A single carrier frequency domain equalisation (SC-FDE) modulation scheme which represents a step forward in the investigation since it obtains higher bit rates than previous proposals with spread spectrum techniques is presented. The focus of this reported work is the data transmission from remote sensors using very low-power HF ionospheric communications. In particular, the authors' research group has been studying the ionospheric channel parameters and data transmission techniques from Antarctica since 2003. Both, the spread spectrum and multicarrier modulations have been tested previously in order to obtain a good trade-off between bit error rate and bit rate. A proof of principle of the single carrier technique with promising results is presented.