Estimating smart antenna performance from directional radio channel measurements

The received power and signal to interference ratio (C/I) for three different smart antenna concepts (switched lobe (SL), phased array (PA) and adaptive array (AA)), have been calculated and compared with a standard “fixed lobe” sector antenna. The calculations were based on wideband directional radio channel measurements in urban and suburban areas. Both SL and PA performs similarly, 4-6 dB gain in power and 4-10 dB gain in C/I. The AA concept gives less received power gain than SL and PA, but is far better on C/I, with a gain of 10-19 dB. In urban areas, both high and low BS antenna positions were measured and calculated, and, in general, highest gain was found for the high antenna positions. The correlation coefficients between power gain and azimuth spread (AS), and the 90% azimuth window (AW₉₀) has been calculated for the PA concepts. Only a weak negative correlation was found, and the spread within a single area was large