Open AccessBlind joint estimation of channel order and the number of active users in direct sequence code‐division multiple‐access multi‐path channels
Author(s) -
Samsami Khodadad Farid,
Abed Hodtani Ghosheh
Publication year - 2014
Publication title -
iet signal processing
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.384
H-Index - 42
eISSN - 1751-9683
pISSN - 1751-9675
DOI - 10.1049/iet-spr.2012.0296
Subject(s) - algorithm , computer science , channel (broadcasting) , fading , path (computing) , subspace topology , signal subspace , decoding methods , code division multiple access , mathematics , speech recognition , mathematical optimization , noise (video) , telecommunications , artificial intelligence , computer network , image (mathematics)
A new, reliable and computationally efficient blind method is proposed for joint estimation of channel order and number of active users in a direct sequence code‐division multiple‐access system with multi‐path fading channel. The proposed method (i) exploits a parametric model used for equalisation of multi‐path channels in finite impulse response multi‐input multi‐output systems, (ii) first, estimates rank of correlation matrix of observation, by combining the subspace method and information‐theoretic criteria, (iii) then, estimates simultaneously channel order and number of active users, by using the estimated rank and the model parameter, without any prior information, (iv) uses only a single antenna, in contrast to the previous methods, while having the ability to jointly estimate higher numbers of active users and channel order in lower signal‐to‐noise ratios. Numerical results show that the proposed method can estimate higher number of users and also has higher detection probability when using minimum mean square error algorithm.