6.1 Overview

36.2113GPPEvolved Universal Terrestrial Radio Access (E-UTRA)Physical channels and modulationRelease 17TS

The smallest time-frequency unit for downlink transmission is denoted a resource element and is defined in clause 6.2.2.

A subset of the downlink subframes in a radio frame can be configured as MBSFN subframes by higher layers. For the MBSFN region is defined as one slot of 3 ms. Except for , each MBSFN subframe is divided into a non-MBSFN region and an MBSFN region.

– For subframes using , the non-MBSFN region spans the first one or two OFDM symbols in an MBSFN subframe where the length of the non-MBSFN region is given according to Clause 6.7.

– For subframes using , , , or slots using , the non-MBSFN region is of zero size.

– The MBSFN region in an MBSFN subframe is defined as the OFDM symbols not used for the non-MBSFN region.

For an MBMS-dedicated cell, subframes where PSS/SSS/PBCH or PDSCH carrying system information are transmitted with are non-MBSFN subframes.

For frame structure type 3, MBSFN configuration shall not be applied to downlink subframes in which at least one OFDM symbol is not occupied or discovery signal is transmitted.

Unless otherwise specified, transmission in each downlink subframe shall use the same cyclic prefix length as used for downlink subframe #0.

6.1.1 Physical channels

A downlink physical channel corresponds to a set of resource elements carrying information originating from higher layers and is the interface defined between TS 36.212 [3] and the present document TS 36.211.
The following downlink physical channels are defined:

– Physical Downlink Shared Channel, PDSCH

– Physical Broadcast Channel, PBCH

– Physical Multicast Channel, PMCH

– Physical Control Format Indicator Channel, PCFICH

– Physical Downlink Control Channel, PDCCH

– Physical Hybrid ARQ Indicator Channel, PHICH

– Enhanced Physical Downlink Control Channel, EPDCCH

– MTC Physical Downlink Control Channel, MPDCCH

– Short Physical Downlink Control Channel, SPDCCH

6.1.2 Physical signals

A downlink physical signal corresponds to a set of resource elements used by the physical layer but does not carry information originating from higher layers. The following downlink physical signals are defined:

– Reference signal

– Synchronization signal

– Discovery signal

– MTC wake-up signal, MWUS