This paper introduces a simple design method of a baseband filter for Inter-Symbol Interference (ISI) cancellation required in modern mobile communications. The proposed filter is obtained by using an structure based on the Interpolated Finite Impulse Response (IFIR) approach. Unlike the classical IFIR scheme, in this proposal the interpolator is designed first as a simple multiplierless filter composed by cascaded subfilters with unitary coefficients. To compensate for the passband droop introduced by the interpolator, the model filter is designed in second place using a linear programming optimization. The resulting filter accomplishes standard magnitude response characteristics with a lower computational complexity in comparison with the standard filter and with the design based on the direct IFIR method.