A method and system for an FIR filter are provided. A sequence of input signal is converted to a corresponding sequence of log signals. FIR filtering coefficients are then added to each log signal to generate a plurality of term signals. The term signals are then converted to inverse-log signals, and the inverse-log signals are summed to produce an output signal. Log/inverse-log conversions of signals are based on estimating a log/inverse-log function using a second-order polynomial.