Measurement and characterization of broadband indoor TVWS radio channel on multipath spread

This paper reports measurements and characterizations of broadband indoor Television White Space (TVWS) channel with center frequency of 670 MHz. The measurements have been carried out in small- and medium-size mixed office and lab indoor environments recently. Channel multipath delay spread of both line-of-sight (LOS) and non-LOS (NLOS) connections are identified by using BPSK signaling of 20-Mbps data rate. The root-mean-square (RMS) delay spreads are found between 20 ns to 32 ns for LOS and 32 ns to 41 ns for NLOS in small-size office and lab environment, and is found about 38 ns for LOS and 39 ns for NLOS in medium-size indoor environment. A general complex low-pass impulse response model is proposed based on our findings and the classic Saleh-Valenzuela (S-V) channel model. With the proposed channel impulse response model, ray clusters may appear before and after the strongest cluster and rays may exist on both sides of the strongest ray in a cluster. Model parameters are extracted from the measurement results. Extensive simulation results show that the model fits the measurements well.