| 摘要 |
A digital phase/frequency detector capable of being implemented with on-chip components and configured to detect signals having small modulation indices. Transition points within the signal are detected and the width between successive transition points measured and averaged. The average width measurements may be converted to width deviation values by subtracting out the width due to the carrier frequency. An interpolation may be performed between the current and previous values of the width deviation values to reduce quantization error. The interpolated values may be converted to frequency deviation values, and a predetermined number of the frequency deviation values may be averaged. The average frequency deviation values may then be equalized in order to reduce intersymbol interference. The resulting equalized values form soft estimates of the underlying source bits. Hard estimates of the source bits may then be derived from the soft estimates.
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