Used for:
• DL/UL Resource Assignments
• Multi-user Transmit Power Control (TPC) commands
• Paging indicators
Different PDCCH formats are defined:
• 1-3 OFDM symbols in a sub-frame
• PCFICH using the first OFDM symbol of each subframe informs PDCCH specific format
PDCCHs are constructed as follows
• CCE is defined as a unit of 36 REs
• A PDCCH instance is constructed as 1, 2, 4 or 8 CCEs
PDCCH Carries DCI – Downlink Control Information
Uplink assignments:
– RB assignment, transport block size, retransmission sequence number, power control command, cyclic shift
of DM RS for SDMA, etc.
Downlink assignments:
– RB assignment, transport block size, HARQ process number, Redundancy Version index, Uplink power
control command
Uplink Power Control Commands
Paging Indicator
L1/L2 control channel for:
DL scheduling, including:
– Regular unicast data
– Scheduling of Paging messages
Acting as a “paging indicator”
– Scheduling of SIBs
– Scheduling of random access responses
UL grants, including:
– Regular unicast data
– Requests for aperiodic CQI reports
Multi-user TPC commands:
– TPC commands for PUCCH or PUSCH for multiple UEs