An efficient and practical spreading function for D-S spread spectrum CDMA systems

The capacity of a spread spectrum CDMA system is greatly influenced by the power spectrum of the function used to do the spreading. This paper introduces a new spreading function that has a power spectrum with a flat mainlobe, a null at the band edge, and low sidelobe power. With this spreading function there is no need for an inband spectral shaping. The proposed spreading function is a non-binary function yet can be incorporated into a system with simple switching multipliers. This spreading function is shown to yield a larger SNR and be more immune to distortion in the transmit and receive band limiting filters than a conventional PN spreading function