The invention discloses a magnetic induction through-the-earth communication method based on OFDM (
Orthogonal Frequency Division Multiplexing), which is applied to mine rescue and comprises the following steps: in a
signal transmitting end, converting an analog voice
signal into a
digital signal, encoding an information source, mapping into a multi-
system code element, carrying out serial-to-parallel conversion, modulating, synthesizing an OFDM symbol, carrying out parallel-to-serial conversion and carrying out first filtering
processing; transmitting the
signal to a magnetic induction through-the-earth
communication channel by using a transmitting antenna; in a signal receiving end, acquiring a signal by using a receiving antenna; and after second filtering
processing, serial-to-parallel conversion, separation to original OFDM subcarriers,
demodulation, parallel-to-serial conversion, conversion back to binary data and information source decoding
processing, a recovered
digital signal is converted to an analog form, and original voice information is output. According to the method, a
multipath effect generated by electromagnetic
waves in a multilayer geological environment is avoided through magnetic induction through-the-earth communication, secondary modulation is performed by using an OFDM technology, the
communication bandwidth utilization rate is effectively improved, and remote mine rescue communication with stable signals is realized.