In a conventional semiconductor device, there was a problem that, in a guard ring region, a shape of a depletion layer is distorted and stable withstand voltage characteristics cannot be obtained. The workpiece is preheated while the weld is being performed. Accordingly, all the contents provided by a content provider can be used regardless of the DRM technology applied to the contents and a platform of a demodulator. The product is deemed authentic if the item identifier from the analog identification indicium substantially matches the item identifier from the digital identification record. For example, a first IDFT processor is implemented to process a first of the mapped signals to generate a first signal stream, and a second IDFT processor is implemented to process a second of the mapped signals to generate a second signal stream.