The present invention is directed to an apparatus for production of scrambling codes that are used for scrambling binary signals transmitted via physical channels in a mobile radio system. The apparatus is also configured to produce preambles that are sent on a physical channel in order to control the access to that particular physical channel. The apparatus includes a scrambling code generator for production of the scrambling codes, and a preamble generator for production of non-scrambled preambles, and at least one multiplier for scrambling the non-scrambled preambles using associated scrambling codes.