A framework for analyzing the user membership in cellular CDMA networks

A theoretical framework is developed to analyze the user membership in cell ular networks. The main interest is on code-division multiple-access (CDMA) networks, although the validity of the proposed approach is not restricted to these networks. The membership of a user terminal to a certain base sta tion (BS) is established if the local mean attenuation to this BS is the Lo west one among all surrounding BS's, The estimate of local mean attenuation on the radio links from a mobile terminal to each of the surrounding BS's is carried out through proper filtering of the sequences of received signal strength measurements taken on broadcast signals at regular time intervals . In CDMA networks, pilot channels can be considered, while broadcast contr ol channels can be generically considered in narrow-band systems. A decisio n is made each time on whether the terminal is to be assigned to its "curre nt" BS or if it would be better served by a different BS, Two performance m easures are considered: the probability that the best BS is not selected an d the average number of membership switchings per time unit, A channel mode l with log-normal shadowing and fast fading superimposed is considered. Ana lytical expressions for the above-mentioned performance measures are derive d in a general system scenario, From numerical results, it is seen that a p roper choice of filter parameters is required to achieve the lowest values for both performance measures. Moreover, these values are not negligible wh en the mobile terminal is close to a boundary cell region. The obtained res ults are considered to be of interest in handover and power control algorit hms.