JPS57140039A - Data transmitting and receiving device - Google Patents

Abstract

PURPOSE:To correct a tap gain of an automatic equalizer even in a transmission system having greater interference between codes, by synchronizing a pseudo random system series generated at a reception side with a transmitted pseudo random system series. CONSTITUTION:At a transmission side, a signal from a repetitive signal generator 1 is transmitted to a line 4 via a switch 3, this is counted at a counter 2 and when the counting value reaches a prescribed amount, the switch 3 gives a signal from a maximum length period series generator 5 to the line 4 up to the prescribed value, and when the value reaches the prescribed value, transmission data 7 is transmitted to the line and the signals are transmitted after orthogonal amplitude modulation 8. At the reception side, a complex number signal subjected to biaxial synchronizing detection is delayed at 12 by a synchronizing detector 11 and added at 13 in complex number, the output is delayed 14 at to output 15 at a conjugate value, multiplied 16 at in complex number, the output is inputted to a real part generator 17 and the real part is outputted. When the real part is inputted to a polarity discriminating circuit 18 and the polarity is inverted, a maximum length period series generator 19 is started, and the tap gain of an automatic equalizer 22 is quickly corrected with a signal of the generator 19 synchronized with the signal from the generator 5.