The LTE air interface physical layer offers data transport services to higher layers. The access to these services is through the use of a transport channel via the MAC sub-layer. The physical layer is expected to perform the following functions in order to provide the data transport service:

• Error detection on the transport channel and indication to higher layers
• FEC encoding/decoding of the transport channel
• Hybrid ARQ soft-combining
• Rate matching of the coded transport channel to physical channels
• Mapping of the coded transport channel onto physical channels
• Power weighting of physical channels
• Modulation and demodulation of physical channels
• Frequency and time synchronisation
• Radio characteristics measurements and indication to higher layers
• Multiple Input Multiple Output (MIMO) antenna processing
• Transmit Diversity (TX diversity)
• Beamforming
• RF processing

Protocol specification

3GPP TS 36.201 - Evolved Universal Terrestrial Radio Access (E-UTRA); LTE physical layer; General description

3GPP TS 36.211 - Evolved Universal Terrestrial Radio Access (E-UTRA); Physical channels and modulation

3GPP TS 36.212 - Evolved Universal Terrestrial Radio Access (E-UTRA); Multiplexing and channel coding

3GPP TS 36.213 - Evolved Universal Terrestrial Radio Access (E-UTRA); Physical layer procedures

3GPP TS 36.214 - Evolved Universal Terrestrial Radio Access (E-UTRA); Physical layer; Measurements