Sat, 26 Jul 2008 06:14:54 BST CiteULike: dcastro's Milstein http://www.citeulike.org/user/dcastro/author/Milstein CiteULike.org en-gb Copyright © 2004-2008 citeulike.org http://www.citeulike.org/user/dcastro/article/755253 <i>Selected Areas in Communications, IEEE Journal on, Vol. 18, No. 8. (2000), pp. 1344-1354.</i><br /><br />To satisfy ever-increasing demands for higher data rates, as well as to allow more users to simultaneously access the network, interest has peaked in what has come to be known as wideband code division multiple access (WCDMA). We discuss those basic characteristics of WCDMA waveforms that make them attractive for high data rate transmission over wireless and mobile channels. We emphasize how the choice of spread bandwidth affects the bit error rate of the system, as well as how it affects the reliability of various subsystems, such as those that perform coarse acquisition and adaptive power control. We then discuss how some of the waveforms being considered for cellular WCDMA systems differ from those in use in the narrowband CDMA cellular system, and emphasize, as an example, multicarrier CDMA. Finally, we discuss other potential enhancements to WCDMA systems, such as the use of interference suppression at the receiver, or multiple antennas at the transmitter Wideband code division multiple access LB Milstein doi:10.1109/49.864000 Selected Areas in Communications, IEEE Journal on, Vol. 18, No. 8. (2000), pp. 1344-1354. 2006-07-12T18:41:14-00:00 2000 Selected Areas in Communications, IEEE Journal on 18 8 1344 1354 access cdma multiple wideband http://www.citeulike.org/user/dcastro/article/2802345 <i>Communications, IEEE Transactions on, Vol. 46, No. 5. (1998), pp. 686-694.</i><br /><br />The focus of this paper is on the initial acquisition of a direct sequence (DS) spread-spectrum signal utilizing a purely parallel search strategy. A parallel search strategy is utilized because it reduces the acquisition time compared to either serial or partially parallel strategies. In particular, the purpose of this paper is to derive the optimal decision rule, based on the maximum-likelihood criterion, for frequency-selective fading channels. The performance of the conventional decision rule, optimized for additive white Gaussian noise and flat-fading channels, the optimal decision rule derived, and a suboptimal decision rule, also presented in this paper, are compared. It is shown that the optimal and suboptimal decision rules for Rayleigh-fading channels outperform the conventional decision rule. For Rician-fading channels, it is shown both that the optimal decision rule outperforms the conventional decision rule, and that the optimum decision rule for Rayleigh-fading channels, when implemented on a Rician-fading channel, yields approximately optimum performance Optimal decision strategies for acquisition of spread-spectrum signals in frequency-selective fading channels RR Rick LB Milstein doi:10.1109/26.668744 Communications, IEEE Transactions on, Vol. 46, No. 5. (1998), pp. 686-694. 2008-05-15T18:37:39-00:00 1998 Communications, IEEE Transactions on 46 5 686 694 acquisition channel fading frequency selective spread-spectrum http://www.citeulike.org/user/dcastro/article/2802245 <i>Communications, IEEE Transactions on, Vol. 47, No. 8. (1999), pp. 1233-1244.</i><br /><br />We present two code-acquisition schemes for a multicarrier direct-sequence code-division multiple-access system, one that uses equal gain combining and the other that uses selection combining. The code-acquisition performance of the two multicarrier systems, as well as that of a single-carrier system, are analyzed in both nonfading and Rayleigh fading channels under the assumption that the receiver is chip-synchronized; the effect of partial-band interference (PBI) on the performance is also included. It is demonstrated that in an additive white Gaussian noise channel, the single-carrier system has a better code-acquisition performance than both multicarrier systems. However, in a Rayleigh fading channel, the code-acquisition performance of a multicarrier system with equal gain combining is better than that of the single-carrier system, while a multicarrier system with selection combining has the same performance as the single-carrier system. Further, the presence of PBI more severely affects the code-acquisition performance of the single-carrier system than those of both multicarrier systems. Finally, the code-acquisition performance of a multicarrier system with equal gain combining is always better than that of the selection combining system Analysis of a multicarrier DS-CDMA code-acquisition system Dongwook Lee LB Milstein Hun Lee doi:10.1109/26.780460 Communications, IEEE Transactions on, Vol. 47, No. 8. (1999), pp. 1233-1244. 2008-05-15T17:57:12-00:00 1999 Communications, IEEE Transactions on 47 8 1233 1244 acquisition cdma code http://www.citeulike.org/user/dcastro/article/2802199 <i>Communications, IEEE Transactions on, Vol. 45, No. 11. (1997), pp. 1466-1476.