A low complexity selective mapping to reduce intercarrier interference in OFDM systems

One of major drawbacks of orthogonal frequency division multiplexing is sensitivity to frequency offsets caused by a mismatch between the transmitter and receiver oscillators. This offset destroys the orthogonality of the sub-carriers and introduces intercarrier interference (ICI), reducing the system performance. Previously, selective mapping was considered for reducing the peak interference-to-carrier ratio (PICR). However, this technique has a high computational complexity due to multiple inverse fast Fourier transform (IFFT) and fast Fourier transform (FFT) operations. In this paper, we exploit the IFFT/FFT structure to generate phase rotated SLM sequences and obtain a low PICR. This technique significantly reduces the computational complexity while providing a PICR performance close to that of the previous SLM technique.