Experimental wideband characterization of a hybrid fibre-coax-wireless channel for mobile local access

This paper deals with the experimental characterization of the wideband properties of a composite hybrid fibre-coax (HFC)/ wireless channel, a transmission medium used for Microcell´s 1997 wireless local access (WLA) trials at North American PCS frequencies (1850-1990 MHz) with simulcast distributed antenna arrays. Such channels have not been characterized in the literature in terms of their wideband behaviour, which is a crucial design parameter when frequency hopping is considered and when differential fibre delays can create very large dispersion characteristics within a simulcast antenna array group. Wireless operators are constantly seeking to implement innovative and cost-effective methods of providing PCS coverage. Traditional builds are characterized by expensive towers and high power base station transceivers with a large area macrocellular design. More recent ideas have pointed to providing coverage and capacity on demand. In addition, operators are tending toward exploiting existing infrastructure in order to reuse their transmission resources. An example of this is the distributed antenna concept using a hybrid fibrecoax plant where a base station transceiver is connected to the head-end of a cable TV plant by means of a fibre link. The distributed antenna concept was notably studied by Kerpez (1996). The basis of the WLA trial at Microcell Connexions was to evaluate the technical as well as economic benefits of using the HFC plant in conjunction with a distributed antenna architecture for GSM based wireless local access. In particular, this test assessed the advantage of frequency hopping in a simulcast configuration