nir-vana innovation network

The computation of the sine and cosine functions is required in devices ranging from application specific signal processors to general purpose floating point units. Even in the latter case, the required functionality can be reduced to computing the sine and/or cosine of multiples of a constant angle.

The latency of a sine/cosine generator can be reduced by using look-up tables. However, a direct implementation with look-up tables may be unfeasible if the input space is huge. In such a case, look-up tables with a number of entries lower than the size of the input space can be used indirectly. In previously published methods, the reduction in the number of table entries is obtained at the expense of increasing the table width and the computational cost. This can be palliated by using a by using a sine/complement generator.

It is possible to compute the sine and the complement of the cosine of the sum of two angles, A and B, from the sines and complements of the cosines of those angles by using a functional unit called a trigonometric adder. Trigonometric adders enable the implementation of a sine/complement generator using a tree structure similar.

At this point, a research team from a Southern Spanish University has patented an invention that makes it possible to reduce the size of the look-up tables as well as the required multiplications of sine/cosine generators.

The device, object of this invention, can be considered a trigonometric adder that allows to calculate trigonometric functions of the sum of two angles.

This technology has application to those fields that require computing trigonometrics like digital signal processing, video processing, radar, sonar, radio astronomy and/or power line communications...

The Spanish team is interested in getting in contact with industrial partners active in the field of electronics for a license agreement.
The potential partner would obtain the right to exploit this patent.

Advantages & innovations

Advantages This invention generates significant advantages if a sine/cosine generator or a branch of it is quadrant restricted. In this case, it should be implemented employing a complement generator. The contribution of the invention/patent is as follows: • The smearing problems are lessened. • It makes is possible to reduce the size of the multipliers. • It makes is possible to reduce the size of the memories used to store precalculated values. Innovations The proposed invention has been used to implement several twiddle factor generators and has enabled the number of hardware DSP (Digital Signal Processing) blocks required to be reduced by between 25% and 44% respect to previous table based techniques. Also, these implementations are about 50% faster than those based on Volder's algorithm.

Stage of development

Field tested/evaluated

Partner sought

It is sought an industry active in the field of manufacturing industry of electronics and/or computer devices. The team is interested in a license agreement with the potential industrial partner. They would be provided with the rights for exploitation of the patent,.