In a radio communications system, a maximum coverage capability is a very important performance index. In the prior art, in order to effectively enhance the maximum coverage capability, a signal to interference plus noise ratio at a receive end is generally reduced. That is, redundancy is added to a transmitted signal, so that the receive end increases a signal-to-noise ratio by combining repeated information, thereby effectively enhancing the maximum coverage capability.
For example, in an existing Long Term Evolution (Long Term Evolution, LTE) system, a code rate may be reduced to decrease the signal to interference plus noise ratio of the receive end and enhance the maximum coverage capability of the radio communications system. In the LTE system, an encoded bit is stored in a cyclic buffer. Based on the cyclic buffer, a transmit end may map the encoded bit to a physical resource block (physical resource block, PRB) of a frequency domain resource in a repeated manner. According to a predefined table, in which a transport block size and a modulation and coding scheme are mapped to carried data bits in Section 7.1.7 of a standard 36.213 currently prepared by a 3GPP organization, a minimum code rate that can be achieved is approximately 0.1.
However, in some special scenarios, for example, if power of a base station is very low, a scope to be covered is very wide, or an environment in which a user equipment (User Equipment, UE) has severe interference, a data transmission manner that supports a lower code rate is required. However, the solution in the prior art is unable to implement data transmission at a code rate lower than 0.1.