Parameter decision for optimal handoff gain in CDMA 2000 system by measured propagation loss

The advantage of soft handoff is the positive gain i.e. reducing fading margin by combining each independent fading path between Mobile Station (MS) and active Base Station (BS). So it is possible to achieve required signal to interference ratio with lower SNR of each handoff path. On the contrary the disadvantage of soft handoff is that it can cause negative gain whenever MS has excess unnecessary branches linked to neighbor BS. In this paper each neighbor BS pilot channel E_c/I_t is calculated using measured propagation loss in a real multi-cell area. With calculated Ec/Io and by changing handoff parameters like static adding threshold (T ADD), dynamic adding threshold (SOFT SLOPE), we will show the change of SNR improvement and the increase of interference level that cause negative gain.