| 摘要 |
PURPOSE:To evade deterioration in the bit error rate to a correct recipient while preventing a data series itself from being acquired by an intercepting personnel by generating a transmission symbol in response to a transmission data and feeding a phase rotation proportional to the output of a random number series generating means and sending the result through modulation. CONSTITUTION:A 2-bit shift register 11 and a transmission symbol table 12 constitute a transmission symbol generating circuit. An M-series g generating circuit 20 and a 5-bit shift register 21 constitute a sender side random number series generating circuit. A phase rotating device 30 regards 5-bit of parallel output of the shift register 21 as a binary number without sign from '0' to '31' to supply the phase rotation of 0 deg. to the input '0' and 90 deg. to the input 31. The reception signal sent from the transmission line 50 is supplied to a multiplier 61 receiving the output of a sinusoidal wave generator 60 and demodulated and supplied to an automatic equalizer 70 via an LPF 62. The automatic equalizer 70 revises the tap coefficient by using an output of a deciding device 100.
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