| 摘要 |
PURPOSE:To attain economical line constitution without provision of an excess spare device by using plural spare radio lines so as to relieve fading of an active radio line in the synchronizing switching for line switching of noncode error in a digital radio communication system and adopting the spare constitution of N:1 against a device fault of less probability. CONSTITUTION:A parity detector is provided to each radio line side before each switch at a reception terminal station to measure the error rate of the line and the synchronous switch switches the line to apply N:2 relief against degrading of quality of each active radio line due to fading by using two spare radio lines. On the other hand, N:1 spare switching is attained by using transmission/reception coaxial switches 2-i and 11-i against a device fault in the transmission/reception code processing circuit. In case of the switching by the coaxial switch, a transmission switch circuit 5 disconnects one of the spare radio lines, e.g., the SP-2 from the transmission code processing circuit 3-S and the disconnected spare radio line SP-2 is used for fading relief of other active radio line. |
