Implementation of optimized trigonometric functions for a self-mixing laser diode displacement sensor under moderate feedback

The real-time hardware implementation of a self-mixing (SM) displacement sensor algorithm for moderate feedback necessitates the optimization of trigonometric functions such as sin and arccos for example, needed for its signal processing. Two approaches, the limited Taylor series as well as the CORDIC (for COordinate Rotation DIgital Computer) method traditionally used in computer systems, have been evaluated for the implementation of these trigonometric functions. The increasingly higher ordered Taylor series cases have been compared along with their 12 bit and 16 bit fixed point implementations. Efforts have been done to optimize these trigonometric functions in order to reduce the error as well as the time needed for a future real-time sensor requiring such signal processing.