SINR threshold lower bound for SINR-based call admission control in CDMA networks with imperfect power control

Signal to interference plus noise ratio (SINR)-based call admission control schemes admit calls as long as SINR is higher than a threshold value (SINR_th). Setting a relatively low SINR_th results in more users admitted into the system and this in turn yields an increased outage probability (P_out). Hence, determining the lower bound of SINR_th (SINR_{th_lb}) is vital to keep P_out below a maximum value, P_{out_max}x. In this letter, we derive SINR_{th_lb} in the reverse link of CDMA systems with imperfect power control by finding the relationship between P_out (due to power control infeasibility and SINR fluctuation) and SINR_th. Then, SINR_{th_lb} is determined as the lowest SINR_th that keeps P_out below a certain P_{out_max}.