A user may control a user device utilizing visible light transmitted from a handheld control device. When the inspection bolt is tightened, the rotation of the wrench is detected before the rotation of the bolt due to the torsion of the wrench itself. Then, a correlation value is determined for each replica code sequence by combining the intermediate results obtained for all groups separately for each replica code sequence, taking into account the values of the samples of the replica sequences in the respective group. It is desirable that a refractive index profile contains at least one annular region between a center core and a cladding region. The mixer-first receiver front-end includes two separate down-conversion paths that help to minimize added noise and voltage gain prior to baseband filtering, which are critical factors in eliminating narrow-band off-chip RF filtering. Organic components are expelled after a first heat treatment.