Drm receiver with analog and digital separation filter and demodulation method

Abstract

A Digital Radio Mondiale (DRM) receiver and demodulation method includes an analog and digital separation filter for filtering and separating a DRM-encoded signal and a non DRM-encoded signal from a composite RF signal received at the receiver. The DRM receiver includes a programmable downsampler and a programmable N-point Fast Fourier Transform (FFT) to recover and demodulate the OFDM symbols in a received DRM-encoded RF signal. The received signal is digitally sampled at a rate operably integer downsampled to achieve a number N samples in the useful portion of the OFDM symbol for input to an N-point FFT, where N equal to a power of two. The downsampling rate and size (N-points) of the FFT depend on the DRM encoding and transmission parameters, notably the robustness mode and spectrum occupancy. The structure and operation of the receiver in this manner simplifies the design and reduces the required filter order of the analog and digital separation filter.