Mobile telephone code generating circuit uses combination of two sets of identical bits by logic circuit to generate code element for orthogonal coding

摘要

One element (EC) of an orthogonal code is generated dynamically. A logic circuit (2,3) provides an intermediate word (NC) having B bits or low weighting identical to B bits of low weighting in the reverse sense. These bits are processed by an AND circuit (5) and an EXCLUSIVE-OR operation to the generate the code element (EC). One element (EC) in one of several orthogonal variable spreading factor (OVSF) codes with at least 2BM elements is generated dynamically. A logic circuit (2,3) provides an intermediate word (NC) having B bits or low weighting identical to B bits of low weighting in the reverse sense. These bits are contained within a word representing a code number (NC) designating the code selected from amongst SF = 2B possible codes with SF elements, and having BM-B bit of heavy weighting with a predetermined state. An AND circuit (5) multiplies the bits in the intermediate word (NC) and a word representative of a given position (PC) of the element in the code to produce a product word (PC) with BM bits. A circuit (6) applies an EXCLUSIVE-OR operation to the bits of the product word to generate the code element (EC).