摘要：A promising choice for signal generation in modern communications systems is direct digital frequency synthesis (DDFS) which is capable of well controlled, rapid changes in signal frequency, over a relatively large frequency range. Unfortunately, a conventional DDFS system requires a high frequency read only memory (ROM) which consumes most of the power. This paper describes a novel low complexity DDFS with smaller lookup table size and lesser hardware overhead. It is based on the Taylor series expansion method for sinusoidal and co-sinusoidal functions combined with an approximation algorithm. It has the advantages of high speed, low complexity, low computational delay and high spectral purity. The proposed DDFS has high SFDR (spurious free dynamic range) and the spectral purity can be as good as 135 dBc.
关键词：direct digital frequency synthesis; Taylor series; low-complexity; spectral;purity; lesser hardware overhead.
