About the nco ip core, Altera dsp ip core features, About the nco ip core -1 – Altera NCO MegaCore Function User Manual
Page 4: Altera dsp ip core features -1
About the NCO IP Core
1
2014.12.15
UG-NCO
The Altera
®
NCO IP core generates numerically controlled oscillators (NCOs) customized for Altera
devices. A numerically controlled oscillator (NCO) synthesizes a discrete-time, discrete-valued
representation of a sinusoidal waveform.
Typically, you can use NCOs in communication systems as quadrature carrier generators in I-Q mixers,
in which baseband data is modulated onto the orthogonal carriers in one of a variety of ways.
Figure 1-1: Simple Modulator
Constellation
Mapper
IF Signal
NCO
Q
I
FIR
Filter
FIR
Filter
cos(wt)
sin(wt)
You can also use NCOs in all-digital phase-locked-loops (PLLs) for carrier synchronization in communi‐
cations receivers, or as standalone frequency shift keying (FSK) or phase shift keying (PSK) modulators.
In these applications, the phase or the frequency of the output waveform varies directly according to an
input data stream.
You can implement ROM-based, CORDIC-based, and multiplier-based NCO architectures,. The wizard
also includes time and frequency domain graphs that dynamically display the functionality of the NCO,
based on your parameter settings.
To decide which NCO implementation to use, consider the spectral purity, frequency resolution,
performance, throughput, and required device resources. Also, consider the trade-offs between some or
all of these parameters.
Altera DSP IP Core Features
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