A PROPOSED DS CDMA SYSTEM USING ANALOG PN SEQUENCES PRODUCED BY ADAPTIVE FILTERS/

This paper proposes a novel asynchronous direct sequence/code division multiple access (DS/CDMA) communication system using analog pseudo no ise (PN) sequences that have an orthogonal relation for all active use rs. Analog PN sequences are produced by an adaptive filter called a '' code-orthogonalizing filter'' (COF). In a base station receiver, the t ap coefficients of the COF can be adaptively controlled ''to orthogona lize'' or ''to approach to orthogonalize'' various received PN sequenc es. The elements of the analog PN sequences consist of the tap coeffic ients of the COF The analog PN sequence produced is assigned to the tr ansmitter of each user in order. As a result, multiple access interfer ence (MAI) caused by other users can be reduced considerably, and mult iple access capacity increased by the proposed system compared with ma tched filter (MF) reception and COF reception.