A highly efficient multi-carrier transmission scheme with message-driven idle subcarriers

This paper develops a highly efficient multi-carrier transmission scheme by using message-driven idle subcarrier identification. The basic idea is to carry part of the information, named carrier bits, through idle subcarrier selection while transmitting ordinary bits regularly on all the other subcarriers. When the number of subcarriers is much larger than the adopted constellation size (e.g., in most OFDM systems), a high spectral efficiency as well as power efficiency can be achieved. This is because that the number of carrier bits transmitted through each idle subcarrier is larger than the number of ordinary bits carried by a regular symbol, and all the carrier bits are transmitted with no power consumption through idle subcarrier selection. When applied to the OFDM framework, the proposed scheme can achieve an even higher spectral efficiency than OFDM, while keeping a higher power efficiency.We further enhance its security and error-tolerance using secure subcarrier assignment, secure symbol mapping and bit vector rearrangement. Both theoretical analysis and numerical results are provided to demonstrate the performance of the proposed scheme.