The invention relates to a receiving end equilibrium method and
system based on
frequency domain communication channel estimation. The method comprises the following steps: training sequences with flat spectrum characteristics are inserted into signals at the transmitting terminal, the received training sequences are transformed into the
frequency domain at the receiving end through fast Fourier transformation, the
transfer function of a
communication channel is obtained through dividing the ideal spectrum corresponding to the
frequency domain, and then the reciprocal of the
transfer function is taken and is transformed into the
time domain through the fast Fourier transformation so as to obtain
time domain filter tapping coefficient; thereafter, filtering is performed to data signals in the
time domain through utilizing the time domain filter tapping coefficient, so that signaling equilibrium is realized. The
system includes various modules realizing the corresponding functions. The method and the
system combine characteristic of avoidance in cost caused by inserting
cyclic prefix / suffix of time domain equilibrium and the characteristic of simple
communication channel estimation of the frequency domain equilibrium; on the condition that the
optical fiber dispersion is smaller or the dispersion is compensated by other arithmetic, the
phase noise compensation is efficiently performed; the arithmetic complexity is small; the calculation time can be saved.