| 摘要 |
The invention relates to a timing system in a receiver for digital data transmission with a timing phase detector. The in-phase and quadrature components of the demodulated incoming signal, from which the signal terms of the double frequency have been removed by low-pass filtering - whereby the incoming signal is produced as an input signal as the product of the incoming signal and the output signal of the carrier oscillator - are input to the timing phase detector and are combined as two control signals in such a way that both these control signals uTR and uTI can be interpreted as the real part and the imaginary part of a complex control quantity uT = uTR + juTI. Both control signals uTR and uTI are averaged and the average values so obtained u &cir& NOt TR, u &cir& NOt TI are evaluated in an evaluation circuit to provide a control quantity which drives the timing correction circuit. A combinatorial circuit is provided in which the two averaged control signals u &cir& NOt TR and u &cir& NOt TI are combined. The complex u &cir& NOt TR, u &cir& NOt TI planes are divided into two regions (1, 2), region 1 containing the positive uTR semi-axis and region 2 containing the negative uTR semi-axis. The combination is achieved by establishing whether the vector peak represented by uTR, UTI lies in region 1. If this is so, the combinatorial circuit emits a signal which indicates that synchronization is provided. |
