A Frequency Domain Adaptive Loop Canceller for Digital Terrestrial Broadcasting Systems

Frequency domain adaptive filters, both orthogonal transform and subband types, are introduced into loop cancellers, which were developed to cope with loop coupling and multipath distortion at relay stations in digital terrestrial broadcasting systems using OFDM (Orthogonal Frequency Division Multiplexing). An additional loop configuration and a coefficient duplicating method are also proposed and evaluated for subband-type cancellers. Computer simulation showed that frequency-domain processing has better performance than transversal-type processing.