Cristian Budianu

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Space-time coding is an efficient technique to exploit transmitting and receiving diversities for wireless channels. One of the key components in the design of receivers for space-time codes is channel estimation. For the block codes based on orthogonal design proposed by Alamouti and Tarokh, a new class of pilot assisted channel estimation schemes are(More)
—This paper investigates the estimation of the number of operating sensors in a sensor network in which the data collection is made by a mobile access point. In this paper, an estimator based on the Good–Turing estimator of the missing mass is proposed and it is generalized to other related problems such as the estimation of the distribution of energy(More)
This paper investigates the placement of training symbols within data packets of a wireless system in which transmissions are subject to asynchronous interference. The minimum mean square error of the training-based channel estimator is expressed as a function of the Fisher information of the received signal. It is shown that the placement that minimizes(More)
The paper [1] proposes an estimator for the number of operating sensors in a wireless sensor network based on the Good-Turing non-parametric estimator of the missing mass. This paper investigates the performance of this estimator using the theory of large deviations. We determine the asymptotic behavior of the large deviations exponent as the ratio n/N(More)
This paper investigates the placement of training symbols within data packets of a wireless system in which transmissions are subject to asynchronous interference. The minimum mean square error of the training-based channel estimator is expressed as a function of the Fisher information of the received signal. It is shown that the placement that minimizes(More)
This paper investigates the placement of training symbols within data packets of a wireless system in which transmissions are subject to asynchronous interference. The minimum mean square error of the training-based channel estimator is expressed as a function of the Fisher information of the received signal. It is shown that the placement that minimizes(More)
663 points per period still fails to capture the full bandwidth needed for an accurate solution estimate. Interpolation of the Gear-2 solution was used to produce a 60-point starting estimate with finer resolution. This time all three methods again converged to almost the same waveform; however, Fig. 3 shows that the direct mapping still gives some small(More)
In a multiple access communication system that uses packet transmissions , the packets of one user might be subject to asynchronous interference from the packets of other users in the system. This paper analyses the influence of the placement of training symbols on the performance of the channel estimator in this scenario. The analysis of the mean square(More)
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