Multipath fading effects in a 40 mhz channel.

Experimental results are presented for the multipath channel characterization of a 40-MHz-wide RF channel in the 4-GHz band. The 40-MHz-wide test signal is transmitted over a 52-km hop. The space-diversity receiver combines the test signal using a continuous-phase maximum-power technique. Channel responses are measured on the main antenna, the diversity antenna, and the combined channel. The effects of bandwidth on in-band power-difference are also described. Results indicate that: (1) single-frequency fading for nondiversity applications follows the empirical L² law; (2) broadband power falls off from the L² law with increasing fade-depth and increasing bandwidth, and (3) space-diversity reception, with maximum-power combining, is very effective at reducing the severity of multipath dispersion and flat fading.