A convex optimization approach to reducing peak-to-average-power ratio in OFDM

Practical transmission of orthogonal frequency division multiplexing (OFDM) signals suffers from high peak-to- average power ratio (PAPR) at the transmit antenna(s). Among various solutions, tone injection is an effective approach to mitigate this problem without incurring bandwidth loss. However, due to its computational complexity, finding the optimal tone injection becomes intractable for OFDM systems with a large number of subcarriers. In this work we present a novel convex optimization approach to numerically determine the near-optimal tone injection solution based on a semi-definite relaxation. This approach leads to significant PAPR reduction with polynomial complexity. An STBC-OFDM extension is also proposed.