Data transmission method, apparatus and system

A UE, comprising:

• a processor configured to read and execute program in a memory:
• to determine a modulation and coding scheme of uplink data for uplink data transmission of an initial access according to a protocol specification, and/or information broadcasted by a gNB (next-Generation Node B), and to encode and modulate the uplink data using the determined modulation and coding scheme;
• and
• a transceiver configured to transmit and receive data under the control of the processor, and configured:
• to transmit a preamble, and the encoded and modulated uplink data.

A gNB (next-Generation Node B), comprising:

• a transceiver configured to transmit and receive data under the control of a processor, and configured:
• to receive encoded and modulated uplink data, and a preamble, transmitted by a UE;
• and
• the processor configured to read and execute program in a memory:
• to determine a modulation and coding scheme of uplink data according to a protocol specification, and/or information broadcasted by the gNB, and to decode and demodulate the uplink data using the determined modulation and coding scheme.