| 摘要 |
FIELD: engineering of devices and methods for receipt and synchronization in direct digital satellite broadcast system. ^ SUBSTANCE: satellite system uses modulation with temporal signals separation and single-frequency network of ground-based re-emitting stations, each of which introduces a delay to ground signal. Delay allows to provide for coincidence of time of receipt of early modulated signal in the center of ground broadcasting zone with time of receipt of appropriate late modulated signal, thus improving switching between ground and satellite signals in receiver. Delay also compensates processing delay, occurring during conversion of satellite modulated stream under direct visibility conditions to multi-frequency modulated stream for transmission of satellite modulated stream under direct visibility conditions to user receivers. Delay is also adjusted in accordance to distance difference between each ground-based re-emitting station and satellite and between each station and center of ground-based broadcasting zone. Adjustment as described above optimizes receipt of temporal signals separation modulated and multi-frequency modulated signals by means of synchronization in the center of single-frequency system of phase of multi-frequency modulated signals, re-emitted from re-emitting stations of single-frequency system. ^ EFFECT: increased quality of radio-signal receipt. ^ 8 cl, 12 dwg |
