Title :
Optimal and suboptimal decision rules for parallel code acquisition in chip-asynchronous DS/SS systems
Author :
Yoon, Seokho ; Song, Iickho ; Park, Cheol Hoon
Author_Institution :
Div. of Eng. & Appl. Sci., Harvard Univ., Cambridge, MA, USA
fDate :
7/1/2002 12:00:00 AM
Abstract :
We investigate optimal and suboptimal decision rules for parallel code acquisition in chip-asynchronous direct-sequence spread-spectrum (DS/SS) systems. The conventional decision rule for parallel acquisition is to choose the largest correlator output of a receiver. However, such a scheme is optimum only for chip-synchronous models. In this letter, an optimal decision rule is derived based on the maximum-likelihood criterion for chip-asynchronous models. A simpler suboptimal decision rule is also discussed. The performance of the optimum and suboptimum decision rules is compared to that of the conventional decision rule. Numerical results show, that for chip-asynchronous models, both the optimal and suboptimal decision rules outperform the conventional decision rule.
Keywords :
decision theory; maximum likelihood estimation; pseudonoise codes; spread spectrum communication; synchronisation; chip-asynchronous DS/SS systems; chip-asynchronous direct-sequence spread-spectrum systems; maximum-likelihood criterion; optimal decision rules; parallel code acquisition; receiver; suboptimal decision rules; AWGN; Additive white noise; Correlators; Delay effects; Frequency synchronization; Maximum likelihood detection; Spread spectrum communication;
Journal_Title :
Signal Processing Letters, IEEE
DOI :
10.1109/LSP.2002.800678