Abstract High speed data transmissions are required for the next generation mobile communication systems. However, broadband mobile channel is composed of many propagation paths with different time delays, producing severe frequency-selective fading channel. Recently, multi-carrier code division multiple access (MC-CDMA) has been attracting much attention for the broadband wireless access in th...

The mechanisms for the origin and maintenance of biological diversity are not fully understood. It is known that frequency-dependent selection, generating advantages for rare types, can maintain genetic variation and lead to speciation, but in models with simple phenotypes (that is, low-dimensional phenotype spaces), frequency dependence needs to be strong to generate diversity. However, we sho...

Maximum spatial-frequency diversity can be achieve by combining bit-interleaved coded modulation (BICM), orthogonal space-time block coding (OSTBC) and orthogonal frequency division multiplexing (OFDM) in frequency selective multi-path fading channels, provided that perfect channel state information (CSI) is available to the receiver. In view of the fact that perfect CSI can be obtained only if...

Asexual organisms can be genetically variable and evolve through time, yet it is not known how genetic diversity is maintained in populations. In sexual organisms, negative frequency-dependent selection plays a role in maintaining diversity at some loci, but in asexual organisms, this mechanism could provide a general explanation for persistent genetic diversity because it acts on the whole gen...

fusarium wilt caused by fusarium oxysporum schltdl. f.sp. phaseoli (fop), is one of the important diseases of the common bean in iran and many of the bean growing countries. incidence of the disease has been reported in tropical and semi-tropical regions of the world. this study was carried out to characterize genetic diversity of f. oxysporum isolates from the common bean by vegetative compati...

The processing complexity of optimal receivers in frequency selective channels grows exponentially with the channel memory length. Linear receivers, alternatively, offer significantly less complexity with the cost of performance degradation. Such degradation can be due to not fully capturing the inherent frequency diversity or degraded coding gain. In this paper we investigate how effectively t...

Recent research with college-aged skilled readers by Adelman and colleagues revealed that contextual diversity (i.e., the number of contexts in which a word appears) is a more critical determinant of visual word recognition than mere repeated exposure (i.e., word frequency) (Psychological Science, 2006, Vol. 17, pp. 814-823). Given that contextual diversity has been claimed to be a relevant fac...

This paper develops an MLSE diversity receiver for the timeand frequency-selective channel corrupted by additive Gaussian noise, when linear constellations are employed. The paper extends Ungerboeck’s derivation of the Extended MLSE receiver for the purely frequency-selective channel to the more general channel with diversity. The new receiver structure and metric assume a known channel. The ma...

— In wireless broadband systems the available time, frequency and spatial diversity can be exploited using complex space-time-frequency codes. However, in order to retain a flexible scheme with low complexity we prefer a concatenated system where a channel code picks up time and frequency diversity and a simple orthogonal design is used to obtain spatial diversity. The channel needs to be const...