DocumentCode :
3064618
Title :
Near-far resistant receivers without a priori synchronization for asynchronous DS-CDMA systems
Author :
Parkvall, Stefan ; Strom, Erik G.
Author_Institution :
Dept. of Signal Process., R. Inst. of Technol., Stockholm, Sweden
Volume :
3
fYear :
1996
fDate :
22-25 Sep 1996
Firstpage :
974
Abstract :
A receiver for data demodulation in an asynchronous direct-sequence code-division multiple access (DS-CDMA) system without prior knowledge of the propagation delays is proposed. Special attention is paid to the near-far problem and the proposed schemes are experimentally shown to be near-far robust. The near-far robustness is obtained by estimating the a priori unknown propagation delay using a subspace based technique. Quantities obtained in the estimation procedure are subsequently used to design a filter, used for suppression of interference, according to the minimum mean-squared error criterion. A simple two-state Viterbi algorithm is used for the data demodulation
Keywords :
Viterbi detection; code division multiple access; delays; filtering theory; interference suppression; land mobile radio; pseudonoise codes; radio receivers; radiofrequency filters; radiofrequency interference; spread spectrum communication; asynchronous DS-CDMA systems; data demodulation; direct sequence code division multiple access; estimation procedure; filter design; interference suppression; minimum mean-squared error; near-far resistant receivers; near-far robustness; propagation delays; subspace based technique; two-state Viterbi algorithm; Delay estimation; Demodulation; Direct-sequence code-division multiple access; Gaussian noise; Matched filters; Multiaccess communication; Propagation delay; Robustness; Signal processing; Viterbi algorithm;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Spread Spectrum Techniques and Applications Proceedings, 1996., IEEE 4th International Symposium on
Conference_Location :
Mainz
Print_ISBN :
0-7803-3567-8
Type :
conf
DOI :
10.1109/ISSSTA.1996.563449
Filename :
563449
Link To Document :
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