseudo random noise sequence, thus exploiting the properties of constant envelope and statistical independence. Our approach is based on the time-frequency characterization of the wireless communication channel by means of discrete evolutionary transform. The properties of the new spreading sequence enables us to estimate the parameters of multi-user channels, both for uplink and downlink transmission cases, and design a receiver that is robust to channel noise, inter-user interference and intentional jammers. The performance of the proposed system is illustrated by simulations.
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REFERENCES

References: 

[1] S. Hara and R. Prasad, .Overview of
multicarrier CDMA,. IEEE Communication
Magazine , Vol. 35, No.12, pp. 126.133,
1997.
[2] J. Tan and G. Stuber, .Anti-jamming
performance of multi-carrier spread spectrum
with constant envelope, IEEE Int. Conf. on
Comm. , Vol. 1, pp. 743.747, May 2003.
[3] Suleesathira, R., Akan, A. and Chaparro, L.
F., .Discrete Evolutionary Transform for
Time-Frequency Signal Analysis,. J. Franklin
Institute, Special Issue on Time-Frequency
Signal Analysis and its Applications, pp.
347-364, Vol. 337, No. 4, Jul. 2000.
[4] Senay, S., Akan, A., Chaparro, L.F., “Time-
Frequency Channel Modeling and Estimation
of Multi-Carrier Spread Spectrum
Communication Systems,” IEEE The 30th
International Conference on Acoustic, Speech
and Signal Processing, ICASSP-2005, Vol. 3,
pp. 754-748, Philadelphia, PA, March 18-23,
2005.
[5] P.A. Bello, .Characterization of randomly
time-variant linear channels,. IEEE Trans. on
Comm. Systems, pp. 360.393, Dec. 1963.
[6] M. Tsatsanis and G.B. Giannakis, .Subspace
Methods for blind estimation of time-varying
FIR channels,. IEEE Trans. Sig. Proc., pp.
3084.3093, Dec. 1997.
[7] A.M. Sayeed and B. Aazhang, .Joint
multipath-Doppler diversity in mobile
wireless communications,.IEEE Trans. on
Comm.,Vol.47, No.1, pp. 123.132, Jan. 1999.
[8] Chaparro, L.F., and Alshehri, A.A., .Channel
Modeling for Spread Spectrum via
Evolutionary Transform,. IEEE Int. Conf. on
Acoustics, Speech, and Signal Processing,
ICASSP'04, Vol. II, pp. 609.612, May 17-21,
2004.
[9] V. Aue and G. Fettweis, .Higher-level multicarrier
modulation and its implementation,.
IEEE Int. Symp. on Spread Spectrum Tech.
and App., Vol. 1, pp. 126. 130, Sept. 1996.
[10] Fetweiss, G.P., Nahler, A., and Khne, J., .A
Time Domain View to Multi-Carrier Spread
Spectrum,. IEEE 6th Int. Symp. on Spread
Spec. Tech and. Appli., pp. 141-144, NJIT,
New Jersey, 2000.
[11] Kuhne, J.,, Nahler, A., and Hosemann, M.,
Fetweiss, G.P., Kovacs, G., and Riha G., .A
Demonstrator for a Low-Cost, Cordless,
Multi-Carrier Spread Spectrum System,.
IEEE Trans. on Ultrasonics, Ferroelectrics
and Frequency Control, Vol. 47, No. 1, pp.
58-64, Jan. 2000.
[12] Kang, S.G., Ha, Y.M., Joo, E.K., .A
comparative investigation on channel
estimation algortihms for OFDM in mobile
communications,. IEEE Transactions on
Broadcasting, Vol. 49, No. 2, pp. 142.149,
June 2003.
A New Spreading Code For Multi-User Mc-Ss Communication Systems
Yalçın ÇEKİÇ , Seda ŞENAY, Aydın AKAN, Luis F. CHAPARRO
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[13] Hahm, M.D., Mitrovski, Z.I., and
Titlebaum, E.L., .Deconvolution in the
Presence of Doppler with Application to
Specular Multipath Parameter Estimation,
IEEE Trans. on Signal Proc., Vol. 45, No. 9,
pp. 2203-2219, Sep. 1997.
[14] Senay, S., Akan, A., and Chaparro, L.F.,
“Time-Frequency Channel Modeling and
Estimation of Multi- Carrier Spread Spectrum
Communication Systems,” to appear in
Journal of the Franklin Institute, Apr. 2005.

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