Abstract: Embodiments provide a data retransmission method and a communications apparatus. The method includes: starting, by a transmit end, a timer before transmitting new data to a receive end, where a preset value of the timer is a maximum transmission latency corresponding to a service type of the data; retransmitting, by the transmit end, the data to the receive end when data needs to be retransmitted; transmitting, by the transmit end, the data to the receive end; and stopping sending, by the transmit end, retransmission data to the receive end when the timer expires, where the retransmission data is a part or all of the data. In this way, the following prior-art problem is avoided: Because a maximum retransmission quantity is not exhausted but a maximum transmission latency is exhausted, the transmit end still sends data, and consequently the receive end receives expiration data. This can avoid redundant transmission and save transmission resources.

Abstract: Embodiments provide a data transmission method and apparatus, and an information transmission method and apparatus. Under the data transmission method, obtaining time-frequency resources used to transmit first data can be obtained. Some or all of the time-frequency resources are used to transmit second data. A transmission parameter used to transmit the second data can also be obtained. A size of a to-be-encoded data block used to encode the first data can be determined based on the transmission parameter. The first data can be encoded based on the size of the to-be-encoded data block. A data block obtained through the encoding to the time-frequency resources can be mapped. In this way, interference caused by one type of data to another type of data can be reduced when same time-frequency resources are multiplexed for data transmission.

Abstract: Embodiments disclose a method and an apparatus for transmitting indication information. The method includes: determining, according to one or more codebooks, a first codebook to be used by a terminal device to send an uplink data stream; determining codebook indication information used to indicate the first codebook; and determining codebook indication information used to indicate the first codebook. For the method and the apparatus for transmitting indication information according to embodiments of the present invention, a network device determines, according to one or more codebooks, a first codebook to be used by a terminal device to send an uplink data stream, determines codebook indication information used to indicate the first codebook, and sends the codebook indication information to the terminal device, so that the terminal device can determine the first codebook assigned by the network device and transmit data by using the first codebook.

Abstract: Example data transmission methods and apparatus are described. One example method includes obtaining at least two signature sequences used to perform multiple access for at least two to-be-sent data packets by a user equipment. The user equipment processes the at least two data packets by respectively using corresponding signature sequences, to obtain at least two transmit sequences. The user equipment sends the at least two transmit sequences to a network device on a same time-frequency resource. Then the network device obtains the at least two signature sequences used by the user equipment to send the at least two transmit sequences, and separately detects a corresponding transmit sequence based on each signature sequence, to obtain the at least two data packets. The user equipment can transmit a plurality of data packets on a same time-frequency resource in a same slot.

Abstract: The present invention discloses an indication information transmission method and apparatus. The method includes: determining, in one or more codebooks, a first codebook used to send a first downlink data stream to a terminal device; determining one or more second codebooks used to send a second downlink data stream; determining codebook indication information used to indicate the first codebook and the one or more second codebooks; and sending the codebook indication information to the terminal device.

Abstract: The present invention discloses an indication information transmission method and apparatus. The method includes determining a first signature sequence and a first modulation constellation that are used to transmit a first downlink data stream to a terminal device and determining one or more second signature sequences and one or more second modulation constellations that are used to transmit a second downlink data stream. The method also includes determining indication information that is used to indicate the first signature sequence, the first modulation constellation, the one or more second signature sequences, and the one or more second modulation constellations and transmitting the indication information to the terminal device.

Abstract: This application provides an uplink transmission method, a terminal, and a network side device. The method includes: storing, by a terminal, an uplink transmission time-frequency resource allocated by a network side device; when the terminal needs to send an uplink signal, determining the to-be-transmitted uplink signal based on a quantity of orthogonal frequency division multiplexing (OFDM) symbols in the uplink transmission time-frequency resource; and sending, by the terminal, the uplink signal to the network side device. During implementation of the uplink transmission method provided in this application, grant free transmission solutions are provided for different uplink transmission time-frequency resources, to effectively improve communication performance.

Abstract: Embodiments of this application provide a data transmission method, a network device, and a terminal device. The method may include detecting, by a network device, a first signal in an uplink signal. The method may also include determining, by the network device, a signal structure of the uplink signal based on a result of detecting the first signal. Furthermore, the method may include receiving, by the network device, the uplink signal based on the signal structure, and/or responding to the uplink signal based on the signal structure. According to the data transmission method in the embodiments of this application, before receiving data, the network device can determine the signal structure, used by the terminal device, of the uplink signal, and then use a corresponding receiving method to avoid complexity and a reliability risk that are caused by completely blind detection performed by the network device, as well as to effectively reduce a delay and signaling overheads.

Abstract: Embodiments of this application provide a data transmission method and device, so as to increase an uplink/downlink data transmission throughput. The method includes: splitting a to-be-transmitted transport block into N code blocks with incompletely equal sizes, where N is an integer greater than or equal to 2; performing error correction coding on the N code blocks to obtain N encoded bit blocks; and non-orthogonally transmitting the N encoded bit blocks by using resources that are the same in at least one dimension of a time domain, a frequency domain, a space domain, and a code domain.

Abstract: A grant-free transmission method, a terminal, and a network device, the method including after determining a grant-free transmission pilot and a sending attribute parameter group, mapping, by a terminal, a pilot sequence to a corresponding location on a grant-free transmission resource block unit based on a relationship between a time-frequency resource location of a pilot and the sending attribute parameter group, and mapping data to another location on the grant-free transmission resource block unit.

