Physical (PHY) layer solutions to support use of mixed numerologies in the same channel

A wireless transmit/receive unit (WTRU) comprising:

• a transceiver;
• and
• a processor, operatively coupled to the transceiver;
• wherein:
• the transceiver is configured to receive a first signal including a primary synchronization signal (PSS) and a secondary synchronization signal (SSS), wherein the PSS and the SSS are received in a resource block of a cell, wherein the resource block has a first numerology, wherein the first numerology has a first subcarrier spacing, wherein other resources of the cell at a same time as the resource block have a second numerology with a different subcarrier spacing than the first numerology;
• the processor and the transceiver are configured to synchronize to a timing of the cell based on the PSS and the SSS;
• the transceiver is configured to receive a second signal in the cell, wherein the second signal has the second numerology;
• and
• the processor and the transceiver are configured to transmit user data.