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Detail
Journal Article
A Numerically Controlled Oscillator with a Fine Phase Tuner and a Rounding Processor
- Authors
- In Gi Lim, Whan Woo Kim
- Issue Date
- 2004-12
- Citation
- ETRI Journal, v.26, no.6, pp.657-660
- ISSN
- 1225-6463
- Publisher
- 한국전자통신연구원 (ETRI)
- Language
- English
- Type
- Journal Article
- Abstract
- We propose a fine phase tuner and a rounding processor for a numerically controlled oscillator (NCO), yielding a reduced phase error in generating a digital sine waveform. By using the fine phase tuner presented in this paper, when the ratio of the desired sine wave frequency to the clock frequency is expressed as a fraction, an accurate adjustment in representing the fractional value can be achieved with simple hardware. In addition, the proposed rounding processor reduces the effects of phase truncation on the output spectrum. Logic simulation results of the NCO using these techniques show that the noise spectrum and mean square error (MSE) for eight output bits of a 3.125 MHz sine waveform are reduced by 8.68 dB and 5.5 dB, respectively, compared to those of the truncation method, and 2.38 dB and 0.83 dB, respectively, compared to those of Paul's scheme.
- KSP Keywords
- Clock frequency, Logic simulation, Noise spectrum, Output spectrum, Wave frequency, mean square error(MSE), numerically controlled oscillator(NCO), phase error, phase truncation, simulation results, sine waveform