 Nz rows have nonzero elements, (ii) the product of Q"H"Pm is a strictly upper triangular matrix of which only the rows have nonzero ele- ments, (iii) the product of Q"Hmp" is a strictly upper triangular matrix of which only the top Np+Nch rows have nonzero elements. Therefore, the sum of three strictly upper trian- gular matrices results in a strictly upper triangular matrix Opre and only the top Np + Nch rows of it have nonzero elements. 2.C Appendix 2.C.1 Proof of Property 2.A.2 The product of Pu/Qu and Hm is a strictly triangular matrix A, with Ai,j = 0, when i> j - As and Qu are matrices with the same structure, we will only give the detailed steps for proving one of them. The other one can be done in a similar manner. 2 Filtered OFDM: An Insight into Intrinsic In-Band Interference j+Nch-1 (2.C.1) Because the condition >j-IL--(Neh when <k<j+Nch - 1, we have k<i+L- (2.C.2) and this gives Puisk = 0 according to (2.6). Therefore, the first term of (2.C.1), j+Nch-1 When +Nch <k<L, we have Hm kj=0 based on (2.10). Therefore, the second term of (2.C.1), j+Neh Puikkm 0, is also proved. As a result, Ai,j = 0 is proved, because both its sum terms in (2.C.1) equal zero, when References 1 Banelli, P., Buzzi, S., Colavolpe, G. et al. (2014). Modulation formats and waveforms for 5G networks: who will be the heir of OFDM?: An overview of alternative modula- tion schemes for improved spectral efficiency. IEEE Signal Processing Magazine 31 (6): 80-93. 2 Wunder, G., Jung, P., Kasparick, M. et al. (2014). 5GNOW: non-orthogonal, asyn- chronous waveforms for future mobile applications. IEEE Communications Magazine 52 (2): 97-105. 3 Farhang-Boroujeny, B. (2011). OFDM versus filter bank multicarrier. IEEE Signal Processing Magazine 28 (3): 92-112. 4 Razavi, R., Xiao, P., and Tafazolli, R. (2015). Information theoretic analysis of OFDM/OQAM with utilized intrinsic interference. IEEE Signal Processing Letters 22 (5): 618-622. 5 Michailow, N., Matth, M., Gaspar, I.S. et al. (2014). Generalized frequency division multiplexing for 5th