Receiver with improved digital intermediate to base band demodulator

摘要

The digital IF baseband demodulator 120 comprises a delta-sigma of the sampler (202 204) for sampling the two channels of the IF signal at a substantially higher sampling rate than the Nyquist rate for the IF signal. Decimating the first pair of decimation filters (206 208) maintains the samples at a sufficient rate to permit delta sigma sampler mate the output message and filters, but for the (202 204), the digital mixing, cross-addition, and the pulse-matched filter . A set of mixers (210 212 214 216) is to mix the two phases, and the output of the first pair of the decimation filter of the digital representation of the local IF signal. A pair of summers to (22 224) is subtracted, and summing the outputs of the set of mixers (210 212 214 216) in order to remove harmonic (harmonics) undesirable. Decimating the second set of decimation filters (226 228) will mate with the output of the summing function by applying a filter matched to the pulse shape of the baseband signal present on the IF signal group (222 224) and mesh filter.; Delta Sigma Sampler, day animation, digital mixer, and intermediate frequency demodulator for radio frequency