nterference plus noise ratio (SINR) can then be calculated as (2.23) xe{f-ISI,b-ISI,ICI) With the provided SINR, some existing works, such as [22, 23], are available for calculat- ing system bit error rate (BER) under various channels and different modulation/coding schemes. 2.3.3 In-Band Interference Mitigation: A Practical Approach for Choosing CR Length Proposition 2.1 implies that in-band interference-free systems can be achieved by adding a sufficient number of redundant samples. The implementation of CR, although elegant and simple, is not entirely free. It comes with a bandwidth and power penalty. Since Ncr redundant samples are transmitted, the actual bandwidth for f-OFDM increases from B to Ncr+N B. Similarly, an additional Ncr samples must be counted against the transmit power budget resulting in a power loss of For an f-OFDM system with stringent frequency localization requirements, the filter length can be chosen up to half of the sym- bol duration, making the satisfaction of interference-free condition in (2.20) unaffordable with respect to the power and bandwidth loss. On the one hand, interference-free sys- tems are preferred due to the benefit to the computational complexity reduction and the SINR improvement. On the other hand, a highly efficient system requires shorter overhead (CP/CS). Therefore, choosing the size of CR, as a trade-off between the two contradicting parties, forms an optimization problem. However, it is very hard to find an optimal solution due to the multi-objective characteristic of the problem. A suboptimal attempt in the literature [10] is suggested by setting the length of overhead to the width of the main lobe, due to the fact that the main lobe of a sinc filter carries most of its energy. However, it neglects the fact that filters of different bandwidth vary in the amount of captured by the main lobes. For instance, a wider subband filter has less energy enclosed in the main lobe. We take this into consideration and propose a subband width-dependent approach for choosing 