Propagation measurements using array signal processing

Propagation measurements using a synthetic aperture array may be used to determine direction of arrival as well as delay of multipath components. The measurement data may then be used to validate ray-tracing propagation models, as well as to evaluate smart antenna array processing techniques. We investigate the limitations of the synthetic aperture measurement technique, in particular, we consider both linear and cross arrays, and determine the corresponding positioning accuracy required. Thus we present both simulated and experimental results of complex impulse responses at 1 GHz, using a synthetic aperture array, taken in several typical scenarios, using both linear array and cross-array processing. We find that the positioning error must be less than 5% for a half-wavelength spaced linear array to ensure that 90 percent of spurious responses are more than 30 dB down relative to the source signal.