Variable-rate true-time delay filter

A variable-rate true-time delay (VR-TTD) decimator for receiving an input data signal and providing an output decimated signal, for real-time control of the VR-TTD decimator based on a variable real-time adjustable desired signal rate, the VR-TTD decimator comprising:

• a VR-TTD decimator input for receiving the input data signal;
• and
• a VR-TTD decimator output for outputting the output decimated signal;
• a numerically controlled oscillator (NCO) for receiving a time delay control signal and a desired rate control signal and for controlling coarse filtering, fine filtering and decimation of the input data signal based on the time delay control signal and desired rate control signal;
• and
• an accumulator for generating the output decimated signal having a rate based on the desired rate control signal, wherein the accumulator comprises a plurality of shift registers, controlled by the NCO.

A method for providing variable-rate true-time delay (VR-TTD) filtering for real-time control of the VR-TTD decimator based on a variable real-time adjustable desired rate control signal, the method comprising:

• receiving an input data signal;
• receiving a time delay control signal and a desired rate control signal at a numerically controlled oscillator (NCO);
• generating, at the NCO, an output sample time signal, a coarse delay signal, and an output sample enable signal;
• and
• accumulating, at an accumulator, a decimator output signal, wherein the decimator output signal includes fine delay, coarse delay and filtering of the input data signal, based on the output sample time signal, the coarse delay signal, and the output sample enable signal from the NCO, wherein the decimator output signal has a rate that is based on the desired rate control signal.