Communication method and communications apparatus for reduction of transmission latency of downlink data

A communication method, the method comprising:

• sending, by a network device, downlink data to a terminal device in a first time unit;
• determining, by the network device, based on a nonnegative integer k1 corresponding to the downlink data, a second time unit in which feedback information corresponding to the downlink data is located, wherein a length of the first time unit is greater than or equal to a length of the second time unit, the k1 corresponding to the downlink data represents a quantity of time units from the first time unit to the second time unit in which feedback information corresponding to the downlink data is located, and the length of the second time unit is less than one slot;
• and
• receiving, by the network device, in the second time unit in which feedback information corresponding to the downlink data is located, a feedback codebook from the terminal device, wherein the feedback codebook comprises the feedback information corresponding to the downlink data,
• wherein the feedback codebook comprises feedback information corresponding to a candidate occasion of a target second time unit, the candidate occasion is used by the terminal device to receive downlink data, and
• the target second time unit is a set of second time units that is determined based on a k1 set and the second time unit in which the feedback information corresponding to the downlink data is located, and the k1 set is a set of values of k1, and the candidate occasion is determined based on configured time domain resources used by the terminal device to receive downlink data, wherein the configured time domain resources comprise a time domain resource whose last symbol belongs to the target second time unit.

A communications apparatus, the apparatus comprising:

• a processor, configured to determine a first time unit for receiving downlink data, wherein
• the processor is further configured to determine, based on a nonnegative integer k1 corresponding to the downlink data, a second time unit in which feedback information corresponding to the downlink data is located, a length of the first time unit is greater than or equal to a length of the second time unit, the k1 corresponding to the downlink data represents a quantity of time units from the first time unit to the second time unit in which feedback information corresponding to the downlink data is located, and the length of the second time unit is less than one slot;
• and
• a transceiver, configured to send, in the second time unit in which feedback information corresponding to the downlink data is located determined by the processor, a feedback codebook to a network device, wherein the feedback codebook comprises the feedback information corresponding to the downlink data,
• wherein the feedback codebook comprises feedback information corresponding to a candidate occasion of a target second time unit, the candidate occasion is used by the communications apparatus to receive downlink data, and
• the target second time unit is a set of second time units that is determined based on a k1 set and the second time unit in which the feedback information corresponding to the downlink data is located, and the k1 set is a set of values of k1, and the candidate occasion is determined based on configured time domain resources used by the communications apparatus to receive the downlink data, wherein the configured time domain resources comprise a time domain resource whose last symbol belongs to the target second time unit.

A communications apparatus, the apparatus comprising:

• a transceiver, configured to send downlink data to a terminal device in a first time unit;
• and
• a processor, configured to determine, based on a nonnegative integer k1 corresponding to the downlink data sent by the transceiver, a second time unit in which feedback information corresponding to the downlink data is located, a length of the first time unit is greater than or equal to a length of the second time unit, the k1 corresponding to the downlink data represents a quantity of time units from the first time unit to the second time unit in which feedback information corresponding to the downlink data is located, and the length of the second time unit is less than one slot, wherein
• the transceiver is further configured to receive, in the second time unit in which feedback information corresponding to the downlink data is located determined by the processor, a feedback codebook from the terminal device, wherein the feedback codebook comprises the feedback information corresponding to downlink data,
• wherein the feedback codebook comprises feedback information corresponding to a candidate occasion of a target second time unit, the candidate occasion is used by the terminal device to receive the downlink data, and
• the target second time unit is a set of second time units that is determined based on a k1 set and the second time unit in which the feedback information corresponding to the downlink data is located, and the k1 set is a set of values of k1, and the candidate occasion is determined based on configured time domain resources used by the terminal device to receive the downlink data, wherein the configured time domain resources comprise a time domain resource whose last symbol belongs to the target second time unit.