A Digital Incremental Oscillator: Generation of Sinusoidal Waveform in DPCM

Based on the concept of incremental computations, a digital oscillator structure is proposed which consists of two incremental integrators and one incremental multiplier. Models for these elements are developed and detailed analyses are made showing that the errors of the proposed structure are extremely low compared with the direct-form one. The proposed oscillator structure can be implemented without a hardware multiplier and can generate sinusoidal waveforms in the differential pulse code modulation representation.     

Digital Oscillator Having Low Sensitivity and Roundoff Errors

A digital oscillator structure is proposed which has very low sensitivity and roundoff errors, particularly for low frequencies. The oscillator coefficient implemented is a normalized scaled value of the two's complement of the original coefficient, such that all bits represented are significant. The signal is scaled where appropriate to keep the overall transfer function unchanged. Multipliers used in the proposed structure have the same width as that in the direct form digital oscillator, although the performance is significantly improved.