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A low‐complexity adaptive receiver for DS‐CDMA systems in unknown code delay environment
Author(s) -
Chen JunDa,
Ueng FangBiau,
Lin PiFeng
Publication year - 2011
Publication title -
international journal of communication systems
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.344
H-Index - 49
eISSN - 1099-1131
pISSN - 1074-5351
DOI - 10.1002/dac.1151
Subject(s) - computer science , code division multiple access , multipath propagation , intersymbol interference , adaptive equalizer , delay spread , algorithm , spread spectrum , offset (computer science) , pseudorandom noise , frequency offset , channel (broadcasting) , electronic engineering , real time computing , telecommunications , equalization (audio) , orthogonal frequency division multiplexing , programming language , engineering
In direct‐sequence code division multiple access (DS/CDMA) multiuser communication systems in multipath channels, both intersymbol interference (ISI) and multiple‐access interference (MAI) must be considered. The multipath channel characterizes the propagation effects including the timing offset and delays, etc. Traditionally, we use the delay‐locked loop (DLL) code tracking loop to recover the timing delay. But DLL cannot work well in multipath environment. In this paper, we propose a low‐complexity adaptive receiver to suppress ISI/MAI and solve the timing offset problems without using conventional DLL code tracking loop. The proposed receiver employs an adaptive filter whose weights are adapted using a block least‐mean square error algorithm with fractional sampling. Simulations confirm the good performance, including learning curves and theoretical analysis of minimum mean‐square error, of the proposed receiver. Copyright © 2010 John Wiley & Sons, Ltd.