Time domain propagation measurements of the UWB indoor channel using PN-sequence in the FCC-compliant band 3.6-6 GHz

We have performed a propagation measurement campaign at the University of Rome Tor Vergata, Rome, Italy. We have sounded the channel by a probing signal at a carrier frequency of 4.78 GHz; modulated by a train of pulses having a duration of 0.4 ns shaped by a pseudonoise (PN) sequence. The measurement band falls (3.6-6 GHz) in the frequency range allowed by the FCC ruling for ultrawide-band (UWB) operations. To characterize the channel behavior over the large and the small scale, the transmitter is moved in six different positions on the floor, while the receiver is moved in 625 different locations within each room. The receiver locations are arranged in a square grid of 25 x 25 points with 2 cm spacing, i.e., less than half of the minimum wavelength of the transmitted signal. A total of 625 x 16 impulse responses are recorded in nonline-of-sight (NLOS) conditions, 625 in line-of-sight (LOS) conditions within the rooms and 11 LOS measurements are made in the corridor at incremental spacing of I m. We describe the measurement technique as well as the procedure by which we process the experimental data to extract the amplitude, phase and delay associated to each component of the multipath profiles. We also derive path-loss and shadowing models for the UWB indoor channel in both LOS and NLOS conditions. Finally, we present an accurate analysis of the time dispersion of the UWB channel.