DocumentCode :
747092
Title :
Performance analysis of slotted random access channels for W-CDMA systems in Nakagami fading channels
Author :
Cooper, William ; Zeidler, James R. ; McLaughlin, Stephen
Author_Institution :
Electr. & Comput. Eng. Dept., Univ. of California at San Diego, La Jolla, CA, USA
Volume :
51
Issue :
3
fYear :
2002
fDate :
5/1/2002 12:00:00 AM
Firstpage :
411
Lastpage :
424
Abstract :
We perform a new analysis of the performance of the wideband code-division multiple access (W-CDMA) randomized slotted-offset random access channel (RAC) with Nakagami-m fading and compare it with that of a comparable randomized slotted-ALOHA-based RAC. Previously, it was shown that the W-CDMA RAC is fast, robust and simple to implement (see Esmailzadeh, R. and Gustafsson, M., Proc. 1997 IEEE ICUPC Conf, p.43-7, 1997). However, it was assumed that any random access packet arrival events involving multiple packets from cochannel mobile stations would result in lost packets. Closed-form equations are developed for the collision process of the arriving random access packets in slotted-offset and slotted-ALOHA RACs. An analysis is developed of the signal-to-interference-and-noise ratio of a packet involved in a multipacket DS-CDMA collision with a generalized Nakagami fading channel and diversity reception at the base station. A closed-form equation is developed for the bit error rate and packet throughput of the slotted-offset- and slotted-ALOHA-based RACs. The results of the analysis show that considerable improvement in the RAC performance can be achieved when multiple arrival collisions, on the same timeslot and with the same signature code, are partially resolved. The results also show the RAC´s sensitivity to fading severity, packet Eb/N 0, spreading gain and number of base station receive selection diversity antennas. Compared to the randomized slotted-ALOHA designs, W-CDMA RAC performs as well in light fading conditions and slightly worse in severe fading conditions
Keywords :
cellular radio; code division multiple access; diversity reception; error statistics; fading channels; packet radio networks; spread spectrum communication; DS-CDMA; Nakagami fading channels; W-CDMA; bit error rate; cellular systems; closed-form equations; cochannel mobile stations; diversity reception; packet throughput; random access packet arrival; signal-to-interference-and-noise ratio; slotted-ALOHA; slotted-offset random access channels; Base stations; Bit error rate; Diversity reception; Equations; Fading; Multiaccess communication; Performance analysis; Robustness; Signal analysis; Wideband;
fLanguage :
English
Journal_Title :
Vehicular Technology, IEEE Transactions on
Publisher :
ieee
ISSN :
0018-9545
Type :
jour
DOI :
10.1109/TVT.2002.1002492
Filename :
1002492
Link To Document :
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