Phase shifters for peak-to-average power ratio reduction in multi-carrier communication systems

摘要

In accordance with the present invention, there are provided peak-to-average power ratio optimal phase shifters for multi-carrier communications. An optimal shifter is shown to be a complex, constant envelope sequence mapped by a multi-tone transformation used to another complex, constant envelope sequence. In the case of the inverse discrete Fourier transform being the multi-tone transformation, a family of principal shifters of the form z(r)=exp(±j*π*p*r²/q), where j²=−1, 0≦rq, q is a number of subcarriers, and p and q are mutually prime integers of different parity, has been analytically constructed. These phase shifters outperform the best existing phase shifter by as much as 2.6 dB.