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调频电视(FM TV)的系统设计中,常采用过频偏传输,以减少接收站的成本。然而过频偏传输是受到传输带宽的制约的。在我国利用 C 波段通信卫星作电视传输时,如何选择合理的接收带宽,使地球站成本低,而又保证一定的传输质量是一个突出的问题。根据模拟试验结果本文提出在16.8MHz 视频峰峰频偏(△f_(ppv))时,传输带宽应取为21.5—22MHz 的建议;在保证一定的视频信噪比(S/N)的条件下,天线口径与△f_(ppv)乘积为一常数的结论。
FM TV system design, often used over frequency transmission, to reduce the cost of the receiving station. However, over-frequency transmission is limited by the transmission bandwidth. When using C-band communications satellites for television transmission in China, how to choose a reasonable receiving bandwidth, make the earth station low in cost, and guarantee a certain transmission quality is a prominent issue. According to the simulation results, this paper proposes a proposal that the transmission bandwidth should be 21.5-22MHz when the peak-to-peak frequency deviation of 16.8MHz video (△ f_ (ppv)) is adopted. Under certain video signal-to-noise ratio , Antenna aperture and △ f_ (ppv) product of a constant conclusion.