PERFORMANCE OF SIMULCAST WIRELESS TECHNIQUES FOR PERSONAL COMMUNICATION-SYSTEMS

Broadband analog transport facilities using fiber or fiber/coax cable can play a significant role in the evolution of the network infrastruc ture for personal communications services (PCS's), Low-power PCS syste ms require a dense grid of radio ports to provide connectivity to the telephone network, Analog transport has a number of important advantag es over digital transmission facilities, including the flexibility to support a variety of air interface formats, shared infrastructure cost with other services such as video distribution, and centralized call processing allowing the use of low cost and simple radio ports, A simu lcast technique can be used in such systems to permit low rates of han doff (no handoff within each simulcast area) and sharing of hardware r esources among multiple radio ports. This paper provides a detailed mo del and a simulation analysis of the cochannel interference and noise performance as well as the resource sharing benefit of a simulcast PCS System, Several potential PCS air interfaces are considered, includin g time division multiple access (TDMA) and code division multiple acce ss (CDMA) techniques, Our investigation shows that the impact of multi ple antenna noise in a simulcast system is offset by the improved sign al-to-interference (SIR) 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 simu lcast group, This limit, however, is shown to have little impact on th e 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 for both TDMA and CDMA systems in suburban environments.