A receiving apparatus (202, 211) in a mobile communication system comprising: a channel estimator for estimating the channel variation between a transmitting apparatus and the receiving apparatus in accordance with a received data signal; a detector for detecting the received data signal in accordance with an estimation result produced by said channel estimator; and a demodulator for demodulating said detected received signal, wherein said received data signal includes a plurality of data symbols (d1 - d4); wherein said channel estimator operates to perform channel estimation based on sampling results of a pilot signal; and wherein said detector is adapted to detect said received data signal for each of said data symbols in accordance with the respective estimation result, wherein said channel estimator is adapted to estimate said channel variation using said pilot signal received from said transmitting apparatus, characterized in that said channel estimator is adapted to receive the pilot signal on a separate channel and sample the received pilot signal and wherein the channel estimator comprises a FIR filter comprising • a plurality of series-connected delay devices for delaying the entered pilot signal sample values, • connected to the output of every other of the delay devices a respective multiplier for multiplying the output of the respective connected delay device by a respective one of a plurality of predetermined coefficients (Wo,...., Wn), and • an adder (105, 702, 805, 902, 1004, 1009, 1305) for adding up the outputs of said multipliers, and uses the output of said adder to estimate said channel variation, wherein at least one of said plurality of coefficients is a negative value. a channel estimator for estimating the channel variation between a transmitting apparatus and the receiving apparatus in accordance with a received data signal; a detector for detecting the received data signal in accordance with an estimation result produced by said channel estimator; and a demodulator for demodulating said detected received signal, wherein said received data signal includes a plurality of data symbols (d1 - d4); wherein said channel estimator operates to perform channel estimation based on sampling results of a pilot signal; and wherein said detector is adapted to detect said received data signal for each of said data symbols in accordance with the respective estimation result, wherein said channel estimator is adapted to estimate said channel variation using said pilot signal received from said transmitting apparatus, characterized in that said channel estimator is adapted to receive the pilot signal on a separate channel and sample the received pilot signal and wherein the channel estimator comprises a FIR filter comprising • a plurality of series-connected delay devices for delaying the entered pilot signal sample values, • connected to the output of every other of the delay devices a respective multiplier for multiplying the output of the respective connected delay device by a respective one of a plurality of predetermined coefficients (Wo,...., Wn), and • an adder (105, 702, 805, 902, 1004, 1009, 1305) for adding up the outputs of said multipliers, • a plurality of series-connected delay devices for delaying the entered pilot signal sample values, • connected to the output of every other of the delay devices a respective multiplier for multiplying the output of the respective connected delay device by a respective one of a plurality of predetermined coefficients (Wo,...., Wn), and • an adder (105, 702, 805, 902, 1004, 1009, 1305) for adding up the outputs of said multipliers, and uses the output of said adder to estimate said channel variation, wherein at least one of said plurality of coefficients is a negative value.