We present a channel spectral estimator for OFDM signals containing pilot carriers, assuming a known delay spread or a bound on this parameter. The estimator is based on modeling the channel’s spectrum as a band-limited function, instead of as the discrete Fourier transform of a tapped delay line (TDL). Its main advantage is its immunity to the truncation mismatch in usual TDL models (Gibbs phe...

Propagation characteristics for the radio channel at 5.2 GHz in typical domestic and office environments are addressed in this paper. Ray tracing techniques are used, which provide realistic values for different environments. Values for the attenuation, the rms delay spread and for the power delay profile are presented for different buildings and at several positions.

|Ultra-wide bandwidth (UWB) signal propagation experiment is performed in a rural terrain to characterize the outdoor UWB signal propagation channel. The bandwidth of the signal used in this experiment is in excess of one GHz. The test apparatus and measurement technique are described. From the measured pulse response the mean delay, delay spread, propagation loss and forestation loss are deter...

A reaction diffusion system with time delay is proposed for virus spread on bacteria immobilized on an agar-coated plate. The delay explicitly accounts for a virus latent period of fixed duration. An interval of possible spreading speeds for virus infection is established, and traveling wave solutions are shown to exist. Linear determinacy of spreading speed breaks down for some parameter values.

This paper presents the results from an ultra wideband (UWB) indoor measurement campaign and describes a 3D beam trace pyramidal method that allows one to characterize the channel over a bandwidth of 850 MHz. The UWB channel characteristics are assessed in terms of mean delay, delay spread and coherence bandwidth.

Delay in access to feed for 1-d-old chicks impairs posthatch growth. It is a standard practice that 1-d-old chicks are deprived of feed for about 48 h before they are placed on farms. During incubation, there is a spread of 24 to 48 h for late versus early hatching. As spread of hatch increases, number of chicks that are feed-deprived for a longer time before free access (IA) to feed and water ...

Dengan berkembangnya teknologi IC terprogram yang semakin canggih dan modern seperti FPGA, FPAA lainnya, maka pada tesis kali ini dibuat suatu modul sistem spread-spektrum dengan FPGA sebagai implementatornya.
 Dalam penelitian dilakukan rancang bangun spread spectrum simulasi kanal multipath berbasis (Field Programmable Gate Array), kode acak semu dipilih jenis Gold. Untuk melihat kinerja...

Wireless networks have biggest constraint of limited bandwidth in comparison to wired networks but in spite of this constraint wireless networks are becoming popular day by day on account of their flexibility, mobility as well as inexpensive physical medium (air). This paper aims to simulate wireless local area network. The performance of the network is evaluated using optimized network enginee...

Channel measurement and modeling are important issues when designing ultra wideband (UWB) communication systems. A Precise model of the channel response is inevitable for designing a UWB telecommunication system. In this article signal propagation in indoor environment and LOS condition is evaluated and the appropriate model of this scenario is presented. Parameters such as the power delay prof...