Signal transmission method under channel polarization condition

The invention discloses a signal transmission method under a channel polarization condition, which comprises the following steps that N polarization sub-channels corresponding to N polarization sub-codes are obtained, the channel capacity of the polarization sub-channel corresponding to the nth polarization sub-code is Cn, n is a positive integer not greater than N, and both beta and T are constants greater than 0 and less than 1; freezing the first K-bit polarization sub-codes to form invalid information, performing invalid information transmission on the polarization sub-channels corresponding to the first K-bit polarization sub-codes, taking the last N-K-bit polarization sub-codes as valid information, and performing valid information transmission on the polarization sub-channels corresponding to the last N-K-bit polarization sub-codes, wherein K is less than N; a relay point R and a destination node D are selected, a source node S directly transmits a polarization code to the destination node D to obtain