Dynamic harq configuration and bitmap based ack/nack

An apparatus for a user equipment (UE) operating in an unlicensed spectrum in time division duplex (TDD), comprising:

• electronic memory to store an acknowledgement (ACK)/negative acknowledgement (NACK) message corresponding to a hybrid automatic repeat request (HARQ) process;
• and
• one or more baseband processors configured to:
• access a bitmap comprising a plurality of positions based on a plurality of supported HARQ processes including the HARQ process;
• map a HARQ process identifier (ID) of the HARQ process to a position from the plurality of positions of the bitmap;
• and
• generate a bitmap message comprising the ACK/NACK message in the position of the bitmap corresponding to the HARQ process ID.

A computer-readable storage medium having stored thereon instructions that, when implemented by a computing device, cause the computing device to:

• generate, at a user equipment (UE) operating in an unlicensed spectrum in time division duplex (TDD), a first acknowledgement (ACK)/negative acknowledgement (NACK) message corresponding to a first hybrid automatic repeat request (HARQ) process and a second ACK/NACK message corresponding to a second HARQ process;
• adjust a size of a bitmap based on a plurality of supported HARQ processes including the first HARQ process and the second HARQ process;
• map a first HARQ process identifier (ID) of the first HARQ process and a second HARQ ID of the second HARQ process to a same position of a bitmap;
• and
• generate a bitmap message comprising at least one of the first ACK/NACK message and the second ACK/NACK message in the same position of the bitmap corresponding to the HARQ process ID.