PDCCH Bits (LTE)

Default: None

Range: None, Demapped, Deinterleaved, Descrambled, Deratematched, Decoded

PDCCH Bits specifies how much coding to undo before showing the bits from PDCCH Physical Downlink Control Channel on the CW0/1 Decoded Symbol Tables. See 3GPP TS Technical Specification 36.212, Section 5.3.3 for a diagram of the coding operations performed on PDCCH.

The following is a list of the available PDCCH Bits selections and the resulting bits shown on the CW0/1 Decoded Symbol Tables. N_REGis the number of resource element groups not allocated for PHICH Physical Hybrid ARQ Indicator Channel or PCFICH Physical Control Format Indicator Channel in a subframe.

Mapped - raw PDCCH bits are shown on the Symbol Table. No PDCCH bits will be shown in the CW0/1 Decoded Symbol Tables
Demapped - N_REG * 8 demapped (interleaved) DCI Downlink Control Information format bits for each subframe
Deinterleaved - N_REG * 8 deinterleaved (scrambled) DCI format bits for each subframe
Descrambled - N_REG * 8 descrambled (rate-matched) bits for each subframe
Deratematched - S (8 + LEN_i) bits for each subframe

Each set of bits for an active PDCCH transmission consists of an 8-bit length field (LEN_i) followed by the deratematched (channel coded) bits.

LEN_i indicates the number of deratematched bits for the i^th PDCCH transmission in a subframe and can be used to determine where a PDCCH ends and the next PDCCH begins in the CW0/1 Decoded Symbol Tables.

LEN_i = 3 * (DCI Payload Length + CRC Cyclic Redundancy Check Length)
Decoded - S (8 + LEN_i) bits for each subframe

Each set of bits for an active PDCCH transmission consists of an 8-bit length field (LEN_i), the decoded (DCI payload + CRC) bits, and the 16-bit CRC.

LEN_i indicates the number of decoded bits (including CRC) for the i^th PDCCH transmission in a subframe and can be used to determine where a PDCCH ends and the next PDCCH begins in the CW0/1 Decoded Symbol Tables.

LEN_i = DCI Payload Length + CRC Length

For both Deratematched and Decoded PDCCH bits, the LTE Long Term Evolution demodulator autodetects the number of active PDCCH transmitted within each subframe, n_PDCCH.

The PDCCH decoder is On when RB Auto Detect Mode is set to Decode PDCCH or when PDCCH Bits is not set to None.

The same PDCCH bits are shown on both CW0 Decoded Symbol Table and CW1 Decoded Symbol Table traces to allow marker coupling.

To determine the location of bits for this physical channel in the CW0/1 Decoded Symbol Tables, use the DemodOFDMSubcarType key in the trace header. This key can be included when saving a trace to disk or can be accessed programmatically from the Trace.MeasurementData.State dictionary.