Multiresolution adaptive structure for acquisition and detection in DS-SS digital receiver in a multiuser environment

Pagès, Rosa; Moreno, J.A.M.; Carrié, Joan Claudi Socoró

doi:10.1109/isspa.2003.1224878

Cited by 2 publications

References 4 publications

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Neural Network Acquisition Estimator for Multiresolutive Adaptive PN Acquisition Scheme in Multiuser Non Selective Fast SNR Variation Environments

Pagès¹,

Segura²,

Carrié³

et al. 2008

2008 Eighth International Conference on Hybrid Intelligent Systems

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One of the most important problems to be solved in Direct Sequence Spread Spectrum systems is to achieve a robust acquisition of the pseudonoise sequence. In multiuser time-varying environments this fact becomes even more important because acquisition and tracking performance can heavily degrade communication reliability. In this paper a new neural network estimator is presented, and it is compared to the performance of a fuzzy logic acquisition estimator [11] and stability acquisition estimator [16] in the multiresolutive acquisition system. The new neural network acquisition estimator improves the results for both fuzzy logic and stability estimators, through the estimation of the probability of being acquired and the signal to noise ratio for single user and multiuser communication.

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Neural Network Acquisition Estimator for Multiresolutive Adaptive PN Acquisition Scheme in Multiuser Non Selective Fast SNR Variation Environments

Pagès¹,

Segura²,

Carrié³

et al. 2008

2008 Eighth International Conference on Hybrid Intelligent Systems

View full text Add to dashboard Cite

show abstract

Fuzzy Logic Estimator for Variant SNR Environments

Pagès

Segura

Carrié

2009

Encyclopedia of Artificial Intelligence

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The acquisition system is one of the most sensitive stages in a Direct Sequence Spread Spectrum (DS-SS) receiver (Peterson, Ziemer & Borth, 1995), due to its critical position in order to demodulate the received information. There are several schemes to deal with this problem, such as serial search and parallel algorithms (Proakis, 1995). Serial search algorithms have slow convergence time but their computational load is very low; on the other hand, parallel systems converge very quickly but their computational load is very high. In our system, the acquisition scheme used is the multiresolutive structure presented in (Moran, Socoró, Jové, Pijoan & Tarrés, 2001), which combines quick convergence and low computational load. The decisional system that evaluates the acquisition stage is a key process in the overall system performance, being a drawback of the structure. This becomes more important when dealing with time-varying channels, where signal to noise ratio (called SNR) is not a constant parameter. Several factors contribute to the performance of the acquistion system (Glisic & Vucetic, 1997): channel distorsion and variations, noise and interference, uncertainty about the code phase, and data randomness. The existence of all these variables led us to think about the possibility of using fuzzy logic to solve this complex acquisition estimation (Zadeh, 1973). A fuzzy logic acquisition estimator had already been tested and used in our research group to control a serial search algorithm (Alsina, Morán & Socoró, 2005) with encouraging results, and afterwards in the multiresolutive scheme (Alsina, Mateo & Socoró, 2007), and other applications to this field can be found in bibliography as (Bas, Pérez & Lagunas, 2001) or (Jang, Ha, Seo, Lee & Lee, 1998). Several previous works have been focused in the development of acquisition systems for non frequency selective channels with fast SNR variations (Moran, Socoró, Jové, Pijoan & Tarrés, 2001) (Mateo & Alsina, 2004).

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Multiresolution adaptive structure for acquisition and detection in DS-SS digital receiver in a multiuser environment

Cited by 2 publications

References 4 publications

Neural Network Acquisition Estimator for Multiresolutive Adaptive PN Acquisition Scheme in Multiuser Non Selective Fast SNR Variation Environments

Neural Network Acquisition Estimator for Multiresolutive Adaptive PN Acquisition Scheme in Multiuser Non Selective Fast SNR Variation Environments

Fuzzy Logic Estimator for Variant SNR Environments

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