7,289 research outputs found
PERFORMANCE OF MODIFIED ORDER-STATISTICS CFAR DETECTORS WITH NONCOHERENT INTEGRATION
No full textThe order statistics cell averaging (OSCA) constant false alarm rate (CFAR) detector and the order statistics greatest of (OSGO) CFAR detector have the good properties of the order statistics (OS) CFAR detector while the processing time of each detector is less than half the processing time of the OS CFAR detector in ordering magnitude of the cells in a reference window. In this paper, we analyze the OSCA and the OSGO CFAR detectors with M-pulse noncoherent integration for chi-square fluctuating targets. We obtain the explicit formulas of false alarm rates and detection probabilities for the OSCA and the OSGO CFAR detectors
Reorganization of the cortico-spinal pathway in patients with chronic complete thoracic spinal cord injury: a study of motor evoked potentials.
No full textDistributed utility-maximization using a resource pricing power control in uplink DS-CDMA
No full textThis letter considers a distributed utility maximization power control scheme in uplink DS-CDMA systems. Maximizing a utility function is solved by Lagrangian dual decomposition, where the Lagrangian multiplier can be considered as a resource price charging to users. By adjusting the price in a distributed fashion, the proposed algorithm results in a bang-bang type power control, 'maximum power transmission' or 'shutdown'. Numerical result shows that the proposed algorithm achieves around 95% of the optimal utility maximization with a modest computational burden
Performance of Broadband Multicarrier DS-CDMA using Space-Time Spreading-Assisted Transmit Diversity
No full textIn this contribution multicarrier direct-sequence code-division multiple-access (MC DS-CDMA) using space–time spreading (STS)-assisted transmit diversity is investigated in the context of broadband communications over frequency-selective Rayleigh-fading channels. We consider the issue of parameter design for the sake of achieving high-efficiency communications in various dispersive environments. Furthermore, in contrast to conventional MC DS-CDMA schemes employing time (T)-domain spreading only, in this contribution we also investigate broadband MC DS-CDMA schemes employing both T-domain and frequency (F)-domain spreading, i.e., employing TF-domain spreading. The bit-error rate (BER) performance of STS-assisted broadband MC DS-CDMA is investigated for downlink transmissions associated with the correlation based single-user detector and the decorrelating multiuser detector. Our study demonstrated that when appropriately selecting the system parameters, broadband MC DS-CDMA using STS-assisted transmit diversity constitutes a promising downlink transmission scheme. This scheme is capable of supporting ubiquitous communications over diverse communication environments without BER performance degradation. Index Terms—Broadband system, code-division multiple access (CDMA), frequency-domain spreading, frequency-selective fading, multicarrier direct-sequence code-division multiple-access (MC-DS-CDMA), multicarrier CDMA, multicarrier modulation, multiuser detection, space–time spreading (STS), transmit diversity
Adaptive Minimum-BER Linear Multiuser Detection for DS-CDMA Signals in Multipath Channels
No full textThe problem of constructing adaptive minimum bit error rate (MBER) linear multiuser detectors is considered for direct-sequence code division multiple access (DS-CDMA) signals transmitted through multipath channels. Based on the approach of kernel density estimation for approximating the bit error rate (BER) from training data, a least mean squares (LMS) style stochastic gradient adaptive algorithm is developed for training linear multiuser detectors. Computer simulation is used to study the convergence speed and steady-state BER misadjustment of this adaptive MBER linear multiuser detector, and the results show that it outperforms an existing LMS-style adaptive MBER algorithm first presented at Globecom'98 by Yeh, Lopes and Barry
Performance of a radar clutter suppression algorithm based on the adaptive clutter whitening filter and doppler filter bank
No full textAdaptive Clutter Rejection and Moving Target detection Algorithms Based on Eigen Filtering
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