Thu, 07 Aug 2008 22:02:55 BST CiteULike: dcastro's rake http://www.citeulike.org/user/dcastro/tag/rake CiteULike.org en-gb Copyright © 2004-2008 citeulike.org http://www.citeulike.org/user/dcastro/article/2815784 <i>Selected Areas in Communications, IEEE Journal on, Vol. 19, No. 12. (2001), pp. 2420-2431.</i><br /><br />This paper deals with the problem of channel tracking for RAKE receivers in propagation environments characterized by closely spaced multipath components. After outlining why conventional single-path channel tracking algorithms fail in such scenarios, several new estimation algorithms are developed that are tailored to channels with closely spaced multipaths. This is achieved by removing or minimizing self-interference caused by multipath components. Other interfering users are treated as noise. Both timing tracking and phasor tracking and their interaction are covered in this paper. The derived algorithms are benchmarked against perfect channel knowledge on one hand and conventional tracking algorithms on the other hand, both in a UMTS test scenario. In moderate scenarios, the use of these new algorithms leads to performance improvements of up to 2 dB, in terms of signal-to-noise ratio (SNR) at moderate bit error rates, and even manages to track the channel in conditions where conventional tracking algorithms fail completely Channel tracking for RAKE receivers in closely spaced multipath environments G Fock J Baltersee P Schulz-Rittich H Meyr doi:10.1109/49.974607 Selected Areas in Communications, IEEE Journal on, Vol. 19, No. 12. (2001), pp. 2420-2431. 2008-05-20T12:01:59-00:00 2001 Selected Areas in Communications, IEEE Journal on 19 12 2420 2431 channel multipath rake receiver tracking http://www.citeulike.org/user/dcastro/article/2776180 <i>Military Communications Conference Proceedings, 1999. MILCOM 1999. IEEE, Vol. 2 (1999), pp. 1328-1332 vol.2.</i><br /><br />This paper discusses an improved method for localization in a DS-CDMA based cellular-phone communication link. This method suggests an optimization for code synchronization, which allows for TDOA (time difference of arrival) estimations to be solved for the position of a mobile phone. It is known that the time delay of a received DS signal, derived from the classical DLL, may express severe timing errors due to multipath effects. A new anti multipath multi-tracking extended Kalman filter loop is shown to achieve far better results especially in the environment of specular multipath. Specifically, this new loop minimizes the errors due to multipath components by letting the EKF decide upon the best weights of its sub-chip processing branches, resulting in a RAKE-like tracking loop. This loop tracks not only the line of sight path, but also the other multipath components as well as their power and phase. It is shown that the implementation of this technique converges to the classical non-coherent code tracking DLL structure when no multipath is assumed, but results in a new and efficient tracking loop structure in the more realistic fading channel case. The application of this technique to the EIA IS-95 system is considered, where accurate location estimations as well as power management utilities are treated Anti multipath cellular radio location for DS/CDMA systems using a novel EKF subchip RAKE tracking loop E Fishler BZ Bobrovsky doi:10.1109/MILCOM.1999.821419 Military Communications Conference Proceedings, 1999. MILCOM 1999. IEEE, Vol. 2 (1999), pp. 1328-1332 vol.2. 2008-05-09T15:42:49-00:00 1999 Military Communications Conference Proceedings, 1999. MILCOM 1999. IEEE 2 1328 1332 vol.2 cdma kalman location loop mobile multipath radio rake tracking