An improved numerically controlled digital oscillator

Adding a small lookup table (LUT) to adjust the feedback in a second-order numerically controlled digital oscillator (NCDO) eliminates all of the stability problems created by roundoff error in digital oscillators. The new NCDO uses less hardware than any of the three major competing approaches: (1) sinusoidal look up table, (2) digital oscillators with roundoff compensation, and (3) CORDIC based designs. The new NCDOs have applications in heterodyne adaptive filters, in FSK and PSK detection, in digital music synthesis and in many other applications.