</i><br /><br />This paper presents the performance of a direct sequence spread spectrum acquisition scheme in a mobile terrestrial communications system. The effects of fading, multipath, power control, shadowing, multiple access interference, out-of-cell interference, vehicle speed, voice activity, and sectorization are examined. The acquisition scheme uses noncoherent detection and a parallel search strategy. The analysis is done for the reverse link of a mobile code-division multiple-access (CDMA) system. The purpose of this paper is to derive the acquisition performance of a mobile communications system under practical assumptions, and give realistic capacity estimates based on acquisition performance criteria Parallel acquisition in mobile DS-CDMA systems RR Rick LB Milstein doi:10.1109/26.649775 Communications, IEEE Transactions on, Vol. 45, No. 11. (1997), pp. 1466-1476. 2008-05-15T17:38:51-00:00 1997 Communications, IEEE Transactions on 45 11 1466 1476 acquisition cdma mobile parallel http://www.citeulike.org/user/dcastro/article/2762226 <i>Microwave Symposium Digest, 1998 IEEE MTT-S International, Vol. 1 (1998), pp. 327-330 vol.1.</i><br /><br />This paper presents several power amplifier approaches that promise to significantly improve efficiency, while meeting the linearity requirements of advanced, spectrally efficient wireless systems. The approaches include: a) use of active integrated antenna structures that provide harmonic terminations for high efficiency Class F amplifiers; b) integrated dc-dc converters for power conditioning and envelope restoration; c) switching mode amplifiers based on bipolar transistors with controlled saturation; and d) the use of band-pass delta-sigma modulators to tailor input signals Device and circuit approaches for improved linearity and efficiency in microwave transmitters PM Asbeck T Itoh Y Qian MF Chang L Milstein G Hanington PF Chen V Schultz DW Lee DW Lee J Arun A10 doi:10.1109/MWSYM.1998.689385 Microwave Symposium Digest, 1998 IEEE MTT-S International, Vol. 1 (1998), pp. 327-330 vol.1. 2008-05-06T18:30:58-00:00 1998 Microwave Symposium Digest, 1998 IEEE MTT-S International 1 327 330 vol.1 efficiency microwave transmitter http://www.citeulike.org/user/dcastro/article/939974 <i>Communications, IEEE Transactions on, Vol. 48, No. 6. (2000), pp. 948-959.</i><br /><br />This paper introduces a hybrid forward-error correction/automatic repeat-request (ARQ) system that employs rate compatible punctured turbo (RCPT) codes to achieve enhanced throughput performance over a nonstationary Gaussian channel. The proposed RCPT-ARQ system combines the performance of turbo codes with the frugal use of incremental redundancy inherent in the rate compatible punctured convolutional codes of Hagenauer (1988). Moreover, this paper introduces the notion of puncturing the systematic code symbols of a turbo code to maximize throughput at signal-to-noise ratios (SNRs) of interest. The resulting system provides both an efficient family of achievable code rates at middle to high SNR and powerful low-rate error correction capability at low SNR On the performance of hybrid FEC/ARQ systems using rate compatible punctured turbo (RCPT) codes DN Rowitch LB Milstein doi:10.1109/26.848555 Communications, IEEE Transactions on, Vol. 48, No. 6. (2000), pp. 948-959. 2006-11-10T23:06:04-00:00 2000 Communications, IEEE Transactions on 48 6 948 959 code correction error performance puncturing turbocode http://www.citeulike.org/user/dcastro/article/954833 <i>Communications, IEEE Transactions on [legacy, pre - 1988], Vol. 30, No. 5. (1982), pp. 855-884.</i><br /><br />Spread-spectrum communications, with its inherent interference attenuation capability, has over the years become an increasingly popular technique for use in many different systems. Applications range from antijam systems, to code division multiple access systems, to systems designed to combat multipath. It is the intention of this paper to provide a tutorial treatment of the theory of spread-spectrum communications, including a discussion on the applications referred to above, on the properties of common spreading sequences, and on techniques that can be used for acquisition and tracking. Theory of Spread-Spectrum Communications--A Tutorial R Pickholtz D Schilling L Milstein Communications, IEEE Transactions on [legacy, pre - 1988], Vol. 30, No. 5. (1982), pp. 855-884. 2006-11-21T08:01:33-00:00 1982 Communications, IEEE Transactions on [legacy, pre - 1988] 30 5 855 884 cdma communications spread-spectrum tutorial http://www.citeulike.org/user/dcastro/article/1839909 <i>Communications, IEEE Transactions on, Vol. 43, No. 234. (1995), pp. 1134-1143.</i><br /><br />The coherent reception of direct sequence-code division multiple access (DS-CDMA) signals in a multipath fading channel is considered. The channel model assumes independent paths with Nakagami fading statistics; this model includes the Rayleigh channel os a special case and is a reasonable model for a frequency-selective fading channel. The bit error rate (BER) performance of a RAKE receiver under various multipath fading conditions is derived and evaluated. The results indicate that over 50 users may access the channel (assuming 127 chips per bit) simultaneously under typical fading conditions, and can achieve an uncoded BER of 0.01 with an average received signal-to-noise ratio per bit of 10 dB Coherent DS-CDMA performance in Nakagami multipath fading T Eng LB Milstein Communications, IEEE Transactions on, Vol. 43, No. 234. (1995), pp. 1134-1143. 2007-10-30T10:50:34-00:00 1995 Communications, IEEE Transactions on 43 234 1134 1143 cdma inserted-bib multipath