Performance of simulcast wireless techniques for personal communication systems

Abstract

Broadband analog transport facilities using fiber or fiber/coax cable can play a significant role in the evolution of the network infrastructure for personal communications services (PCS). Low-power PCS systems require a dense grid of radio ports to provide connectivity to the telephone network. A simulcast technique can be used in such systems to permit low rates of handoff (no handoff within each simulcast area) and sharing of hardware resources among multiple radio ports. This paper presents a simulation analysis of the cochannel interference and noise performance as well as the resource sharing benefit of a simulcast PCS system. Our investigation shows that the the impact of multiple antenna noise in a simulcast system is offset by the improved signal-to-interference ratio brought about by distributed antennas. Even with distributed antennas, multiple antenna noise places a limit on the maximum number of radio ports that can be assigned to each simulcast group. This limit, however, is shown to have little impact on the achievable resource sharing benefit of simulcasting (i.e., grouping beyond this limit has diminishing returns). A saving of 40% to 60%, in terms of the required central hardware resources, is typical in suburban environments.