Terminology » Mobile Communication » WCDMA PICH (Paging Indicator Channel) Explained

WCDMA PICH (Paging Indicator Channel) Explained

wcdma pich umts paging channel mobile communication

This page describes the PICH, or Paging Indicator Channel, with respect to the WCDMA/UMTS system. The Paging Indicator Channel (PICH) is always associated with a Paging Channel (PCH) on the S-CCPCH (Secondary Common Control Physical Channel).

The PICH carries the Page Indicators (PIs). A PI indicates to a subset of UEs (User Equipments) within a cell whether they should check the next S-CCPCH frame for paging messages.

​In WCDMA, PICH is downlink physical channel designed to efficiently notify UE about incoming paging messages.

WCDMA PICH

Key characteristics of PICH

  • Symbol rate: 15 ksps (kilo symbols per second)
  • Spreading factor: 256
  • Spreading code: OVSF (Orthogonal Variable Spreading Factor)
  • Scrambling: Gold sequence - 3.84Mcps (Mega chips per second), 10 ms periodic
  • Number of PI (Page Indicators): 18 / 36 / 72 / 144

Summary

The PICH plays a vital role in the efficient operation of WCDMA networks by enabling UEs to manage their power consumption effectively while ensuring timely reception of paging messages.