TECHNICAL FIELD

The present invention relates to the field of wireless communications technologies, and in particular, to a signal transmission method and apparatus.

BACKGROUND

Orthogonal frequency division multiplexing (OFDM) and discrete fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM) are two typical waveforms in wireless communication. The OFDM is a multi-carrier waveform and has advantages of a high anti-multipath capability and a flexible frequency division multiplexing manner, but has a disadvantage of an excessively high peak to average power ratio (PAPR). The DFT-S-OFDM introduces a DFT spread before inverse fast fourier transform (IFFT) of the OFDM, and provides a PAPR far lower than that in the OFDM while inheriting a plurality of advantages of the OFDM. Although the DFT-S-OFDM introduces a subcarrier processing process of the OFDM, the DFT-S-OFDM is essentially a single-carrier waveform.

Currently, in a new generation wireless communications standard, new radio (NR), of the 3rd Generation Partnership Project (3GPP), it is determined to use both the OFDM waveform and the DFT-S-OFDM waveform for an uplink. The OFDM waveform can provide a larger capacity in a high signal-to-noise ratio scenario and is suitable for cell center users, while the DFT-S-OFDM waveform features a low PAPR, can provide a higher output power for a power amplifier, therefore can provide wider coverage, and is suitable for cell edge users limited by coverage. In the NR, it is determined that UE needs to support both the OFDM waveform and DFT-s-OFDM waveform, and a network side determines a waveform used for each transmission. The DFT-s-OFDM is used only for single-stream transmission.

In long term evolution (LTE), a modulation and coding scheme (MCS) is used to represent a modulation order and a transport block size of an uplink data channel or a downlink data channel, and a coding bit rate can be determined based on a transport block size. Each downlink or uplink scheduling signaling carries an MCS configuration, so that a terminal device determines a modulation and coding scheme for this downlink or uplink data channel transmission.

However, in the LTE, the terminal device supports only the DFT-S-OFDM waveform during uplink transmission, similarly to a downlink, and supports 32 MCS indexes (index) from 0 to 31 in an uplink. However, in the NR, it is determined that the terminal device needs to support both the OFDM waveform and the DFT-s-OFDM waveform. If an MCS configuration method in the LTE is introduced to the NR, that is, a single MCS configuration is used to correspond to two uplink waveforms, the UE cannot separately use modulation and coding corresponding to the two uplink waveforms, or differences between the respective waveforms cannot be reflected.

SUMMARY

Embodiments of the present invention provide a signal transmission method and apparatus, to reflect a difference between an OFDM waveform and a DFT-s-OFDM waveform in new radio.

According to a first aspect, a signal transmission method is provided, and the method includes:

receiving, by a terminal device, MCS information sent by a network device, then determining, based on the MCS information sent by the network device, information about a waveform used by the terminal device, and a preset correspondence between an MCS index and a modulation order, a modulation order used by the terminal device for data transmission, and transmitting data based on the determined modulation order.

The terminal device obtains, based on the MCS information sent by the network device, the information about the waveform used by the terminal device, the preset correspondence between an MCS index and a modulation order, the modulation order used by the terminal device for data transmission, to transmit data, so that a difference between different waveforms can be reflected, and modulation and coding schemes corresponding to different waveforms are obtained.

With reference to the first aspect, in a first possible implementation of the first aspect, the determining a modulation order used by the terminal device for data transmission further includes: determining, by the terminal device based on the MCS information sent by the network device, the information about the waveform used by the terminal device, the preset correspondence between an MCS index and a modulation order, and information about an MCS supported by the terminal device, the modulation order used by the terminal device for data transmission.

The information about the MCS supported by the terminal device is further considered, while the modulation order used by the terminal device for data transmission is determined. A range of the determined MCS index supported by the terminal device is further limited, thereby improving efficiency of determining the modulation order used by the terminal device for data transmission.

