Information transmission method, device, and system

An information transmission method, comprising:

• receiving, by a second device, scrambled first data sent by a first device;
• and
• descrambling, by the second device, the first data according to a first scrambling code sequence, wherein the first data is carried on a first time resource on an unlicensed carrier, and the first scrambling code sequence is generated according to a sequence number of a second time resource on a licensed carrier or a first value;
• wherein the first time resource is a first timeslot, wherein the first timeslot belongs to a first subframe, and the first subframe comprises N orthogonal frequency division multiplexing (OFDM) symbols;
• when N is greater than M/2, the first timeslot comprises first N−M/2 OFDM symbols of the N OFDM symbols;
• M is a quantity of OFDM symbols comprised in one complete subframe;
• wherein M and N are positive integers, and M≥N.

A first device, comprising:

• a processor configured to scramble, according to a first scrambling code sequence, first data carried on a first time resource on an unlicensed carrier, wherein the first data is data that is sent by the first device to a second device, and the first scrambling code sequence is generated according to a sequence number of a second time resource on a licensed carrier or a first value;
• and
• a transmitter configured to send first data scrambled by the processor to the second device;
• wherein the first time resource is a first timeslot, wherein the first timeslot belongs to a first subframe, and the first subframe comprises N orthogonal frequency division multiplexing (OFDM) symbols;
• when N is greater than M/2, the first timeslot comprises first N−M/2 OFDM symbols of the N OFDM symbols;
• wherein M is a quantity of OFDM symbols comprised in one complete subframe, M and N are positive integers, and M≥N.