Improved real-time adaptive detection, enhancement, or elimination of multiple sinusoids

A simple modification to the approach of T. Kwan and K. Martin (1989) for adaptive detection and enhancement of multiple sinusoids allows practical real-time hardware to detect as many as 10 sinusoids in the presence of noise or other signals. The modification is a novel method of generating the gradients in the cascaded system of notch filters that reduces the geometric increase of hardware with the number of sinusoids to an arithmetic increase of hardware. Hence, the new approach requires only 29 biquads to implement a system with 10 sinusoids rather than the 65 required by Kwan and Martin. Simulations show that the new algorithm is robust and works extremely well in a large variety of environments likely to be encountered in practical applications