Abstract: The disclosure provides an uplink transmission method, a terminal, and a network side device. The method includes: pre-allocating, by a network side device, an uplink transmission time-frequency resource to a terminal, and storing, by the terminal, the uplink transmission resource; and when the terminal needs to send a data packet, sending, by the terminal, the data packet to the network side device by using the uplink transmission resource, where the data packet includes indication information, the indication information is used to indicate whether the data packet is initially transmitted by the terminal or the data packet is retransmitted by the terminal, and the network side device can correctly receive the data packet and perform combination processing on the data packet based on the indication information. According to embodiments of the disclosure, reliability of grant-free transmission can be ensured, and communication performance can be effectively improved.

Abstract: The present invention discloses a pilot sequence transmission method and apparatus. A terminal device determines a first pilot number, determines a first pilot sequence and a second pilot sequence according to the first pilot number, respectively maps the first pilot sequence and the second pilot sequence to a first OFDM symbol and a second OFDM symbol of a grant free transmission resource, and sends the first pilot sequence and the second pilot sequence by using the first OFDM symbol and the second OFDM symbol. Therefore, a network device can determine activeness of the terminal device by detecting the first pilot sequence, and can detect only the second pilot sequence corresponding to the first pilot sequence, and does not need to detect all possible second pilot sequences, so that a quantity of detected pilots can be significantly reduced, and pilot detection complexity is reduced.

Abstract: A grant-free transmission method, a terminal, and a network device are disclosed. In an embodiment, a grant-free transmission method includes sending, by a network device, information about P dedicated transmission resources used for grant-free transmission to a terminal, wherein P is a positive integer and P?2, detecting, by the network device, a dedicated transmission resource, and detecting, by the network device, data based on a transmission parameter set corresponding to the dedicated transmission resource when grant-free transmission is detected.

Abstract: Embodiments of the present invention provide a resource mapping method. The method includes: obtaining a modulation symbol generated based on M code words, where M is a positive integer greater than or equal to 1; mapping the modulation symbol generated based on the M code words to a time-frequency resource in one or more mapping patterns, where the mapping pattern is a pattern of mapping every Q modulation symbols to one mapping unit, the mapping unit includes F resource units, F is a positive integer greater than or equal to 1, Q is a positive integer meeting 1?Q?F, the mapping pattern includes a sparse mapping pattern, and the sparse mapping pattern is a mapping pattern meeting F?2 and 1?Q<F; and sending the mapped modulation symbol generated based on the M code words.

Abstract: A data transmission method, a terminal, and a network device are provided, to improve reliability of data transmission performed by a terminal in a grant-free mode. In embodiments of the present invention, a terminal sends, in a grant-free mode, first data to a network device by using a grant-free resource, and if the terminal needs to switch from the grant-free mode to a grant mode, the terminal sends, in the grant mode, second data to the network device by using a grant resource. When the terminal initially transmits the first data in the grant-free mode, if the terminal needs to switch from the grant-free mode to the grant mode, the terminal may fall back to the grant mode and transmit data in the grant mode. In this way, reliability of data transmission is improved and a success rate of data transmission is improved to a relatively great extent.

Abstract: The present disclosure describes a downlink control information transmission method and apparatus. The method includes: determining multiple terminal devices used for downlink scheduling; determining downlink control information used by the multiple terminal devices to receive downlink data flows, where the downlink control information includes common control information shared by the multiple terminal devices, dedicated control information of each of the multiple terminal devices, and device identifier information of each terminal device, and an order of the device identifier information of each terminal device is the same as an order of the dedicated control information of each terminal device; and sending the downlink control information to the multiple terminal devices.

Abstract: Embodiments of this application provide a grant-free transmission method, a terminal device, and a network device, to improve grant-free transmission reliability. The grant-free transmission method includes: obtaining, by a terminal device, an interleaving pattern based on at least one of a cell identity of the terminal device, a terminal device identifier, time-domain resource information, and frequency-domain resource information; interleaving data based on the obtained interleaving pattern, to obtain interleaved data; and sending the interleaved data.

Abstract: The present disclosure discloses an indication information transmission method and apparatus. The method includes: determining a first signature sequence and a first modulation constellation that are used to transmit an uplink data stream by a terminal device; determining indication information that is used to indicate the first signature sequence and the first modulation constellation; and transmitting the indication information to the terminal device. In this way, a system network capacity can be effectively increased.

Abstract: The present disclosure relates to the field of mobile communications technologies, and discloses a method for configuring a resource to a DRB, and an apparatus. The method is specifically: first determining, by a first CBS, resource configuration information used by a first DBS to separately allocate a resource to at least one DRB of UE; and then, sending, to the first DBS, a first resource allocation indication that carries the determined resource configuration information, so that the first DBS separately allocates the resource to the at least one DRB of the UE according to the resource configuration information. In this way, effectively implementing resource configuration for a protocol entity in a DBS according to a QoS requirement of a DRB.

Abstract: Embodiments of this application disclose a pilot signal sending and receiving method and apparatus, wherein the pilot signal sending method includes: establishing a first correspondence between a carrier identifier and a pilot pattern of a first type of pilot signal; establishing a second correspondence between a carrier identifier and a resource block set; acquiring a target carrier identifier of a target carrier; determining a location of a target resource block set corresponding to the target carrier identifier; determining a target pilot pattern that is of a first type of pilot signal and that corresponds to the target carrier identifier; mapping, according to the target pilot pattern, the first type of pilot signal to each resource block in the target resource block set on the target carrier. In this method, mapping is performed on a pilot signal only in a resource block set, which may reduce pilot redundancy and overheads.