Brno University of Technology Digital Library (Brno University of Technology) · 2009 · 16 citations · 4 references
Open access
EngineeringComputer EngineeringElectrical EngineeringAnalog ElectronicsDigital CommunicationMicroelectronicsConfigurable Logic BlocksDigital Signal ProcessingLookup TablesMixed-signal Integrated Circuit DesignModulationSignal ProcessingCharge Pump CircuitsCharge-pump ConvertersFrequency Shift KeyingGaussian Minimum Shift KeyingLut ArchitectureMinimum Shift KeyingModulation TechniquesPulse Shaping
Abstract. Due to wide power spectrums of rectangular data streams, it is important for base-band signals to be heavily band limited before modulation. That can be achieved by pulse shaping of rectangular bits. Some of the most common are a half-sine pulse shaper and a Gaussian pulse shaper which are used in Minimum Shift Keying (MSK), Gaussian Minimum Shift Keying (GMSK) and Gaussian Frequency Shift Keying (GFSK) modulations, respectively. The most common solutions of such shapers use PCM based look-up-table (LUT), which requires an n-bit D/A converter. We proposed the use of a 1-bit Sigma Delta Modulation (SDM) LUT, which results in smaller ROM capacity, a 1-bit wide output word, and a simple1-bit D/A converter realized as an out-of-chip first-order lowpass RC filter, or an in-chip charge pump. This article
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