CODE GENERATION, IN PARTICULAR FOR UMTS DIGITAL COMMUNICATIONS

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).