Title :
A maximum likelihood approach for estimating DS-CDMA multipath fading channels
Author :
Ström, Erik G. ; Malmsten, Fredrik
Author_Institution :
Dept. of Signals & Syst., Chalmers Univ. of Technol., Goteborg, Sweden
Abstract :
We propose a maximum likelihood approach for near-far robust synchronization of asynchronous direct sequence code division multiple access (DS-CDMA) systems operating over multipath channels. The algorithm is suitable for use in, for instance, a slotted system where each user transmits a short data burst with an embedded training sequence. The algorithm is shown to outperform the standard sliding correlator estimator. The Cramer-Rao bound is derived and is used to indicate the best performance that can be achieved by an unbiased estimator.
Keywords :
code division multiple access; fading channels; frequency shift keying; maximum likelihood estimation; multipath channels; multiuser channels; parameter estimation; spread spectrum communication; synchronisation; BPSK; Cramer-Rao bound; DS-CDMA multipath fading; algorithm; asynchronous DS-CDMA systems; binary PSK system; direct sequence code division multiple access; embedded training sequence; fading estimation; maximum likelihood approach; multiuser multipath static channel; near-far robust synchronization; performance; short data burst transmission; slotted system; standard sliding correlator estimator; unbiased estimator; Channel estimation; Delay estimation; Direct-sequence code-division multiple access; Fading; Maximum likelihood estimation; Multiaccess communication; Multipath channels; Parameter estimation; Power control; Robustness;
Journal_Title :
Selected Areas in Communications, IEEE Journal on
