Fast-convolution filter bank approach for non-contiguous spectrum use

Fast-convolution processing, consisting of an FFT, frequency-domain weights, and an IFFT, offers an effective and very flexible way for implementing multirate filters and filter banks. In recent years, fast-convolution filter banks (FC-FBs) have been considered for channelization filtering in software defined radios and recently also for implementing nearly perfect reconstruction transmultiplexers. FC-FB provides an alternative way of implementing filter bank multicarrier systems with good spectral containment and high flexibility in tuning the subchannel bandwidths and center frequencies. These features make FC-FBs a particularly interesting choice for multicarrier transmission in challenging radio scenarios like dynamic spectrum access, cognitive radio, and fragmented spectrum use. This paper develops an FC-FB based transmission scheme of the FBMC/OQAM type with the main parameters of the 5 MHz LTE system. The main application in mind is the development of broadband data communication service to the evolution of TETRA standards for the Professional Mobile Radio (PMR). In this development, a challenging coexistence scenario is commonly considered, since the idea is to use the spectral slots in the PMR band between the active narrowband TETRA channels for broadband communication.