Asynchronous near-far resistant DS-CDMA receivers without a priori synchronization
1999 (English)In: IEEE Transactions on Communications, ISSN 0090-6778, E-ISSN 1558-0857, Vol. 47, no 1, 78-88 p.Article in journal (Refereed) Published
In this paper, several receivers for data demodulation in an asynchronous direct-sequence code-division multiple access (DS-CDMA) system operating without prior knowledge of the propagation delays are proposed and compared. Special attention is paid to the near-far problem, and the proposed schemes are numerically shown to he near-far resistant, The near-far resistance is obtained by estimating the a priori unknown propagation delay using a subspace-based technique. Quantities obtained in the estimation procedure are used to design a filter used for suppression of interference, according to the minimum mean square error criterion. Either a decision feedback technique or a simple two-state Viterbi algorithm is subsequently used for the data demodulation in the uncoded case, By extending the trellis used in the Viterbi algorithm, error correcting coding is easily implemented.
Place, publisher, year, edition, pages
1999. Vol. 47, no 1, 78-88 p.
Channel estimation, code-division multiple access, detection, near–far problem, spread spectrum
IdentifiersURN: urn:nbn:se:kth:diva-60023DOI: 10.1109/26.747815ISI: 000078736000012OAI: oai:DiVA.org:kth-60023DiVA: diva2:477147
NR 201408052012-01-122012-01-122012-02-13Bibliographically approved