Distribution of uplink signal to interference ratio in WCDMA random access channel (RACH)

The random access channel (RACH) is defined by 3rd generation partnership project (3GPP) as an uplink channel that is used for random-access transmission and short data bursts transportation from the user equipment (UE) to the network side in the absence of a dedicated traffic channel. The random-access transmission is based on a slotted Aloha approach with fast acquisition indication, carried by the acquisition indicator channel (AICH). In this paper, the RACH performance indicators such as delay and access success ratio are obtained for different traffic loads, in a single omni cell under shadowing and fast-fading conditions. We also propose an approximation for preamble signal to interference ratio (SIR) measured at base station point, in terms of mean level and standard deviation.