| 摘要 |
This invention provides a user signal transmitting method in an OFDMA system, where all the time-frequency grids of each timeslot are divided into sub-channels, each sub-channel comprises Nf sub-carriers overlapping in time, Nf≧4, and in each sub-channel, a maximum value of a frequency interval between adjacent sub-carriers is no less than three times of a minimum value thereof; and when a user message is sent, comprising: generating a modulating signal; allocating a time-frequency grid set which is a union set of sub-channel, where the sub-channel's quantity is determined by the user message's size, and the sub-channel's time-frequency position is selected according to a rule; and mapping the modulating signal to the time-frequency grid set to generate a frequency-domain signal; performing IFFT on the frequency-domain signal to generate a time-domain signal for transmission. This invention also provides a corresponding user signal receiving method, user signal transmitting and receiving apparatus and access system. |