With reference to the first aspect or the first possible implementation of the first aspect, in a second possible implementation of the first aspect, the determining a modulation order used by the terminal device for data transmission includes: determining, by the terminal device, MCS offset information based on the information about the waveform used by the terminal device and the information about the MCS supported by the terminal device, and determining, based on the MCS offset information, the MCS information sent by the network device, and the preset correspondence between an MCS index and a modulation order, the modulation order used by the terminal device for data transmission.

By using the MCS offset information obtained by using the information about the waveform used by the terminal device and the MCS information supported by the terminal device, MCS indexes corresponding to different waveforms can be distinguished based on the preset correspondence between an MCS index and a modulation order, so that modulation and coding schemes corresponding to different waveforms can be obtained.

With reference to the first aspect or the first possible implementation of the first aspect, in a third possible implementation of the first aspect, the determining a modulation order used by the terminal device for data transmission includes: determining, by the terminal device based on the information about the waveform used by the terminal device and the information about the MCS supported by the terminal device, a mapping relationship between the MCS information sent by the network device and an MCS index, and determining, based on the determined mapping relationship between the MCS information sent by the network device and an MCS index, the MCS information sent by the network device, and the preset correspondence between an MCS index and a modulation order, the modulation order used by the terminal device for data transmission.

The mapping relationship between the MCS information sent by the network device and an MCS index is obtained based on the information about the waveform used by the terminal device and the information about the MCS supported by the terminal device, and MCS indexes corresponding to different waveforms can be distinguished based on the preset correspondence between an MCS index and a modulation order, so that modulation and coding schemes corresponding to different waveforms can be obtained.

With reference to the first aspect or the first possible implementation of the first aspect, in a fourth possible implementation of the first aspect, the determining a modulation order used by the terminal device for data transmission includes: determining, by the terminal device based on the information about the waveform used by the terminal device, a correspondence between an MCS index corresponding to the waveform used by the terminal device and a modulation order, and determining, based on the MCS information sent by the network device, the information about the MCS supported by the terminal device, and the determined correspondence between an MCS index corresponding to the waveform used by the terminal device and a modulation order, the modulation order used by the terminal device for data transmission.

The preset correspondence between an MCS index corresponding to the information about the waveform used by the terminal device and a modulation order may be obtained based on the information about the waveform used by the terminal device, and each waveform corresponds to a preset correspondence between an MCS index and a modulation order. Then, the modulation order used by the terminal device for data transmission may be quickly obtained based on the MCS information sent by the network device, to obtain a corresponding modulation and coding scheme.

With reference to the first aspect, in a fifth possible implementation of the first aspect, the determining a modulation order used by the terminal device for data transmission includes: determining, by the terminal device, MCS offset information based on the information about the waveform used by the terminal device, and determining, based on the MCS offset information, the MCS information sent by the network device, and the preset correspondence between an MCS index and a modulation order, the modulation order used by the terminal device for data transmission.

By using the MCS offset information obtained based on the information about the waveform used by the terminal device, MCS indexes corresponding to different waveforms can be distinguished based on the preset correspondence between an MCS index and a modulation order, so that modulation and coding schemes corresponding to different waveforms can be obtained.

With reference to the first aspect, in a sixth possible implementation of the first aspect, the determining a modulation order used by the terminal device for data transmission includes: determining, by the terminal device based on the information about the waveform used by the terminal device, a mapping relationship between the MCS information sent by the network device and an MCS index, and determining, based on the determined mapping relationship between the MCS information sent by the network device and an MCS index, the MCS information sent by the network device, and the preset correspondence between an MCS index and a modulation order, the modulation order used by the terminal device for data transmission.

The mapping relationship between the MCS information sent by the network device and an MCS index is obtained based on the information about the waveform used by the terminal device, and MCS indexes corresponding to different waveforms can be distinguished based on the preset correspondence between an MCS index and a modulation order, so that modulation and coding schemes corresponding to different waveforms can be obtained.

