A resource unit setting method, comprising: setting, by a transmit end device based on a setting threshold of a null resource unit and/or a scheduling parameter, a plurality of null resource units at time domain and/or frequency domain locations associated with phase tracking reference signal resource units of one or more orthogonal frequency division multiplexing, OFDM, symbols, wherein power of a null resource unit is zero; and sending, by the transmit end device, the one or more OFDM symbols; characterized in that the setting threshold of the null resource unit comprises at least one of a modulation and coding scheme threshold and a modulation order threshold; wherein the setting, by the transmit end device based on the setting threshold of the null resource unit and/or the scheduling parameter, the plurality of null resource units comprises at least one of the following steps: if a modulation and coding scheme used by the transmit end device is greater than or equal to the modulation and coding scheme threshold, setting, by the transmit end device, the plurality of null resource units at the time domain and/or frequency domain locations associated with the phase tracking reference signal resource units of the one or more OFDM symbols; and if a modulation order used by the transmit end device is greater than or equal to the modulation order threshold, setting, by the transmit end device, the plurality of null resource units at the time domain and/or frequency domain locations associated with the phase tracking reference signal resource units of the one or more OFDM symbols. setting, by a transmit end device based on a setting threshold of a null resource unit and/or a scheduling parameter, a plurality of null resource units at time domain and/or frequency domain locations associated with phase tracking reference signal resource units of one or more orthogonal frequency division multiplexing, OFDM, symbols, wherein power of a null resource unit is zero; and sending, by the transmit end device, the one or more OFDM symbols; characterized in that the setting threshold of the null resource unit comprises at least one of a modulation and coding scheme threshold and a modulation order threshold; wherein the setting, by the transmit end device based on the setting threshold of the null resource unit and/or the scheduling parameter, the plurality of null resource units comprises at least one of the following steps: if a modulation and coding scheme used by the transmit end device is greater than or equal to the modulation and coding scheme threshold, setting, by the transmit end device, the plurality of null resource units at the time domain and/or frequency domain locations associated with the phase tracking reference signal resource units of the one or more OFDM symbols; and if a modulation order used by the transmit end device is greater than or equal to the modulation order threshold, setting, by the transmit end device, the plurality of null resource units at the time domain and/or frequency domain locations associated with the phase tracking reference signal resource units of the one or more OFDM symbols. if a modulation and coding scheme used by the transmit end device is greater than or equal to the modulation and coding scheme threshold, setting, by the transmit end device, the plurality of null resource units at the time domain and/or frequency domain locations associated with the phase tracking reference signal resource units of the one or more OFDM symbols; and if a modulation order used by the transmit end device is greater than or equal to the modulation order threshold, setting, by the transmit end device, the plurality of null resource units at the time domain and/or frequency domain locations associated with the phase tracking reference signal resource units of the one or more OFDM symbols.