DIGITAL SIGNAL-PROCESSING TECHNIQUES APPLIED TO MOBILE RADIO CHANNEL SOUNDING

A novel implementation of a wideband channel sounder for mobile radio using digital signal processing techniques is presented. The system uses the principle of pulse compression at the receiver. By performing in-phase and quadrature (I and Q) down conversion and matched digital filtering in the frequency domain, an improved dynamic range of 15-20 dB over sounders using SAW matched filters can be achieved. The impulse response of the channel is measured in real-time and thus the sounder does not suffer from any of the compromises associated with the non-real-time sliding correlator sounder. The use of a software approach gives the system great flexibility. In particular, the matched filter compensates for the effect of the amplitude and phase response of the transmitter and receiver filters on the probing pulse.