WCDMA PICH (Paging Indicator Channel) Explained

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.

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.

Explore More WCDMA Channel Types

• WCDMA AICH (Acquisition Indicator Channel)
• WCDMA CD/CA-ICH Collision Detection/Channel Assignment Indicator Channel
• WCDMA CPICH Common Pilot Channel
• WCDMA CSICH CPCH STATUS INDICATION CHANNEL
• WCDMA DPCCH UPLINK DEDICATED PHYSICAL CONTROL CHANNEL
• WCDMA DPCH DOWNLINK DEDICATED PHYSICAL CHANNEL
• WCDMA DPDCH UPLINK DEDICATED PHYSICAL DATA CHANNEL
• WCDMA PCCPCH PRIMARY COMMON CONTROL PHYSICAL CHANNEL
• WCDMA PCPCH PHYSICAL COMMON PACKET CHANNEL
• WCDMA PDSCH PHYSICAL DOWNLINK SHARED CHANNEL
• WCDMA PRACH CHANNEL
• WCDMA SCCPCH SECONDARY COMMON CONTROL PHYSICAL CHANNEL
• WCDMA SYNCHRONIZATION CHANNEL SCH
• WCDMA SIB TYPES