COMPLEMENT BLOCK CODING SCHEME FOR REDUCING PEAK-TO-AVERAGE POWER RATIO OF OFDM SYSTEMS

A new scheme termed as Complement Block Coding (CBC) technique is proposed to reduce the Peak-to-Average Power Ratio (PAPR) of OFDM signals. Utilizing the complement bits which are added to the original information bits,this method can effectively reduce the PAPR of OFDM systems with random frame size N and the coding rate R ≤ (N - k)/N, where kis a positive integer and k ≤ N/2. The performance results obtained with CBC are given and compared with that of some well known schemes, such as Simple Block Coding (SBC), Modified Simple Block Coding (MSBC) and Simple Odd Parity Code (SOPC) for the same purpose. The results show that, at the same coding rate 3/4, the CBC can achieve almost the same performance as SBC, MSBC, but with lower complexity, and that the same performance can be obtained with higher coding rate by using CBC. At the same coding rate (N - 1)/N, the PAPR reduction of CBC is almost the twice as that of SOPC when N ≥ 16. Further more, the PAPR reductions with coding rate (N - 1)/N are almost the same as that with coding rate less than (N - 1)/N,so the proposed scheme CBC is more suitable for the large frame size with high coding rate and can provide error detection.