Data transmitter and method of generating none return to zero optical signal with clock component amplification

Abstract

The present invention relates to none return to zero (NRZ) modulation method. The NRZ optical modulation is performed by combining a clock signal and NRZ data at a sending end and signal distortion capable of being generated when the clock signal and the NRZ data are combined is optimized by controlling the magnitude and phase of the clock signal. At the receiving end, the clock signal is extracted by performing narrow band band-pass filtering of the detected optical signal transmitted from a transmitter and data is recovered using the clock signal. Therefore, a receiver structure for clock extraction is simpler, an error rate of data recovery is lower by clearly extracting the clock signal, and transmission distance of the optical signal is longer.

1 . A data transmitter generating an NRZ optical signal with clock component amplification, comprising: 
 an attenuator which attenuates the magnitude of an electrical clock signal;    a phase shifter which controls the phase of the magnitude-attenuated electrical clock signal;    a driver which amplifies the magnitude of electrical NRZ data; and    an optical modulator with dual RF input port driven by the electrical NRZ data from the driver and the phase-controlled electrical clock signal from the phase shifter.    
   
   
       2 . The data transmitter of  claim 1 , wherein the NRZ optical-modulated signal is used for clock recovery by extracting the clock signal by a narrow band band-pass filter included in a receiver.  
   
   
       3 . A data transmitting method generating an NRZ optical signal with clock component amplification, comprising: 
 attenuating the magnitude of an electrical clock signal;    controlling the phase of the magnitude-attenuated electrical clock signal;    amplifying the magnitude of electrical NRZ data; and    performing an NRZ optical modulation of the amplified electrical NRZ data and the phase-controlled electrical clock signal.    
   
   
       4 . The method of  claim 3 , wherein the NRZ optical-modulated signal is used for clock recovery by extracting the clock signal by a narrow band band-pass filter included in a receiver.