Patent ID: 7966360

Claim:
A finite impulse response filter to which a digital signal obtained by performing sampling on an analog signal at a rate of M times of a symbol rate where M is an even number of two or more, is input, and which has characteristics of even taps, comprising: a plurality of tap-coefficient multipliers, each of the tap-coefficient multipliers multiplying an input to the respective tap-coefficient multiplier with a tap coefficient; a first plurality of delay elements corresponding to the plurality of tap-coefficient multipliers; a second plurality of delay elements corresponding to the plurality of tap-coefficient multipliers, a switcher that switches an input to each of the plurality of tap-coefficient multipliers between an output of one of the first plurality of delay elements and an output of one of the second plurality of delay elements; and an adder that adds outputs of the tap-coefficient multipliers, wherein the switcher inputs output signals of the first plurality of delay elements to the plurality of tap-coefficient multipliers in a forward direction or inputs output signals of the second plurality of delay elements to the tap-coefficient multipliers in a reverse direction.