Patent ID: 8422567

Claim:
A signal transmission apparatus comprising: a transmission unit transmitting a signal, and comprising transmission signal control means for controlling an amplitude of the signal and an emphasis characteristic of the signal; a reception unit receiving the signal, and comprising reception signal equalizing means for controlling an equalization characteristic of the signal; a transmission path connecting the transmission unit and the reception unit, and transmitting the signal; a signal output unit outputting the signal to the transmission path; a network analyzer analyzing the signal on the transmission path in a state that the reception signal equalizing means is cut off from the reception unit; a frequency characteristic measurement unit measuring frequency characteristics of the transmission path based on the analysis by the network analyzer; a selection unit selecting a plurality of combinations of amplitude, emphasis characteristic, and equalization characteristic based on the frequency characteristics; a measurement unit measuring a BER (bit error rate) and an eye opening of the transmission path for the plurality of combinations of amplitude, emphasis characteristics, and equalization characteristics; a setting unit extracting single combination from the plurality of combinations of amplitude, emphasis characteristics, and equalization characteristics based on the measurement of the BER and the eye opening, and setting the extracted amplitude, the extracted emphasis characteristic, and the extracted equalization characteristic to the transmission unit and the reception unit; wherein the measurement unit comprises a BER measurement unit measuring the BER of the transmission path, and an eye opening measurement unit measuring the eye opening of the transmission path; wherein the selection unit selects one or more amplitudes satisfying a selection condition that is determined based on the frequency characteristics, selects one or more equalization characteristics having a frequency band that is determined based on the frequency characteristics, and selects a center value and a plurality of values above and below the center value of the selected equalization characteristic as the equalization characteristic; wherein the frequency characteristics comprise Scattering parameters (S parameters); wherein the determined selection condition is a condition that is defined using Differential Return Loss Scattering parameters (SDD11 parameters) defined in a model of the Scattering parameters (S parameters); and wherein the determined frequency band is a frequency below an upper limit value of the SDD11 parameters in the model of the Scattering parameters (S parameters).