Abstract: A multiple-access constant envelope orthogonal frequency division multiplexing (OFDM) method and wireless communication system are disclosed. The method and system include a transmitter that sequentially processes the information and/or information bits of each user by digital modulation, symmetric mapping, frequency-domain to time-domain transformation, phase modulation, time-domain to frequency-domain transformation, frequency domain offsetting, frequency-domain to time-domain transformation, and cyclic prefix addition to obtain a baseband transmission signal, which is then sent to one or more receivers through a channel, and a receiver that sequentially processes the received signal by time-domain to frequency-domain transformation, user signal separation, equalization offsetting, frequency-domain to time-domain transformation, phase demodulation, another time-domain to frequency-domain transformation, demapping, and decision-making to obtain detection results for the corresponding user.

Abstract: The present invention provides a process for preparing; a high water-containing elastomer medical catheter and a urinary catheter prepared by the process. The process comprises a) heating a mixture consisting of polyvinyl alcohol, water, sulfoxide and linear alkane, in a sealed vessel with agitating; b) pouring the resulting homogeneous fluid into a mould; c) solidifying the fluid by cooling; d) releasing the solidified fluid from the mould; and e) heat-treating the resulting medical catheter and washing with a polar organic solvent. The medical catheter and the urinary catheter of the present invention have excellent lubricity.

Abstract: The present invention provides a process for preparing a high water-containing elastomer medical catheter and a urinary catheter prepared by the process. The process is carried out by a) heating a mixture consisting of polyvinyl alcohol, water, sulfoxide and linear alkane, in a sealed vessel with agitating; b) pouring the resulting homogeneous fluid into a mould; c) solidifying the fluid by cooling; d) releasing the solidified fluid from the mould; and e) heat-treating the resulting medical catheter and washing with a polar organic solvent. The medical catheter and the urinary catheter of the present invention have excellent lubricity.