| 摘要 |
PURPOSE:To attain transmission power control with high reliability by measuring a bit error rate of its own station transmission burst so as to estimate the change in the attenuation in the transmission line so as to control the transmission power so that the bit error rate is always at a prescribed level in a time division multiplex multiple access satellite communication system. CONSTITUTION:Since a carrier to noise ratio (C/N) and a bit error rate (BER) on a satellite line correspond to each other, the C/N of its own station loopback is measured by measuring the BER. The measurement of BER is simply realized by applying again error correction coding to an output data of an error correction decoder 11 and comparing the result with an input data of the error correction decoder 11 in a bit error rate measuring device 12. The deterioration of the C/N estimated by the measurement of BER is used and the quantity of rainfall attenuation is shared to the incoming/outgoing links depending on the carrier frequency of the incoming and outgoing links of the satellite line, then the share corresponding to the attenuation of the incoming link is controlled by the variable attenuator 7 to increase the transmission power for the transmission power control.
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