With reference to the first aspect, in a seventh possible implementation of the first aspect, the determining a modulation order used by the terminal device for data transmission includes: determining, by the terminal device based on the information about the waveform used by the terminal device, a correspondence between an MCS index corresponding to the waveform used by the terminal device and a modulation order, and determining, based on the MCS information sent by the network device and the determined correspondence between an MCS index corresponding to the waveform used by the terminal device and a modulation order, the modulation order used by the terminal device for data transmission.

The preset correspondence between an MCS index corresponding to the information about the waveform used by the terminal device and a modulation order may be obtained based on the information about the waveform used by the terminal device, and each waveform corresponds to a preset correspondence between an MCS index and a modulation order. Then, the modulation order used by the terminal device for data transmission may be quickly obtained based on the MCS information sent by the network device, to obtain a corresponding modulation and coding scheme.

According to a second aspect, a signal transmission method is provided, and the method includes:

determining, by a network device, MCS information of a terminal device, where the MCS information is used to indicate a modulation order used by the terminal device for data transmission, and the modulation order of the terminal device is determined based on the MCS information of the terminal device, information about a waveform used by the terminal device, and a preset correspondence between an MCS index and a modulation order; and sending, by the network device, the determined MCS information.

With reference to the second aspect, in a first possible implementation of the second aspect, the modulation order of the terminal device is determined based on the MCS information of the terminal device, MCS offset information, and the preset correspondence between an MCS index and a modulation order, and the MCS offset information is determined based on the information about the waveform used by the terminal device.

With reference to the second aspect, in a second possible implementation of the second aspect, the modulation order of the terminal device is determined based on the MCS information of the terminal device, a mapping relationship between the MCS information of the terminal device and an MCS index, and the preset correspondence between an MCS index and a modulation order, and the mapping relationship between the MCS information of the terminal device and an MCS index is determined based on the information about the waveform used by the terminal device.

With reference to the second aspect, in a third possible implementation of the second aspect, the modulation order of the terminal device is determined based on the MCS information of the terminal device, a correspondence between an MCS index corresponding to the waveform used by the terminal device and a modulation order, and the preset correspondence between an MCS index and a modulation order, and the correspondence between an MCS index corresponding of the waveform used by the terminal device and a modulation order is determined based on the information about the waveform used by the terminal device.

According to a third aspect, a signal transmission apparatus is provided, including:

a transceiver unit, configured to receive MCS information sent by a network device; a processing unit, configured to determine, based on the MCS information sent by the network device, information about a waveform used by a terminal device, and a preset correspondence between an MCS index and a modulation order, a modulation order used by the terminal device for data transmission, and transmit data based on the determined modulation order.

With reference to the third aspect, in a first possible implementation of the third aspect, when determining the modulation order used by the terminal device for data transmission, the processing unit is further configured to determine, based on the MCS information sent by the network device, the information about the waveform used by the terminal device, the preset correspondence between an MCS index and a modulation order, and information about an MCS supported by the terminal device, the modulation order used by the terminal device for data transmission.

With reference to the third aspect or the first possible implementation of the third aspect, in a second possible implementation of the third aspect, when determining the modulation order used by the terminal device for data transmission, the processing unit is specifically configured to determine MCS offset information based on the information about the waveform used by the terminal device and the information about the MCS supported by the terminal device, and determine, based on the MCS offset information, the MCS information sent by the network device, and the preset correspondence between an MCS index and a modulation order, the modulation order used by the terminal device for data transmission.

With reference to the third aspect or the first possible implementation of the third aspect, in a third possible implementation of the third aspect, when determining the modulation order used by the terminal device for data transmission, the processing unit is specifically configured to determine, based on the information about the waveform used by the terminal device and the information about the MCS supported by the terminal device, a mapping relationship between the MCS information sent by the network device and an MCS index, and determine, based on the determined mapping relationship between the MCS information sent by the network device and an MCS index, the MCS information sent by the network device, and the preset correspondence between an MCS index and a modulation order, the modulation order used by the terminal device for data transmission.

