A comparison between single code and multiple code transmission schemes in a CDMA system

Two transmission schemes for the mobiles in a CDMA system are compared. In the first scheme which is used presently, referred to as the single code scheme, transmission is achieved by using a single spreading code. In the other, called the multi-code scheme, the bit stream to be transmitted is split into several parallel streams. Each stream is then spread by a code out of a set of orthogonal codes, and then transmitted in parallel. It is shown that despite the dynamic range requirements being quite different, the interference properties of these two schemes, which affect the bit error rate, are identical.