Indoor 1.8 GHz AOA-TDOA measurements with simple channel sounding approaches

This work reports the results of indoor joint AOA-TDOA (angle-of-arrival - time-delay-of-arrival) measurements based on the use of a typical wideband propagation channel sounder, suited for indoor environments: a frequency domain sounder. Such kind of sounder allows the measurement of the channel impulse response, that is, the time-delay spectrum (TDOA). In order to also measure AOA, a simple approach is the use of an antenna array properly designed for spatial sampling, like the uniform linear array. Since a channel vector response is needed, which would ideally require a dedicated receiver for each array element, some hardware simplifications may be very convenient, like the synthetic aperture concept, for instance. Alternatively, if an actual array is adopted, a single receiver may be shared in time, simply switching the array elements fast enough. Both approaches have been deployed in our survey, which has been carried out at 1.8 GHz, with a 200 MHz bandwidth. Spatial spectral estimation algorithms such as beamforming and MUSIC have been applied. Despite the simplicity of both techniques, the estimated results were in fair agreement with the theoretical expected values. © 2006 SBMO.