High-performance DDFS design using the equi-section division method.

Area of Science:

• Electrical Engineering
• Digital Signal Processing

Background:

• Direct Digital Frequency Synthesizers (DDFS) are crucial for generating precise frequencies.
• Traditional DDFS designs often require significant memory resources for waveform generation.
• Optimizing memory usage in DDFS is essential for reducing hardware complexity and cost.

Purpose of the Study:

• To propose a novel equi-section division method for designing Direct Digital Frequency Synthesizers (DDFS).
• To leverage waveform symmetry and amplitude approximation for efficient Read-Only Memory (ROM) compression.
• To reduce the memory footprint and hardware complexity of DDFS implementations.

Main Methods:

• Dividing a quarter period of a sinusoidal waveform into equi-sections.
• Storing error values between line segments and sinusoidal amplitudes in ROM for waveform reconstruction.
• Deriving error bounds to determine minimum ROM wordlength and total ROM size.
• Implementing the equi-section division method on a Field Programmable Gate Array (FPGA).

Main Results:

• The proposed equi-section division method achieves a superior compression ratio compared to traditional methods.
• The method results in lower hardware complexity for the DDFS.
• Spectrum performance remains unaffected by the ROM compression technique.
• Experimental validation on an FPGA board confirms the effectiveness of the approach.

Conclusions:

• The equi-section division method offers an effective strategy for ROM compression in DDFS.
• This approach provides a significant advantage in terms of compression ratio and complexity reduction.
• The method is suitable for practical implementation in DDFS designs, offering performance benefits.