Synchronization signals for license assisted access

An apparatus for a user equipment (UE), the apparatus comprising:

• memory;
• and
• processing circuitry coupled with the memory, the processing circuitry is configured to:
• configure the UE to receive a downlink transmission from an evolved node B (eNodeB), wherein the UE and eNodeB are configured for license assistance access (LAA) using carrier aggregation with a secondary cell (Scell) in an unlicensed spectrum, and wherein the downlink transmission is to occupy one or more consecutive subframes, and is to start within a first subframe and is to end with a last subframe, the last subframe either fully occupied or following a downlink pilot time slot (DwPTS) duration;
• for non-empty subframes of the one or more consecutive subframes of the downlink transmission that are located at predetermined positions in a frame and include at least a predetermined number of Orthogonal Frequency Division Multiplexing (OFDM) symbols, extract a primary synchronization signal (PSS) and a secondary synchronization signal (SSS) from fixed positions of the subframes.

A non-transitory computer-readable medium, having instructions stored thereon, which when performed by processing circuitry of an evolved Node B (eNodeB) cause following operations to be performed:

• wherein the Evolved NodeB (eNodeB) is configured for license assistance access (LAA) using carrier aggregation with a secondary cell (Scell) in an unlicensed spectrum, and the operations comprises:
• encoding one or more consecutive subframes for a downlink transmission within the Scell, wherein the downlink transmission is to occupy the one or more consecutive subframes and is to start within a first subframe and is to end with a last subframe, the last subframe either fully occupied or following a downlink pilot time slot (DwPTS) duration;
• wherein a frame includes 10 subframes identified as subframes 0 to 9, the operations further comprises:
• for a subframe of the one or more consecutive subframes of the downlink transmission that is neither a subframe 0 nor subframe 5 of a frame, refraining from encoding the subframe to include a primary synchronization signal (PSS) and a secondary synchronization signal (SSS);
• and
• for a subframe of the one or more consecutive subframes of the downlink transmission that is either a subframe 0 or subframe 5 of a frame:
• encoding the subframe to include both the PSS and SSS at fixed positions of the subframes, if the subframe is non-empty and includes at least a predetermined number of Orthogonal Frequency Division Multiplexing (OFDM) symbols;
• and
• refraining from encoding the subframe to include the PSS and the SSS, if the subframe does not include at least the predetermined number of OFDM symbols.