We introduce a new approach for achieving diversity in spread-spectrum communications over fast-fading multipath channels. The RAKE receiver used in existing systems suffers from significant performance degradation due to the rapid channel variations encountered under fast fading. We show that the Doppler spread induced by temporal channel variations in fact provides another means for diversity...

In this paper, the space time transmit diversity (STTD) decoding combined with minimum mean square error (MMSE) equalization and antenna diversity reception is presented for MC-CDMA downlink and uplink in the presence of multiple users. The equalization weights that minimize the mean square error (MSE) for each subcarrier are used. From computer simulation, it was found that the downlink BER pe...

This paper describes a new type of ensembles that aims at improving the predictive performance of these approaches in time series forecasting. Ensembles are recognised as one of the most successful approaches to prediction tasks. Previous theoretical studies of ensembles have shown that one of the key reasons for this performance is diversity among ensemble members. Several methods exist to gen...

The severity of fading on mobile communication channels calls for the combining of multiple diversity sources to achieve acceptable error rate performance. Traditional approaches perform the combining of the different diversity sources using either: the Conventional Selective diversity combining (CSC), Equal-Gain combining (EGC), or Maximal-Ratio combining (MRC) Schemes. CSC and MRC are the two...

In the past twenty years the growing diverse work force in organizations has led scholars to pay increased attention to this issue. Organizations will be successful only to the extent that they are able to embrace & encourage work force diversity. This study explores by reviewing recent literature the increasing influence of the work force diversity and its relationship with organizational perf...

Abstract In this paper, the space time transmit diversity (STTD) decoding combined with minimum mean square error combining (MMSEC) equalization is presented for MC-CDMA. The STTD decoding weights that minimize the MSE for each subcarrier before despreading are derived. From computer simulation, it is found that the BER performance of STTD with MMSEC equalization using the weights derived in th...

In this letter, the performance of frequency-hopping spread-spectrum systems employing noncoherent reception and transmission diversity is analyzed for frequency-selective Rayleigh fading channels. Two different types of transmission diversity systems, a fast frequency-hopping (FFH) system and a multicarrier frequency-hopping (MCFH) system, are investigated. In order to combine received signals...

Influenza has a long history of causing morbidity and mortality in the human population through routine seasonal spread and global pandemics. The high mutation rate of the RNA genome of the influenza virus, combined with assortment of its multiple genomic segments, promote antigenic diversity and new subtypes, allowing the virus to evade vaccines and become resistant to antiviral drugs. There i...

1. Although populations harbour considerable diversity, most ecological studies still assume they are homogeneous. However, mounting evidence suggests that intraspecific diversity is not only common, but also important for interactions with community members. Here, intraspecific variation in Daphnia dentifera in haemoglobin content is shown to be a marker of hypolimnion use. 2. Hypolimnion use ...