| 摘要 |
PURPOSE:To improve the time efficiency by generating a time slot synchronizing signal from a demodulation signal and using the time slot synchronizing signal to obtain a signal level at the maximum point of the opening of the eye of the demodulation signal so as to eliminate the need for the transmission of the synchronizing code for the time slot synchronization. CONSTITUTION:A phase modulation signal inputted to an input terminal 1 becomes two base band signals via an orthogonal demodulator 2 and low pass filters 3, 4. Samplers 5, 6 sample them at a time interval DELTAt and output the sample value to storage devices 7, 8. An envelope calculator 9 calculates an envelope z(t) of the base band signals. When the envelope z(t) exceeds a prescribed level, a burst detector 12 outputs a detection signal, a counter 13 counts up from the initial value '1' at each DELTAt and outputs a write stop signal to the storage devices 7, 8, 11 after 1 burst time length. Then the time maximizing the absolute value of the data from the data stored in the storage device at each time slot is obtained, the time having a maximum probability maximizing the opening of the eye from the time obtained is calculated by interpolation, the signal level at this time is obtained and the level is sent to the decoder. |
