Ultra-wideband spatio-temporal channel sounding with use of an OFDM signal in the presence of narrowband interference

Abstract

An Ultra wideband (UWB) spatio-temporal channel sounder, employing an orthogonal frequency division multiplexing (OFDM) signal and a receiving virtual array antenna was prototyped and evaluated in a narrowband interference environment. Channel information of the OFDM signal was estimated from the measured data. Time of arrival (TOA) was calculated by correlating the received waveforms with a template. Angle of arrival (AOA) was derived by employing a multiple signal classification (MUSIC) algorithm and an angular histogram method proposed by the authors. The frequency spectrum and the AOA of the narrowband interference signal can be simultaneously estimated by means of the same methodology. Propagation experiments were carried out to validate the techniques in one- and two-path environments in a radio anechoic chamber. The bandwidths of the UWB OFDM and the narrowband signals were respectively 500 and 20 MHz. The TOA and the AOA of the wideband signal were estimated within reasonable bounds of error in the presence of narrowband interference, and the AOA and the occupied bandwidth of the narrowband signal were also satisfactorily estimated.