| 摘要 |
<p>A radio receiver (200) is used for receiving a multi-level (4) signal that includes a plurality of symbols (3200sps), wherein each level is representative of a symbol of data. Baseband samples are generated for each symbol, whereby each baseband sample has a phase and a signal level. The radio receiver circuit (200) measures the received signal environment. A digital circuit (212) selects a scan duration (90 milliseconds) from a scan duration table based on the measured signal environment and a combination of signal types (4 level versus 2 level) used for classification of the received signal. The digital circuit tallies, by categories (800hz), occurrences (0- 80Hz) of the baseband samples, whereby each category is representative of one of a plurality of phases (6), and one of the plurality of signal level ranges. The digital circuit selects a set of optimized thresholds based on the measured signal environment and a combination of signal types (4 level versus 2 level), and correlates the tallies to at least one template and classifies the multi-level (4) signal according to the correlation results and the selected optimized thresholds.</p> |
