filter is implemented by moving the delay elements while conserving the time relationship of the signals by means of u201c retiming u201d fig2 shows a structure of an adaptive equalizer subjected to this retiming process according to the structure of fig2 a direct fir filter is converted into a transposition filter in filter processing unit 1 the propagation path of the input and output signals are transposed more specifically in filter processing unit 1 the input signal from delay element sr 0 is applied to multipliers m 0 u02dc m 3 provided corresponding to tap coefficients h 0 u02dc h 3 respectively adders ad 0 u02dc ad 2 are provided corresponding to multipliers m 0 u02dc m 2 delay elements td 0 u02dc td 2 are provided at the inputs of adders ado u02dc ad 2 delay element td 0 delays the output signal of adder ad 1 by 1 clock cycle to provide the delayed signal to adder ad 0 delay element td 1 delays the output signal of adder ad 2 by 1 clock cycle to provide the delayed signal to adder ad 1 delay element td 2 delays the output signal of multiplier m 3 by 1 clock cycle to provide the delayed signal to adder ad 2 in the structure of the transposition filter of filter processing unit 1 output signal y n is represented by the following equation in the structure of this transposition filter.