With reference to the third aspect or the first possible implementation of the third aspect, in a fourth possible implementation of the third aspect, when determining the modulation order used by the terminal device for data transmission, the processing unit is specifically configured to determine, based on the information about the waveform used by the terminal device, a correspondence between an MCS index corresponding to the waveform used by the terminal device and a modulation order, and determine, based on the MCS information sent by the network device, the information about the MCS supported by the terminal device, and the determined correspondence between an MCS index corresponding to the waveform used by the terminal device and a modulation order, the modulation order used by the terminal device for data transmission.

With reference to the third aspect, in a fifth possible implementation of the third aspect, when determining the modulation order used by the terminal device for data transmission, the processing unit is specifically configured to determine MCS offset information based on the information about the waveform used by the terminal device, and determine, based on the MCS offset information, the MCS information sent by the network device, and the preset correspondence between an MCS index and a modulation order, the modulation order used by the terminal device for data transmission.

With reference to the third aspect, in a sixth possible implementation of the third aspect, when determining the modulation order used by the terminal device for data transmission, the processing unit is specifically configured to determine, based on the information about the waveform used by the terminal device, a mapping relationship between the MCS information sent by the network device and an MCS index, and determine, based on the determined mapping relationship between the MCS information sent by the network device and an MCS index, the MCS information sent by the network device, and the preset correspondence between an MCS index and a modulation order, the modulation order used by the terminal device for data transmission.

With reference to the third aspect, in a seventh possible implementation of the third aspect, when determining the modulation order used by the terminal device for data transmission, the processing unit is specifically configured to determine, based on the information about the waveform used by the terminal device, a correspondence between an MCS index corresponding to the waveform used by the terminal device and a modulation order, and determine, based on the MCS information sent by the network device and the determined correspondence between an MCS index corresponding to the waveform used by the terminal device and a modulation order, the modulation order used by the terminal device for data transmission.

According to a fourth aspect, a signal transmission apparatus is provided, including:

a processing unit, configured to determine MCS information of a terminal device, where the MCS information is used to indicate a modulation order used by the terminal device for data transmission, and the modulation order of the terminal device is determined based on the MCS information of the terminal device, information about a waveform used by the terminal device, and a preset correspondence between an MCS index and a modulation order; and a transceiver unit, configured to send the determined MCS information.

With reference to the fourth aspect, in a first possible implementation of the fourth aspect, the modulation order of the terminal device is determined based on the MCS information of the terminal device, MCS offset information, and the preset correspondence between an MCS index and a modulation order, and the MCS offset information is determined based on the information about the waveform used by the terminal device.

With reference to the fourth aspect, in a second possible implementation of the fourth aspect, the modulation order of the terminal device is determined based on the MCS information of the terminal device, a mapping relationship between the MCS information of the terminal device and an MCS index, and the preset correspondence between an MCS index and a modulation order, and the mapping relationship between the MCS information of the terminal device and an MCS index is determined based on the information about the waveform used by the terminal device.

With reference to the fourth aspect, in a third possible implementation of the fourth aspect, the modulation order of the terminal device is determined based on the MCS information of the terminal device, a correspondence between an MCS index corresponding to the waveform used by the terminal device and a modulation order, and the preset correspondence between an MCS index and a modulation order, and the correspondence between an MCS index corresponding of the waveform used by the terminal device and a modulation order is determined based on the information about the waveform used by the terminal device.

According to a fifth aspect, a signal transmission device is provided, including a transceiver and a processor. The transceiver and processor are configured to perform the method provided in the first aspect or any implementation of the first aspect.

According to a sixth aspect, a signal transmission device is provided, including a transceiver and a processor. The transceiver and processor are configured to perform the method provided in the second aspect or any implementation of the second aspect.

According to a seventh aspect, a computer storage medium is provided, and is configured to store a computer software instruction executed by the processor provided in the fifth aspect, to perform the method according to the first aspect or the possible implementation of the first aspect.

According to an eighth aspect, a computer storage medium is provided, and is configured to store a computer software instruction executed by the processor provided in the sixth aspect, to perform the method according to the second aspect or the possible implementation of the second aspect.

