HARQ for dynamic change of the TDD UL/DL configuration in LTE TDD systems

A method of reconfiguring a time division duplex (TDD) uplink/downlink (UL/DL) configuration, the method comprising:

• identifying, at a base station, a first TDD UL/DL predetermined configuration for a first radio frame;
• communicating data using the first TDD UL/DL predetermined configuration in the first radio frame;
• in response to a change in traffic ratio between UL and DL transmissions, identifying, at the base station, a second TDD UL/DL predetermined configuration for a second radio frame adjacent the first radio frame, the second TDD UL/DL predetermined configuration identified based, at least in part, on one or more subframes of the second TDD UL/DL predetermined configuration that can communicate at least one hybrid automatic repeat request (HARQ) acknowledgement/negative acknowledgement (ACK/NACK) indicator for a corresponding subframe of the first TDD UL/DL predetermined configuration, wherein the first TDD UL/DL predetermined configuration supports a greater number of HARQ processes than the second TDD UL/DL predetermined configuration, and the second TDD UL/DL predetermined configuration is associated with a second number of HARQ buffers;
• communicating data using the second TDD UL/DL predetermined configuration in the second radio frame;
• and
• executing a second number of HARQ processes associated with the first TDD UL/DL predetermined configuration, the second number of HARQ processes equal to the second number of HARQ buffers.

A base station for reconfiguring a time division duplex (TDD) uplink/downlink (UL/DL) configuration, comprising:

• one or more processors configured to:
• identify, at the base station, a first TDD UL/DL predetermined configuration for a first radio frame;
• communicate data using the first TDD UL/DL predetermined configuration in the first radio frame;
• in response to a change in traffic ratio between UL and DL transmissions, identify, at the base station, a second TDD UL/DL predetermined configuration for a second radio frame adjacent the first radio frame, the second TDD UL/DL predetermined configuration identified based, at least in part, on one or more subframes of the second TDD UL/DL predetermined configuration that can communicate at least one hybrid automatic repeat request (HARQ) acknowledgement/negative acknowledgement (ACK/NACK) indicator for a corresponding subframe of the first TDD UL/DL predetermined configuration, wherein the first TDD UL/DL predetermined configuration supports a greater number of HARQ processes than the second TDD UL/DL predetermined configuration, the HARQ processes are uplink (UL) HARQ processes
• communicate data using the second TDD UL/DL predetermined configuration in the second radio frame;
• store excess UL HARQ processes in a queue;
• and
• upon receiving a negative new data indicator, execute a first UL HARQ process of the UL HARQ processes stored in the queue.

A non-transitory computer-readable medium containing instructions which, when executed, cause a computing device to perform operations comprising:

• identifying, at a base station, a first time division duplex (TDD) uplink/downlink (UL/DL) predetermined configuration for a first radio frame;
• communicating data using the first TDD UL/DL predetermined configuration in the first radio frame;
• in response to a change in traffic ratio between UL and DL transmissions, identifying, at the base station, a second TDD UL/DL predetermined configuration for a second radio frame adjacent the first radio frame, the second TDD UL/DL predetermined configuration identified based, at least in part, on one or more subframes of the second TDD UL/DL predetermined configuration that can communicate at least one hybrid automatic repeat request (HARQ) acknowledgement/negative acknowledgement (ACK/NACK) indicator for a corresponding subframe of the first TDD UL/DL predetermined configuration, wherein the first TDD UL/DL predetermined configuration supports a greater number of HARQ processes than the second TDD UL/DL predetermined configuration, and the second TDD UL/DL predetermined configuration is associated with a second number of HARQ buffers;
• communicating data using the second TDD UL/DL predetermined configuration in the second radio frame;
• and
• executing a second number of HARQ processes associated with the first TDD UL/DL predetermined configuration, the second number of HARQ processes equal to the second number of HARQ buffers.