Signal transmission method, terminal device, access network device, and transmission system for signal transmission on an unlicensed spectrum resource

A terminal device, comprising:

• one or more processors configured to determine that permission to use a channel in an unlicensed spectrum is obtained at a first time point, wherein the first time point is any time point within a time window after a preset start time of a preset cyclic prefix of a symbol, wherein
• a start time point of the time window is a start time point of a symbol or is prior to the start time point of the symbol, an end time point of the time window is a second time point or is prior to the second time point, the second time point is within a time occupied by the symbol, the symbol is a symbol used to send a signal, the signal comprises at least an actual cyclic prefix and an information segment, the actual cyclic prefix and the information segment are temporally continuous, the actual cyclic prefix is prior to the information segment, a first duration of the actual cyclic prefix is less than a preset duration of a preset cyclic prefix when the actual cyclic prefix starts at the first time point after the preset start time point of the preset cyclic prefix of the symbol, and the first duration of the actual cyclic prefix is greater than the preset duration of the preset cyclic prefix when the actual cyclic prefix starts at the first time point being before the preset start time point of the present cyclic prefix of the symbol, the first duration is a time length between the start time point of the symbol and the second time point, wherein the duration of the actual cyclic prefix is less than the first duration and greater than or equal to a second duration, wherein the second duration is greater than or equal to a sum of maximum round-trip duration of signal transmission time between an edge terminal device in a cell of the terminal device and an access network device and a maximum channel delay spread;
• and
• a transmitter configured to send the signal from the first time point.

An access network device, comprising:

• one or more processors configured to determine indication information, wherein the indication information comprises at least one of length information of a time window, start time point information of the time window, end time point information of the time window, start time point information of a symbol, second time point information, first duration information, and second duration information;
• and
• a transmitter configured to send the indication information determined by the one or more processors to a terminal device, so that the terminal device determines the time window, the start time point information of the symbol, a second time point, or a preset cyclic prefix based on the indication information, wherein the sending of the indication information causes the terminal device to determine a first duration of an actual cyclic prefix the terminal device uses when sending information using the access network device, and wherein the first duration is determined to be less than a preset duration of a preset cyclic prefix of the symbol when the actual cyclic prefix starts at a first time point after a preset start time point of a preset cyclic prefix, and the first duration of the actual cyclic prefix is greater than the preset duration of the preset cyclic prefix of the symbol when the actual cyclic prefix starts at the first time point being before the preset start time point of the present cyclic prefix, the first duration is a time length between a start time point of a symbol and a second time point at the end of the symbol, wherein the duration of the actual cyclic prefix is less than the first duration and greater than or equal to the second duration, wherein the second duration is greater than or equal to a sum of maximum round-trip duration of signal transmission time between an edge terminal device in a cell of the terminal device and the access network device and a maximum channel delay spread.

A non-transitory computer readable storage medium having instructions stored thereon, which when executed by at least one processor of a terminal device, causes the at least one processor to perform one or more operations of a signal transmission method, the one or more operations comprising:

• determining that permission to use a channel in an unlicensed spectrum is obtained at a first time point, wherein the first time point is any time point within a time window after a preset start time of a preset cyclic prefix of a symbol, wherein
• a start time point of the time window is a start time point of a symbol or is prior to the start time point of the symbol, an end time point of the time window is a second time point or is prior to the second time point, the second time point is within a time occupied by the symbol, the symbol is a symbol used to send a signal, the signal comprises at least an actual cyclic prefix and an information segment, the actual cyclic prefix and the information segment are temporally continuous, the actual cyclic prefix is prior to the information segment, a first duration of the actual cyclic prefix is less than a preset duration of a preset cyclic prefix when the actual cyclic prefix starts at the first time point after the preset start time point of the preset cyclic prefix of the symbol, and the first duration of the actual cyclic prefix is greater than the preset duration of the preset cyclic prefix when the actual cyclic prefix starts at the first time point being before the preset start time point of the present cyclic prefix of the symbol, the first duration is a time length between the start time point of the symbol and the second time point, wherein the duration of the actual cyclic prefix is less than the first duration and greater than or equal to a second duration, wherein the second duration is greater than or equal to a sum of maximum round-trip duration of signal transmission time between an edge terminal device in a cell of the terminal device and an access network device and a maximum channel delay spread;
• and
• sending the signal from the first time point.