| 摘要 |
To ensure that a phase-locked loop locks quickly to the pilot tone of the stereo-multiplex signal when a new transmitter is tuned in, the stereo-multiplex signal is multiplied in a multiplier M by the quadrature component of the pilot tone generated by a digital oscillator, is low-pass-filtered in a low-pass filter, and is fed as a control signal to the oscillator which is composed of a table of length N and a counter for addressing the table entries. The zero phase angle phi0 is set by a counter offset n0 by incrementing or decrementing the counter. It is advantageous to employ a virtual table of length N+ which is larger than the length N of the real table. To access the real table, however, only the corresponding MSBs of the actual count n(k) are used which match the address space of the real table of length N.
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