Title :
Markovian SS codes imply inversion-free code acquisition in asynchronous DS/CDMA systems
Author :
Eshima, Nobuoki ; Jitsumatsu, Yutaka ; Kohda, Tohru
Author_Institution :
Dept. of Med. Inf. Anal., Oita Med. Univ., Japan
Abstract :
Conventional single user correlators for asynchronous DS/CDMA systems provide only one scalar value for each data period. Code acquisition is expected to be improved if sampling is performed once each chip time. This accurate code acquisition method is shown to require the covariance matrix of SS codes, while the optimum method needs inversion of the covariance matrix. However, Markovian SS codes with eigen value -2+√3 do not need matrix inversion, which is the same value needed to achieve minimum bit error rate.
Keywords :
Markov processes; code division multiple access; correlators; covariance matrices; data acquisition; eigenvalues and eigenfunctions; error statistics; sampling methods; spread spectrum communication; Markovian SS codes; asynchronous DS-CDMA systems; bit error rate; covariance matrix; eigenvalues; inversion free code acquisition method; matrix inversion; optimum method; sampling method; single user correlator; Bit error rate; Character generation; Chromium; Correlators; Covariance matrix; Eigenvalues and eigenfunctions; Information analysis; Interference; Multiaccess communication; Sampling methods;
Conference_Titel :
Circuits and Systems, 2004. ISCAS '04. Proceedings of the 2004 International Symposium on
Print_ISBN :
0-7803-8251-X
DOI :
10.1109/ISCAS.2004.1329079
