PAR reduction via constellation shaping

We introduce a novel scheme using a constellation shaping approach to reduce the peak-to-average ratio (PAR) in orthogonal frequency-division multiplexing (OFDM) systems. In the time domain, the peak power bound traces out a hypercube boundary. We map this square time-domain boundary back to the frequency domain via the DFT and construct a method for indexing the OFDM constellation points. The encoding and decoding of the constellation use generators and relations from group theory. The end result is a coding scheme with nearly 20 dB of PAR reduction with no reduction in data rate or performance.