Parameters of the NCO module

Jul 14, 2025#数字通信 #MATLAB4

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The NCO module can generate real or complex sine signals and provides hardware-friendly control signals. Key parameters include: 1. **Accumulator Bit Width**: The frequency resolution of the sine wave depends on the size of the accumulator's bit width. The bit width can be calculated using the formula: $$ N=ceil(log_2(\frac{F_s}{\Delta f})) $$ 2. **Quantization Bit Width**: The output of the quantized accumulator can enhance frequency resolution without increasing the lookup table size. The quantization bit width is determined by the spurious-free dynamic range (SFDR) using the formula: $$ Q=ceil(\frac{SFDR-12}{6}) $$ 3. **Phase Increment**: The phase increment is calculated as: $$ phInc=round(\frac{f\times 2^N}{F_s}) $$

The NCO module can generate real or complex sine signals while providing hardware-friendly control signals.

Accumulator Bit Width#

The frequency resolution of the sine wave depends on the size of the accumulator bit width. The bit width can be calculated based on the frequency resolution, and the data type word length of the accumulator is set according to this bit width.

The calculation formula is

N=ceil(log_2(\frac{F_s}{\Delta f}))

Quantization Bit Width#

Quantizing the output of the accumulator can improve frequency resolution without increasing the size of the lookup table.

To calculate the quantization bit width based on the spurious-free dynamic range, the calculation formula is

Q=ceil(\frac{SFDR-12}{6})

Phase Increment#

phInc=round(\frac{f\times 2^N}{F_s})