UWB Radio Propagation Measurements in a Desktop Environment

The ultra-wideband wireless personal area networks are expected to be most commonly employed in desktop environments. This paper presents a measurement campaignconducted on a typical office desk. A pair of omnidirectionalUWB antennas and a vector network analyzer were used tomeasure the impulse responses over a frequency rang spanning from 6 GHz to 8.5 GHz, in accordance with the UWB regulations in Europe. The coherence bandwidth and the rms delay spread are calculated from the measurement results. A significant correlation between these wideband parameters is found, but only at higher correlation thresholds

Hard-input-hard-output capacity analysis of UWB BPSK systems with timing errors

The hard-input-hard-output capacity of a binary phase-shift keying (BPSK) ultrawideband system is analyzed for both additive white Gaussian noise and multipath fading channels with timing errors. Unlike previous works that calculate the capacity with perfect synchronization and/or multiple-access interference only, our analysis considers timing errors with different distributions, as well as the interpath (IPI), interchip (ICI), and intersymbol (ISI) interferences, as in practical systems. The sensitivity of the channel capacity to the timing error is examined. The effects of pulse shape, the multiple-access technique, the number of users, and the number of chips are studied. It is found that time hopping is less sensitive to the pulse shape and that the timing error has higher capacity than direct sequence due to its low duty of cycle. Using these results, one can choose appropriate system parameters for different applications

Interference analysis of uwb systems for IEEE channel models using first- and second-order moments

Statistical moments of the inter-path interference, the inter-chip interference and the intersymbol interference in a direct-sequence binary phase shift keying ultra-wide bandwidth (UWB) system are analyzed for the IEEE UWB channel models. Exact expressions for the first- and second-order moments are derived. The effects of the duration of the monocycle pulse, the spreading gain, and the number of interfering symbols on the average powers of the interferences are examined