Pulse Shaping Applied to Cyclic Block FMT for Improved Spectrum Usage

Out-of-Band (OOB) emissions are a drawback that affect the OFDM scheme. To mitigate the issue, time domain pulse shaping (PS) has been introduced in the known Pulse Shaped OFDM (PS-OFDM) scheme. This paper extends the PS idea to the Cyclic Block Filtered Multitone (CB-FMT) modulation scheme. CB-FMT represents a filtered multitone modulation scheme where, however, the filter bank uses cyclic convolutions instead of linear convolutions. However, while PS-OFDM starts from OFDM that has sinc-like sub-channel frequency responses, Pulse Shaped CB-FMT (PS-CB-FMT) deploys well frequency localized sub-channel pulses. Therefore, PS-CB-FMT has a more confined spectrum which is of particular importance in applications that have to offer agile spectrum usage to fulfill norms and coexistence with other systems. One of these applications is Power Line Communication (PLC) which is subject to strict EMC regulations. In this context, we show that PS-CB-FMT is capable to fulfill the spectral masks much more efficiently than PS-OFDM adopted in all relevant PLC standards. In turn, this provides improved capacity performance.