2014/10/20 by Rodrigo C. de Lamare, R. C. de Lamare, de Lamare, R. C. +3
Computer Science · Engineering · Mathematics · #Advanced Adaptive Filtering Techniques #Advanced Wireless Communication Techniques #FOS: Computer and information sciences #Information Theory (cs.IT) #Wireless Communication Networks Research #cs.IT #math.IT
paper · pdf · doi:10.48550/arxiv.1410.5510
10 pages, 4 figures, Signal Processing, 2012
openalex publication_date 2014/10/20 · arxiv created 2014/10/21 · arxiv updated 2014/10/22 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
In this paper we present low-complexity blind multi-input multi-output (MIMO) adaptive linear multiuser receivers for direct sequence code division multiple access (DS-CDMA) systems using multiple transmit antennas and space-time block codes (STBC) in multipath channels. A space-time code-constrained constant modulus (CCM) design criterion based on constrained optimization techniques and low-complexity stochastic gradient (SG) adaptive algorithms are developed for estimating the parameters of the space-time linear receivers. The receivers are designed by exploiting the unique structure imposed by both spreading codes and STBC. A blind space-time channel estimation scheme for STBC systems based on a subspace approach is also proposed along with an efficient SG algorithm. Simulation results for a downlink scenario assess the receiver structures and algorithms and show that the proposed schemes achieve excellent performance, outperforming existing methods.