Receiver with frequency deviation detection capability and method therefor

摘要

A receiver (100, Fig. 1) includes an analog receiver and a digital processor. The analog receiver has an input for receiving a radio frequency RF signal, and an output for providing a digital Intermediate Frequency signal. The digital processor has an input for receiving the digital Intermediate Frequency signal, and an output for providing digital symbols. The digital processor measures peak-to-peak frequency deviation 230 of the digital Intermediate Frequency signal, and performs a digital signal processing function on the digital Intermediate Frequency signal to provide the digital symbols based on the peak-to-peak frequency deviation so measured. In one embodiment slicing levels/thresholds of a slicer 250 are dynamic and adjusted 240 based on the measured peak-to-peak frequency deviation. In a second embodiment (Figs. 7 & 8) a coefficient used by the digital processor for filtering Inter-Symbol Interference is adjusted based on the measured peak-to-peak frequency deviation. The peak-to-peak frequency deviation may be determined during reception of a preamble or synchronisation word. The receiver may receive a M-ary Frequency Shift Keyed signal such as 4GFSK.