ABSTRACT
Filter-bank modulation techniques are well suited for data transmission over channels that exhibit high signal attenuation at frequencies within the passband. The task of modulating several carriers in parallel is efficiently accomplished in the digital domain by employing filter banks. Symbol-vector sequences are presented at the filter-bank input, where the symbol period is typically much longer than that of a single-carrier system transmitting at the same bit rate. The narrowband subchannel signals obtained at the filter-bank output are transmitted over the channel. At the receiver, demodulation is also accomplished by filter-bank techniques. The orthogonality conditions and the efficient implementation of critically sampled filter banks are addressed first. Then the implementation and various system aspects of filterbank modulation techniques are discussed, with emphasis on discrete multitone (DMT) modulation, offset quadrature amplitude modulation (O-QAM) orthogonal frequency division multiplexing (OFDM) modulation, and filtered multitone (FMT) modulation.
