In this paper, Ultra-wideband (UWB) multiple access relay channel with correlated noises at the relay and receiver is investigated. We obtain outer and inner bounds for the IEEE 802.15.3a UWB multiple access relay channel, and also, a diversity gain bound. Finally, we evaluate some results numerically and show that noise correlation coefficients play important role in determining relay position.

In this study, we introduce a new two-way relay channel and obtain an inner bound and an outer bound for the discrete and memoryless multiple access relay channels with receiver-source feedback via two-way relay channel in which end nodes exchange signals by a relay node. And we extend these results to the Gaussian case. By numerical computing, we show that our inner bound is the same with o...

In recent years, there has been considerable interest in the use of CDMA in mobile communications. Bit error rate is one of the most important parameters in the evaluation of CDMA systems. In this paper, we develop a technique to find an accurate approximation to the probability of bit error for asynchronous direct–sequence code division multiple–access (DS/CDMA) systems by modeling the multipl...

many appealing multicast services such as on-demand tv, teleconference, online games and etc. can benefit from high available bandwidth in multi-radio multi-channel wireless mesh networks. when multiple simultaneous transmissions use a similar channel to transmit data packets, network performance degrades to a large extant. designing a good multicast tree to route data packets could enhance the...

In this channel,we study rate region of a Gaussian two-way diamond channel which operates in half-duplex mode. In this channel, two transceiver (TR) nodes exchange their messages with the help of two relay nodes. We consider a special case of the Gaussian two-way diamond channels which is called Compute-and-Forward Multiple Access Channel (CF-MAC). In the CF-MAC, the TR nodes transmit their mes...

Hardware problems are the most detrimental issues to channel estimates in wireless communication systems. Because of enormous number antennas at base station (BS) cellular massive multiple-input multiple-output (MIMO) systems and because one radio frequency (RF) chain per antenna is required, hardware impairments such will be quite severe. Many research publications have used a quality-cost tra...

We study the problem of simulating a two-user multiple-access channel (MAC) over multiple access network noiseless links. Two encoders observe independent and identically distributed (i.i.d.) copies source random variable each, while decoder observes i.i.d. side-information variable. There are rate-limited communication links between each encoder decoder, there is pairwise shared randomness all...

multiple sclerosis (ms) is a chronic inflammatory disease of the central nervous system characterized by widespread inflammation, focal demyelination and a variable degree of axonal and neuronal loss. ionic conductances regulate t cell activation as well as neuronal function and thus have been found to play a crucial role in ms pathogenesis. since present therapeutical approaches are only parti...

the purpose of this research is to examine consumers’ brand value and brand loyalty toward luxury brands and current distribution channels for those brands (i.e. free standing, shopping center, specialty store, internet retailing). the population consisted of  the costumers, aged 19-39 years, who use branded apparel that is in kerman. about 200 questionnaires were distributed among the consumer...