Indoor 1.8 GHz AOA-TDOA measurements extending the use of a wideband propagation channel sounder with the synthetic aperture concept

This work reports the results of indoor joint AOA-TDOA measurements, using a typical wideband propagation channel sounder. The whole survey has been carried out in 1.8 GHz, with a 200 MHz bandwidth. Since such kind of sounder only allows the measurement of the channel impulse response, that is, the time-delay spectrum, a synthetic aperture uniform linear antennae array was adopted in order to extend its use to perform also angle-of-arrival measurements. Spatial spectral estimation algorithms such as beamforming, Capon and MUSIC have been applied. Despite the simplicity of the technique, the estimated results were in fair agreement with the theoretical expected values, validating the use of the "modified" sounder.