Abstract: Disclosed are a spandex fiber with a reversible triple-shape memory effect and a preparation method thereof. In the present disclosure, the spandex fiber includes the following raw materials in parts by weight: 3 parts to 100 parts of a crystalline polyester diol or a crystalline polyether diol, 1 part to 30 parts of a diisocyanate, 0.1 parts to 15 parts of a polyurethane chain extender, and 0.2 parts to 11 parts of a polyurethane cross-linking agent, where the crystalline polyester diol or the crystalline polyether diol has a number-average molecular weight of 1,000-10,000 Daltons. The spandex fiber has a reversible deformation process, shows an ability to transform between “stretched” and “shortened” states infinitely under the action of a temperature field, and can memorize two temporary shapes. Moreover, the spandex fiber has easily accessible raw materials and a simple preparation method, and is suitable for large-scale industrial production.

Abstract: The present disclosure provides an FBMC-based pilot sending method, a channel estimation method, and a related apparatus. The FBMC-based pilot sending method includes: for each transmit antenna port, inserting a pilot symbol group at four consecutive FBMC time-frequency resource locations, where the pilot symbol group includes two auxiliary pilot symbols and two primary pilot symbols; calculating a transmit value of each auxiliary pilot symbol in the pilot symbol group according to obtained interference coefficient values and obtained transmit values of data symbols at time-frequency resource locations in a time-frequency resource location range in which each primary pilot symbol is interfered with; and sending the pilot symbol group, where the pilot symbol group includes the calculated transmit values of the auxiliary pilot symbols.

Abstract: The present invention provides a signal sending method and a signal sending device, where the signal sending method includes: canceling interference from symbols of a boundary between at least two precoding code blocks in a multiple input multiple output filter bank multicarrier MIMO-FBMC system, where the precoding code block includes at least one time-frequency resource element that uses same precoding; performing precoding on a to-be-sent symbol in the precoding code block to obtain a precoded symbol; and sending the precoded symbol. In the present invention, mutual interference between precoding code blocks at a time-frequency critical location can be completely or partially canceled.

Abstract: A data receiving method and receiver are provided. A receiver determines the length of a pre-tail and the length of a post-tail of a frame by obtaining a start time and an end time of the main part of the signal of the frame at a fixed time, and determines a start time and an end time of a frame receiving window according to the start time and the end time of the main part of the signal of the frame and according to the length of the pre-tail and the length of the post-tail; and receiving a frame between the start time and the end time of the frame receiving window, so that the receiver can accurately and completely receive the main part of the signal and the pre-tail and post-tail of each frame to accurately and completely receive signals.

Abstract: The present disclosure provides an FBMC-based pilot sending method, a channel estimation method, and a related apparatus. The FBMC-based pilot sending method includes: for each transmit antenna port, inserting a pilot symbol group at four consecutive FBMC time-frequency resource locations, where the pilot symbol group includes two auxiliary pilot symbols and two primary pilot symbols; calculating a transmit value of each auxiliary pilot symbol in the pilot symbol group according to obtained interference coefficient values and obtained transmit values of data symbols at time-frequency resource locations in a time-frequency resource location range in which each primary pilot symbol is interfered with; and sending the pilot symbol group, where the pilot symbol group includes the calculated transmit values of the auxiliary pilot symbols.

Abstract: A data receiving method and receiver are provided. A receiver determines the length of a pre-tail and the length of a post-tail of a frame by obtaining a start time and an end time of the main part of the signal of the frame at a fixed time, and determines a start time and an end time of a frame receiving window according to the start time and the end time of the main part of the signal of the frame and according to the length of the pre-tail and the length of the post-tail; and receiving a frame between the start time and the end time of the frame receiving window, so that the receiver can accurately and completely receive the main part of the signal and the pre-tail and post-tail of each frame to accurately and completely receive signals.

Abstract: The present invention provides a signal sending method and a signal sending device, where the signal sending method includes: canceling interference from symbols of a boundary between at least two precoding code blocks in a multiple input multiple output filter bank multicarrier MIMO-FBMC system, where the precoding code block includes at least one time-frequency resource element that uses same precoding; performing precoding on a to-be-sent symbol in the precoding code block to obtain a precoded symbol; and sending the precoded symbol. In the present invention, mutual interference between precoding code blocks at a time-frequency critical location can be completely or partially canceled.

Abstract: A method is disclosed for coating a positive active material of a lithium-ion battery. The method includes the step of dissolving at least one salt that contains a coating metal in a solvent to provide a solution, the step of dissolving a lithium-containing positive active material in the solution and adjusting the pH value of the solution to deposit M(OH)2n on the lithium-containing positive active material, the step of drying the M(OH)2n and the lithium-containing positive active material, and the step of sintering the M(OH)2n and the lithium-containing positive active material to coat the lithium-containing positive active material with MOn.