Delay estimation of a code-spread codedivision multiple-access (CS-CDMA) system using low-rate maximum free distance (MFD) convolutional codes for bandwidth expansion is studied. Using the repetitive structure of the low-rate MFD codes, the codewords are first permuted using a criterion based on the Cramér-Rao bound that results in good delay estimation properties. Thereafter, an approximate ma...

This paper presents a ray tracing technique to predict path loss and delay spread in buildings. A computer program to predict radio propagation in buildings based on site-specific information such as wall locations and building materials is described. Using geometrical optics-based assumptions, rays are traced in three dimensions from a transmitter location. Line-of-sight, specularly transmitte...

A study of time dispersion in different indoor line-ofsight radio channels in the 492–862 MHz band is presented in this paper. A combined method to filter the noise in the measured impulse response is described. The effect of frequency windowing on the impulse responses and the root mean square (rms) delay spread is also investigated. It has been found that, in general, the use of windows with ...

This paper reports the measurement and analysis of wideband radio channel in urban propagation environment. RMS delay spread values are evaluated as well as the coherence bandwidth of the channel is derived by the frequency correlation function for 0.9 correlation. Furthermore, delay windows and signal to self-interference ratios are reported. Mean delay spread was found 0.353 μs and 2.061 μs f...

Estimations of coherence bandwidth from wideband channel sounding measurements made in the 30KHz–100MHz band in several indoor environments are described. Results are intended for applications in high-capacity indoor powerline networks. The coherence bandwidth and the RMS delay spread parameters are estimated from measurements of the complex transfer function of the Powerline Communications (PL...