Abstract—For improving bandwidth efficiency, FTN (Faster-Than Nyquist) method which transmits faster than the Nyquist rate is applied in wireless communications. However, performance degrade arising from ISI(Inter-Symbol Interference) induced by increasing the interference rate. To overcome this problem, we propose the multiband OFDM(Orthogonal Frequency Division Multiplexing)-FTN method which is uniformly dividing and allocating the encoded bits into multiband, and transmits the encoded bits using the frequency allocated to each band by applying the FTN transmission method to each band. Through simulation results by setting the interference ratio to 25%, we show that the performance of the proposed multiband FTN method is improved about 0.3 dB ~ 0.5 dB than that of single band FTN method. In multipath channels, only multiband FTN method was vulnerable to multipath whereas the multiband OFTM-FTN method was efficient for multipath. In addition, we confirmed that the performance improved as the subcarrier number of the proposed multiband OFDM-FTN method increased.

Index Terms—FTN, Inter-symbol interference, Multiband, OFDM, Multiband OFDM-FTN.

Cite: Jung-Hyun Seo, Chang-Uk Baek, Hee-Su Lee, and Ji-Won Jung, " Multiband Faster Than Nyquist Techniques in Multipath Channel for Spectrum Efficiency," Journal of Communications, vol. 14, no. 2, pp. 128-134, 2019. Doi: 10.12720/jcm.14.2.128-134.