Title :
Blind SDMA with a signal space geometry matched algorithm
Author :
Xavier, João ; Barroso, Victor
Author_Institution :
Inst. de Sistemas e Robotica, Inst. Superior Tecnico, Lisbon, Portugal
Abstract :
We address the problem of the blind reconstruction of binary sequences transmitted by P sources, sharing simultaneously the same frequency channel. This is the situation in space division multiple access (SDMA) systems, where an array receiver is used to discriminate the spatial signatures of the sources. We exploit the geometry induced by the finite nature of the sources alphabet in order to derive a blind multichannel inversion algorithm. This algorithm minimizes a generalized constant modulus (GCM) cost function, subject to the constraints imposed by the signal space geometry (geometric priors). We define the GCM cost function for the case of additive Gaussian noise channels. We show that, except for a sign ambiguity, the minimization of the GCM criterion has a unique solution. Therefore, convergence to the global minimum is guaranteed. Computer simulations illustrate the performance achieved with the proposed method
Keywords :
Gaussian channels; array signal processing; binary sequences; convergence of numerical methods; direction-of-arrival estimation; interference suppression; intersymbol interference; inverse problems; minimisation; multi-access systems; multipath channels; radio receivers; signal reconstruction; additive Gaussian noise channels; array receiver; binary sequences; blind SDMA; blind multichannel inversion algorithm; blind reconstruction; computer simulations; convergence; frequency channel; generalized constant modulus cost function; geometric priors; geometry; global minimum; intersymbol interference; minimization; multipath propagation; performance; sign ambiguity; signal space geometry; signal space geometry matched algorithm; sources alphabet; space division multiple access; spatial signatures; wireless channel; Additive noise; Binary sequences; Cost function; Frequency; Geometry; Hypercubes; Multiaccess communication; Signal processing algorithms; Signal to noise ratio; Wireless communication;
Conference_Titel :
Acoustics, Speech, and Signal Processing, 1997. ICASSP-97., 1997 IEEE International Conference on
Conference_Location :
Munich
Print_ISBN :
0-8186-7919-0
DOI :
10.1109/ICASSP.1997.604603