ed to the BER performance [17]. The theoretical analyses of the proposed mirror-mapping-based schemes over frequency-selective UWA channels in terms of BER will be considered as our future work. 1 ICI Cancellation Techniques Based on Data Repetition for OFDM Systems Table 1.2 Packet information. Packet index Scheme Effective SNR Transmit time T-R pair M0000043.DAT 12.47 18:16:00 05/21/13 N5-N9 M0000044.DAT 12.55 18:16:25 05/21/13 N5-N9 M0000046.DAT 12.27 18:16:55 05/21/13 N5-N9 M0000047.DAT 12.15 18:17:21 05/21/13 N5-N9 M0000049.DAT 12.21 18:17:51 05/21/13 N5-N9 M0000050.DAT 12.29 18:18:16 05/21/13 N5-N9 M0000052.DAT 12.31 18:18:46 05/21/13 N5-N9 M0000053.DAT 12.36 18:19:11 05/21/13 N5-N9 Plain OFDM (QPSK) Plain OFDM (BPSK) Figure 1.14 BER performance of the plain OFDM and the mirror-mapping-based schemes. 1.6 Summary In this chapter, four effective low-complexity mirror-mapping-based ICI cancellation schemes without explicitly estimating ICI coefficients or CFO were introduced. ICI self-cancellation schemes, namely MSR and MCSR, are robust against the CFO devi- ation between the first OFDM symbol and the second OFDM symbol. However, they require the mirror-mapped pilot structure, which does not facilitate OFDM system standardization. In addition, compared with conjugate-based schemes, conversion-based schemes, namely MSR and MCVT, have better CIR performance. However, their CIR performance is degraded for multipath Rayleigh fading channels with large channel length. Thus, scheme selection depends on the actual system requirement and chan- nel conditions. Finally, all mirror-mapping-based schemes were tested in a recent sea experiment conducted in Taiwan in May 2013. Decoding results showed that the proposed References mirror-mapping-based schemes provide much lower BER than plain OFDM. This confirms that mirror-mapping-based schemes are very effective for ICI mitigation. References 1 Chang, R.W. (1966). Synthesis of band-limited orthogonal signals for multichannel data transmission. Bell System Technical Journal